JP2012191721A - Wireless power transmission device and wireless power transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless power transmission device and a wireless power transmission method for enhancing the wireless power transmission efficiency between a power transmission unit and a power reception unit.SOLUTION: A wireless power transmission unit includes: a transmission efficiency calculation part for calculating the wireless power transmission efficiency between a power transmission unit and a power reception unit; and a control part for controlling a first element of at least one of the power transmission unit and the power reception unit when the above calculated transmission efficiency does not meet the prescribed threshold. The control part instructs the power transmission unit to transmit trial power, and instructs the power transmission unit to start transmitting the amount of the power requested by the power reception unit when the trial power transmission efficiency meets the prescribed threshold.

Description

  The present invention relates to a technique for supplying power to a battery mounted on a moving body.

  In the field of land transportation, research and development of automobiles that run on electric power has been actively conducted due to concerns about air pollution and depletion of fossil fuels. As a technique for supplying electric power to such an electric vehicle, conventionally, an electrode installed at a station and an electrode installed at the front or rear of the vehicle are brought into contact with each other through the contact of the electrode, that is, for charging. There is a technique for charging using a cable (see Patent Document 1).

JP 2000-50508 A

  However, a method in which the vehicle is charged with priority connection to the power supply source and the vehicle and the power supply source are charged without contacting with the charging cable, that is, charging wirelessly is not considered. . For example, when charging an electric vehicle wirelessly at the time of parking, it may be necessary to adjust the control content due to individual differences of the electric vehicle or individual differences of the power transmission equipment, but an appropriate method has been established. This is not a situation. The individual difference of the electric vehicle includes, for example, the corresponding charging method, the charging device type, the storage amount, the variation in the mounting position of the power receiving device, the parts used for the power receiving device, and the power transmission equipment type with the right to use (for example, Whether or not there is a contract with a company that owns transmission equipment). The individual difference between the power transmission facilities is, for example, the corresponding charging method, the type of the power transmission device, the installation position of the power transmission device, and the power transmission facility type (for example, power transmission facility possessing company data).

  In view of the above problems, an object of the present invention is to provide a wireless power transmission device and a wireless power transmission method that improve the efficiency of wireless power transmission between a power transmission unit and a power reception unit.

In order to solve the above problems, the present invention includes a wireless power transmission apparatus including the following means. That is, according to the present invention, the wireless power transmission device calculates a transmission efficiency of power wirelessly transmitted between the power transmission unit and the power receiving unit, and the transmission efficiency calculated by the transmission efficiency calculation unit is predetermined. When the threshold value is not satisfied, a control unit that controls the first element of at least one of the power transmission unit or the power reception unit;
Is provided.

  Until the transmission efficiency satisfies the predetermined threshold, the wireless power transmission device controls the first element, whereby the transmission efficiency can be improved to the predetermined threshold.

In addition, the control unit instructs the transmission unit to transmit the trial power, and when the transmission efficiency in the transmission of the trial power satisfies a predetermined threshold, the control unit instructs the transmission unit to start transmission of the amount of power requested by the power reception unit. You may make it indicate. By separating the stage in which trial power is transmitted from the power transmission unit and the stage in which the amount of power required by the power reception unit is transmitted from the power transmission unit, waste of power transmission can be reduced throughout the entire wireless power transmission process. it can.

  For example, the first element may be a position of at least one of a power transmission unit and a power reception unit. The second element may be a resonance frequency of the power transmission coil and the power reception coil.

  In addition, the power transmission unit may include a plurality of power transmission coils. In this case, the transmission efficiency calculation unit calculates the power transmission efficiency with the power reception unit for each of the plurality of power transmission coils, and the control unit You may make it select use of the power transmission coil with the best transmission efficiency.

  Furthermore, the present invention can be grasped as a method or a program executed by a computer. Further, the present invention may be a program in which such a program is recorded on a recording medium readable by a computer, other devices, machines, or the like. Here, a computer-readable recording medium is a recording medium that stores information such as data and programs by electrical, magnetic, optical, mechanical, or chemical action and can be read from a computer or the like. Say.

  For example, the present invention includes a step in which a wireless power transmission device including a power transmission unit including a power transmission coil and a power reception unit including a power reception coil calculates power transmission efficiency between the power transmission unit and the power reception unit; Instructing the unit to transmit trial power or request power from the power receiving unit, and while the trial power is transmitted from the power transmission unit, transmit power until the calculated transmission efficiency satisfies a predetermined threshold. During the step of controlling the first element of at least one of the unit and the power receiving unit, and while the required power is transmitted from the power transmission unit, according to the calculated transmission efficiency, the first of the power transmission unit and the power receiving unit A step of controlling two elements, and a wireless power transmission method to be executed.

  According to the present invention, the efficiency of wireless power transmission between a power transmission unit and a power reception unit can be improved.

It is a figure which shows the structural example of the electric power feeding system in 1st Embodiment. It is the figure which showed the example of the outline of a structure of vehicle equipment. It is a figure which shows the structural example of a wireless power transmission system. It is the figure which showed the example of the function structure of the receiving unit. It is a figure which shows the example of a function structure of a power transmission unit. It is a figure which shows the example of the outline | summary of a transmission preparation process. It is an example of the flowchart of a power transmission / reception apparatus confirmation process. It is an example of the flowchart of trial transmission processing. It is an example of the flowchart of an efficiency improvement process. It is an example of the flowchart of an efficiency improvement process. It is a figure which shows the outline | summary of a transmission process. It is an example of the flowchart of a danger avoidance process. It is an example of the flowchart of a resonance frequency adjustment process. It is an example of the flowchart of an initial parameter learning process. It is an example of the flowchart of the amount of electric power monitoring process. It is an example of the flowchart of a transmission completion determination process. It is an example of the flowchart of an efficiency improvement process in case a power transmission unit calculates transmission efficiency. It is an example of the flowchart of an efficiency improvement process in case a power transmission unit calculates transmission efficiency. It is an example of the flowchart of an efficiency improvement process in case a power transmission unit calculates transmission efficiency.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings. The configuration of the following embodiment is an exemplification, and the present invention is not limited to the configuration of the embodiment.

<First Embodiment>
The first embodiment is an example of a power feeding system that feeds power to a vehicle-mounted battery mounted on a vehicle such as an electric vehicle or a hybrid electric vehicle by wireless power transmission using magnetic field resonance. A transmission process between the apparatus and a power receiving apparatus capable of receiving wirelessly transmitted power and a control process related to the transmission process will be described in detail. The transmission processing in the first embodiment and the control processing related to the transmission processing are various wireless power transmission methods other than the magnetic field resonance method in the first embodiment, for example, a method using electromagnetic induction between coils, and a microwave transmission method. The present invention can also be applied to a power feeding system employing various transmission methods such as.

(Configuration of the entire power supply system)
FIG. 1 is a diagram illustrating a configuration example of a power feeding system according to the first embodiment. The power feeding system includes a power receiving side system 100 that is mounted on a vehicle and performs power receiving related operations, a power feeding side system 300 that is installed in a parking lot and performs power feeding related operations, a power receiving side system 100 of each vehicle, and a power feeding side that is installed in various places. A VICS (VICS) that has a system 300 and a center system 200 that exchanges and processes various types of information as a basic configuration, and that provides various types of vehicle-related information useful for vehicles such as traffic information to the power receiving side system 100. A real-time road information distribution system 400 such as a Vehicle Information and Communication System) is provided as an expansion configuration for function expansion. Then, the power receiving system 100, the center system 200, the power feeding side system 300, and the real-time road information distribution system 400 are connected to each other via a network to constitute a power feeding system.

As the network, for example, a network in which the Internet, a mobile phone network, a dedicated line, a private network, an intranet, and the like are connected to each other can be used. As a specific network, a network suitable for the information center server 2 of the center system 200, the power supply facility management server 3 of the power supply side system 300, the vehicle-mounted device 1 of the power reception side system 100, and the like to communicate with each other is adopted. It is preferable. For example, in 1st Embodiment, the vehicle equipment 1 transmits / receives information between the information center server 2 or the electric power feeding equipment management server 3 using a mobile telephone network via a user's mobile telephone 5. FIG. However, for information transmission and reception, satellite communications and mobile WiMAX (Worldwide Interoperability for Microwave
Other communication methods such as “Access” are also applicable.

  The vehicle on which the in-vehicle device 1 is mounted is, for example, an electric vehicle that is driven by electric power, a hybrid electric vehicle that uses electric power and energy from gasoline as driving sources, and the like. The in-vehicle device 1 can be implemented as a so-called car navigation system. At this time, in the car navigation system that performs processing, a part that provides an interface to the user (an operation unit such as operation switches, a display unit such as a display panel, an audio output unit such as a speaker, etc.) and information related to the vehicle Other than the part to be acquired, it is not necessarily installed in the vehicle. Necessary input is transmitted to the navigation device main body or server device installed outside, and necessary navigation-related processing (for example, route search processing, map image generation processing, etc.) is performed in the main body or server device, and the processing result is sent to the vehicle-mounted device 1. A method may be employed in which the information is transmitted and displayed.

The center system 200 has various information about each power supply system such as parking lot information, charging information for power supply by the power supply facility, etc., and an information center server 2 that performs information storage and information processing in a data center that performs various information processing. Have Receives information from the power receiving system 100 (vehicle equipment 1) and the power feeding system 300 (power supply facility management server 3) via the network, stores the information, receives information requests, and receives the information request. Necessary information is provided to the machine 1) and the power supply side system 300 (power supply facility management server 3). Here, the parking lot information includes parking lot availability information, reservation information, and service information (power supply equipment information: presence / absence of power supply equipment, specifications, availability information, etc.). A system that provides road information from the center system 200 to the power receiving system 100 (the vehicle-mounted device 1) can also be realized. In this case, the road information can be realized by accumulating information distributed from the real-time road information distribution system 400 such as VICS. The road information includes traffic jam information, construction information, sightseeing spot information, and the like.

  The power supply side system 300 includes a power supply facility management server 3 as a system control device. The power supply facility management server 3 is, for example, a server that manages each power supply facility provided in each parking area of a parking lot, and provides information for controlling the operation of each power supply facility to each power supply facility. Information such as the operation status is obtained and stored from the power supply equipment, and the information is processed. In addition, the power supply facility management server 3 exchanges various information with the in-vehicle device 1 and the power transmission device 110 via the network, stores and processes these information, and performs operations of the in-vehicle device 1 and the power transmission device 110 and each power supply facility. Provide necessary information. Information handled by the power supply facility management server 3 includes the power supply method, standard, power supply capability (rapid chargeability, etc.) of the power supply facility, facility availability information, reservation information (information regarding charging conditions such as reservation time and charge amount, etc. Information on reserved vehicles such as standard information of power receiving facilities in reserved vehicles).

(Configuration of in-vehicle device)
FIG. 2 is a diagram illustrating a schematic example of the configuration of the in-vehicle device 1. The in-vehicle device 1 includes an input / output device 8 including a central processing unit (CPU) 13, a random access memory (RAM) 10, a read only memory (ROM) 11, a hard disk drive (HDD) 12, a touch panel display, a push button switch, and the like. , An information processing apparatus in which a CD / DVD deck 14, a TV / AM / FM tuner 15, a communication interface 9 and the like are electrically connected. In-vehicle device 1 is connected to power amplifier 16, speaker 17, GPS receiver 18, vehicle speed sensor 19, and charge / discharge control device 131 for in-vehicle battery 133.

  The CPU 13 is a central processing unit, and controls the RAM 10, HDD 12, input / output device 8, and the like by processing instructions and data expanded in the RAM 10 and the like. The RAM 10 is a main storage device and is controlled by the CPU 13 to write and read various commands and data. The HDD 12 is an auxiliary storage device, and information to be retained is mainly written and read even when the power of the vehicle-mounted device 1 is turned off. The input / output device 8 includes a touch panel display, various push button switches, and the like. The input / output device 8 is controlled by the CPU 13 to display the output display data and accept an operation by the user. The contents input from the input / output device 8 are recorded in the RAM 10 and processed by the CPU 13.

  In the in-vehicle device 1, an input / output device including a touch panel display and a push button switch is used as the input / output device 8, and mainly provides information through the user's vision, through a touch operation or a button switch pressing operation by the user. Accepts user input. As the user interface, for example, in addition to input / output via a touch panel display or the like, input / output by voice, input by image recognition using a camera, or the like may be used.

The HDD 12 stores various data used by the in-vehicle device 1 in addition to various programs loaded into the RAM 10. Specifically, the HDD 12 stores a point information database necessary for vehicle navigation, and stores map data and the like. The vehicle-mounted device 1 performs vehicle navigation based on signals from the GPS receiver 18 and the vehicle speed sensor 19, point information, map data, and the like stored in the HDD 12.

  The point information database is a database in which the point information is stored so as to be searchable. In the point information, in addition to the name, address, position information, attribute information (facility type, etc.) of each point, information related to the power supply equipment ( Power supply facility information).

  The communication interface 9 is an interface for the in-vehicle device 1 to communicate with the power receiving unit 120. The communication interface 9 is realized by a LAN (Local Area Network) interface board, for example, and is connected to the in-vehicle device 1 by a communication (LAN) cable. Note that a wireless communication method can be applied to the communication interface 9, and for example, a wireless LAN, Bluetooth (registered trademark), or the like can be applied. Further, the communication interface 9 may be configured to connect a serial or parallel communication cable using a connector without using a LAN, using a serial or parallel communication interface.

(Configuration of wireless power transmission device)
FIG. 3 is a diagram illustrating a configuration of the wireless power transmission system. In the first embodiment, wireless power transmission is used as a power feeding method for the in-vehicle battery 133. The wireless power transmission system roughly includes a power transmission unit 110 (corresponding to “power transmission device”) and a power reception unit 120 (corresponding to “power reception device”). The power transmission unit 110 is provided, for example, on the ground side where the vehicle stops, such as a parking space, and is connected to the power supply facility management server 3. The power receiving unit 120 is mounted on a device that needs to be charged, for example, a vehicle such as an electric vehicle or a hybrid electric vehicle. When the vehicle on which the power receiving unit 120 is mounted enters the parking space where the power transmission unit 110 is installed and the power reception unit 120 and the power transmission unit 110 face each other, power transmission / reception by wireless power transmission is performed. Be started. In FIG. 3, the signal flow of the control system is indicated by a dotted line. In FIG. 3, the signal flow of the power supply system is indicated by a solid line.

  The power transmission unit 110 includes a power transmission controller 117, a converter 113, a power transmission amplifier 114, a power transmission coil 115, a resonance control unit 116, an oscillation circuit 118, a communication interface 119, an antenna 111, and a data transmission / reception unit 112. The power transmission coil 115 is preferably provided at a position where the vehicle can be easily aligned when the vehicle is stopped, such as a predetermined position based on the parking stop of the parking space. That is, when the power transmission coil 115 is stopped in a state where the vehicle tire is in contact with the vehicle stop, the power reception unit 120 provided on the bottom surface of the vehicle (the power reception coil 125 is installed at a predetermined position with respect to the vehicle tire). It is preferable to be provided so as to face the power receiving coil 125 included in the above. A plurality of power transmission coils 115 may be provided.

The data transmission / reception unit 112 (shown as “transmission / reception unit” in FIG. 3) is a communication interface for wireless communication connected to the antenna 111. The data transmission / reception unit 112 communicates with the data transmission / reception unit 122 of the power reception unit 120 via the antenna 111. Data received by the data transmission / reception unit 112 is output to the power transmission controller 117. As a communication method between the data transmission / reception unit 112 of the power transmission unit 110 and the data transmission / reception unit 122 of the power reception unit 120, for example, short-range wireless communication such as DARC (Dedicated Short Range Communication), infrared communication, Bluetooth (registered trademark), or the like is used. The data transmission / reception unit 112 includes a decoder, an encoder, a modulation circuit, a demodulation circuit, a tuning circuit, an amplification circuit, and the like corresponding to the communication method.

Converter 113 converts AC or DC power supplied from an external power source into DC power having a predetermined voltage and supplies the power to power transmission amplifier 114. The output voltage of converter 113 is controlled by power transmission controller 117.

  The oscillation circuit 118 outputs a signal having an oscillation frequency specified by the instruction signal from the power transmission controller 117 to the power transmission amplifier 114. Further, the oscillation circuit 118 changes the oscillation frequency in accordance with the instruction signal from the power transmission controller 117 and outputs it to the power transmission amplifier 114.

  The power transmission amplifier 114 modulates the direct-current power supplied from the converter 113 with a signal having a transmission frequency supplied from the oscillation circuit 118 to generate an alternating-current power, and outputs the alternating-current power to the power transmission coil 115. That is, the power transmission coil 115 is supplied with AC power whose voltage and frequency are appropriately controlled. Further, the AC power supplied to the power transmission coil 115 is controlled by the oscillation frequency output from the oscillation circuit 118 so that the frequency matches the resonance frequency. The power transmission amplifier 114 monitors the amount of power output to the power transmission coil 115 and outputs the transmission power monitor result to the power transmission controller 117.

  The resonance control unit 116 receives the resonance frequency of the power transmission unit 110 in accordance with an instruction signal from the power transmission controller 117 by, for example, controlling the capacity of a resonance frequency variable capacitor (capacitor) connected to the power transmission coil 115. Control is performed so as to match the resonance frequency of the unit 120. That is, the power transmission controller 117 controls the resonance frequency of the power transmission unit 110 to coincide with the resonance frequency of the power reception unit 120, and controls the power transmission electromagnetic wave to output the power transmission electromagnetic wave at this resonance frequency, so Enable transmission.

The communication interface 119 is configured by a LAN or WAN (Wide Area Network) interface board according to the distance from the power supply facility management server 3, for example, and performs communication with the power supply facility management server 3. The power transmission unit 110 communicates with the power supply facility management server 3 through the communication interface 119, and acquires various information, control command signals, and the like. Data input to the communication interface 119 is output to the power transmission controller 117. The power transmission controller 117 is, for example, a microcomputer equipped with a microprocessor. The power transmission controller 117 obtains the data received from the power receiving unit 120 from the data transmission / reception unit 112 and the transmission power monitor result from the power transmission amplifier 114. The power transmission controller 117 sets the oscillation frequency to be instructed to the oscillation circuit 118 and the resonance to be instructed to the resonance control unit 116 based on the preset power transmission settings, the data transmission / reception result with the power receiving unit 120, and the transmission power monitor result. The capacitance of the frequency variable capacitor and the output voltage to be instructed to the converter 113 are determined, and an instruction signal is output to each of them. In addition, the power transmission controller 117 controls communication establishment processing and power supply start preparation processing with the power receiving unit 120 via the data transmission / reception unit 112.

  The power reception unit 120 includes a power reception controller 127, a power reception coil 125, a resonance control unit 126, a rectifier circuit 128, a DC / DC converter 129, a communication interface 130, an antenna 121, and a data transmission / reception unit 122. Here, the power receiving coil 125 is preferably provided at a predetermined position on the vehicle bottom surface with respect to the vehicle tire so as to face the power transmission unit 110 installed on the ground. The power receiving unit 120 is connected to the in-vehicle battery 133 and the motor 132 via the in-vehicle charge / discharge control device 131. The charge / discharge control device 131 discharges the vehicle driving power from the in-vehicle battery 133 in response to the accelerator operation, and when the deceleration operation is performed, the regenerative power generated by the motor 132 is in-vehicle. Control is performed so that the battery 133 is charged.

The data transmission / reception unit 122 is a communication interface connected to the antenna 121 for wireless communication. The data transmission / reception unit 122 communicates with the data transmission / reception unit 112 of the power transmission unit 110 via the antenna 121. Data transmission / reception unit 1
22 preferably communicates with the data transmission / reception unit 112 of the power transmission unit 110 via the antenna 121 using, for example, DARC, infrared communication, Bluetooth (registered trademark), or the like. The data transmission / reception unit 122 includes a decoder, an encoder, a modulation circuit, a demodulation circuit, a tuning circuit, an amplification circuit, and the like corresponding to the communication method. Data received by the data transmission / reception unit 122 is output to the power receiving controller 127.

  In the power receiving coil 125, magnetic field resonance occurs due to the electromagnetic wave output from the power transmitting coil 115, and current is generated. The rectifier circuit 128 (AC / DC converter) converts AC power generated in the power receiving coil 125 into DC power and outputs the DC power to the DC / DC converter 129. The rectifier circuit 128 monitors the amount of power generated in the power receiving coil 125 and outputs the received power monitor result to the power receiving controller 127.

  The DC / DC converter 129 stabilizes the voltage of the DC power output from the rectifier circuit 128 at a predetermined value. The voltage of the DC power is controlled by the power reception controller 127. DC power of a predetermined voltage output from the DC / DC converter 129 is stored in the battery 133 via the charge / discharge control device 131.

  The resonance control unit 126 transmits the resonance frequency of the power reception unit 120 in accordance with an instruction signal from the power reception controller 127 by, for example, controlling the capacitance of a capacitor for changing the resonance frequency connected to the power reception coil 125 (capacitor). Control is performed so as to match the resonance frequency of the unit 110.

  The communication interface 130 is configured by, for example, a LAN interface card, and communicates with the in-vehicle device 1 and the charge / discharge control device 131. In addition to the wired communication interface by LAN, for example, an interface of a serial or parallel wired communication system or a wireless communication system such as a wireless LAN can be applied. The power receiving unit 120 communicates with the in-vehicle device 1 through the communication interface 130 and acquires various information, control command signals, and the like from the in-vehicle device 1. In addition, the power receiving unit 120 acquires the remaining battery level of the in-vehicle battery 133 from the charge / discharge control device 131 through the communication interface 130. Data received by the communication interface 130 is output to the power receiving controller 127.

  The power receiving controller 127 is, for example, a microcomputer equipped with a microprocessor. The power reception controller 127 acquires the data transmission / reception result from the data transmission / reception unit 122 and the reception power monitor result from the rectifier circuit 128. The power reception controller 127 controls the resonance control unit 126 and the DC / DC converter 129 based on preset settings for power reception, a data transmission / reception result with the power transmission unit 110, and a received power monitor result. Specifically, the power reception controller 127 outputs an instruction signal that instructs the resonance control unit 126 to specify the capacitance of the capacitor for changing the resonance frequency. The power receiving controller 127 controls the DC / DC converter 129 to control the DC power voltage for stabilizing the DC power output from the rectifier circuit 128 at a predetermined value. In addition, the power reception controller 127 controls transmission preparation processing and transmission processing with the power transmission unit 110 via the data transmission / reception unit 122.

  FIG. 4 is a diagram illustrating an example of a functional configuration of the power reception controller 127 of the power reception unit 120. FIG. 4 shows the connection of the control system, and the connection of the power system (charging power transmission line) is omitted. The power supply unit is composed of, for example, a DC / DC converter 129 and the like. The power reception controller 127 executes a power transmission / reception program stored in a memory (not shown) provided in the power reception unit 120, thereby obtaining a livestock power acquisition unit 21, a power reception amount acquisition unit 22, a transmission efficiency calculation unit 23, It operates as the side information generation unit 24, the power reception control unit 25, and the measurement unit 26.

  For example, when receiving an instruction from the power reception control unit 25, the storage amount acquiring unit 21 acquires the amount of stored electricity (or remaining battery power) of the in-vehicle battery 133 mounted on the vehicle from the charge / discharge control device 131 through the communication interface 130. . The power storage amount acquisition unit 21 notifies the power reception side information generation unit 24 and the power reception control unit 25 of the power storage amount of the acquired in-vehicle battery 133.

  When power transmission / reception by wireless power transmission is started, the power reception amount acquisition unit 22 monitors the rectifier circuit 128 and acquires the power reception amount from the power transmission unit 110. For example, when receiving an instruction periodically or when receiving an instruction, the received power amount acquiring unit 22 acquires the received power amount per predetermined duration and outputs the received power amount to the transmission efficiency calculating unit 23. In addition, the power reception amount acquisition unit 22 measures the total power reception amount from the start of power transmission / reception by wireless power transmission. Upon receiving an instruction from the power reception control unit 25, the power reception amount acquisition unit 22 outputs the total power reception amount to the power reception control unit 25.

  For example, when power transmission / reception by wireless power transmission is started, the transmission efficiency calculation unit 23 calculates the transmission efficiency in the power receiving unit 120. For example, the transmission efficiency is obtained as a percentage of the ratio of the amount of power received by the power receiving unit 120 to the amount of power transmitted from the power transmission unit 110 during a predetermined duration. The transmission efficiency calculation unit 23 obtains the power transmission amount for a predetermined duration transmitted from the power transmission unit 110 by, for example, notification from the power transmission unit 110. Further, the transmission efficiency calculation unit 23 acquires, for example, the received power amount received by the power receiving unit 120 for a predetermined duration from the received power amount acquisition unit 22. It is assumed that the predetermined duration is a time in which the power transmission unit 110 and the power reception unit 120 match and are synchronized. The transmission efficiency calculation unit 23 outputs the calculated transmission efficiency to the power reception control unit 25.

  When the power receiving side information generation unit 24 receives the generation instruction of the wireless power transmission method data from the power reception control unit 25, the power receiving side information generation unit 24 generates the wireless power transmission method data. The wireless power transmission method data includes, for example, the identifier of the power receiving unit 120, the type of the wireless transmission method, the livestock capacity, the current livestock power amount, the received voltage or current rating, the allowable amount of the received power, Information about the power receiving unit 120 such as the size of the apparatus may be included. The power receiving side information generating unit 24 transmits the wireless power transmission method data to the power receiving control unit 25. The wireless power transmission method data is transmitted to the power transmission unit 110 by the power reception control unit 25.

  The measurement unit 26 measures the height of the power receiving unit 120, that is, the distance from the power transmission unit 110. For example, when the power transmission unit 110 is embedded in the ground of the parking space, the measurement unit 26 measures the distance of the power reception unit 120 from the ground. For example, an optical sensor, a laser, an ultrasonic wave, an image focus, or the like is used for measuring the distance to the power transmission unit 110. The measurement unit 26 outputs the distance between the power reception unit 120 and the power transmission unit 110 to the power reception control unit 25.

  The power reception control unit 25 controls transmission preparation processing and transmission processing. The transmission preparation process is a preparation process for starting wireless power transmission between the power transmission unit 110 and the power reception unit 120.

  The power reception control unit 25 receives the transmission efficiency from the transmission efficiency calculation unit 23 in the transmission preparation process and the transmission process, and controls the elements of the power reception unit 120 so that the transmission efficiency is improved. For example, the power reception control unit 25 adjusts the position of the vehicle on which the power reception unit 120 is mounted, and adjusts the resonance frequency. For example, the elements of the power receiving unit 120 are the position of the power receiving unit 120 (including the three directions of vertical, horizontal, and height) and the resonance frequency. Details of control contents in the transmission preparation process and the transmission process of the power reception control unit 25 will be described later.

FIG. 5 is a diagram illustrating an example of a functional configuration of the power transmission controller 117 of the power transmission unit 110. FIG. 5 shows the connection of the control signal system, and the connection of the power system (charging power transmission line) is omitted. The power transmission controller 117 executes a power transmission / reception program stored in a memory (not shown) provided in the power transmission unit 110 to thereby transmit a power transmission amount acquisition unit 51, a transmission efficiency calculation unit 52, a determination unit 53, and a power transmission control unit. 54 and the measurement unit 58. Note that the transmission efficiency calculation unit 52 and the measurement unit 58 do not operate in the first embodiment. Therefore, the transmission efficiency calculation unit 52 and the measurement unit 58 will not be described here, but will be described in a later-described modification.

  The power transmission amount acquisition unit 51 monitors the power transmission amplifier 114 and acquires the power transmission amount of power transmitted from the power transmission unit 110. For example, when receiving an instruction regularly or when receiving an instruction, the power transmission amount acquisition unit 51 acquires the power amount transmitted per predetermined duration as the power transmission amount and outputs the power transmission amount to the power transmission control unit 54. The power transmission amount is transmitted from the power transmission control unit 54 to the power receiving unit 120 and used for calculating the transmission efficiency of the power receiving unit 120. In addition, the power transmission amount acquisition unit 51 measures the total power transmission amount from the start of power transmission / reception by wireless power transmission.

  When the power transmission unit 110 receives the wireless power transmission method data from the power reception unit 120, the determination unit 53 determines whether or not power supply to the power reception unit 120 is possible based on information included in the wireless power transmission method data. For example, the determination unit 53 determines whether or not power supply is possible depending on the type of the wireless power transmission method of the power receiving unit 120 included in the wireless power transmission method data. For example, when the type of the wireless power transmission method is different between the power receiving unit 120 and the power transmission unit 110, the wireless power transmission cannot be performed, and thus the determination unit 53 determines that power feeding is not possible. When the types of the wireless power transmission methods match between the power reception unit 120 and the power transmission unit 110, the determination unit 53 determines whether power can be supplied. The determination unit 53 outputs a determination result on whether power supply to the power receiving unit 120 is possible to the power transmission control unit 54.

  The power transmission control unit 54 obtains, as an input, a determination result of whether power can be supplied to the power receiving unit 120 from the determination unit 53 and notifies the power receiving unit 120 of the result. The power transmission control unit 54 transmits to the power receiving unit 120 the result of determining whether or not power can be supplied to the power receiving unit 120 together with the power reception condition confirmation for confirming reception of the wireless power transmission method data from the power receiving unit 120.

  The power transmission control unit 54 controls the power transmission unit 110 in the transmission preparation process and the transmission process. During the execution of the transmission preparation process and the transmission process, for example, according to a request from the power receiving unit 120, control for improving the transmission efficiency is performed such as adjusting the resonance frequency. At the end of the transmission process, the power transmission control unit 54 generates billing information including information such as a power transmission amount or a power reception amount, a charge according to the power transmission amount or the power reception amount, and transmits the billing information to the power reception unit 120. . Details of control contents of the power transmission control unit 54 in the transmission preparation process and the transmission process will be described later.

(Details of transmission preparation processing)
FIG. 6 is an example of an outline flowchart of the transmission preparation process. For example, when a vehicle including the power receiving unit 120 is parked in a pay parking space where the power transmission unit 110 is installed in order to charge the in-vehicle battery 133, communication between the power receiving unit 120 and the power transmission unit 110 is established. 6 is started. The transmission preparation process is started, for example, when a signal instructing the power reception unit 120 to start power reception is input, and is repeatedly executed while the power reception unit 120 is activated. Hereinafter, in the transmission preparation process and the transmission process, data transmission / reception between the power transmission unit 110 and the power reception unit 120 is performed using the data transmission / reception unit 112 of the power transmission unit 110 and the data transmission / reception unit 122 of the power reception unit 120. It shall be by distance communication.

The transmission preparation process is executed by cooperation between the power reception unit 120 and the power transmission unit 110. Transmission preparation processing is largely divided into power transmission / reception device confirmation processing (OP1) and trial transmission processing (OP2).
And the efficiency improvement process (OP3), and are executed in this order.

  The power transmission / reception device confirmation process (OP1) is a process for the power transmission unit 110 and the power reception unit 120 to confirm each other's power transmission or power reception conditions. The trial transmission process (OP2) is a process for trying power transmission / reception before power transmission / reception is started, and whether or not there is a foreign object between the power transmission unit 110 and the power reception unit 120. It is confirmed. The efficiency improvement process (OP3) is a process for improving the transmission efficiency in the power reception unit 120 or the transmission efficiency in the power transmission unit 110. For example, the distance between the power reception unit 120 and the power transmission unit 110 is adjusted, The position of the power receiving unit 120 is adjusted. Details of the power transmission / reception device confirmation processing, trial transmission processing, and efficiency improvement processing will be described later.

(Details of power transmission / reception device confirmation processing)
FIG. 7 is an example of a flowchart of power transmission / reception device confirmation processing. The power transmission / reception device confirmation process is a process performed first in the transmission preparation process, and is a process for the power transmission unit 110 and the power reception unit 120 to confirm each other's existence and conditions. The power transmission / reception device confirmation process is started when a signal instructing the power reception unit 120 to start power reception is input, for example, when the user presses a push button switch or the like.

  In OP <b> 101, the power reception controller 127 generates wireless power transmission method data and transmits it to the power transmission unit 110. The wireless power transmission method data includes, for example, the identifier of the power receiving unit 120, the type of the wireless transmission method, the livestock capacity, the current livestock power amount, the received voltage or current rating, the allowable amount of the received power, Includes the size of the device. The type of wireless transmission method, the amount of livestock power, the current amount of livestock power, the rating of received power voltage or current, the allowable amount of received power, the size of the device of the power receiving unit 120, etc. are also referred to as power receiving conditions.

  In OP102, the power transmission controller 117 determines whether or not transmission / reception method data has been received from the power receiving unit 120. When the power transmission / reception system data is received (OP102: YES), the process proceeds to OP103. When the power transmission / reception system data is not received (OP102: NO), the transmission preparation process ends.

  In OP103, the power transmission controller 117 determines whether or not power supply to the power receiving unit 120 is possible based on the transmission / reception method data. For example, the power transmission controller 117 determines whether the power reception unit 120 can be powered by determining whether the type of the wireless power transmission method of the power reception unit 120 included in the transmission / reception method data matches that of the power transmission unit 110. Determine. In this case, if the type of the wireless power transmission method matches that of the power transmission unit 110, the power transmission controller 117 determines whether power can be supplied to the power receiving unit 120. If it is determined that power can be supplied to the power receiving unit 120 (OP103: YES), the process proceeds to OP104. If power supply to the power receiving unit 120 is not possible (OP103: NO), the process proceeds to OP105.

  In OP <b> 104, the power transmission controller 117 determines power transmission conditions based on information included in the wireless power transmission method data from the power receiving unit 120. The power transmission conditions are, for example, a power transmission voltage or power transmission current, an upper limit of power transmission power, and the like. The power transmission controller 117 transmits a power reception condition confirmation (OK) response including power transmission conditions to the power reception unit 120 that power supply is possible. When the power reception unit 120 receives the power reception condition confirmation response, the power reception unit 120 causes the power transmission unit 110 to receive the power reception conditions (type of wireless transmission method, livestock capacity, current capacity included in the wireless power transmission method data from the power receiving unit 120. It is possible to check that the amount of livestock power, the rating of the received voltage or received current, the allowable amount of received power, the size of the device of the power receiving unit 120) and set the power transmission conditions in accordance therewith.

  In OP105, since the power transmission controller 117 determines that power cannot be supplied to the power receiving unit 120, the power transmission controller 117 transmits a power reception condition confirmation (NG) response including that power cannot be supplied to the power receiving unit 120. In this case, since power supply (power transmission) to the power receiving unit 120 is not performed, the power transmission / reception device confirmation process and the transmission preparation process are completed.

  In OP106, the power reception controller 127 determines whether or not a power reception condition confirmation response has been received from the power transmission unit 110. When the power reception condition confirmation response is received (OP106: YES), the process proceeds to OP107. When the power reception condition confirmation response is not received (OP106: NO), the power transmission / reception device confirmation process and the transmission preparation process are finished.

  In OP107, the power reception controller 127 determines whether power supply is possible or power supply is not possible by the power reception condition confirmation response. If the power reception condition confirmation response indicates that power can be supplied (OP107: YES), the process proceeds to OP108. When the power reception condition confirmation response indicates that power supply is not possible (OP107: NO), the power transmission / reception device confirmation process and the transmission preparation process are completed.

  In OP108, the power reception controller 127 extracts the power transmission condition included in the power reception condition confirmation response, confirms that it matches the power reception condition of itself, and transmits the power transmission condition confirmation response to the power transmission unit 110. By receiving the power transmission condition confirmation response, the power transmission unit 110 can recognize that the power receiving unit 120 has confirmed the power transmission condition of the power transmission unit 110. When the power transmission condition confirmation is transmitted, the power reception controller 127 ends the power transmission / reception device confirmation processing in the power reception unit 120, and then starts trial transmission processing.

  In OP109, the power transmission unit 110 receives a power transmission condition confirmation response from the power receiving unit 120. When the power receiving unit 120 receives the power reception condition confirmation response from the power transmission unit 110 and the power transmission unit 110 receives the power transmission condition confirmation response from the power reception unit 120, the conditions or states of each other can be confirmed. When transmitting the power transmission condition confirmation, the power transmission controller 117 ends the power transmission / reception device confirmation processing in the power transmission unit 110, and then starts trial transmission processing.

  The power reception control unit 25 is realized by a part of OP101, and the processing of OP106, OP107, and 108. The power receiving side information generation unit 24 is realized by a part of the processing of OP101. The determination unit 53 is realized by the processing of OP102 and OP103. The power transmission control unit 54 is realized by the processing of OP104, OP105, and OP109.

(Details of trial transmission process)
FIG. 8 is an example of a flowchart of trial transmission processing. In the power transmission / reception device confirmation process shown in FIG. 7, when it is determined that power supply is possible and the power transmission / reception device confirmation process ends, trial transmission processing is started.

  In OP201, the power receiving controller 127 transmits a trial power transmission start request for requesting trial power transmission to the power transmission unit 110. In OP202, the power transmission controller 117 determines whether or not a trial power transmission start request has been received. When the trial power transmission start request is received (OP202: YES), the process proceeds to OP203. When the trial power transmission start request is not received (OP202: NO), the trial transmission process and the transmission preparation process are finished.

  In OP203, the power transmission controller 117 transmits a trial power transmission start response to the power receiving unit 120. Thereafter, in the power transmission unit 110, the process proceeds to OP205.

In OP204, the power receiving controller 127 determines whether or not a trial power transmission start response has been received. When the trial power transmission start response is received (OP204: YES), in the power receiving unit 120, the process proceeds to OP206. When the trial power transmission start response is not received (OP204: NO), the trial transmission process and the transmission preparation process are finished.

  In OP205, the power transmission controller 117 starts trial power transmission. For example, under the control of the power transmission controller 117, the power output from the converter 113 is input to the power transmission coil 115 at the frequency given from the oscillation circuit 118 and power transmission is started. In the case of trial power transmission, a small power (trial power) predetermined for trial power transmission under the control of the power transmission controller 117 is output from the converter 113 and applied to the power transmission coil 115 at a frequency given from the oscillation circuit 118. Entered. Thereafter, in the power transmission unit 110, the process proceeds to OP207.

  In OP206, in the power receiving unit 120, when a current flows through the power transmission coil 115 by trial power transmission, a current flows through the power receiving coil 125 due to magnetic field resonance with the power transmission coil 115, and the rectifier circuit 128, the DC / DC converter 129, The in-vehicle battery 133 is charged through the discharge control device 131. The power receiving controller 127 also monitors the rectifier circuit 128 and acquires the amount of power received by trial power transmission. Thereafter, in the power receiving unit 120, the process proceeds to OP208.

  In OP <b> 207, the power transmission controller 117 transmits the power transmission amount obtained as a result of monitoring by the power transmission amplifier 114 to the power receiving unit 120 when performing trial power transmission. Thereafter, in the power transmission unit 110, the process proceeds to OP213.

In OP <b> 208, the power reception controller 127 receives a power transmission amount by trial power transmission from the power transmission unit 110.

  In OP209, the power receiving controller 127 obtains the transmission efficiency by the trial power transmission from the power transmission amount by the trial power transmission transmitted from the power transmission unit 110 and the power reception amount by the trial power transmission acquired in OP206. The transmission efficiency is, for example, a percentage of the amount of power received by trial power transmission with respect to the amount of power transmitted by trial power transmission transmitted from the power transmission unit 110.

  In OP210, the power receiving controller 127 determines whether or not the transmission efficiency calculated in OP209 is equal to or higher than the minimum value of the transmission efficiency. The minimum value of transmission efficiency is a value of transmission efficiency that should be guaranteed at least in wireless power transmission, and is set within a range of 20 to 50%. If the transmission efficiency is equal to or higher than the minimum value (OP210: YES), the process proceeds to OP211. When the transmission efficiency is less than the minimum value (OP210: NO), the process proceeds to OP212.

  In OP 211, the power reception controller 127 transmits trial completion (OK) to the power transmission unit 110. When the trial completion (OK) is transmitted, the power receiving controller 127 ends the trial transmission process in the power receiving unit 120, and then starts the efficiency improvement process in the power receiving unit 120.

In OP212, since the transmission efficiency is smaller than the minimum value, the power receiving controller 127 transmits a trial completion (NG) to the power transmission unit 110. For example, if a conductor such as a metal exists between the power receiving unit 120 and the power transmission unit 110 as a foreign object, the power from the power transmission unit 110 is absorbed by the foreign object, and the transmission efficiency in the power receiving unit 120 decreases. Therefore, when the transmission efficiency in the trial power transmission is smaller than the minimum value, there is a high possibility that a foreign object exists between the power receiving unit 120 and the power transmission unit 110. When the trial completion (NG) is transmitted, the power receiving controller 127 ends the trial transmission process in the power receiving unit 120 and ends the transmission preparation process in the power receiving unit 120.

  In OP213, the power transmission controller 117 determines whether or not a trial completion (OK) has been received. When the trial completion (OK) is received (OP213: YES), the power transmission controller 117 ends the trial transmission process in the power transmission unit 110, and then starts the efficiency improvement process in the power transmission unit 110. When trial completion (NG) is received (OP213: NO), the power transmission controller 117 ends the trial transmission process in the power transmission unit 110 and also ends the transmission preparation process in the power transmission unit 110.

  In OP210, when the transmission efficiency in the trial power transmission is smaller than the minimum value, the wireless power transmission is not executed, so that unnecessary power transmission can be omitted at an earlier stage.

  Note that the power reception control unit 25 is realized by the processing of part of OP201, OP204, OP206, and OP208, part of OP209, OP210, OP211 and OP212. The received power acquisition unit 22 is realized by a part of processing of OP 206 (acquired power reception). The transmission efficiency calculation unit 23 is realized by a part of processing of OP209 (transmission efficiency calculation). The power transmission control unit 54 is realized by a part of OP202, OP203, OP205, OP207, and processing of OP213. The power transmission amount acquisition unit 51 is realized by part of the processing of OP207 (transmission amount acquisition).

(Details of efficiency improvement processing)
9A and 9B are examples of flowcharts of the efficiency improvement process. The efficiency improvement process is a process performed to improve transmission efficiency in the power receiving unit 120. The flow shown in FIGS. 9A and 9B is executed, for example, when the trial transmission process shown in FIG. 8 is successful, that is, after trial completion (OK) is transmitted from the power receiving unit 120 to the power transmission unit 110.

  The transmission efficiency in the power reception unit 120 depends on, for example, 1) the distance between the power reception coil 125 and the power transmission coil 115, and 2) the alignment between the power reception unit 120 and the power transmission unit 110. In FIG. 9A, assuming that the power receiving unit 120 is movable or the height of the vehicle can be adjusted by a suspension or the like, the power receiving unit 120 and the power transmitting unit 110 are adjusted by adjusting the height of the power receiving unit 120 from the ground. The flow of the efficiency improvement process in the case of adjusting the distance to and improving the transmission efficiency is shown.

  In OP301, the power reception controller 127 measures the distance from the power transmission unit 110. The power reception controller 127 may measure the distance from the power transmission unit 110 using, for example, an optical sensor, a laser, an ultrasonic wave, an image focus, or the like. Further, for example, when the power transmission unit 110 is embedded in the ground of the parking space, the height data is acquired from the data such as the vehicle type of the vehicle on which the power reception unit 120 is mounted, and the distance from the power transmission unit 110 is also obtained. Good.

In OP <b> 302, the power reception controller 127 acquires a distance from the power transmission unit 110. For example, a memory (not shown) provided in advance in the power receiving unit 120 holds a graph, a table, an equation, or the like indicating the relationship between the distance to the power transmitting unit 110 and the transmission efficiency. Based on these, the distance to the power transmission unit 110 is acquired. For example, when the power reception unit 120 itself is movable within a predetermined range from the installation position of the vehicle, the power reception controller 127 moves the power reception unit 120 in the vertical direction and adjusts the distance from the power transmission unit 110. For example, when the vehicle on which the power receiving unit 120 is mounted can adjust the height by suspension or the like, the power receiving controller 127 instructs the unit that controls the suspension to adjust the height of the vehicle, and adjusts the vehicle height. By adjusting, the distance to the power transmission unit 110 is adjusted.

  In OP303, the power reception controller 127 transmits a trial power transmission start request to the power transmission unit 110 to perform a trial power transmission in order to confirm a change in transmission efficiency due to the adjustment of the distance to the power transmission unit 110, thereby reducing the transmission efficiency of the trial power transmission. calculate. The processing from OP303 to OP311 is the same as the processing from OP201 to OP209 described in FIG.

  In OP312, the power receiving controller 127 determines whether or not the transmission efficiency calculated in OP311 is larger than the target value. The target value of the transmission efficiency is, for example, a value obtained by averaging the highest values of the transmission efficiency in each transmission process, or a value within the range of 70% to 90%. When the transmission efficiency is less than or equal to the target value (OP312: NO), the efficiency improvement process is temporarily terminated and is repeatedly executed until the transmission efficiency becomes larger than the target value. If the transmission efficiency is greater than the target value (OP312: YES), the process proceeds to OP313.

  In OP313, the power reception controller 127 transmits distance setting completion to the power transmission unit 110. Upon receiving the distance setting completion to the power transmission unit 110, the power reception controller 127 ends the efficiency improvement process in the power reception unit 120 and ends the transmission preparation process in the power reception unit 120. As a result, the power receiving unit 120 is ready to start transmission processing.

  In OP314, the power transmission controller 117 determines whether or not distance setting completion has been received. When the distance setting completion is received (OP314: YES), the power transmission controller 117 ends the efficiency improvement process in the power transmission unit 110 and ends the transmission preparation process in the power transmission unit 110. As a result, the power transmission unit 110 is ready to start transmission processing. When the distance setting completion is not received (OP314: NO), the efficiency improvement process in the power transmission unit 110 is temporarily ended, and the flow illustrated in FIG. 9A is repeatedly executed.

  In FIG. 9A, control of the distance between the power reception unit 120 and the power transmission unit 110 is executed until the transmission efficiency becomes larger than the target value. Instead, for example, the control of the distance between the power reception unit 120 and the power transmission unit 110 may be repeated a predetermined number of times, and the height of the power reception unit 120 when the transmission efficiency is the highest may be adopted.

  The measurement unit 26 is realized by the processing of OP301. The power reception control unit 25 is realized by processing of part of OP302, OP303, OP306, OP308, part of OP310, OP311, OP312 and OP313. The received power acquisition unit 22 is realized by a part of processing of OP308 (acquired power reception). The transmission efficiency calculation unit 23 is realized by a part of the processing of OP 311 (transmission efficiency calculation). The power transmission control unit 54 is realized by the processing of OP304, OP305, OP307, part of OP309, and OP314. The transmission amount acquisition unit 51 is realized by a part of processing of OP 309 (acquisition of transmission amount).

  In FIG. 9B, when the power receiving unit 120 itself is movable, the power receiving coil 120 and the power transmitting coil 115 are more appropriately moved by moving the power receiving unit 120 or moving a vehicle on which the power receiving unit 120 is mounted. The flow of the efficiency improvement process in the case where the horizontal position of the power receiving unit 120 is adjusted so as to face each other and the transmission efficiency is improved is shown.

In OP321, the power reception controller 127 acquires horizontal position information of the power reception unit 120. For example, the dimensional data of the vehicle, the dimensional data of the power receiving unit 120, and the mounting position of the power receiving unit are stored in the memory in advance, and the vehicle-mounted device 1 acquires the coordinates of the vehicle from the GPS receiver 18, whereby the power receiving controller 127 is obtained. Acquires the position information of the power receiving unit 120 in the horizontal direction.

  In OP322, the power reception controller 127 transmits a coil position information request to the power transmission unit 110 in order to acquire position information such as coordinate information of the power transmission coil 115 of the power transmission unit 110. Thereafter, in the power receiving unit 120, the process proceeds to OP325.

  In OP323, the power transmission controller 117 determines whether a coil position information request has been received. When the coil position information request is received (OP323: YES), the process proceeds to OP324. When the coil position information request is not received (OP323: NO), the efficiency improvement process is once terminated in the power transmission unit 110 and repeatedly executed.

  In OP324, the power transmission controller 117 transmits the coil position information to the power receiving unit 120. For example, the power transmission controller 117 reads position information of the power transmission coil 115 held in a memory (not shown) provided in the power transmission unit 110 and transmits the position information to the power reception unit 120 as coil position information. In addition, you may acquire the positional information on the power transmission coil 115 from the electric power feeding equipment server 3, for example.

  In OP325, the power reception controller 127 determines whether or not the position information of the power transmission coil 115 has been received from the power transmission unit 110. When the position information of the power transmission coil 115 is received (OP325: YES), the process proceeds to OP326. When the position information of the power transmission coil 115 is not received (OP325: NO), the efficiency improvement process is once completed in the power receiving unit 120, and then repeatedly executed.

  In OP326, the power reception controller 127 acquires the movement direction and the movement distance in the horizontal direction of the power reception unit 120 from the position information of the power reception unit in the horizontal direction and the position information of the power transmission coil, and controls the position of the power reception unit 120. . Examples of the horizontal position control of the power receiving unit 120 include the following methods.

  (1) For example, when the power receiving unit 120 itself is movable within a predetermined range from the installation position of the vehicle, the power receiving controller 127 moves the power receiving unit 120 in the horizontal direction. (2) For example, using an output device such as a display or a speaker provided in the in-vehicle device 1, the power receiving controller 127 instructs the user to move the vehicle, and adjusts the position of the power receiving unit 120 by moving the vehicle. (3) For example, the power receiving controller 127 transmits the moving direction and moving distance of the vehicle to the power supply facility management server 3 or the information center 2, and the power supply facility management server 3 or the information center 2 sends the vehicle's mobile phone terminal to the vehicle The user is instructed to move the vehicle by transmitting the moving direction and the moving distance. (4) The position of the vehicle is automatically adjusted using an IPA (Intelligent Parking Assist) system.

  In OP327, when the adjustment of the horizontal position of the power receiving unit 120 is completed, the power receiving controller 127 transmits a trial power transmission start request to the power transmission unit 110, performs trial power transmission, and confirms the change in transmission efficiency. Calculate the transmission efficiency of power transmission. The processing from OP327 to OP335 is the same as the processing from OP201 to OP209 described in FIG.

In OP336, the power receiving controller 127 determines whether or not the transmission efficiency calculated in OP335 is larger than the target value. When the transmission efficiency is equal to or lower than the target value (OP336: NO), the efficiency improvement process in the power receiving unit 120 is temporarily terminated and repeatedly executed to further improve the transmission efficiency. When the transmission efficiency is larger than the target value (OP336: Y
ES), the process proceeds to OP337.

  In OP <b> 337, the power reception controller 127 transmits position setting completion to the power transmission unit 110. When the position setting completion is transmitted to the power transmission unit 110, the power reception controller 127 ends the efficiency improvement process in the power reception unit 120 and also ends the transmission preparation process in the power reception unit 120. As a result, the power receiving unit 120 is ready to start transmission processing.

  In OP338, the power transmission controller 117 determines whether or not a position setting completion has been received. When the position setting completion is received (OP338: YES), the power transmission controller 117 ends the efficiency improvement process in the power transmission unit 110 and ends the transmission preparation process in the power transmission unit 110. As a result, the power transmission unit 110 is ready to start transmission processing. When the position setting completion is not received (OP338: NO), the processing in the power transmission unit 110 is temporarily ended and then repeatedly executed.

  The measurement unit 26 is realized by the processing of OP321. The power reception control unit 25 is realized by the processes of OP322, OP325, OP326, OP327, OP330, OP332, part of OP334, OP335, OP336, and OP337. The received power acquisition unit 22 is realized by a part of processing of OP 332 (acquisition of received power). The transmission efficiency calculation unit 23 is realized by a part of processing of OP335 (transmission efficiency calculation). The power transmission control unit 54 is realized by the processes of OP323, OP324, OP328, OP329, OP331, OP333, and OP338. The transmission amount acquisition unit 51 is realized by a part of processing of OP 333 (acquisition of transmission amount).

  In the first embodiment, two examples of efficiency improvement processing have been described in FIGS. 9A and 9B. Depending on the performance of the vehicle on which the power receiving unit 120 is mounted, either one of the efficiency improvement processes may be executed, or both may be executed in combination.

  When the transmission preparation process is completed as described above and the power transmission unit 110 and the power reception unit 120 are ready to transmit and receive power, the transmission process is started.

(Details of transmission processing)
FIG. 10 is a diagram showing an outline of the transmission process. In the transmission process, when wireless power transmission is started between the power transmission unit 110 and the power receiving unit 120 (OP4), in parallel with the wireless power transmission, a risk avoidance process (OP5), a resonance frequency adjustment process (OP6), The initial parameter learning process (OP7), the livestock power monitoring process (OP8), and the transmission completion determination process (OP9) are repeatedly executed. When the wireless power transmission is stopped in the danger avoidance process (OP5) and the transmission completion determination process (OP9), the resonance frequency adjustment process (OP6), the initial parameter learning process (OP7), and the livestock energy monitoring process (OP8) are finished. . Thereafter, an information providing process (OP10) is performed, and the transmission process is completed.

  While power transmission to the power receiving unit 120 is being executed, the power transmission controller 117 periodically acquires the power transmission amount and transmits it to the power receiving unit 120. While receiving power transmission from the power transmission unit 110, the power reception controller 127 periodically acquires the amount of power received and calculates transmission efficiency. The power reception controller 127 transmits the calculated transmission efficiency to the power transmission unit 110, and the power transmission controller 117 of the power transmission unit 110 stores the transmission efficiency in a memory (not shown) provided in the power transmission unit 110. While wireless power transmission is being performed between the power transmission unit 110 and the power reception unit 120, such processing is periodically repeated.

In the risk avoidance process (OP5), for example, when an abnormality is detected in power transmission / reception between the power transmission unit 110 and the power reception unit 120, is the abnormality due to the presence of a foreign object between the power transmission unit 110 and the power reception unit 120? This is a process for determining whether or not power is leaked due to the presence of a foreign object.

  The resonance frequency adjustment process (OP6) is a process for detecting a change in the resonance frequency due to heat generation of the coil or the like by monitoring the transmission efficiency and adjusting the resonance frequency. The initial parameter learning process (OP7) is a process of monitoring the transmission efficiency and holding the parameter when the maximum value of the transmission efficiency is recorded as an initial parameter at the time of executing the next transmission preparation process and transmission process.

  The livestock power monitoring process (OP8) is a process performed in the power receiving unit 120. The livestock power monitoring of the in-vehicle battery 133 is monitored and stored to some extent (for example, about 80% of the livestock power at full charge). In this case, it is a process for reducing the charging speed. The transmission completion determination process (OP9) is a process for determining the completion of power transmission / reception. The information providing process (OP10) is a process of providing information such as billing information and total power transmission amount to the power receiving unit 120 when power transmission / reception is completed. Details of each of the risk avoidance process, the resonance frequency adjustment process, the initial parameter learning process, the stored electricity amount monitoring process, the transmission completion determination process, and the information providing process will be described later.

(Details of risk avoidance processing)
FIG. 11 is a diagram illustrating an example of the flow of danger avoidance processing. When wireless power transmission is started between the power transmission unit 110 and the power receiving unit 120, danger avoidance processing is started, and is repeatedly executed while wireless power transmission is being performed.

  In OP501, the power receiving controller 127 determines whether or not the abnormality detection condition is satisfied. The abnormality detection conditions include, for example, the following conditions.

  (A) Communication of power transmission amount notification and transmission efficiency notification that is periodically performed between the power receiving unit 120 and the power transmission unit 110 is disconnected. For example, the power reception controller 127 detects an abnormality when the notification of the amount of power transmitted from the power transmission unit 110 that is periodically received is not received. (B) The power reception controller 127 detects a forcible stop signal due to an operation button connected to the power reception unit 120 or a user operation through the vehicle-mounted device 1. (C) The power receiving controller 127 of the power receiving unit 120 detects a forced stop signal from an external device such as an alarm device mounted on a mobile phone or a vehicle. In this case, the forced stop signal from the external device is transmitted to the power receiving unit 120 through the in-vehicle device 1 once via the information center 2 or the power supply facility management server 3, for example.

  When the power receiving controller 127 detects any abnormality detection condition (A) to (C) (OP501: YES), the process proceeds to OP502. When the abnormality detection condition is not detected (OP501: NO), the danger avoidance process in the power receiving unit 120 is once ended and then repeatedly executed.

  In OP502, the power receiving controller 127 acquires the latest transmission efficiency. In OP503, the power receiving controller 127 determines whether an abnormality has occurred based on whether the acquired transmission efficiency is equal to or higher than the minimum threshold value. For example, the abnormality is detected when a foreign object is inserted between the power transmission unit 110 and the power reception unit 120. When the transmission efficiency is equal to or higher than the minimum threshold, the power reception control unit 25 determines that no abnormality has occurred. When the transmission efficiency is smaller than the minimum threshold, the power reception control unit 25 determines the occurrence of an abnormality. If the occurrence of an abnormality is not determined (OP503: NO), the danger avoidance process is once terminated in the power receiving unit 120 and then repeatedly executed. If it is determined that an abnormality has occurred (OP503: YES), the process proceeds to OP504.

  In OP <b> 504, the power receiving controller 127 transmits an abnormality occurrence notification to the power transmission unit 110. Thereafter, in the power receiving unit 120, the process proceeds to OP507.

  In OP505, the power transmission controller 117 determines whether an abnormality occurrence notification has been received. When an abnormality occurrence notification is received (OP505: YES), the process proceeds to OP506. When the abnormality occurrence notification is not received (OP505: NO), the danger avoidance process in the power transmission unit 110 ends and is repeatedly executed thereafter.

  In OP506, the power transmission controller 117 receives the abnormality occurrence notification, and therefore stops power transmission.

  In OP507, the power reception controller 127 stops the power reception when the abnormality occurrence notification is transmitted.

  In OP508, the power receiving controller 127 sets the variable i to an initial value of 1. In OP509, for example, trial transmission processing in FIG. 8 is performed between the power reception unit 120 and the power transmission unit 110.

  In OP510, the power receiving controller 127 determines whether or not the trial transmission process is successful. If the trial transmission process is successful (OP510: YES), the process proceeds to OP511. If the trial transmission process is not successful (OP510: NO), the process proceeds to OP515.

  In OP511, the power reception controller 127 transmits a power transmission start request to the power transmission unit 110 and requests power transmission. In OP512, the power transmission controller 117 determines whether a power transmission start request has been received. If a power transmission start request is received (OP512: YES), the process proceeds to OP513. When the power transmission start request is not received (OP512: NO), the danger avoidance process in the power transmission unit 110 is once ended and then repeatedly executed.

  In OP513, the power transmission controller 117 starts power transmission. When power transmission is started, the danger avoidance process in the power transmission unit 110 is terminated and then repeatedly executed.

  In OP514, when the power transmission unit 110 starts power transmission, the power reception controller 127 starts power reception.

  In OP515, the power receiving controller 127 determines whether or not the variable i is greater than or equal to a constant n. The constant n is an upper limit value for repeating the trial transmission process. When the variable i is smaller than the constant n (OP515: NO), the process proceeds to OP516. If the variable i is greater than or equal to the constant n (OP515: YES), it indicates that the transmission / reception trial process will not succeed even if the upper limit value of the trial transmission process is exceeded. In this case, for example, a foreign substance that absorbs and absorbs power is inserted between the power transmission unit 110 and the power reception unit 120, and it is suspected that the power is flowing out. The unit 25 ends the danger avoidance process in the power receiving unit 120. In addition, the power reception control unit 25 notifies the power transmission unit 110 of the end of the risk avoidance process, and upon receiving the notification of the end of the risk avoidance process, the power transmission unit 110 ends the risk avoidance process in the power transmission unit 110.

In OP516, the power receiving controller 127 adds 1 to the variable i and updates it. Thereafter, the process returns to OP509, and the processes of OP509, OP510, OP515, and OP516 are repeated until the trial transmission process is successful or the upper limit value of the trial transmission process is reached.

  In this way, when it is detected that the abnormality detection condition is satisfied, the power receiving unit 120 determines the occurrence of abnormality based on the transmission efficiency, and when the occurrence of abnormality is determined, Stop power transmission and reception and perform trial transmission again. If the trial transmission process is not successful even if the trial transmission process is performed a predetermined number of times, the wireless power transmission ends. As a result, when an abnormality is detected, for example, when there is no abnormality in which a foreign object exists between the power transmission unit 110 and the power receiving unit 120, wireless power transmission is resumed. In addition, when an abnormality is detected, for example, when an abnormality such as a foreign object actually exists between the power transmission unit 110 and the power reception unit 120, the wireless power transmission is stopped, Can prevent spillage.

  Note that the power reception control unit 25 is realized by processing of a part of OP501 and OP502, and OP503-OP511, OP515, and OP516. The transmission efficiency calculation unit 23 is realized by a part of processing of OP502 (transmission efficiency calculation). The power transmission control unit 54 is realized by the processing of OP505, OP506, a part of OP509, OP512, and OP513.

(Details of resonance frequency adjustment processing)
FIG. 12 is an example of a flowchart of the resonance frequency adjustment process. The resonance frequency changes due to heat generation of the coil or the like when power transmission / reception is continued. If the resonance frequency changes, the transmission efficiency may decrease. In the resonance frequency adjustment process, a decrease in transmission efficiency is detected, and a decrease in transmission efficiency is prevented by adjusting the resonance frequency. The flow shown in FIG. 12 starts when wireless power transmission is started, and is repeatedly executed while wireless power transmission is being performed.

  In OP602, the power reception controller 127 acquires the transmission efficiency at the transmission efficiency acquisition timing. For example, the power receiving controller 127 may acquire the transmission efficiency every second.

  In OP603, the power receiving controller 127 determines whether or not the transmission efficiency has decreased by a predetermined amount. If the transmission efficiency has decreased by a predetermined amount or more (OP603: YES), the process proceeds to OP604. When the transmission efficiency is not lower than the predetermined amount (OP603: NO), the resonance frequency adjustment process in the power receiving unit 120 is once ended and then repeatedly executed.

  In OP604, the power receiving controller 127 controls the resonance frequency. For example, the power receiving controller 127 changes the resonance frequency according to the amount of change in transmission efficiency, and determines a new resonance frequency. The power receiving controller 127 notifies the resonance control unit 126 of the determined resonance frequency. In the resonance control unit 126, for example, the resonance frequency is changed by changing the capacitance of the capacitor or changing the inductance of the power receiving coil 125. In OP605, the power reception controller 127 notifies the power transmission unit 110 of the determined new resonance frequency.

  In OP606, the power transmission controller 117 determines whether or not a notification of a new resonance frequency has been received from the power receiving unit 120. When a notification of a new resonance frequency is received (OP606: YES), the process proceeds to OP607. When the notification of the new resonance frequency is not received (OP606: NO), the resonance frequency adjustment process in the power transmission unit 110 is once ended and then repeatedly executed.

  In OP607, the power transmission controller 117 controls the resonance frequency so that the received new resonance frequency is obtained. For example, the power transmission controller 117 notifies the resonance control unit 116 of the received new resonance frequency. In the resonance control unit 116, for example, the resonance frequency is changed by changing the capacitance of the capacitor or changing the inductance of the power transmission coil 115. Further, the power transmission controller 117 notifies the oscillation circuit 118 of the received resonance frequency, and the oscillation circuit 118 performs control so that the notified resonance frequency matches the circuit frequency. In OP608, when the control of the resonance frequency is completed, the power transmission controller 117 transmits a resonance frequency setting completion to the power receiving unit 120. Thereafter, the resonance frequency adjustment process in the power transmission unit 110 is once completed and then repeatedly executed.

  In OP609, the power reception controller 127 determines whether or not the resonance frequency setting completion is received from the power transmission unit 110. When the resonance frequency setting completion is received (OP609: YES), the process proceeds to OP610. When the completion of the resonance frequency setting is not received (OP609: NO), the resonance frequency adjustment process in the power receiving unit 120 is once completed and then repeatedly executed.

  In OP610, the power receiving controller 127 acquires transmission efficiency. Note that the transmission efficiency at this time is a transmission efficiency calculated from the power transmission amount and the power reception amount after the resonance frequency is controlled by both the power reception unit 120 and the power transmission unit 110.

  In OP611, the power receiving controller 127 determines whether or not the transmission efficiency is greater than the target value. When the transmission efficiency is larger than the target value (OP611: YES), the resonance frequency adjustment process in the power receiving unit 120 is finished and then repeatedly executed. When the transmission efficiency is smaller than the target value (OP611: NO), the process returns to OP604, and the processes of OP604 to OP611 are repeatedly executed.

  The resonance frequency adjustment process is terminated when, for example, the wireless power transmission is stopped in the danger avoidance process or the transmission completion determination process.

  The power receiving unit 120 detects a decrease in transmission efficiency and controls the resonance frequency, so that even when the resonance frequency changes due to heat generation of the power receiving coil 125 due to wireless power transmission and the transmission efficiency decreases, the transmission efficiency is again set to the target value. Can be.

  Note that the power reception control unit 25 is realized by the processing of a part of OP602, OP603-OP605, and OP609-OP611. The transmission efficiency calculation unit 23 is realized by a part of processing of OP602 and a part of processing of OP610 (transmission efficiency calculation). The power transmission control unit 54 is realized by the processing of OP606 to OP608.

(Details of initial parameter learning process)
FIG. 13 is an example of a flowchart of the initial parameter learning process. The power receiving unit 120 uses, for example, a parameter when the transmission efficiency is the best as an initial parameter in each chargeable parking space such as a home parking lot, a company parking lot, and a frequently used charging spot. Hold. The flow shown in FIG. 13 starts when wireless power transmission is started, and is repeatedly executed while wireless power transmission is being performed.

  In OP <b> 702, the power reception controller 127 acquires the transmission efficiency at the transmission efficiency acquisition timing. For example, the power receiving controller 127 may acquire the transmission efficiency every second. Further, the transmission efficiency acquisition timing may be the same as, for example, OP601 of the resonance frequency adjustment process shown in FIG.

  In OP703, the power receiving controller 127 determines whether or not the acquired transmission efficiency is better than the transmission efficiency corresponding to the initial parameter held in the memory included in the power receiving unit 120. If the acquired transmission efficiency is better than the transmission efficiency corresponding to the initial parameter (OP703: YES), the process returns to OP704. If the acquired transmission efficiency is not better than the transmission efficiency corresponding to the initial parameter (OP703: NO), the initial parameter learning process is terminated and then repeatedly executed.

  In OP704, the power receiving controller 127 updates the initial parameter with the current parameter. The parameters are, for example, the resonance frequency, the position (coordinates, etc.) of the power receiving unit 120, the distance between the power receiving unit 120 and the power transmitting unit 110, and the like. The power receiving controller 127 records the parameter and the transmission efficiency at that time in association with the position information of the parking space. Thereafter, the initial parameter learning process is completed, and then repeatedly executed. In this way, for example, the initial parameters and the transmission efficiency corresponding to the initial parameters are recorded for each parking space such as a home parking lot or a company parking lot.

  The initial parameter learning process is ended when, for example, the wireless power transmission is stopped in the danger avoidance process or the transmission completion determination process.

  As shown in FIG. 13, the parameters when the transmission efficiency is the best are held as initial parameters, and the initial parameters are used when charging in the same parking space, so that the transmission preparation process and the transmission process can be performed efficiently. It becomes possible to execute.

  Note that the power reception control unit 25 is realized by the processing of part of OP702, OP703, and OP704. The transmission efficiency calculation unit 23 is realized by a part of processing of OP 702 (transmission efficiency calculation).

(Details of livestock monitoring process)
FIG. 14 is an example of a flowchart of the amount of electric power monitoring process. For example, in the livestock power monitoring process, the power receiving unit 120 has a plurality of threshold values m (m = 1, 2,... K (k: constant)) with respect to the full charge amount of the in-vehicle battery 133 in order to prevent overcharging. Each time the amount of electricity stored in the in-vehicle battery 133 exceeds the threshold value m, the power reception is controlled so as to decrease the charging speed. For example, a plurality of threshold values are prepared in stages, such that the threshold value 1 is 70% of the full charge amount of the in-vehicle battery, the threshold value 2 is 75%, and the threshold value 3 is 80%. The flow shown in FIG. 14 is started when wireless power transmission is started.

  In OP801, the power receiving controller 127 sets the variable m to an initial value of 1. The variable m is a variable for specifying a plurality of livestock electricity thresholds. In OP803, the power reception controller 127 acquires the amount of electricity stored in the in-vehicle battery 133 at the time when the amount of stored electricity is acquired.

  In OP804, the power reception controller 127 determines whether or not the acquired amount of stored electricity in the in-vehicle battery 133 is equal to or greater than the threshold value m. If the acquired amount of electricity stored in the in-vehicle battery 133 is greater than or equal to the threshold value m (OP804: YES), the process proceeds to OP805. If the acquired amount of electricity stored in the in-vehicle battery 133 is smaller than the threshold value m (OP804: NO), the processes of OP802 and OP804 are repeated until the amount of stored electricity in the in-vehicle battery 133 becomes equal to or greater than the threshold value m.

In OP <b> 805, the power receiving controller 127 transmits a power transmission speed adjustment request for requesting to decrease the power transmission speed to the power transmission unit 110. For example, the memory of the power receiving unit 120 holds a graph, a table, an equation, and the like indicating the relationship between the amount of livestock power and the power transmission speed, and the power receiving controller 127 determines the power transmission speed based on these. It should be noted that the relationship between the amount of livestock power and the power transmission speed is determined such that the power transmission speed decreases as the amount of livestock power increases. The determined transmission speed is included in the transmission speed adjustment request.

  In OP806, the power transmission controller 117 determines whether a power transmission speed adjustment request is received from the power receiving unit 120. If a transmission speed adjustment request is received (OP806: YES), the process proceeds to OP807. When the request for power transmission speed adjustment has not been received (OP806: NO), the amount of livestock power monitoring process in the power transmission unit 110 is completed and then started again.

  In OP807, the power transmission controller 117 controls the power transmission speed so as to be the power transmission speed included in the power transmission speed adjustment request. For example, the power transmission controller 117 controls the power transmission speed by controlling the output voltage from the converter 113. In OP808, the power transmission controller 117 transmits a power transmission speed adjustment completion response for notifying that the control of the power transmission speed is completed to the power receiving unit 120. Thereafter, the livestock amount monitoring process in the power transmission unit 110 is completed and started again.

  In OP809, the power reception controller 127 determines whether or not a power transmission speed adjustment completion response has been received from the power transmission unit 110. If a power transmission speed adjustment completion response is received (OP809: YES), the process proceeds to OP810. When the power transmission speed adjustment completion response has not been received (OP809: NO), the livestock power monitoring process in the power receiving unit 120 is finished, and then, for example, the livestock power monitoring process may be started again, or an error will occur. It may be output.

  In OP810, the power receiving controller 127 adds 1 to the variable m and updates it. Thereafter, the process returns to OP803. The power storage amount monitoring process is terminated when, for example, the wireless power transmission is stopped in the danger avoidance process or the transmission completion determination process.

  The power receiving unit 120 monitors the amount of power stored in the in-vehicle battery 133 during power transmission / reception by wireless power transmission, and requests the power transmission unit 110 to decrease the power transmission speed when the amount of stored power exceeds the threshold value m. Since the power transmission unit 110 reduces the power transmission speed in response to a request, it is possible to prevent the vehicle-mounted battery 133 from being overcharged.

  Note that the power reception control unit 25 is realized by the processing of part of OP801, OP803, OP804, OP805, OP809, and OP810. The livestock energy acquisition unit 21 is realized by a part of processing of OP803 (acquisition of livestock energy). The power transmission control unit 54 is realized by the processing of OP806 to OP808.

(Details of transmission completion judgment processing)
FIG. 15 is an example of a flowchart of a transmission completion determination process. The flow shown in FIG. 15 is started together with the start of wireless power transmission.

  In OP902, the power reception controller 127 acquires the total power reception amount from the start of power transmission / reception. In OP903, the power reception controller 127 determines whether or not the total power reception amount is equal to or greater than the amount of power (request amount or required power) requested by the power reception unit 120 from the power transmission unit 110. If the power transmission / reception amount is equal to or greater than the required amount (OP903: YES), the wireless power transmission is completed, and the process proceeds to OP904 to end the power transmission / reception. When the power transmission / reception amount is smaller than the requested amount (OP903: NO), the transmission completion determination process in the power reception unit 120 is once ended and restarted.

In OP904, the power receiving controller 127 transmits a transmission end request for requesting the power transmission unit 110 to end power transmission.

  In OP <b> 905, the power transmission controller 117 determines whether a transmission end request is received from the power receiving unit 120. If a transmission end request is received (OP905: YES), the process proceeds to OP906. When the transmission end request is not received (OP905: NO), the transmission completion determination process in the power transmission unit 110 is once ended and restarted.

  In OP906, the power transmission controller 117 stops power transmission. In OP907, when the power transmission stops, the power transmission controller 117 transmits a transmission end response to the power receiving unit 120. When transmitting the transmission end response to the power receiving unit 120, the power transmission controller 117 ends the transmission completion determination process in the power transmission unit 110 and starts the information providing process in the power transmission unit 110.

  In OP908, the power receiving controller 127 determines whether or not a transmission end response has been received from the power transmission unit 110. If a transmission end response has been received (OP908: YES), the process proceeds to OP909. When the transmission end response is not received (OP908: NO), the transmission completion determination process in the power receiving unit 120 is once ended and restarted.

  In OP909, the power reception controller 127 stops power reception. When the power reception controller 127 stops the power reception, the power reception unit 120 ends the transmission completion determination process and starts the information provision process in the power reception unit 120.

  Note that the power reception control unit 25 is realized by the processing of OP903, OP904, OP908, and OP909. The received power acquisition unit 22 is realized by the processing of OP902. The processing of the power transmission control unit 54 is realized by the processing of OP <b> 905 to OP <b> 907.

(Details of information provision processing)
For example, when the wireless power transmission is stopped in the danger avoidance process or when the wireless power transmission is completed in the transmission completion determination process, the power transmission controller 117 sets the charge, total power transmission amount, average power transmission speed, power transmission time, and the like. The included power transmission / reception information is transmitted to the power receiving unit 120.

  When the power reception controller 127 receives the power transmission / reception information, the power reception controller 127 may transmit the content included in the power transmission / reception information to, for example, the vehicle-mounted device 1 and display the content on the display mounted on the vehicle-mounted device 1. Alternatively, the power receiving controller 127 may transmit the information to the information center 2 or the power supply facility management server 3 via the power transmission / reception information to the user's mobile phone and display it on the mobile phone display.

  When the power transmission controller 117 transmits the power transmission / reception information to the power reception unit 120, the information transmission process in the power transmission unit 110 is terminated, and the transmission process in the power transmission unit 110 is terminated. When receiving power transmission / reception information from the power transmission unit 110, the power reception controller 127 ends the information providing process in the power reception unit 120 and ends the transmission process in the power reception unit 120.

<Operational effects of the first embodiment>
In the first embodiment, in the transmission preparation process for wireless power transmission, trial power transmission is performed, the transmission efficiency is obtained in the power receiving unit 120, and the position of the power receiving unit 120 and the power receiving unit 120 are set so that the transmission efficiency becomes a better value. The distance with the power transmission unit 110 is adjusted. Also, during the transmission process of wireless power transmission, the transmission efficiency is regularly monitored, and the resonance frequency is controlled so that the transmission efficiency does not decrease. By adjusting the position of the power receiving unit 120 and the resonance frequency in two stages of transmission preparation processing and transmission processing, waste of power transmission can be eliminated throughout the entire wireless power transmission. By these, more efficient wireless power transmission can be realized.

<Modification>
In the first embodiment, the transmission efficiency is calculated on the power reception unit 120 side, and the elements of the power reception unit 120 (the position of the power reception unit, the height from the ground with the power reception unit, etc.) are controlled so that the transmission efficiency is improved. did. Instead of the power receiving unit 120, the power transmission unit 110 may calculate the transmission efficiency and control the elements of the power transmission unit 110 so that the transmission efficiency is improved. The elements of the power transmission unit 110 are, for example, the position of the power transmission unit 110 (including the three directions of vertical, horizontal, and height) and the resonance frequency.

  When the power transmission unit 110 calculates the transmission efficiency, the power transmission unit 110 further includes a transmission efficiency calculation unit 52 (see FIG. 5). The power transmission unit 110 acquires the power transmission amount from the power transmission amount acquisition unit 51 after the trial of power transmission is completed during the execution of the trial transmission process or periodically during the execution of the transmission process. In addition, the power reception control unit 25 of the power reception unit 120 transmits the received power amount to the power transmission unit 110 after the trial of power transmission is completed during the execution of the trial transmission process or periodically during the execution of the transmission process. . The transmission efficiency calculation unit 52 receives the power reception amount transmitted from the power reception unit 120.

  The transmission efficiency calculation unit 52 calculates, as the transmission efficiency, the percentage of the amount of power received with respect to the amount of power transmitted from the power transmission amount acquired from the power transmission amount acquisition unit 51 and the amount of power received from the power receiving unit 120. The transmission efficiency calculation unit 52 transmits the calculated transmission efficiency to the power transmission control unit 54.

  As described above, the power transmission unit 110 can calculate the transmission efficiency.

  In the trial transmission process, instead of the power receiving unit 120, the power transmission unit 110 may calculate the transmission efficiency and determine whether or not a foreign object exists between the power receiving unit 120 and the power transmission unit 110.

  In the efficiency improvement process, instead of the power receiving unit 120, the power transmission unit 110 calculates the transmission efficiency, and controls the distance between the power receiving unit 120 and the power transmission unit 110 so that the transmission efficiency is improved. May be instructed to adjust. The power transmission unit 110 may control the position of the power receiving unit 120 in the horizontal direction and instruct the power receiving unit 120 to move the vehicle on which the power receiving unit 120 is mounted.

  When the power transmission unit 110 calculates the transmission efficiency and controls the efficiency improvement process, the power transmission unit 110 further includes a measurement unit 58 (see FIG. 5). The measurement unit 58 measures the distance from the power receiving unit 120 using, for example, an optical sensor, a laser, an ultrasonic wave, an image focus, and the like. When the power transmission unit 110 calculates the transmission efficiency and controls the efficiency improvement process, for example, the following examples are given.

  FIG. 16A, FIG. 16B, and FIG. 16C are examples of flowcharts of efficiency improvement processing when the power transmission unit 110 calculates transmission efficiency. 16A, FIG. 16B, and FIG. 16C are executed, for example, when the trial transmission process shown in FIG. 8 is successful, that is, after trial completion (OK) is transmitted from the power receiving unit 120 to the power transmission unit 110. .

In the example shown in FIG. 16A, assuming that the power transmission unit 110 or the power transmission coil 115 is movable, the power reception unit 120 and the power transmission coil 115 are adjusted by adjusting the vertical position (height) of the power transmission unit 110 or the power transmission coil 115. A flow of processing for adjusting the distance to the power transmission unit 110 is shown. In the initial state, power transmission coil 110 is assumed to be embedded in the ground of the parking space.

  In OP341, the power transmission controller 117 measures the distance from the power receiving unit 120. For example, when the power transmission unit 110 is embedded in the ground of the parking space, the power transmission controller 117 measures the distance of the power reception unit 120 from the ground. Further, the power transmission controller 117 may measure the distance from the power receiving unit 120 using, for example, an optical sensor, a laser, an ultrasonic wave, an image focus, or the like. Further, the power transmission controller 117 may obtain height data from data such as a vehicle type of the vehicle on which the power receiving unit 120 is mounted, and may obtain the distance from the power receiving unit 120.

  In OP <b> 342, the power transmission controller 117 stores, for example, a graph, a table, an equation, or the like indicating the relationship between the distance to the power receiving unit 120 and the transmission efficiency in a memory (not shown) provided in advance in the power transmission unit 110. Based on these, the distance to the appropriate power receiving unit 120 is acquired. For example, the power transmission controller 117 moves the power transmission unit 110 in a direction perpendicular to the ground, and adjusts the distance from the power reception unit 120.

  In OP343, the power transmission controller 117 transmits a trial power reception start request for requesting the power reception unit 120 to prepare for power reception for trial power transmission in order to confirm a change in transmission efficiency.

  In OP344, the power reception controller 127 determines whether or not a trial power reception start request has been received. When the trial power reception start request is received (OP344: YES), the process proceeds to OP345. When the trial power reception start request has not been received (OP344: NO), the efficiency improvement process in the power reception unit 120 is once ended and started again.

  In OP345, the power reception controller 127 instructs each unit to enter the power reception state, and transmits a trial power reception start response to the power transmission unit 110.

  In OP346, the power transmission controller 117 determines whether or not a trial power reception start response has been received. When the trial power reception start response is received (OP346: YES), the process proceeds to OP347. When the trial power reception start response is not received (OP346: NO), the efficiency improvement process in the power transmission unit 110 is once ended and started again.

  In OP347, the power transmission controller 117 instructs each unit to start trial power transmission and starts trial power transmission.

  In OP348, the power receiving controller 127 receives power when trial power transmission is started. In OP349, the power reception controller 127 acquires the amount of power received and transmits it to the power transmission unit 110 when the reception of the small power (trial power) transmitted by the trial power transmission is completed.

  In OP350, the power transmission controller 117 receives the amount of power received from the power receiving unit 120. In OP351, the power transmission controller 117 acquires the power transmission amount, and calculates the transmission efficiency from the power reception amount and the power transmission amount received from the power receiving unit 120. In OP352, the power transmission controller 117 determines whether or not the transmission efficiency is greater than the target value. The target value of transmission efficiency may be, for example, a value obtained by averaging the maximum values of transmission efficiency in each transmission process, or a value within a range of 70% to 90% may be set. If the transmission efficiency is greater than the target value (OP352: YES), the process proceeds to OP353. When the transmission efficiency is less than or equal to the target value (OP352: NO), the efficiency improvement process in the power transmission unit 110 is temporarily terminated and restarted for further improvement of the transmission efficiency.

In OP353, the power transmission controller 117 transmits the distance setting completion to the power receiving unit 120. When transmitting the distance setting completion to the power receiving unit 120, the power transmission controller 117 ends the efficiency improvement process in the power transmission unit 110 and ends the transmission preparation process in the power transmission unit 110.

  In OP354, the power receiving controller 127 determines whether or not the distance setting completion is received from the power transmission unit 110. When the distance setting completion is received (OP354: YES), the power receiving controller 127 ends the efficiency improvement process in the power receiving unit 120 and ends the transmission preparation process in the power receiving unit 120. When the distance setting completion is not received (OP354: NO), the efficiency improvement process in the power receiving unit 120 is once ended and restarted.

  The power reception control unit 25 is realized by a part of the processes of OP344, OP345, OP348, and OP349 and the process of OP354. The power reception amount acquisition unit 22 is realized by a part of processing of OP349 (power reception amount acquisition). The measurement unit 58 is realized by the processing of OP341. The power transmission control unit 54 is realized by the processing of OP342, OP343, OP346, OP347, OP350, part of OP351, and the processing of OP352 and OP353. The power transmission amount acquisition unit 51 is realized by a part of processing of OP351 (transmission amount acquisition). The transmission efficiency calculation unit 52 is realized by a part of processing of OP351 (transmission efficiency acquisition).

  Next, FIG. 16B shows that when the power transmission unit 110 or the power transmission coil 115 is movable, the power transmission unit 110 or the power transmission coil 115 is moved in the horizontal direction so that the power reception coil 125 and the power transmission coil 115 face each other more appropriately. Thus, an example of a flowchart of efficiency improvement processing for improving transmission efficiency is shown.

  In OP361, the power transmission controller 117 transmits a position information request for requesting horizontal position information of the power receiving unit 120 (or the power receiving coil 125) to the power receiving unit 120.

  In OP362, the power receiving controller 127 determines whether a position information request has been received. When the position information request is received (OP362: YES), the process proceeds to OP363. When the position information request is not received (OP362: NO), the efficiency information processing in the power receiving unit 120 is once ended and restarted.

  In OP363, the power reception controller 127 obtains horizontal position information of the power reception unit 120 (or the power reception coil 125). For example, the power receiving unit 120 acquires the coordinates of the power receiving unit 120 (or the power receiving coil 125) from the vehicle coordinates acquired by the in-vehicle device 1 by the GPS receiver 18, the vehicle dimension data, and the dimension data of the power receiving unit 120. By doing so, the horizontal position information of the power receiving unit 120 is acquired. In OP364, the power receiving controller 127 transmits the horizontal position information of the power receiving unit 120 (or the power receiving coil 125) to the power transmitting unit 110.

  In OP365, the power transmission controller 117 determines whether or not the position information of the power receiving unit 120 (or the power receiving coil 125) has been received from the power receiving unit 120. When the position information of the power receiving unit 120 is received (OP365: YES), the process proceeds to OP366. When the position information of the power receiving unit 120 is not received (OP365: NO), the efficiency improvement process in the power transmission unit 110 is once ended and restarted.

In OP366, the power transmission controller 117 controls the position of the power transmission unit 110 or the power transmission coil 115. For example, the horizontal position information of the power transmission coil 115 is stored in advance in a memory provided in the power transmission unit 110. The power transmission controller 117 moves in the horizontal direction of the power transmission unit 110 (or power transmission coil 115) from the position information in the horizontal direction of the power transmission coil 115 and the position information in the horizontal direction of the power reception unit 120 (or power reception coil 125). And the movement distance is acquired and the position of the power transmission unit 110 or the power transmission coil 115 is controlled.

  In OP367, since the adjustment of the horizontal position of the power transmission unit 110 (or the power transmission coil 115) has been completed, the power transmission controller 117 requests the power reception unit 120 to perform trial power transmission in order to confirm a change in transmission efficiency. The processing from OP367 to OP375 for performing trial power transmission and calculating the transmission efficiency of trial power transmission is the same as the processing from OP343 to OP351 described in FIG.

  In OP376, the power transmission controller 117 determines whether or not the transmission efficiency calculated in OP375 is larger than the target value. If the transmission efficiency is greater than the target value (OP376: YES), the process proceeds to OP377. When the transmission efficiency is equal to or lower than the target value (OP376: NO), the processing from OP361 to OP376 is repeated until the transmission efficiency becomes larger than the target value in order to further improve the transmission efficiency.

  In OP377, the power transmission controller 117 transmits the position setting completion to the power receiving unit 120. When transmitting the position setting completion to the power receiving unit 120, the power transmission controller 117 ends the efficiency improvement process in the power transmission unit 110 and ends the transmission preparation process in the power transmission unit 110.

  In OP378, the power receiving controller 127 determines whether or not a position setting completion has been received. When the position setting completion is received (OP378: YES), the efficiency improving process in the power receiving unit 120 is ended and the transmission preparation process in the power receiving unit 120 is ended. When the position setting completion is not received (OP378: NO), the efficiency improvement process in the power receiving unit 120 is once ended and restarted.

  Note that the power reception control unit 25 is realized by the processing of OP362, OP364, OP368, OP369, OP372, OP373, and OP378. The measurement part 26 is implement | achieved by the process of OP363. The power transmission control unit 54 is realized by the processing of OP361, OP365, OP366, OP367, OP370, OP371, OP374, a part of OP375, OP376, and OP377. The power transmission amount acquisition unit 51 is realized by a part of the processing of OP375 (transmission amount acquisition). The transmission efficiency calculation unit 52 is realized by a part of processing of OP375 (transmission efficiency calculation).

  Next, FIG. 16C is an example of a flowchart of an efficiency improvement process in which the power transmission coil having the highest transmission efficiency is selected from the plurality of power transmission coils and used when the power transmission unit 110 includes a plurality of power transmission coils. In FIG. 16C, it is assumed that the power transmission unit 110 includes X power transmission coils 115. Further, it is assumed that identification numbers from 0 to X-1 are assigned to the X power transmission coils 115.

  In OP381, the power transmission controller 117 sets the variable a to the initial value 0 in order to obtain the transmission efficiency of each power transmission coil 115. The variable a is for designating identification numbers of a plurality of power transmission coils 115.

  In OP382, the power transmission controller 117 determines use of the power transmission coil 115 having the identification number a. In OP383, the power transmission controller 117 transmits a trial power reception start request to the power reception unit 120 in order to perform trial power transmission using the power transmission coil 115 having the identification number a. Since the processing from OP383 to OP391 is the same as the processing from OP343 to OP351 in FIG. 16A, the description thereof is omitted.

  In OP392, the power transmission controller 117 associates the transmission efficiency acquired in OP391 with the identification number a of the power transmission coil 115 and stores them in the memory.

  In OP393, the power transmission controller 117 determines whether or not the variable a is equal to or greater than the number X of the power transmission coils 115. When the variable a is equal to or greater than the number X of the power transmission coils 115 (OP393: YES), the process proceeds to OP395. When the variable a is smaller than the number X of the power transmission coils 115 (OP393: NO), the process proceeds to OP394.

  In OP394, the power transmission controller 117 adds 1 to the variable a and updates it to obtain the transmission efficiency of the next power transmission coil 115. Thereafter, the processing from OP382 to OP394 is repeated until the transmission efficiency is calculated for all the power transmission coils 115.

  In OP395, since the variable a is equal to or greater than the number X of the power transmission coils 115 and the transmission efficiency is obtained for all the power transmission coils 115, the power transmission controller 117 reads the transmission efficiency of all the power transmission coils 115 from the memory and transmits the most. An efficient power transmission coil 115 is selected as a power transmission coil to be used. In OP396, the power transmission controller 117 transmits the use coil selection completion to the power receiving unit 120 including the identification number of the power transmission coil 115 to be used. When transmitting the use coil selection completion to the power receiving unit 120, the power transmission controller 117 ends the efficiency improvement process in the power transmission unit 110 and ends the transmission preparation process in the power transmission unit 110.

  In OP397, the power receiving controller 127 determines whether or not the use coil selection completion is received. When the use coil selection completion is received (OP397: YES), the power receiving controller 127 ends the efficiency improvement process in the power receiving unit 120 and ends the transmission preparation process in the power receiving unit 120. The identification number of the power transmission coil 115 to be used notified to the power reception unit 120 may be held as one of the parameters in the initial parameter learning process. When the use coil selection completion is not received (OP397: NO), the efficiency improvement process in the power receiving unit 120 is once ended and restarted.

  The power reception control unit 25 is realized by the processing of OP384, OP385, OP388, and OP397. The power reception amount acquiring unit 22 is realized by the processing of OP389. The power transmission control unit 54 is realized by the processing of OP381, OP382, OP383, OP386, OP387, OP390, a part of OP392, and OP393-OP396. The power transmission amount acquisition unit 51 is realized by a part of processing of OP391 (acquisition of power transmission amount). The transmission efficiency calculation unit 52 is realized by a part of processing of OP391 (transmission efficiency calculation).

  As described above, the power transmission unit 110 can calculate the transmission efficiency and execute the efficiency improvement process. Further, the efficiency improvement processes described in FIGS. 9A, 9B, 16A, 16B, and 16C may be executed in combination.

  When the efficiency improvement process ends, the transmission preparation process ends, and the transmission process starts. When the power transmission unit 110 calculates the transmission efficiency, the power reception unit 120 periodically transmits the amount of power received to the power transmission unit 110 while the wireless power transmission is being executed, and the power transmission unit 110 periodically transmits the transmission efficiency. Is calculated.

In the danger avoidance process, instead of the power receiving unit 120, the power transmission controller 117 of the power transmission unit 110 detects that the abnormality detection condition is satisfied, and if the abnormality detection condition is satisfied, the abnormality is caused by the transmission efficiency. Occurrence may be determined. Even in this case, the abnormality detection conditions may be the same as the abnormality detection conditions (A) to (C) described in the first embodiment. For example, the power transmission unit 110 communicates with the in-vehicle device 1 of the vehicle on which the power receiving unit 120 is mounted and the user's mobile phone through the information center 2 or the power supply facility management server 3 to detect the abnormality detection conditions (A) to (C). ) Can be detected.

  In the resonance frequency adjustment process, instead of the power receiving unit 120, the power transmission controller 117 of the power transmission unit 110 monitors the transmission efficiency calculated periodically, and controls the resonance frequency when the transmission efficiency decreases. May be.

  In the initial parameter learning process, the power transmission controller 117 of the power transmission unit 110 stores the transmission efficiency calculated periodically, and when the transmission efficiency of a value better than the stored transmission efficiency is calculated, The transmission efficiency may be transmitted, and the initial parameter may be updated with the parameter at that time.

  In the transmission completion determination process, instead of the power receiving unit 120, the power transmission controller 117 of the power transmission unit 110 detects that the abnormality detection condition is satisfied, and acquires the total power transmission amount when the abnormality detection condition is satisfied. Then, it may be determined whether or not the amount of power required by the power receiving unit 120 has been transmitted, and the completion of power transmission and reception may be determined.

  As described above, the power transmission unit 110 can calculate the transmission efficiency and control the transmission preparation process and the power transmission process. In addition, in the trial transmission process, the efficiency improvement process, the risk avoidance process, the resonance frequency adjustment process, the initial parameter is the learning process, and the transmission completion determination process, either the power transmission unit 110 or the power reception unit 120 calculates the transmission efficiency and determines it. It is not necessary to be unified so as to perform processing (processing indicated by diamonds in the flow diagram). As appropriate, a combination may be made such that the power receiving unit 120 calculates the transmission efficiency in one process and performs the determination process, and the power transmission unit 110 calculates the transmission efficiency and performs the determination process in another process. It is also possible to design the power receiving unit 120 to calculate the transmission efficiency and to use the transmission efficiency to perform the determination process.

  Further, in the first embodiment, the communication between the power transmission unit 110 and the power reception unit 120 is assumed to use short-range communication such as DSRC or Bluetooth (registered trademark) by the data transmission / reception unit 112 and the data transmission / reception unit 122. It was. Instead, for example, data is transmitted from the power receiving unit 120 to the information center 2 or the power supply facility management server 3 via the vehicle-mounted device 1 or the user's mobile phone, and from the information center 2 or the power supply facility management server 3 to the power transmission unit 110. Communication between the power reception unit 120 and the power transmission unit 110 may be performed so as to be transmitted.

  In addition, for example, when the in-vehicle device 1 acquires data from the power transmission unit 110 and the power reception unit 120, the power reception control unit 25 of the power reception unit 120 of the first embodiment can be realized as a function of the in-vehicle device 1. It is. Alternatively, when the information center 2 or the power supply facility management server 3 acquires data from the power transmission unit 110 and the power reception unit 120, the power reception control unit 25 of the power reception unit 120 and the determination unit 53 of the power transmission unit 110 according to the first embodiment. It is also possible to realize the power transmission control unit 54 as a function of the information center 2 or the power supply facility management server 3.

DESCRIPTION OF SYMBOLS 1 Vehicle equipment 21 Charge amount acquisition part 22 Received power amount acquisition part 23 Transmission efficiency calculation part 24 Receiving side information generation part 25 Power reception control part 26 Measurement part 51 Transmission amount acquisition part 52 Transmission efficiency calculation part 53 Judgment part 54 Transmission power control part 58 Measurement Unit 110 Power transmission unit 115 Power transmission coil 117 Power transmission controller 120 Power reception unit 125 Power reception coil 127 Power reception controller

Claims (6)

A transmission efficiency calculation unit that calculates the transmission efficiency of power wirelessly transmitted between the power transmission unit and the power reception unit;
When the transmission efficiency calculated by the transmission efficiency calculation unit does not satisfy a predetermined threshold, a control unit that controls at least one first element of the power transmission unit or the power reception unit;
A wireless power transmission device comprising: The controller is
Instructing the transmission unit to transmit trial power,
The wireless power transmission apparatus according to claim 1, wherein when the transmission efficiency of the trial power transmission satisfies the predetermined threshold, the transmission unit is instructed to start transmission of the amount of power required by the power receiving unit. The wireless power transmission device according to claim 1, wherein the first element is a position of at least one of the power transmission unit and the power reception unit. 4. The wireless power transmission device according to claim 1, wherein the first element is a resonance frequency of the power transmission coil and the power reception coil. 5. The power transmission unit includes a plurality of power transmission coils,
The transmission efficiency calculation unit calculates the transmission efficiency of power between the power receiving unit for each of the plurality of power transmission coils,
The wireless power transmission device according to claim 1, wherein the control unit selects use of a power transmission coil having the best transmission efficiency. Wireless power transfer device
Calculating power transmission efficiency between the power transmission unit and the power reception unit;
If the calculated transmission efficiency does not satisfy a predetermined threshold, controlling at least one first element of the power transmission unit and the power reception unit;
A wireless power transmission method for executing.

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