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WO2017217662A1 - Procédé de détection d'objets étrangers, ainsi qu'appareil et système associés - Google Patents

Procédé de détection d'objets étrangers, ainsi qu'appareil et système associés Download PDF

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Publication number
WO2017217662A1
WO2017217662A1 PCT/KR2017/005146 KR2017005146W WO2017217662A1 WO 2017217662 A1 WO2017217662 A1 WO 2017217662A1 KR 2017005146 W KR2017005146 W KR 2017005146W WO 2017217662 A1 WO2017217662 A1 WO 2017217662A1
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WO
WIPO (PCT)
Prior art keywords
current
power
wireless power
foreign matter
transmission
Prior art date
Application number
PCT/KR2017/005146
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English (en)
Korean (ko)
Inventor
채용석
권용일
Original Assignee
엘지이노텍(주)
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Filing date
Publication date
Application filed by 엘지이노텍(주) filed Critical 엘지이노텍(주)
Publication of WO2017217662A1 publication Critical patent/WO2017217662A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
    • G01V3/10—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils
    • G01V3/101—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils by measuring the impedance of the search coil; by measuring features of a resonant circuit comprising the search coil
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
    • G01N27/20—Investigating the presence of flaws
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
    • G01V3/00—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation
    • G01V3/08—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
    • G01V3/10—Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices using induction coils
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J5/00—Circuit arrangements for transfer of electric power between AC networks and DC networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/60—Circuit arrangements or systems for wireless supply or distribution of electric power responsive to the presence of foreign objects, e.g. detection of living beings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
    • H02J50/80—Circuit arrangements or systems for wireless supply or distribution of electric power involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices

Definitions

  • the present invention relates to wireless power transmission technology, and more particularly, to a foreign material detection method on a wireless charging system, and an apparatus and system therefor.
  • Wireless power transmission or wireless energy transfer is a technology that transmits electrical energy wirelessly from a transmitter to a receiver using the principle of induction of magnetic field, which is already used by electric motors or transformers using the electromagnetic induction principle in the 1800s. Since then, there have been attempts to transmit electrical energy by radiating electromagnetic waves such as high frequency, microwaves, and lasers. Electric toothbrushes and some wireless razors that we commonly use are actually charged with the principle of electromagnetic induction.
  • energy transmission using wireless may be classified into magnetic induction, electromagnetic resonance, and RF transmission using short wavelength radio frequency.
  • the magnetic induction method uses the phenomenon that magnetic flux generated at this time causes electromotive force to other coils when two coils are adjacent to each other and current flows to one coil, and is rapidly commercialized in small devices such as mobile phones. Is going on. Magnetic induction is capable of transmitting power of up to several hundred kilowatts (kW) and has high efficiency, but the maximum transmission distance is less than 1 centimeter (cm).
  • the magnetic resonance method is characterized by using an electric or magnetic field instead of using electromagnetic waves or current. Since the magnetic resonance method is hardly affected by the electromagnetic wave problem, it has the advantage of being safe for other electronic devices or the human body. On the other hand, it can be utilized only in limited distances and spaces, and has a disadvantage in that energy transmission efficiency is rather low.
  • the short wavelength wireless power transmission scheme implies, the RF transmission scheme— takes advantage of the fact that energy can be transmitted and received directly in the form of RadioWave.
  • This technology is a wireless power transmission method of the RF method using a rectenna, a compound word of an antenna and a rectifier (rectifier) refers to a device that converts RF power directly into direct current power.
  • the RF method is a technology that converts AC radio waves to DC and uses them. Recently, research on commercialization has been actively conducted as efficiency is improved.
  • Wireless power transfer technology can be used in various industries, such as the mobile, IT, railroad and consumer electronics industries.
  • the FO may include a coin, a clip, a pin, a ballpoint pen, and the like.
  • the wireless charging efficiency is significantly lowered but also the temperature of the wireless power receiver and the wireless power transmitter may rise together due to an increase in the ambient temperature of the FO. If the FO located in the charging area is not removed, not only power is wasted but also overheating may cause damage to the wireless power transmitter and the wireless power receiver.
  • the conventional FO detection method calculates a path loss using the strength of the power transmitted from the wireless power transmitter and the power received from the wireless power receiver, and when the calculated path loss is equal to or less than a predetermined reference value, the FO The path loss calculation method which is judged to exist is typical.
  • the present WPC Qi standard discloses a foreign matter detection method before power transmission using a quality factor value, but when the foreign matter is located in the charging region during power transmission, a method of effectively detecting the foreign matter has not been disclosed.
  • Wireless power transmission or wireless energy transfer is a technology that transmits electrical energy wirelessly from a transmitter to a receiver using the principle of induction of magnetic field, which is already used by electric motors or transformers using the electromagnetic induction principle in the 1800s. Since then, there have been attempts to transmit electrical energy by radiating electromagnetic waves such as high frequency, microwaves, and lasers. Electric toothbrushes and some wireless razors that we commonly use are actually charged with the principle of electromagnetic induction.
  • energy transmission using wireless may be classified into magnetic induction, electromagnetic resonance, and RF transmission using short wavelength radio frequency.
  • the magnetic induction method uses the phenomenon that magnetic flux generated at this time causes electromotive force to other coils when two coils are adjacent to each other and current flows to one coil, and is rapidly commercialized in small devices such as mobile phones. Is going on. Magnetic induction is capable of transmitting power of up to several hundred kilowatts (kW) and has high efficiency, but the maximum transmission distance is less than 1 centimeter (cm).
  • the magnetic resonance method is characterized by using an electric or magnetic field instead of using electromagnetic waves or current. Since the magnetic resonance method is hardly affected by the electromagnetic wave problem, it has the advantage of being safe for other electronic devices or the human body. On the other hand, it can be utilized only in limited distances and spaces, and has a disadvantage in that energy transmission efficiency is rather low.
  • the short wavelength wireless power transmission scheme implies, the RF transmission scheme— takes advantage of the fact that energy can be transmitted and received directly in the form of RadioWave.
  • This technology is a wireless power transmission method of the RF method using a rectenna, a compound word of an antenna and a rectifier (rectifier) refers to a device that converts RF power directly into direct current power.
  • the RF method is a technology that converts AC radio waves to DC and uses them. Recently, research on commercialization has been actively conducted as efficiency is improved.
  • Wireless power transfer technology can be used in various industries, such as the mobile, IT, railroad and consumer electronics industries.
  • the FO may include a coin, a clip, a pin, a ballpoint pen, and the like.
  • the wireless charging efficiency is significantly lowered but also the temperature of the wireless power receiver and the wireless power transmitter may rise together due to an increase in the ambient temperature of the FO. If the FO located in the charging area is not removed, not only power is wasted but also overheating may cause damage to the wireless power transmitter and the wireless power receiver.
  • the conventional FO detection method calculates a path loss using the strength of the power transmitted from the wireless power transmitter and the power received from the wireless power receiver, and when the calculated path loss is equal to or less than a predetermined reference value, the FO The path loss calculation method which is judged to exist is typical.
  • the present WPC Qi standard discloses a foreign matter detection method before power transmission using a quality factor value, but when the foreign matter is located in the charging region during power transmission, a method of effectively detecting the foreign matter has not been disclosed.
  • the present invention can provide a foreign matter detection method and apparatus and system therefor.
  • determining a reference current / voltage ratio when entering a power transmission step, determining a reference current / voltage ratio, calculating a current / voltage ratio at a predetermined period and the current current It may include the step of determining the presence of foreign matter based on the / voltage ratio and the reference current / voltage ratio.
  • the reference current / voltage ratio may be determined.
  • the outgoing power is adjusted based on a power control feedback signal received from a wireless power receiver, and when the amount of power controlled by the power control feedback signal is within a predetermined first reference value or zero, the outgoing power is stabilized. It can be judged that.
  • the power control feedback signal includes a correction error packet (CEP) defined in the WPC standard, and when the correction error value included in the CEP is 0 for a predetermined number of consecutive times, the transmission power is stabilized. You can judge.
  • CEP correction error packet
  • the foreign matter detection method may further include updating the reference current / voltage ratio with a current current / voltage ratio calculated at a corresponding time when the amount of power adjusted according to the power control feedback signal exceeds a predetermined second reference value. It may include.
  • the current / voltage ratio may be a ratio of the strength of the current flowing in the transmission coil to the strength of the voltage applied to the inverter.
  • the determining of the presence or absence of the foreign matter may include calculating a difference value between the current current / voltage ratio and the reference current / voltage ratio and comparing the calculated difference value with at least one predetermined reference value. It may include determining the existence.
  • comparing the calculated difference value with at least one predetermined reference value, determining whether there is a foreign substance may include checking whether the calculated difference value is greater than or equal to a first predetermined reference value, and as a result of the checking, the first reference value. And comparing the calculated difference value with a predetermined second reference value and determining that the foreign matter problem exists when the calculated difference value is greater than or equal to the second reference value.
  • the second reference value may be greater than the first reference value.
  • the calculated difference value is greater than or equal to the first reference value and less than the second reference value, it may be determined that there is an alignment problem between the transmission and reception coils.
  • the foreign matter detection method may further include outputting a predetermined alarm signal corresponding to the problem when it is determined that the foreign matter problem exists or the alignment problem exists.
  • an apparatus for transmitting power wirelessly includes a DC-DC converter for converting DC power applied from a power source into a specific DC power, and an inverter for converting DC power received from the DC-DC converter into AC power.
  • An LC circuit comprising a resonant capacitor and an inductor for wirelessly transmitting the AC power; and a sensing unit measuring an intensity of a voltage applied to the inverter and an intensity of a current flowing through the inductor. The presence of foreign matter may be determined based on the current / voltage ratio calculated based on the strength of the current flowing through the inductor and the voltage applied to the inverter.
  • the reference current / voltage ratio determiner when entering the power transfer step, the reference current / voltage ratio determiner for determining the reference current / voltage ratio and the current current / voltage ratio at a predetermined period in the power transfer step It may include a current / voltage ratio calculation unit to calculate and a detection unit for determining the presence of foreign matter based on the current current / voltage ratio and the reference current / voltage ratio.
  • the reference current / voltage ratio determiner may determine the reference current / voltage ratio when the output power is stabilized after entering the power transfer step.
  • the foreign matter detection apparatus further comprises a communication unit for demodulating a signal received through in-band communication, the transmission power is adjusted based on the power control feedback signal received through the communication unit, the reference current / voltage ratio determination The unit may determine that the output power is stabilized based on the amount of power controlled by the power control feedback signal.
  • the power control feedback signal includes a correction error packet (CEP) defined in the WPC standard, and the correction error value included in the CEP is zero or adjusted by the correction error value continuously for a predetermined number of times.
  • CEP correction error packet
  • the reference current / voltage ratio determiner may update the reference current / voltage ratio with the current current / voltage ratio calculated at the time when the amount of power adjusted according to the power control feedback signal exceeds a predetermined second reference value. Can be.
  • the current / voltage ratio may be calculated by dividing a current value flowing in the transmission coil by a voltage value applied to the inverter.
  • the detector may calculate a difference value between the current current / voltage ratio and the reference current / voltage ratio, and compare the calculated difference value with at least one predetermined reference value to determine whether a foreign substance exists.
  • the detection unit may determine whether the calculated difference value is greater than or equal to a predetermined first reference value, and if the result of the check indicates that the calculated difference value is greater than or equal to the first reference value, the calculated difference value is compared with a predetermined second reference value, and as a result of the comparison, If the calculated difference value is greater than or equal to the second reference value, it is determined that the foreign matter problem exists, and the second reference value may be greater than the first reference value.
  • the calculated difference value is greater than or equal to the first reference value and less than the second reference value, it may be determined that there is an alignment problem between the transmitting and receiving coils.
  • the foreign matter detection apparatus may further include an alarm unit configured to output a predetermined alarm signal corresponding to the foreign matter when it is determined that the foreign matter problem exists or the alignment problem exists.
  • a computer-readable recording medium may be provided that records a program for executing any one of the foreign matter detection methods.
  • the present invention has an advantage of providing a foreign matter detection method for wireless charging and an apparatus and system therefor.
  • the present invention has the advantage of providing a wireless power transmitter capable of detecting a foreign matter after the start of power transmission.
  • the present invention has the advantage of minimizing power and device damage wasted by foreign matter.
  • the present invention has the advantage of detecting the presence of foreign matter regardless of the communication state by detecting the presence of a foreign object during power transmission by the wireless power transmitter itself without separate feedback information from the wireless power receiver.
  • the present invention is a foreign matter detection method and apparatus therefor capable of identifying whether the alignment problem between the transmission and reception coils or the foreign matter problem based on the change in the ratio of the voltage (V_rail) at the inverter input terminal and the current (I_coil) flowing in the resonant coil.
  • FIG. 1 is a block diagram illustrating a wireless charging system according to an embodiment of the present invention.
  • FIG. 2 is a block diagram illustrating a wireless charging system according to another embodiment of the present invention.
  • FIG 3 is a view for explaining a detection signal transmission procedure in a wireless charging system according to an embodiment of the present invention.
  • FIG. 4 is a state transition diagram for explaining a wireless power transmission procedure defined in the WPC standard.
  • 5 is a state transition diagram for explaining a wireless power transmission procedure defined in the WPC (Qi) standard.
  • FIG. 6 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment of the present invention.
  • FIG. 7 is a block diagram illustrating a structure of a wireless power receiver interworking with the wireless power transmitter according to FIG. 6.
  • FIG. 8 is a diagram for describing a method of modulating and demodulating a wireless power signal according to an embodiment of the present invention.
  • FIG. 9 is a diagram for describing a packet format according to an embodiment of the present invention.
  • FIG. 10 is a view for explaining the types of packets defined in the WPC (Qi) standard according to an embodiment of the present invention.
  • FIG. 11 is a block diagram illustrating a structure of a wireless power transmission apparatus according to an embodiment of the present invention.
  • FIG. 12 illustrates a message structure of a FOD status packet according to an embodiment of the present invention.
  • FIG. 13 is a diagram illustrating a message structure of a configuration packet according to an embodiment of the present invention.
  • a receiver type identifier mapping table in which a current change threshold corresponding to a receiver type identifier is defined according to an embodiment of the present invention.
  • 15 is a receiver type identifier mapping table in which a current change threshold ratio corresponding to a receiver type identifier is defined according to another embodiment of the present invention.
  • 16 is a flowchart illustrating a foreign material detection method in a wireless power transmission apparatus according to an embodiment of the present invention.
  • FIG. 17 is a flowchart illustrating a foreign material detection method in a wireless power transmission apparatus according to another embodiment of the present invention.
  • FIG. 18 is a flowchart illustrating a foreign material detection method in a wireless power transmission apparatus according to another embodiment of the present invention.
  • 19 is an embodiment of a transmitting coil mounted to a wireless power transmitting apparatus according to an embodiment of the present invention.
  • 20A to 20B are graphs illustrating measurement results of inductor input current intensity and transmit coil input current intensity for each position of a transmitting coil according to FIG. 19.
  • 21 to 22 show a change pattern of the coil current and the inverter input current when the foreign matter is located in the charging region in the ping step at position 1 of FIG. 19.
  • FIG. 23 is a flowchart illustrating a foreign material detection method in a power transmission step according to an embodiment of the present invention.
  • FIG. 24 is a flowchart illustrating a foreign material detection method in a power transmission step according to another embodiment of the present invention.
  • 25 is an experimental result table showing a ratio of the transmit coil current strength measured by the wireless power transmitter and the inverter input voltage strength according to the presence of foreign matter and the state of the transmission / reception coil arrangement according to the present invention.
  • FIG. 26 is a table showing experimental results of the inverter input voltage and the transmitter coil current measured according to the presence of foreign matter and the position of the wireless power receiver on the charging region.
  • FIG. 27 is a block diagram illustrating a structure of a foreign substance detection apparatus according to an embodiment of the present invention.
  • determining a reference current / voltage ratio when entering a power transmission step, determining a reference current / voltage ratio, calculating a current / voltage ratio at a predetermined period and the current current It may include the step of determining the presence of foreign matter based on the / voltage ratio and the reference current / voltage ratio.
  • the top (bottom) or the bottom (bottom) is the two components are in direct contact with each other or One or more other components are all included disposed between the two components.
  • up (up) or down (down) may include the meaning of the down direction as well as the up direction based on one component.
  • a device equipped with a function for transmitting wireless power on the wireless charging system is a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a wireless power transmitter, a transmitter, a transmitter, a transmitter for convenience of description.
  • a transmitter side, a wireless power transmitter, a wireless power transmitter, and the like will be used interchangeably.
  • a wireless power receiver, a wireless power receiver, a wireless power receiver, a wireless power receiver, a wireless power receiver, a receiver terminal, a receiver, Receivers, receivers and the like can be used interchangeably.
  • the transmitter according to the present invention may be configured in a pad form, a cradle form, an access point (AP) form, a small base station form, a stand form, a ceiling buried form, a wall hanging form, and the like. You can also transfer power.
  • the transmitter may comprise at least one wireless power transmission means.
  • the wireless power transmission means may use various wireless power transmission standards based on an electromagnetic induction method that generates a magnetic field in the power transmitter coil and charges using the electromagnetic induction principle in which electricity is induced in the receiver coil under the influence of the magnetic field.
  • the wireless power transmission means may include a wireless charging technology of the electromagnetic induction method defined by the Wireless Power Consortium (WPC) and the Power Matters Alliance (PMA) which is a wireless charging technology standard apparatus.
  • WPC Wireless Power Consortium
  • PMA Power Matters Alliance
  • the receiver according to an embodiment of the present invention may be provided with at least one wireless power receiving means, and may simultaneously receive wireless power from two or more transmitters.
  • the wireless power receiving means may include an electromagnetic induction wireless charging technology defined by the Wireless Power Consortium (WPC) and the Power Matters Alliance (PMA), which are wireless charging technology standard organizations.
  • WPC Wireless Power Consortium
  • PMA Power Matters Alliance
  • the receiver according to the present invention is a mobile phone, smart phone, laptop computer, digital broadcasting terminal, PDA (Personal Digital Assistants), PMP (Portable Multimedia Player), navigation, MP3 player, electric It may be used in a small electronic device such as a toothbrush, an electronic tag, a lighting device, a remote control, a fishing bobber, a wearable device such as a smart watch, but is not limited thereto. If the device is equipped with a wireless power receiver according to the present invention, the battery can be charged. It is enough.
  • FIG. 1 is a block diagram illustrating a wireless charging system according to an embodiment of the present invention.
  • a wireless charging system includes a wireless power transmitter 10 that largely transmits power wirelessly, a wireless power receiver 20 that receives the transmitted power, and an electronic device 20 that receives the received power. Can be configured.
  • the wireless power transmitter 10 and the wireless power receiver 20 may perform in-band communication for exchanging information using the same frequency band as the operating frequency used for wireless power transmission.
  • the wireless power transmitter 10 and the wireless power receiver 20 perform out-of-band communication for exchanging information using a separate frequency band different from an operating frequency used for wireless power transmission. It can also be done.
  • the information exchanged between the wireless power transmitter 10 and the wireless power receiver 20 may include control information as well as status information of each other.
  • the status information and control information exchanged between the transmitting and receiving end will be more clear through the description of the embodiments to be described later.
  • the in-band communication and the out-of-band communication may provide bidirectional communication, but are not limited thereto. In another embodiment, the in-band communication and the out-of-band communication may provide one-way communication or half-duplex communication.
  • the unidirectional communication may be performed by the wireless power receiver 20 only transmitting information to the wireless power transmitter 10, but is not limited thereto.
  • the wireless power transmitter 10 may transmit information to the wireless power receiver 20. It may be to transmit.
  • bidirectional communication between the wireless power receiver 20 and the wireless power transmitter 10 is possible, but at one time, only one device may transmit information.
  • the wireless power receiver 20 may obtain various state information of the electronic device 30.
  • the state information of the electronic device 30 may include current power usage information, information for identifying a running application, CPU usage information, battery charge status information, battery output voltage / current information, and the like.
  • the information may be obtained from the electronic device 30 and may be utilized for wireless power control.
  • the wireless power transmitter 10 may transmit a predetermined packet indicating whether to support fast charging to the wireless power receiver 20.
  • the wireless power receiver 20 may notify the electronic device 30 when it is determined that the connected wireless power transmitter 10 supports the fast charging mode.
  • the electronic device 30 may indicate that fast charging is possible through predetermined display means provided, for example, it may be a liquid crystal display.
  • the user of the electronic device 30 may control the wireless power transmitter 10 to operate in the fast charge mode by selecting a predetermined fast charge request button displayed on the liquid crystal display.
  • the electronic device 30 may transmit a predetermined quick charge request signal to the wireless power receiver 20.
  • the wireless power receiver 20 may convert the normal low power charging mode into the fast charging mode by generating a charging mode packet corresponding to the received fast charging request signal to the wireless power transmitter 10.
  • FIG. 2 is a block diagram illustrating a wireless charging system according to another embodiment of the present invention.
  • the wireless power receiver 20 may be configured with a plurality of wireless power receivers, and a plurality of wireless power receivers are connected to one wireless power transmitter 10 so that the wireless Charging may also be performed.
  • the wireless power transmitter 10 may distribute and transmit power to the plurality of wireless power receivers in a time division manner, but is not limited thereto.
  • the wireless power transmitter 10 may distribute and transmit power to a plurality of wireless power receivers by using different frequency bands allocated for each wireless power receiver.
  • the number of wireless power receivers that can be connected to one wireless power transmitter 10 may include at least one of a required power amount for each wireless power receiver, a battery charge state, power consumption of an electronic device, and available power amount of the wireless power transmitter. Can be adaptively determined based on the
  • the wireless power transmitter 10 may be configured with a plurality of wireless power transmitters.
  • the wireless power receiver 20 may be connected to a plurality of wireless power transmitters at the same time, and may simultaneously receive power from the connected wireless power transmitters and perform charging.
  • the number of wireless power transmitters connected to the wireless power receiver 20 may be adaptively based on the required power of the wireless power receiver 20, the state of charge of the battery, the power consumption of the electronic device, and the available power of the wireless power transmitter. Can be determined.
  • FIG 3 is a view for explaining a detection signal transmission procedure in a wireless charging system according to an embodiment of the present invention.
  • the wireless power transmitter may be equipped with three transmitting coils 111, 112, and 113. Each transmission coil may overlap some other area with another transmission coil, and the wireless power transmitter may detect a predetermined detection signal 117, 127 for detecting the presence of the wireless power receiver through each transmission coil, for example, Digital ping signals are sent sequentially in a predefined order.
  • the wireless power transmitter sequentially transmits the detection signal 117 through the primary detection signal transmission procedure illustrated in FIG. 110, and receives a signal strength indicator from the wireless power receiver 115.
  • the strength indicator 116 can identify the received transmission coils 111, 112.
  • the wireless power transmitter sequentially transmits the detection signal 127 through the secondary detection signal transmission procedure shown in FIG. 120, and transmits power among the transmission coils 111 and 112 where the signal strength indicator 126 is received.
  • the reason why the wireless power transmitter performs two sensing signal transmission procedures is to more accurately identify which transmitting coil is well aligned with the receiving coil of the wireless power receiver.
  • the wireless power transmitter Based on the signal strength indicator 126 received at each of the first transmitting coil 111 and the second transmitting coil 112 selects the best-aligned transmitting coil and performs wireless charging using the selected transmitting coil. .
  • FIG. 4 is a state transition diagram for explaining a wireless power transmission procedure defined in the WPC standard.
  • power transmission from a transmitter to a receiver according to the WPC standard is largely selected from a selection phase 410, a ping phase 420, an identification and configuration phase 430, It may be divided into a power transfer phase 440.
  • the selection step 410 may be a step of transitioning when a specific error or a specific event is detected while starting or maintaining the power transmission.
  • the transmitter may monitor whether an object exists on the interface surface. If the transmitter detects that an object is placed on the interface surface, it may transition to the ping step 420 (S401).
  • the transmitter transmits a very short pulse of an analog ping signal, and may detect whether an object exists in an active area of the interface surface based on a change in current of a transmitting coil.
  • ping step 420 when an object is detected, the transmitter activates the receiver and sends a digital ping to identify whether the receiver is a receiver that is compliant with the WPC standard. If the transmitter does not receive a response signal (for example, a signal strength indicator) from the receiver in response to the digital ping in step 420, it may transition back to the selection step 410 (S402). In addition, in the ping step 420, when the transmitter receives a signal indicating that power transmission is completed, that is, a charging completion signal, from the receiver, the transmitter may transition to the selection step 410 (S403).
  • a response signal for example, a signal strength indicator
  • the transmitter may transition to the identification and configuration step 430 for collecting receiver identification and receiver configuration and status information (S404).
  • the transmitter receives an unexpected packet, a desired packet has not been received for a predefined time, a packet transmission error, or a power transmission contract. If this is not set (no power transfer contract) it may transition to the selection step (410) (S405).
  • the transmitter may transition to the power transmission step 240 for transmitting the wireless power (S406).
  • the transmitter receives an unexpected packet, the desired packet has not been received for a predefined time, or a violation of a preset power transfer contract occurs. transfer contract violation), if the filling is completed, the transition to the selection step (410) (S407).
  • the transmitter may transition to the identification and configuration step 430 (S408).
  • the power transmission contract may be set based on state and characteristic information of the transmitter and the receiver.
  • the transmitter state information may include information about the maximum amount of power that can be transmitted, information about the maximum number of receivers that can be accommodated, and the receiver state information may include information about required power.
  • 5 is a state transition diagram for explaining a wireless power transmission procedure defined in the WPC (Qi) standard.
  • power transmission from a transmitter to a receiver according to the WPC (Qi) standard is largely selected as a selection phase 510, a ping phase 520, an identification and configuration phase, and so on. 530, a negotiation phase 540, a calibration phase 550, a power transfer phase 560, and a renegotiation phase 560.
  • the selection step 510 may be a transition step, for example, S502, S504, S506, S509, S, when a specific error or a specific event is detected while starting or maintaining power transmission.
  • the transmitter may monitor whether an object exists on the interface surface. If the transmitter detects that an object is placed on the interface surface, it may transition to ping step 520. In the selection step 510, the transmitter transmits a very short pulse of an analog ping signal and an object in the active area of the interface surface based on the current change of the transmitting coil or the primary coil. Can detect the presence of
  • the transmitter activates the receiver and sends a digital ping to identify whether the receiver is a receiver that is compliant with the WPC standard. If in ping step 520 the transmitter does not receive a response signal (eg, a signal strength packet) to the digital ping from the receiver, it may transition back to selection step 510. Further, in ping step 520, the transmitter may transition to selection step 510 when it receives a signal from the receiver indicating that power transmission is complete, i.e., a charge complete packet.
  • a response signal eg, a signal strength packet
  • the transmitter may transition to identification and configuration step 530 to identify the receiver and collect receiver configuration and status information.
  • the transmitter receives an unexpected packet, a desired packet has not been received for a predefined time, a packet transmission error, or a power transmission contract. If this is not set (no power transfer contract) it may transition to selection step 510.
  • the transmitter may determine whether entry into the negotiation step 540 is necessary based on a negotiation field value of the configuration packet received in the identification and configuration step 530.
  • the transmitter may enter a negotiation step 540 and perform a predetermined FOD detection procedure.
  • the transmitter may directly enter the power transmission step 560.
  • the transmitter may receive a Foreign Object Detection (FOD) status packet including a reference quality factor value.
  • FOD Foreign Object Detection
  • the transmitter may determine a threshold for FO detection based on the reference quality factor value.
  • the transmitter may detect whether the FO exists in the charging region by using the determined threshold value and the currently measured quality factor value, and may control power transmission in the FO detection result.
  • the transmitter may return to selection step 510.
  • the transmitter may enter the power transmission step 560 via the correction step 550.
  • the transmitter determines the strength of the power received at the receiving end, and determines the power loss at the receiving end and the transmitting end to determine the strength of the power transmitted at the transmitting end. It can be measured. That is, the transmitter may predict the power loss based on the difference between the transmit power of the transmitter and the receive power of the receiver in the correction step 550.
  • the transmitter may correct the threshold for FOD detection by reflecting the predicted power loss.
  • the transmitter receives an unexpected packet, an outgoing desired packet for a predefined time, or a violation of a predetermined power transmission contract occurs. transfer contract violation), if the filling is complete, transition to selection step 510.
  • the transmitter may transition to renegotiation step 570 if it is necessary to reconfigure the power transmission contract according to a change in the transmitter state. At this time, if the renegotiation is normally completed, the transmitter may return to the power transmission step (560).
  • the power transmission contract may be set based on state and characteristic information of the transmitter and the receiver.
  • the transmitter state information may include information about the maximum amount of power that can be transmitted, information about the maximum number of receivers that can be accommodated, and the receiver state information may include information about required power.
  • FIG. 6 is a block diagram illustrating a structure of a wireless power transmitter according to an embodiment of the present invention.
  • the wireless power transmitter 600 may largely include a power converter 610, a power transmitter 620, a communication unit 630, a controller 640, and a sensor 650.
  • the configuration of the wireless power transmitter 600 is not necessarily an essential configuration, and may include more or fewer components.
  • the power converter 610 may perform a function of converting the power into power of a predetermined intensity.
  • the power converter 610 may include a DC / DC converter 611 and an amplifier 612.
  • the DC / DC converter 611 may perform a function of converting DC power supplied from the power supply unit 650 into DC power of a specific intensity according to a control signal of the controller 640.
  • the sensing unit 650 may measure the voltage / current of the DC-converted power and provide the same to the control unit 640. In addition, the sensing unit 650 may measure the internal temperature of the wireless power transmitter 600 to determine whether overheating occurs, and provide the measurement result to the controller 640. For example, the controller 640 may adaptively block power supply from the power supply unit 650 or block power supply to the amplifier 612 based on the voltage / current value measured by the sensing unit 650. Can be. To this end, one side of the power converter 610 may be further provided with a predetermined power cut-off circuit for cutting off the power supplied from the power supply unit 650, or cut off the power supplied to the amplifier 612.
  • the amplifier 612 may adjust the intensity of the DC / DC converted power according to the control signal of the controller 640.
  • the controller 640 may receive power reception state information or (and) power control signal of the wireless power receiver through the communication unit 630, and may be based on the received power reception state information or (and) power control signal.
  • the amplification factor of the amplifier 612 can be dynamically adjusted.
  • the power reception state information may include, but is not limited to, strength information of the rectifier output voltage and strength information of a current applied to the receiving coil.
  • the power control signal may include a signal for requesting power increase, a signal for requesting power reduction, and the like.
  • the power transmitter 620 may include a multiplexer 621 (or a multiplexer) and a transmission coil 622.
  • the power transmitter 620 may further include a carrier generator (not shown) for generating a specific operating frequency for power transmission.
  • the carrier generator may generate a specific frequency for converting the output DC power of the amplifier 612 received through the multiplexer 621 into AC power having a specific frequency.
  • the AC signal generated by the carrier generator is mixed with the output terminal of the multiplexer 621 to generate AC power.
  • this is only one embodiment, and the other example is before the amplifier 612. Note that it may be mixed in stages or later.
  • the frequencies of AC power delivered to each transmitting coil in accordance with one embodiment of the present invention may be different.
  • the resonance frequency of each transmission coil may be set differently by using a predetermined frequency controller having a function of differently adjusting the LC resonance characteristics for each transmission coil.
  • the power transmitter 620 includes a multiplexer 621 and a plurality of transmit coils 622—that is, a first to control the output power of the amplifier 612 to be transmitted to the transmit coil. To n-th transmission coils.
  • the controller 640 may transmit power through time division multiplexing for each transmission coil.
  • three wireless power receivers i.e., the first to third wireless power receivers, are each identified through three different transmitting coils, i.e., the first to third transmitting coils.
  • the controller 640 may control the multiplexer 621 to control power to be transmitted to a specific transmission coil in a specific time slot.
  • the amount of power transmitted to the corresponding wireless power receiver may be controlled according to the length of the time slot allocated to each transmitting coil, but this is only one embodiment.
  • By controlling the amplification factor of the amplifier 612 of the wireless power receiver may be controlled to transmit power.
  • the controller 640 may control the multiplexer multiplexer 621 to sequentially transmit the sensing signals through the first to nth transmitting coils 622 during the first sensing signal transmission procedure. At this time, the control unit 640 may identify the time when the detection signal is transmitted using the timer 655. When the transmission signal transmission time arrives, the control unit 640 controls the multiplexer 621 to detect the detection signal through the corresponding transmission coil. Can be controlled to be sent. For example, the timer 650 may transmit a specific event signal to the controller 640 at a predetermined period during the ping transmission step. When the corresponding event signal is detected, the controller 640 controls the multiplexer 621 to transmit the specific event signal. The digital ping can be sent through the coil.
  • control unit 640 stores a predetermined transmission coil identifier and a corresponding transmission coil for identifying which transmission coil has received a signal strength indicator from the demodulator 632 during the first detection signal transmission procedure. Signal strength indicator received through the can be received. Subsequently, in the second detection signal transmission procedure, the control unit 640 controls the multiplexer 621 so that the detection signal may be transmitted only through the transmission coil (s) in which the signal strength indicator was received during the first detection signal transmission procedure. You may. As another example, the controller 640 transmits the second sensed signal to the transmit coil in which the signal strength indicator having the largest value is received when there are a plurality of transmit coils in which the signal intensity indicator is received during the first sensed signal transmit procedure. In the procedure, the sensing signal may be determined as the transmitting coil to be transmitted first, and the multiplexer 621 may be controlled according to the determination result.
  • the modulator 631 may modulate the control signal generated by the controller 640 and transmit the modulated control signal to the multiplexer 621.
  • the modulation scheme for modulating the control signal is a frequency shift keying (FSK) modulation scheme, a Manchester coding modulation scheme, a PSK (Phase Shift Keying) modulation scheme, a pulse width modulation scheme, a differential 2 Differential bi-phase modulation schemes may be included, but is not limited thereto.
  • the demodulator 632 may demodulate the detected signal and transmit the demodulated signal to the controller 640.
  • the demodulated signal may include a signal strength indicator, an error correction (EC) indicator for controlling power during wireless power transmission, an end of charge (EOC) indicator, an overvoltage / overcurrent / overheat indicator, and the like.
  • EC error correction
  • EOC end of charge
  • the present invention is not limited thereto, and may include various state information for identifying a state of the wireless power receiver.
  • the demodulator 632 may identify from which transmission coil the demodulated signal is received, and may provide the control unit 640 with a predetermined transmission coil identifier corresponding to the identified transmission coil.
  • the demodulator 632 may demodulate a signal received through the transmission coil 623 and transmit the demodulated signal to the controller 640.
  • the demodulated signal may include a signal strength indicator, but is not limited thereto.
  • the demodulated signal may include various state information of the wireless power receiver.
  • the wireless power transmitter 600 may obtain the signal strength indicator through in-band communication that communicates with the wireless power receiver using the same frequency used for wireless power transmission.
  • the wireless power transmitter 600 may not only transmit wireless power using the transmission coil 622 but also exchange various information with the wireless power receiver through the transmission coil 622.
  • the wireless power transmitter 600 further includes a separate coil corresponding to each of the transmission coils 622 (that is, the first to nth transmission coils), and wireless power using the separate coils provided. Note that in-band communication with the receiver may also be performed.
  • the wireless power transmitter 600 and the wireless power receiver perform in-band communication by way of example.
  • this is only one embodiment, and is a frequency band used for wireless power signal transmission.
  • Short-range bidirectional communication may be performed through a frequency band different from that of FIG.
  • the short-range bidirectional communication may be any one of low power Bluetooth communication, RFID communication, UWB communication, and Zigbee communication.
  • the wireless power transmitter 600 may adaptively provide a fast charging mode and a general low power charging mode according to a request of the wireless power receiver.
  • the wireless power transmitter 600 may transmit a signal of a predetermined pattern-a business card called a first packet-for convenience of description.
  • the wireless power receiver 600 may identify that the wireless power transmitter 600 being connected is capable of fast charging.
  • the wireless power receiver may transmit a predetermined first response packet requesting fast charging to the wireless power transmitter 6000.
  • the wireless power transmitter 600 may automatically switch to the fast charging mode and start fast charging.
  • the first packet is transmitted through the transmission coil 622.
  • the first packet may be sent in the identification and configuration step 430 of FIG. 4 or the identification step 530 of FIG. 5.
  • information for identifying whether fast charging is supported may be encoded and transmitted in the digital ping signal transmitted by the wireless power transmitter 600.
  • the wireless power receiver may transmit a predetermined charging mode packet to the wireless power transmitter 600 in which the charging mode is set to fast charging.
  • the charging mode packet will be more clearly through the description of FIGS. 8 to 12 to be described later.
  • the wireless power transmitter 600 and the wireless power receiver are changed to the fast charging mode, the fast charging mode is used.
  • the internal operation can be controlled so that the corresponding power can be transmitted and received.
  • the charging mode is changed from the normal low power charging mode to the fast charging mode, the over voltage judgment criteria, the over temperature judgment criteria, the low voltage / high voltage judgment criteria, the optimum voltage Values such as level (Optimum Voltage Level), power control offset, etc. may be changed and set.
  • the threshold voltage for determining the overvoltage may be set to be high to enable fast charging.
  • the threshold temperature may be set to be high in consideration of the temperature rise due to the fast charging.
  • the power control offset value which means the minimum level at which power is controlled at the transmitting end, may be set to a larger value than the general low power charging mode so as to quickly converge to a desired target power level in the fast charging mode.
  • FIG. 7 is a block diagram illustrating a structure of a wireless power receiver interworking with the wireless power transmitter according to FIG. 6.
  • the wireless power receiver 700 includes a receiving coil 710, a rectifier 720, a DC / DC converter 730, a load 740, a sensing unit 750, and a communication unit ( 760), and may include a main controller 770.
  • the communication unit 760 may include a demodulator 761 and a modulator 762.
  • the wireless power receiver 700 illustrated in the example of FIG. 7 is illustrated as being capable of exchanging information with the wireless power transmitter 600 through in-band communication, this is only one embodiment.
  • the communication unit 760 may provide short-range bidirectional communication through a frequency band different from the frequency band used for wireless power signal transmission.
  • the AC power received through the receiving coil 710 may be transferred to the rectifier 720.
  • the rectifier 720 may convert AC power into DC power and transmit the DC power to the DC / DC converter 730.
  • the DC / DC converter 730 may convert the strength of the rectifier output DC power into a specific intensity required by the load 740 and then transfer it to the load 740.
  • the sensing unit 750 may measure the intensity of the rectifier 720 output DC power and provide the same to the main controller 770. In addition, the sensing unit 750 may measure the strength of the current applied to the receiving coil 710 according to the wireless power reception, and may transmit the measurement result to the main controller 770. In addition, the sensing unit 750 may measure the internal temperature of the wireless power receiver 700 and provide the measured temperature value to the main controller 770.
  • the main controller 770 may determine whether the overvoltage is generated by comparing the measured intensity of the rectifier output DC power with a predetermined reference value. As a result of the determination, when the overvoltage is generated, a predetermined packet indicating that the overvoltage has occurred may be generated and transmitted to the modulator 762.
  • the signal modulated by the modulator 762 may be transmitted to the wireless power transmitter 600 through the receiving coil 710 or a separate coil (not shown).
  • the main controller 770 may determine that a sensing signal has been received. When the sensing signal is received, a signal strength indicator corresponding to the sensing signal may be modulated.
  • the demodulator 761 demodulates an AC power signal or a rectifier 720 output DC power signal between the receiving coil 710 and the rectifier 720, identifies whether a detection signal is received, and then identifies the identification result. It may be provided to the unit 770. In this case, the main controller 770 may control the signal strength indicator corresponding to the detection signal to be transmitted through the modulator 761.
  • the main controller 770 may determine whether the connected wireless power transmitter is a wireless power transmitter capable of fast charging based on the information demodulated by the demodulator 760.
  • the main control unit 770 when a predetermined fast charge request signal for requesting fast charge is received from the electronic device 30 of FIG. 1, the main control unit 770 generates a charge mode packet corresponding to the received fast charge request signal and modulator. Can be sent to (761).
  • the fast charge request signal from the electronic device may be received according to a user menu selection on a predetermined user interface.
  • the main controller 770 When the main controller 770 according to another embodiment of the present invention determines that the connected wireless power transmitter supports the fast charging mode, the main controller 770 automatically requests the wireless power transmitter for fast charging or wireless power based on the remaining battery power. You can also control the transmitter to stop fast charging and switch to normal low power charging mode.
  • the main controller 770 may monitor the power consumption of the electric device in real time during charging in the general low power charging mode. If the power consumption of the electronic device is greater than or equal to a predetermined reference value, the main controller 770 may generate a predetermined charging mode packet for requesting switching to the fast charging mode and transmit the generated charging mode packet to the modulator 761.
  • the main control unit 770 may determine whether overheating occurs by comparing the internal temperature value measured by the sensing unit 750 with a predetermined reference value. If overheating occurs during fast charging, the main controller 770 may generate and transmit a charging mode packet so that the wireless power transmitter switches to the normal low power charging mode.
  • the main controller 770 may change the charging mode based on at least one of a battery charge rate, an internal temperature, a strength of the rectifier output voltage, a CPU usage rate mounted on the electronic device, and a user menu selection. If it is necessary to determine whether, and as a result of the determination, it is necessary to change the charging mode, it is possible to generate a charging mode packet including the change of the charging mode value and transmit to the wireless power transmitter.
  • FIG. 8 is a diagram for describing a method of modulating and demodulating a wireless power signal according to an embodiment of the present invention.
  • the wireless power transmitter 10 and the wireless power receiver 20 may encode or decode a transmission target packet based on an internal clock signal having the same period.
  • the wireless power signal when the wireless power transmitter 10 or the wireless power receiver 20 does not transmit a specific packet, the wireless power signal is modulated with a specific frequency, as shown by reference numeral 41 of FIG. 1. AC signal may not be.
  • the wireless power transmitter 10 or the wireless power receiver 20 transmits a specific packet the wireless power signal may be an AC signal modulated by a specific modulation scheme as shown in FIG.
  • the modulation scheme may include, but is not limited to, an amplitude modulation scheme, a frequency modulation scheme, a frequency and amplitude modulation scheme, a phase modulation scheme, and the like.
  • Differential bi-phase encoding may be applied to binary data of a packet generated by the wireless power transmitter 10 or the wireless power receiver 20 as shown in FIG.
  • differential two-stage encoding allows two state transitions to encode data bit 1 and one state transition to encode data bit zero. That is, data bit 1 is encoded such that a transition between a HI state and a LO state occurs at a rising edge and a falling edge of the clock signal, and data bit 0 is HI at the rising edge of the clock signal.
  • the transition between state and LO state may be encoded to occur.
  • the encoded binary data may be applied with a byte encoding scheme, as shown at 830.
  • the byte encoding scheme includes a start bit and a stop bit for identifying a start and type of a corresponding bit stream for an 8-bit encoded binary bit stream.
  • the method may be a method of inserting a parity bit for detecting whether an error of a corresponding bit stream (byte) occurs.
  • FIG. 9 is a diagram for describing a packet format according to an embodiment of the present invention.
  • a packet format 900 used for information exchange between the wireless power transmitter 10 and the wireless power receiver 20 may be used for acquiring synchronization for demodulating the packet and identifying the correct start bit of the packet.
  • the packet receiving end may identify the size of the message 930 included in the packet based on the header 920 value.
  • the header 920 may be defined in each step of the wireless power transfer procedure, and in some, the same value may be defined in different steps of the header 920.
  • the header values corresponding to the end power transfer of the ping step and the end of the power transfer of the power transfer step may be equal to 0x02.
  • the message 930 includes data to be transmitted at the transmitting end of the packet.
  • the data included in the message 930 field may be a report, a request, or a response to the counterpart, but is not limited thereto.
  • the packet 900 may further include at least one of a transmitter identification information for identifying a transmitter that transmitted the packet and a receiver identification information for identifying a receiver for receiving the packet.
  • the transmitter identification information and the receiver identification information may include IP address information, MAC address information, product identification information, and the like, but are not limited thereto and may be information capable of distinguishing a receiver and a transmitter from a wireless charging system.
  • the packet 900 may further include predetermined group identification information for identifying the corresponding reception group when the packet is to be received by a plurality of devices.
  • FIG. 10 is a diagram for describing types of packets transmitted from a wireless power receiver to a wireless power transmitter according to an embodiment of the present invention.
  • a packet transmitted from a wireless power receiver to a wireless power transmitter includes a signal strength packet for transmitting strength information of a detected ping signal, and a type of power transmission for requesting the transmitter to stop power transmission.
  • End Power Transfer a power control hold-off packet for transmitting time information waiting to adjust the actual power after receiving a control error packet for control control
  • a configuration for transmitting the configuration information of the receiver Packet, identification packet and extended identification packet for transmitting receiver identification information general request packet for sending general request message, special request packet for sending special request message, reference quality factor value for FO detection FOD status packet, control error packet for controlling the transmitter power of the transmitter, renegotiation packet for renegotiation initiation,
  • a 24-bit received power packet and 8-bit received power packet for transmitting strength information of the received power, and a charging state packet for transmitting charge state information of a current load may be included.
  • Packets transmitted from the wireless power receiver to the wireless power transmitter may be transmitted using in-band communication using the same frequency band as the frequency band used for wireless power transmission.
  • FIG. 11 is a block diagram illustrating a structure of a wireless power transmission apparatus according to an embodiment of the present invention.
  • the wireless power transmitter 1100 includes a power supply 1101, a DC-DC converter 1102, an inverter 1103, a resonant capacitor 1104, and a transmission coil 1105.
  • the quality factor measuring unit 1106, the demodulator 1107, the modulator 1108, the sensing unit 1109, the control unit 1110, and the alarm unit 1111 may be configured.
  • the power supply 1101 may receive DC power through an external power supply terminal and transmit the DC power to the DC-DC converter 1102.
  • the DC-DC converter 1102 may convert the intensity of the DC power received from the power supply unit 1101 into the DC power of a specific intensity under the control of the controller 1110.
  • the DC-DC converter 1102 may be configured as a variable voltage device capable of adjusting the strength of the voltage, but is not limited thereto.
  • the inverter 1103 may convert the converted DC power into AC power.
  • the inverter 1103 may convert a DC power signal input through a plurality of switch controls provided into an AC power signal and output the converted AC power signal.
  • the inverter 1103 may be configured to include a full bridge circuit, but is not limited thereto.
  • the inverter 1103 may be configured to include a half bridge.
  • the inverter 1103 may be configured to include both a half bridge circuit and a full bridge circuit.
  • the controller 1110 may operate the inverter 1103 as a half bridge or a full bridge. You can also decide.
  • the wireless power transmission apparatus may adaptively control the bridge mode of the inverter 1103 according to the strength of the power required by the wireless power receiver. For example, when the wireless power receiver requires 5W of low power, the controller 1110 may control the half bridge circuit of the inverter 1103 to be driven.
  • the controller 1110 may control the full bridge circuit to be driven.
  • the wireless power transmitter may adaptively drive the full bridge circuit or the half bridge circuit according to the sensed temperature. For example, when the temperature of the wireless power transmitter exceeds a predetermined reference value while transmitting wireless power using the half bridge circuit, the controller 1110 may deactivate the half bridge circuit and activate the full bridge circuit. That is, the wireless power transmitter lowers the temperature of the wireless power transmitter below a reference value by increasing the voltage through the full bridge circuit and decreasing the strength of the current flowing through the transmission coil 1105 for power transmission of the same intensity. have.
  • the amount of heat generated in an electronic component mounted on an electronic device may be more sensitive to the strength of the current than the strength of the voltage applied to the electronic component.
  • the inverter 1103 may not only convert DC power into AC power, but also change the strength of AC power.
  • the inverter 1103 may adjust the intensity of the AC power output by adjusting the frequency of a reference alternating current signal used to generate AC power under the control of the controller 1110.
  • the inverter 1103 may be configured to include a frequency oscillator for generating a reference AC signal having a specific frequency, but this is only one embodiment, another example is that the frequency oscillator is separate from the inverter 1103 It may be configured to be mounted.
  • the quality factor measuring unit 1106 may measure a quality factor value of the transmission coil of the wireless power transmitter by monitoring a change in inductance (or voltage or current) value across the resonance capacitor 1104. In this case, the measured current quality factor value may be transmitted to the controller 1110, and the controller 1110 may store the measured current quality factor value received from the quality factor measurement unit 1106 in a predetermined recording area.
  • the controller 1110 may measure the quality factor values in the selection steps 410 and 510 of FIGS. 4 to 5.
  • the controller 1110 is a foreign object detection quality factor threshold value (FOD_QFT_Value) for determining whether there is a foreign matter based on a reference quality factor value (RQF_Value) received from the wireless power receiver. ) Can be determined.
  • the controller 1110 may perform a foreign matter detection procedure based on the quality factor value to determine whether there is a foreign matter by comparing the measured quality factor values (Measured_Quality_Factor_Value, MQF_Value) and FOD_QFT_Value.
  • the RQF_Value may be determined as a value having the smallest value among the quality factor values measured at a plurality of points on the charging region of the specific wireless power transmitter designated for the performance test.
  • FOD_QFT_Value can be determined by subtracting RQF_Value from reference quality factor accuracy and production and measurement errors.
  • the reference quality factor accuracy may be an allowable range of an error for the reference quality factor value measured when no foreign matter is present.
  • the reference quality factor value to which the tolerance range is applied may be set at a rate that increases or decreases with respect to the reference quality factor value received from the wireless power receiver, but is not limited thereto.
  • the current WPC Qi standard is defined to apply the same reference quality factor accuracy for all products.
  • the reference quality factor accuracy may have different values depending on the manufacturer of the product and the type of product.
  • the wireless power receiver of A company and the wireless power receiver of B company may measure a reference quality factor value in association with the same wireless power transmitter.
  • the accuracy of the reference quality factor values measured for the two products may differ. Therefore, the FOD_QFT_Value for determining whether there is a foreign matter determined based on different reference quality factor accuracy for each wireless power receiver may not be an accurate threshold for determining whether there is a foreign matter.
  • the test result of the same wireless power transmitter the reference quality factor value measured for the wireless power receiver of Company A is 100
  • the reference quality factor value measured for the wireless power receiver of Company B may be 70
  • the reference quality factor accuracy corresponding to company B's wireless power receiver is set to +/- 7%
  • the reference quality factor accuracy corresponding to company A's wireless power receiver is set to +/- 10%.
  • the probability of detecting foreign matter more accurately can be increased.
  • the same reference quality factor accuracy is applied to all wireless power receivers in the FOD certification test according to the WPC Qi standard, there is a problem in that the accurate FOD certification test cannot be performed.
  • the demodulator 1107 demodulates the in-band signal received from the wireless power receiver and transmits the demodulated in-band signal to the controller 1110.
  • the demodulator 1107 may demodulate and transmit the FOD status packet of FIG. 12, the configuration packet of FIG. 13, and a correction error packet (CEP) of FIG. 14 to the controller 1110.
  • the FOD status packet or the configuration packet may include a predetermined receiver type identifier for identifying the type and type of the wireless power receiver.
  • the controller 1110 may determine a predetermined current change threshold (Delta_Current_Threshold) for determining whether a foreign substance exists based on the received receiver type identifier. The controller 1110 may determine whether there is a foreign substance by comparing the change amount Delta_RAIL_Current of the I_rail measured in the ping step with the determined current change threshold.
  • Delta_Current_Threshold a predetermined current change threshold for determining whether a foreign substance exists based on the received receiver type identifier.
  • the controller 1110 may determine whether there is a foreign substance by comparing the change amount Delta_RAIL_Current of the I_rail measured in the ping step with the determined current change threshold.
  • the controller 1110 may determine whether there is a foreign substance in the identification and configuration step 530 of FIG. 5.
  • the controller 1110 may determine whether a foreign object exists in the negotiation step 540 of FIG. 5.
  • the controller 1110 may transition the state of the wireless power transmitter to the selection step.
  • the controller 1110 may enter the selection step without entering the power transmission step 560.
  • a current intensity threshold or a current change threshold ratio corresponding to the receiver type identifier may be defined as shown in FIGS. 14 to 15 to be described later, but is not limited thereto.
  • the modulator 1108 modulates the control packet received from the controller 1110 and transmits the modulated control packet through the transmission coil 1105. For example, when the FOD status packet including the receiver type identifier is received, the controller 1110 determines a current change threshold corresponding to the corresponding receiver type identifier, and determines the current change amount of the inverter 1103 in the previously measured ping step. By comparing Delta_Rail_Current- with the determined current change threshold, it is possible to finally determine the presence of foreign substances. According to the determination result of the presence of the foreign matter, the controller 1110 may generate an ACK packet or a NACK packet and transmit the generated ACK packet or the NACK packet to the modulator 1108.
  • the ACK packet may mean that the foreign matter was not detected, and the NACK packet may mean that the foreign matter was detected.
  • the controller 1110 may determine whether a foreign matter exists by comparing Delta_Rail_Current and Delta_Current_Threshold, and then perform a foreign matter detection procedure based on a quality factor value.
  • a procedure of determining whether there is a foreign matter by comparing Delta_Rail_Current and Delta_Current_Threshold will be referred to as a foreign matter detection procedure based on a current change amount.
  • the controller 1110 may determine that there is a foreign substance when it is determined that the foreign substance exists by performing the foreign substance detection procedure based on the current change amount and the foreign substance detection procedure based on the quality factor value.
  • the controller 1110 may finally determine that the foreign matter exists. have.
  • the controller 1110 may control to perform the foreign matter detection procedure based on the current change amount when it is determined that the foreign matter exists through the foreign matter detection procedure based on the quality factor value. In this case, the controller 1110 may finally determine that the foreign substance exists only when it is determined that the foreign substance exists through the foreign substance detection procedure based on the amount of current change.
  • the controller 1110 may finally determine whether the foreign substance exists by performing only the foreign substance detection procedure based on the current change amount. Note that it may.
  • the controller 1110 notifies the user of the presence of the foreign matter in the charging region without entering the power transmission step 560 in the negotiation step 540 of FIG. 5.
  • the means can be controlled.
  • the notifying means may include, but is not limited to, a beeper, an LED lamp, a vibrating element, a liquid crystal display, and the like.
  • the sensing unit 1109 may measure voltage, current, power, temperature, etc. at a specific node, a specific component, a specific location, etc. of the wireless power transmitter.
  • the sensing unit 1109 measures the intensity change of the current / voltage / power or the intensity of the current / voltage / power between the DC-DC converter 1102 and the inverter 1103 and controls the measurement result. 1110.
  • the current flowing between the DC-DC converter 1102 and the inverter 1103 is I_rail, and the voltage applied to the DC-DC converter 1102 output terminal or the inverter 1103 input terminal is V_rail, DC-DC. Power transmitted from the converter 1102 to the inverter 1103 will be referred to as P_rail.
  • the sensing unit 1109 measures the strength of the current flowing through the transmitting coil 1105, that is, the inductor, and the voltage applied to both ends of the transmitting coil 1105, and measures the measurement result in the control unit 1110. You can also pass it on.
  • the control unit 1110 calculates the change amount of the intensity I_rail of the current applied to the inverter 1103 based on the sensing information received from the sensing unit 1109 in the ping step, and the calculated current intensity The amount of change can be stored in a predetermined recording area.
  • the controller 1110 may determine the possibility of the presence of foreign substances (that is, the probability) by comparing the amount of change of the current intensity previously stored with the predetermined current change threshold in the identification and configuration steps.
  • the controller 1110 may adjust the reference quality factor accuracy to a lower level. For example, when it is determined that there is a high possibility of the presence of foreign substances, the controller 1110 may determine the FOD_QFT_Value by adjusting the reference quality factor accuracy from +/- 10% to +/- 5%. Through this, the controller 1110 may improve the foreign matter detection accuracy when determining the presence of the foreign matter based on the quality factor value. On the other hand, if it is determined that the foreign matter is less likely to exist, the controller 1110 may determine the FOD_QFT_Value based on a predefined reference quality factor accuracy.
  • the controller 1110 may determine that a foreign matter exists. If a foreign object exists, the controller 1110 may not enter the power transmission step 560 in the negotiation step 540 of FIG. 5. In this case, the controller 1110 may control a predetermined notification means provided in the wireless power transmission apparatus so that the user recognizes that the foreign matter exists in the charging region.
  • the notification means may include, but is not limited to, a beeper, an LED lamp, a vibrating element, a liquid crystal display, and the like.
  • the controller 1110 may determine that no foreign matter exists in the charging region. If there is no foreign matter, the controller 1110 may enter the power transmission step and control the power required by the wireless power transmission apparatus to be transmitted.
  • control unit 1110 is a current value measured in the ping step, for example, the output current (I_rail) of the DC-DC converter or the current (I_coil) applied to the transmitting coil (1105). May be compared to a predetermined reference current value. As a result of the comparison, when the measured current value is larger than the reference current value, it may be determined that the presence of foreign matter is low. In this case, even when the FOD status packet is received in the negotiation step, the controller 1110 may enter the power transmission step without proceeding with the foreign material determination procedure based on the quality factor value.
  • the inverter input current I_rail is DC power, and the current flowing through the transmitting coil 1105 is AC current.
  • the current input to the inverter 1103 in the ping step is DC power having a constant level, but the output power of the inverter 1103 is AC power transmitted discontinuously at a constant cycle. Therefore, the time average value of I_rail may be relatively larger than the time average value of I_coil. Therefore, determining the possibility of the presence of foreign objects based on the change in I_rail can significantly reduce the probability of determination error.
  • the controller 1110 may determine the presence of foreign substances by monitoring the change in the intensity of the current I_rail applied to the inverter 1103 in the ping step.
  • the control unit 1110 when the transmission power is stabilized after entering the power transmission step, the ratio of the input voltage (V_rail) of the inverter 1103 and the intensity (I_coil) of the current flowing through the transmission coil 1105 Can be calculated. In this case, the controller 1110 may compare the calculated ratio with a predetermined reference value to determine whether the wireless power receiver is aligned or foreign matter caused by moving the wireless power receiver on the chargeable area during power transmission.
  • the controller 1110 may stabilize the output power when the predetermined target voltage (or) and the target current are reached through a power control based on a feedback signal received from the wireless power receiver, for example, may be a CEP packet. It may be determined, but is not limited thereto.
  • the wireless power receiver may send a CEP packet to the wireless power transmitter until the target current and / or the target voltage is reached.
  • the controller 1110 may determine that the output power is stabilized when the intensity change amount during at least one unit time of the inverter input voltage and the inverter input current is equal to or less than a predetermined reference value.
  • the controller 1110 may determine that the transmission power is stabilized when the transmission power control is performed within a preset range for a predetermined time.
  • control unit 1110 may determine that the transmission power is stabilized when a CEP in which the control error value is set to 0 indicating the power maintenance is continuously received a predetermined number of times.
  • control unit 1110 may transmit a predetermined control signal to the alarm unit 1111 to control a predetermined alarm signal indicating that the wireless power receiver is not normally aligned.
  • the controller 1110 may transmit a predetermined control signal to the alarm unit 1111 to control a predetermined notification signal indicating that the foreign matter exists in the charging area.
  • the controller 1110 may control to transition to the selection step in the power transmission step.
  • FIG. 12 illustrates a message structure of a FOD status packet according to the present invention.
  • the FOD status packet message 1200 may have a length of 2 bytes, a 6-bit receiver type identifier (1201), a 2-bit mode (Mode, 1202) field, and the like. It may be configured to include a reference quality factor value 1203 of 1 byte in length.
  • the length of the receiver type identifier 1201 field is shown in FIG. 12 as 6 bits, it is only one embodiment, and it should be noted that the size of the receiver type identifier 1201 may be smaller than 6 bits according to the design of a person skilled in the art. .
  • the reference quality factor value measured and determined with the power of the wireless power receiver turned off is stored in the reference quality factor value 1203 field. It may mean that it is recorded.
  • FIG. 13 is a diagram illustrating a structure of a configuration packet according to an embodiment of the present invention.
  • a message format of a configuration packet may have a length of 5 bytes, and includes a power class field, a maximum power field, and a power control field. , A count field, a window size field, a window offset field, and first to third reserved fields 1301 to 1303.
  • the power class assigned to the wireless power receiver may be recorded in the power class field.
  • the strength value of the maximum power that can be provided by the rectifier output of the wireless power receiver may be recorded.
  • the maximum power amount Pmax desired to be provided at the rectifier output terminal of the wireless power receiver may be calculated as (b / 2) * 10 a .
  • the power control field may be used to indicate according to which algorithm the power control in the wireless power transmitter should be made. For example, if the power control field value is 0, this means that the power control algorithm is defined in the standard, and if the power control field value is 1, it may mean that power control is performed according to an algorithm defined by the manufacturer.
  • the count field may be used to record the number of option configuration packets to be transmitted by the wireless power receiver in the identification and configuration steps.
  • the window size field may be used to record the window size for calculating the average received power.
  • the window size may be a positive integer value greater than 0 and having a unit of 4 ms.
  • the window offset field may record information for identifying the time from the end of the average received power calculation window to the start of the transmission of the next received power packet.
  • the window offset may be a positive integer value greater than 0 and having a unit of 4 ms.
  • the receiver type identifier described with reference to FIGS. 11 through 12 may be recorded in at least one reserved field of the first through third reserved fields 1301 through 1303 of FIG. 13 and transmitted to the wireless power transmitter.
  • the number of bits allocated for the receiver type identifier may have a different length according to the design of a person skilled in the art, and does not limit the number of bits.
  • a receiver type identifier mapping table in which a current change threshold corresponding to a receiver type identifier is defined according to an embodiment of the present invention.
  • the receiver type identifier field has a length of 6 bits and may range from 0 to 63.
  • the current change threshold has a unit of mA and may be defined such that 100 mA is increased as the type identifier is increased by 1, but this is only one embodiment, and is a current change corresponding to the type identifier. It should be noted that the threshold may be defined differently according to the design of those skilled in the art. For example, the current change threshold may be defined such that 50 mA increases as the type identifier increases by one.
  • receiver type identifier field has been described as having a length of 6 bits, the embodiment of FIG. 13 is only one embodiment, and the length of the receiver type identifier field may be configured to be larger or smaller than 6 bits. Note that it may.
  • the receiver type identifier corresponding to the wireless power receiver A is binary “000101”. May be assigned.
  • the wireless power receiver may transmit a receiver type identifier assigned to the wireless power transmitter through a configuration packet in a configuration and identification step.
  • the wireless power receiver may transmit the receiver type identifier assigned to the wireless power transmitter to the wireless power transmitter through the FOD status packet in the negotiation step.
  • 15 is a receiver type identifier mapping table in which a current change threshold ratio corresponding to a receiver type identifier is defined according to another embodiment of the present invention.
  • the receiver type identifier has a length of 2 bits, and the current change threshold ratio is a current value of the digital ping signal measured when the wireless power receiver is not placed in the charging region, hereinafter, for convenience of description.
  • the initial inverter input current value (Initial_Inverter_Input_Current_Value) may be defined as the rate of change of the current value of the digital ping signal (Measured_Inverter_Inpurt_Current_Value)-that is, the inverter input current strength value-measured after the wireless power receiver is placed in the charging region. .
  • the rate of change of current in the ping step is
  • the receiver type identifier corresponding to the corresponding wireless power receiver may be defined as binary “10”, as shown in FIG. 15.
  • the receiver type identifier has a length of 2 bits, and the current change threshold ratio corresponding to each receiver type identifier is shown to have a range of 20%.
  • 16 is a flowchart illustrating a foreign material detection method in a wireless power transmission apparatus according to an embodiment of the present invention.
  • the apparatus for transmitting power wirelessly may measure the strength of the current applied to the inverter in the ping step and store information about the measured inverter input current strength in a predetermined recording area (S1601).
  • the apparatus for transmitting power wirelessly may receive a packet including a receiver type identifier (S1602).
  • the receiver type identifier may be received through the configuration packet in the configuration and identification phase, but this is only one embodiment, and in another embodiment, the receiver type identifier may be received through the FOD status packet in the negotiation phase. .
  • the apparatus for transmitting power wirelessly may determine a current intensity threshold corresponding to the receiver type identifier in operation S1603.
  • the current intensity threshold may be determined with reference to the receiver type identifier mapping table described with reference to FIG. 14, but is not limited thereto.
  • the apparatus for transmitting power may compare the inverter input current intensity and the current intensity threshold stored in operation 1601 to determine whether a foreign substance exists in the charging region (S1604). For example, when the inverter input current intensity exceeds the current intensity threshold, the wireless power transmitter may determine that foreign matter exists in the charging region. On the other hand, if the inverter input current intensity is less than or equal to the current intensity threshold, it may be determined that no foreign matter exists in the charging region.
  • the wireless power transmitter may enter a selection step after outputting a predetermined alarm signal indicating that the foreign substance is detected (S1605).
  • the wireless power transmitter may enter the negotiation step or the power transmission step (S1606).
  • FIG. 17 is a flowchart illustrating a foreign material detection method in a wireless power transmission apparatus according to another embodiment of the present invention.
  • the apparatus for transmitting power wirelessly may measure the strength of the current input to the inverter in the ping step and store information about the measured inverter input current strength (Measured_I_Rail) in a predetermined recording area (S1701).
  • the wireless power transmitter transmits information about the strength of the current input to the inverter when no object is detected, that is, information on the initial inverter input current value (Initial_Inverter_Input_Current_Value), and the inverter input current value (Measured_Inverter_Input_Current_Value) measured at the ping step.
  • the rate of change of the inverter input current I_rail may be calculated using the information (S1702).
  • the rate of change of the inverter input current may be calculated as ⁇ (Measured_Inverter_Inpurt_Current_Value-Initial_Inverter_Input_Current_Value) / (Initial_Inverter_Input_Current_Value) ⁇ * 100.
  • the apparatus for transmitting power wirelessly may receive a packet including a receiver type identifier (S1703).
  • the receiver type identifier may be received through the configuration packet in the configuration and identification phase, but this is only one embodiment, and in another embodiment, the receiver type identifier may be received through the FOD status packet in the negotiation phase. .
  • the apparatus for transmitting power wirelessly may determine a current intensity threshold ratio corresponding to the receiver type identifier (S1704).
  • the current intensity threshold ratio may be determined with reference to the receiver type identifier mapping table described with reference to FIG. 15, but is not limited thereto.
  • the apparatus for transmitting power wirelessly may compare the change ratio of the inverter input current calculated in operation 1702 with the current intensity threshold ratio determined in operation 1704 to determine whether a foreign substance exists in the charging region (S1705). For example, when the rate of change of the inverter input current exceeds the current intensity threshold ratio, the wireless power transmitter may determine that the foreign matter exists in the charging region. On the other hand, if the rate of change of the inverter input current is less than or equal to the current intensity threshold ratio, the wireless power transmitter may determine that there is no foreign matter in the charging region.
  • the wireless power transmitter may enter a selection step after outputting a predetermined alarm signal indicating that the foreign substance is detected (S1706).
  • the wireless power transmitter may enter the negotiation step or the power transmission step (S1707).
  • FIG. 18 is a flowchart illustrating a foreign material detection method in a wireless power transmission apparatus according to another embodiment of the present invention.
  • the apparatus for transmitting power wirelessly may perform a foreign matter detection procedure based on the change of the inverter input current intensity in the ping step (S1801).
  • the wireless power transmitter may perform the foreign matter detection procedure based on the quality factor value in the negotiation step (S1803). At this time, the wireless power transmitter may correct the reference quality factor accuracy used to determine the quality factor threshold. For example, the reference quality factor accuracy may be adjusted from +/- 10% to +/- 5% so that foreign matter can be detected more accurately.
  • the wireless power transmission apparatus may determine whether or not a foreign matter exists by performing a foreign matter detection procedure based on the quality factor value (S1805). As a result of the determination, when the foreign material exists, the wireless power transmitter may enter the selection step after transmitting the NACK packet (S1805). On the other hand, when the foreign matter does not exist as a result of the determination in step 1804, the wireless power transmission apparatus may enter the power transmission step after the transmission of the ACK packet and start charging (S1807).
  • the wireless power transmitter may perform step 1806 without performing a foreign matter detection procedure based on the quality factor value.
  • the apparatus for transmitting wireless power may generate an ACK packet and transmit the ACK packet to the corresponding wireless power receiver after the FOD status packet is received in the negotiation step.
  • 19 is an embodiment of a transmitting coil mounted to a wireless power transmitting apparatus according to an embodiment of the present invention.
  • the wireless power transmission apparatus may be arranged such that three transmission coils overlap a predetermined area.
  • Position 1 which is the center of the transmission coil block
  • Position 2 which is 20 mm away from it
  • FIGS. 20A to 20B the intensity of the inverter input current
  • Position 3 which is 40mm away from the center of the transmitting coil block, is characterized by a small change in the inverter input current for all foreign materials.
  • 20A to 20B are graphs illustrating measurement results of inductor input current intensity and transmit coil input current intensity for each position of a transmitting coil according to FIG. 19.
  • FIG. 20A illustrates a measurement result of an inverter input current intensity and a transmission coil input current intensity according to a foreign material type at position 1 of FIG. 19.
  • 20B illustrates a measurement result of an inductor input current intensity and a transmission coil input current intensity according to the type of foreign matter in position 2 of FIG. 19.
  • the intensity of the current measured at Position 1 is greater than the intensity of the current measured at Position 2 as a whole.
  • the intensity of the current measured in the absence of the foreign matter during the ping transmission is greater than the strength of the current measured in the presence of the foreign matter.
  • 21 to 22 show a change pattern of the coil current and the inverter input current when the foreign matter is located in the charging region in the ping step at position 1 of FIG. 19.
  • FIG. 21 shows a case where the foreign material is a 10 won coin
  • FIG. 22 shows an experimental result when the foreign matter is a 500 won coin.
  • the graph shown in FIG. 21 shows that the amount of change in the coil current and the inverter input current at the first ping transmission point when the foreign material is not located in the charging region is several tens of mA, but at the second ping transmission point when the foreign material is located in the charging region.
  • the change in coil current and inverter input current shows several hundred mA.
  • the amount of change in the coil current and the inverter input current at the second ping transmission point in which the foreign material is located in the charging region is thousands of mA.
  • FIG. 23 is a flowchart illustrating a foreign material detection method in a power transmission step according to an embodiment of the present invention.
  • the wireless power transmitter may control the strength of the transmitted power based on a power control feedback packet received from the wireless power receiver and a preset power control algorithm (S2301). .
  • the wireless power transmitter may be a fixed frequency method having a fixed operating frequency, and configured to support an amplitude control method for controlling the intensity of the output power through voltage regulation.
  • the intensity of the output power may be controlled by adjusting the inverter input voltage V_rail value according to the power control feedback packet.
  • the range of the voltage to be adjusted is 0V ⁇ 12V, the minimum control unit may be 10mV, but is not limited thereto.
  • the apparatus for transmitting power may determine whether transmission power is stabilized (2302). For example, the wireless power transmission apparatus reaches a predetermined target voltage (or) and a target current through a transmission signal control based on a feedback signal received from the wireless power receiver, which may be, for example, a CEP (Correction Error Packet).
  • the transmission power may be determined to be stabilized, but is not limited thereto.
  • the apparatus for transmitting power wirelessly may determine that the output power is stabilized when the intensity change amount for a predetermined unit time with respect to at least one of the inverter input voltage and the inverter input current is equal to or less than a predetermined reference value.
  • the wireless power transmitter may determine that the transmission power is stabilized when the intensity of the voltage / current / power that is adjusted and transmitted according to the power control feedback signal is within a predetermined reference range.
  • the strength of the voltage / current / power may be measured in an inverter or an LC circuit, but is not limited thereto.
  • the wireless power transmitter may calculate the reference current / voltage ratio Reference_I / V_rate by measuring the initial inverter input voltage Initial_V_rail and the initial transmission coil current Initial_I_coil (S2303 to S2304).
  • Reference_I / V_rate may be calculated by dividing Initial_I_coil by Initial_V_rail, but this is only one embodiment. Another example may be calculated by dividing Initial_I_coil by Initial_V_rail and multiplying by 100.
  • the apparatus for transmitting power wirelessly may calculate the current voltage / current ratio Current_I / V_rate by periodically measuring the current inverter input voltage Current_V_rail and the transmission coil current Current_I_coil (S2305).
  • Current_I / V_rate may be calculated by dividing Current_I_coil by Current_V_rail, but this is only one embodiment. Another example may be calculated by dividing Current_I_coil by Current_V_rail and multiplying by 100.
  • the apparatus for transmitting power wirelessly may calculate a change amount Delta_I / V of the current voltage / current ratio Current_I / V_rate to the reference current / voltage ratio Reference_I / V_rate.
  • Delta_I / V may be a value obtained by subtracting Reference_I / V_rate from Current_I / V_rate, but is not limited thereto.
  • the apparatus for transmitting power wirelessly may compare whether Delta_I / V is greater than the first reference value (S2307).
  • the wireless power transmitter may compare whether Delta_I / V is greater than the second reference value (S2308).
  • the second reference value is determined as a value larger than the first reference value, and may be a constant value for identifying whether the change in the inverter voltage and the transmission coil current is due to an alignment problem between the transmission and reception coils or a foreign matter located between the transmission and reception coils.
  • the wireless power transmitter may return to step 2305 if Delta_I / V is less than or equal to the first reference value.
  • the wireless power transmitter determines that Delta_I / V is less than or equal to the second reference value and is an alignment problem between the transmission and reception coils, and outputs a predetermined notification signal indicating that the alignment problem is detected. There is (S2309).
  • the wireless power transmission apparatus may determine that there is a foreign matter and may output a predetermined notification signal indicating that the foreign matter has been detected (S2310). .
  • FIG. 24 is a flowchart illustrating a foreign material detection method in a power transmission step according to another embodiment of the present invention.
  • the wireless power transmitter may perform power control based on the received power control feedback packet and a preset power control algorithm (S2401 to S2402).
  • the apparatus for transmitting power wirelessly may calculate an amount of change in intensity of the output power according to the power control.
  • the intensity change amount of the output power is applied to the intensity change amount of the current input to the inverter, the intensity change amount of the input voltage applied to the inverter, the intensity change amount of the power input to the inverter, the intensity change amount of the current flowing through the transmitting coil, and the both ends of the transmitting coil.
  • the wireless power transmitter measures the current inverter input voltage (Current_V_rail) strength and the current transmit coil current (Current_I_coil) strength to determine the current voltage / current ratio (Current_I / V_rate). It can be calculated (S2404).
  • the wireless power transmitter may determine the calculated current voltage / current ratio Current_I / V_rate as a new new reference voltage / current ratio (S2405).
  • the wireless power transmitter may detect the alignment problem and the foreign matter by calculating Delta_I / V of FIG. 23 based on the newly determined reference voltage / current ratio.
  • FIG. 25 is an experimental result table showing a ratio of a transmission coil current strength measured by a wireless power transmitter and an inverter input voltage strength according to the presence or absence of a foreign matter and an arrangement state of a transmission / reception coil according to the present invention.
  • the current / voltage ratio measured in a state in which the transmission and reception coils are not aligned and in a state in which foreign matter is present between the transceivers is measured in a state where there is no foreign matter. It has a large value compared to the current / voltage ratio.
  • the experimental result of FIG. 25 shows that the first to fourth receivers have a rising width of the current / voltage ratio measured in the presence of the foreign matter as compared with the current / voltage ratio measured in the state where the first to fourth receivers are aligned without the foreign matter. It shows a large relative to the rise of the measured current / voltage ratio in the unaligned state.
  • an I / V value measured in a state where the transmission / reception coils are aligned without foreign matters is 0.21, and an I / V measured in a state where the transmission / reception coils are not aligned.
  • the value is 0.23 and the I / V value measured in the presence of foreign matter is 0.268.
  • the rising width 0.02 of the measured I / V value when the transmitting / receiving coil is not aligned with respect to the I / V value measured when the transmitting / receiving coil is not aligned with the foreign material is measured. It can be seen that the relative increase is relatively small compared to 0.058. Accordingly, when the first reference value to the second reference value of FIG.
  • the first reference value and the second reference value may be determined to be 0.02 and 0.04, respectively, but are not limited thereto. It should be noted that the first reference value and the second reference value may be applied to different values based on experimental result values for the corresponding products.
  • FIG. 26 is a table showing experimental results of the inverter input voltage and the transmitter coil current measured according to the presence of foreign matter and the position of the wireless power receiver on the charging region.
  • an inverter input voltage value and a transmission coil current value measured according to which position of the chargeable area 2603 is located may be different. Can be.
  • the inverter input voltage (V_rail) value and the transmit coil current (I_coil) value are measured to be lowest at the second position (center) where the alignment between the transmission and reception coils is the best, that is, the position where the coupling coefficient is the most. It can be seen that.
  • the coupling coefficient when the coupling coefficient is bad, it can be seen that the rising width of the V_rail value is relatively larger than that of the I_coil. In other words, it can be seen that the limit of the rise of I_coil exists.
  • the coupling coefficient between the transmitting and receiving coils may worsen as the Z-distance between the transmitting coil receiving coils increases or the separation distance from the center of the transmitting coil to the X axis and / or Y axis increases. Can be.
  • the inverter input voltage value and the transmission coil current value measured in the state where the foreign matter 2604 exists between the wireless power transmitter and the wireless power receiver 2602 at the second position It can be seen that it is larger than the measured values in the absence of foreign matter at the same position.
  • the V_rail value and the I_Coil value for the receiver A measured at the second position (center) in the absence of foreign matter are 5700 mV and 1180 mA, respectively.
  • the V_rail and I_coil values for receiver A measured at the second position (center) in the presence of the material are 8370mV and 2320mA, respectively. In other words, when foreign matter is present in the charging region, V_rail and I_coil are rapidly raised.
  • FIG. 27 is a block diagram illustrating a structure of a foreign substance detection apparatus according to an embodiment of the present invention.
  • the foreign matter detection device 2700 may include a communication unit 2710, a sensing unit 2720, a current / voltage ratio calculator 2730, a reference current / voltage ratio determiner 2740, a detector 2750, It may be configured to include an alarm unit 2760 and the control unit 2770.
  • the foreign matter detection apparatus 2700 according to an embodiment of the present invention may be mounted or mounted on the wireless power transmitter, and may be operated in cooperation with other components included in the wireless power transmitter.
  • the communication unit 2710 may perform communication with a wireless power receiver.
  • in-band communication may be used, but the present invention is not limited thereto, and it should be noted that out-of-band communication may be used using a frequency different from an operating frequency used for wireless power transmission.
  • the out-of-band communication may include short range wireless communication such as low power Bluetooth communication.
  • the sensing unit 2720 may measure the strength of the voltage or (and) current or (and) power input to the inverter. In addition, the sensing unit 2710 may measure the intensity of the current flowing through the inductor of the LC circuit.
  • the current / voltage ratio calculator 2730 may calculate the current / voltage ratio based on the current I_coil flowing through the inductor and the voltage V_rail input to the inverter.
  • the reference current / voltage ratio determiner 2740 may determine a reference current / voltage ratio to be used for foreign material detection according to the control signal of the controller 2770. For example, the reference current / voltage ratio determiner 2740 may determine the current / voltage ratio as the reference current / voltage ratio at the time when the transmission power is stabilized after entering the power transmission step. In addition, the reference current / voltage ratio determiner 2740 is measured when the intensity of the transmission power is changed according to the power control feedback signal (for example, may be a CEP signal of the WPC standard), when the intensity of the transmission power is changed The current / voltage ratio may be determined as the new reference current / voltage ratio.
  • the power control feedback signal for example, may be a CEP signal of the WPC standard
  • the detector 2750 may determine whether foreign matter exists in the charging region based on the difference value Delta_I / V between the reference current / voltage ratio and the current current / voltage ratio in the power transmission step. As an example, the detector 2750 may determine that there is a foreign substance when Delta_I / V exceeds a predetermined second reference value. In addition, the detector 2750 may determine that there is an alignment problem between the transmission and reception coils when Delta_I / V is greater than or equal to the first predetermined reference value and less than or equal to the second reference value.
  • the second reference value is a value larger than the first reference value.
  • the alarm unit 2760 may output a predetermined alarm signal indicating that the foreign matter is detected in the charging area according to the determination result of the detection unit 2750. Also, when it is detected that there is an alignment problem between the transmission and reception coils, the alarm unit 2760 may output a predetermined alarm signal indicating that there is an alignment problem according to the determination result of the detection unit 2750.
  • the controller 2770 may control the overall operation of the foreign matter detection apparatus 2700.
  • the methods according to the embodiments described above may be stored in a computer-readable recording medium that is produced as a program for execution in a computer, and examples of the computer-readable recording medium may include ROM, RAM, CD-ROM, and magnetic tape. , Floppy disks, optical data storage devices, and the like.
  • the computer readable recording medium can be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.
  • functional programs, codes, and code segments for implementing the above-described method may be easily inferred by programmers in the art to which the embodiments belong.
  • the present invention can be used in the field of wireless charging, and in particular, it can be applied to devices and systems for detecting foreign matter on the wireless charging system.

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Abstract

La présente invention concerne un procédé de détection d'objets étrangers, ainsi qu'un appareil et un système associés. Un procédé de détection d'objets étrangers dans un dispositif de transmission d'énergie sans fil selon un mode de réalisation de la présente invention peut comprendre les étapes consistant à : déterminer un rapport courant-tension de référence, lors de l'entrée dans une étape de transmission d'énergie ; calculer un rapport courant-tension actuel à des périodes prédéfinies ; et déterminer s'il existe un objet étranger, sur la base du rapport courant-tension actuel et du rapport courant-tension de référence. Par conséquent, la présente invention présente un avantage en ce qu'il est possible de détecter un objet étranger dans l'étape de transmission d'énergie.
PCT/KR2017/005146 2016-06-13 2017-05-18 Procédé de détection d'objets étrangers, ainsi qu'appareil et système associés WO2017217662A1 (fr)

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CN116762256A (zh) 2021-01-18 2023-09-15 三星电子株式会社 无线发射电力的电子装置、无线接收电力的无线电力接收装置及其操作方法
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