JP6904652B2 - Communication device of non-contact power supply device - Google Patents

Description

The present invention relates to a communication device of a non-contact power feeding device. That is, it relates to a communication device used in a non-contact power feeding device to transmit and receive power feeding information.

《Technical background》
For electric vehicles (EVs), electric vehicles, etc., a non-contact power supply device (WPT) that supplies power wirelessly without mechanical connection such as a cable has been developed and is widely used.
In the non-contact power supply device, based on the mutual induction action of electromagnetic induction, there is an air gap between the power transmission coil on the power transmission side connected to the high frequency power supply and the power reception coil on the power reception side connected to the battery, and they face each other in a non-contact manner. Positioned and powered.
Therefore, in the non-contact power feeding device, it is necessary that the power transmitting coil and the power receiving coil are positioned facing each other at the start of power feeding.

<< Conventional technology >>
By the way, in such a non-contact power feeding device, a communication device is used. Communication devices are provided in pairs on the power transmission side and the power reception side to transmit and receive power supply information.
For example, power supply information such as a power supply instruction and required power is transmitted / received from a power receiving side of an electric vehicle or the like to a power transmitting side such as an external ground power supply stand by a communication device.

By the way, the power supply of such a communication device is as follows. First, on the power receiving side, it is not appropriate to use the battery to be supplied from now on as the power source for the communication device.
That is, on the power receiving side, the battery to be supplied with power from now on naturally has a residual capacity of zero in many cases, whereas the communication device starts up and operates even if the residual capacity of the battery is zero. It is not appropriate to use a battery as a power source because it is necessary to do so.
Starting and operating the communication device from a state where there is no power supply, such as when the remaining battery capacity is zero, is called a cold start. On the other hand, at the start of power supply, as described above, the power transmission coil and the power reception coil must be positioned facing each other, and the authentication is called the initial authentication of the power reception partner.

In order to be able to perform a cold start and to be able to perform initial authentication of the power receiving partner, some kind of passive detection means has been conventionally required prior to the start of power supply.
That is, in order to enable both the cold start of the communication device and the initial authentication of the power receiving partner that the power transmitting coil and the power receiving coil are positioned facing each other, a passive detection means on the power receiving side prior to the start of power supply. Was needed. There was a need for passive sensing means that did not require energy on the receiving side, that is, without active action.
For example, the passive detection means are as follows. For example, a wave generation source such as an electromagnetic wave, a sound wave, or light is arranged on the power transmission side, and a reflector that reflects the wave is arranged on the power reception side, or a magnetic sensor is arranged on the power transmission side, for example. At the same time, a method in which a ferromagnetic material such as iron or ferrite is arranged on the power receiving side and a magnetic sensor captures the strength or change of magnetism has been considered.
Then, by such a passive detection means, after the power receiving partner is initially authenticated, power supply is started, and transmission / reception of the communication device is carried out using the supplied battery as a power source.

Japanese Unexamined Patent Publication No. 2008-288889

<< Problems of conventional technology >>
By the way, the following problems have been pointed out as problems with the communication device of such a conventional non-contact power feeding device.
First, it has been pointed out that a passive detection means is required, which increases the cost.
That is, it has been pointed out that it is necessary to newly install a wave source, a magnetic sensor, etc. on the power transmission side and a reflector, a ferromagnet, etc. on the power reception side, and the equipment cost increases accordingly. ..
In addition, problems with reliability have been pointed out due to various ambient noises.
That is, since the passive detection means uses electromagnetic waves, sound waves, light, magnetism, etc., noise, errors, obstacles, etc. are likely to occur due to the influence of the surrounding electromagnetic environment, sound source, light source, etc., and the operation is stable. Problems were pointed out in terms of sex and reliability.
Incidentally, as a conventional example of a communication device of a non-contact power feeding device, for example, the above-mentioned Patent Document 1 can be mentioned.
However, as described above, since such a conventional communication device cannot be cold-started as it is, initial authentication cannot be performed. That is, when the remaining battery capacity on the power receiving side was zero, it could not be started up and operated, and the initial authentication of the confrontation positioning of the power transmission coil and the power receiving coil was impossible.
Therefore, a cold start can be performed and the initial authentication of the receiving party becomes possible. The advent of communication devices has long been coveted.

<< About the present invention >>
In view of such circumstances, the communication device of the non-contact power feeding device of the present invention has been made to solve the above-mentioned problems of the prior art.
The present invention proposes a communication device for a non-contact power supply device, which can firstly perform cold start and initial authentication of a power receiving partner, and secondly, realize these in excellent cost and reliability. The purpose is to do.

<< About each claim >>
As described in claim 1, the technical means of the present invention for solving such a problem is as follows.
This communication device is used in a non-contact power supply device.
The non-contact power feeding device has an air gap in the power feeding stage from the power transmitting coil on the power transmitting side connected to the high frequency power supply to the power receiving coil on the power receiving side connected to the load battery based on the mutual induction action of electromagnetic induction. It is non-contact and close to each other to supply power.
The communication device is provided as a pair on the power transmission side and the power reception side to transmit and receive power supply information, and in the search stage prior to the power supply stage, initial authentication that the power transmission coil and the power reception coil are positioned facing each other. Information can be sent and received.
Then, this initial authentication information is obtained based on the fact that a minute magnetic field is formed around the power transmission coil and the power receiving coil is within the range of the minute magnetic field in the search stage.

In the power transmission coil, the minute magnetic field is formed around the search stage by the search current, which is a minute exciting current that is significantly reduced from the exciting current of the power feeding stage.
Then, when the power receiving coil is positioned confronting the power transmission coil in the search stage and enters the range of the minute magnetic field, induced power is generated based on the mutual induction action of electromagnetic induction.
In the search stage, the communication device on the power receiving side transmits initial authentication information based on the fact that the power is supplied by the induced power generated in the power receiving coil to start up and operate.
Then, based on this initial authentication information, the power transmission coil has a rated operating current whose exciting current is significantly higher than the search current of the search stage, and thus serves as a power feeding stage.

Then, in the power feeding stage, the operating frequency of the high frequency power supply is set to the constant voltage region frequency.
In the search stage, the operating frequency of the high-frequency power supply is set to a constant current region frequency different from the constant voltage region frequency of the power feeding stage. Therefore, the power supply voltage to the communication device on the power receiving side becomes higher than when the constant voltage region frequency is left as it is.
As a result, the fluctuation range of the power supply voltage to the communication device is narrowed.

<< About action >>
Since the present invention comprises such means, it is as follows.
(1) In this non-contact power feeding device, a search stage is performed prior to the power feeding stage.
(2) In the search stage, a minute exciting current is applied to the power transmission coil, thereby forming a minute magnetic field around it.
(3) Then, when the power receiving coil is positioned opposite to the power transmission coil and enters the micromagnetic field range of the power transmission coil, induced power is generated in the power receiving coil based on the mutual induction action of electromagnetic induction.
(4) As a result, the communication device on the power receiving side is supplied with power, started up, and operated. Then, the initial authentication information indicating that the power receiving coil is confronted with the power transmitting coil is transmitted.
(5) From the search stage to the power supply stage, power is supplied from the power transmission coil to the power reception coil based on the mutual induction action of electromagnetic induction.
(6) Since such a search stage is adopted prior to the power supply stage in the present invention, it is possible to perform a cold start of the communication device and initial authentication of the power receiving partner even if the battery remaining capacity on the power receiving side is zero. be.
(7) And the present invention realizes these without adopting or newly installing new equipment and configurations. Further, since a minute magnetic field is used, there is no possibility of being adversely affected by the surrounding electromagnetic environment or the like.
(8) The exciting current of the search stage is composed of a minute value that is significantly reduced as compared with the feeding stage. That is, the minute magnetic field generated by the power transmission coil is at a level that does not cause deterioration of the surrounding electromagnetic environment.
(9) The operating frequency of the high-frequency power supply on the power transmission side is set in the constant voltage region in the power supply stage, whereas it is set in the constant current region in the search stage where the exciting current is throttled, and the communication device on the power reception side. The power supply voltage to can be increased. As a result, the fluctuation range of the feed voltage becomes narrower, so that a general-purpose product can be used for the DC / DC converter of the communication device on the power receiving side.
(10) Therefore, the communication device of the non-contact power feeding device according to the present invention exerts the following effects.

<< First effect >>
First, cold start and initial authentication of the receiving party will be possible.
In the present invention, in the search stage prior to the power feeding stage, a minute magnetic field is formed around the power transmission coil, and when the power receiving coil is positioned facing each other and enters the minute magnetic field, an induced power is generated. Therefore, the communication device on the power receiving side is supplied with power, started up, operated, and the initial authentication information is transmitted and received.
As described above, the communication device of the present invention can be started up, operated, and cold-started without relying on the battery power even if the remaining battery capacity on the power receiving side is zero, and the power receiving coil is positioned confronting the power transmission coil. It is possible to send and receive the initial authentication information to that effect.
Unlike the communication device of this type of conventional non-contact power supply device described above, the cold start cannot be performed as it is, so that the situation where the initial authentication cannot be performed is solved.

<< Second effect >>
Secondly, these are realized with excellent cost and reliability.
The present invention realizes the above-mentioned first effect based on forming a minute magnetic field around the power transmission coil by using a minute search current as an exciting current in the search stage prior to the feeding stage.
As in the conventional example of this type described above, the passive can be cold-started and the initial authentication of the receiving party can be performed without newly adopting or newly installing a detection means and other new equipment and configurations. Therefore, the equipment cost does not increase and the cost is excellent.
Further, since it is a method of forming a minute magnetic field, there is no problem in reliability due to various ambient noises unlike the above-mentioned method requiring a passive detection means of the conventional example. That is, it is not easily affected by the surrounding electromagnetic environment, sound source, light source, etc., noise, errors, obstacles, etc. are prevented from occurring, and it is excellent in stability and reliability. In addition, there is no risk of adversely affecting the surrounding electromagnetic environment or the like.
By changing the operating frequency between the constant voltage region and the constant current region of the high-frequency power supply on the power transmission side, the fluctuation range of the power supply voltage can be narrowed for the DC / DC power supply (DC / DC converter) of the communication device on the power reception side. , General-purpose products can be used, and it is excellent in terms of cost.
As described above, the effects exhibited by the present invention are remarkably great, such as solving all the problems existing in the prior art of this kind.

The communication device of the non-contact power feeding device according to the present invention will be described in a mode for carrying out the present invention. Then, (1) is a block diagram of an electric system, and (2) is an equivalent circuit diagram of a basic circuit. It is provided for the description of the embodiment for carrying out the present invention. (1) is a frequency characteristic diagram of the load voltage, and (2) is a frequency characteristic diagram of the output power. It is provided for the description of the embodiment for carrying out the present invention. (1) is a frequency characteristic diagram of the power transmission coil, and (2) is a side schematic view of the entire non-contact power feeding device.

Hereinafter, the present invention will be described with reference to the drawings.
<< Outline of the present invention >>
First, the outline of the present invention is as follows.
The communication device 1 of the present invention is used in the non-contact power feeding device 2.
In the power feeding stage A, the non-contact power feeding device 2 has an air gap G between the power transmitting coil L1 on the power transmitting side and the power receiving coil L2 on the power receiving side, and positions the power in close proximity to each other based on the mutual induction action of electromagnetic induction. Supply.
The communication device 1 is provided as a pair on the power transmission side and the power reception side, and transmits / receives power supply information. Then, in the search stage B prior to the power feeding stage A, initial authentication information indicating that the power transmitting coil L1 and the power receiving coil L2 are confronted and positioned can be transmitted and received.
Then, this initial authentication is obtained based on the fact that the micro magnetic field D is formed around the power transmission coil L1 and the power receiving coil L2 is within the range of the micro magnetic field D in the search stage B.
In the power feeding stage A, the operating frequency of the high frequency power supply V1 is set to the constant voltage region frequency. In contrast search stage B, the operating frequency of the high frequency power source, the feeding stage to the constant voltage region frequency A is set to the constant current region frequencies differ, with and supply voltage to the power receiving side of the communication device 1 _2, constant It will be higher than if the voltage region frequency is left as it is.
Thus, as the range of variation of the supply voltage to the communication device 1 ₂ is narrowed.
The outline of the present invention is as described above. Hereinafter, the communication device 1 of the non-contact power feeding device 2 of the present invention will be described in more detail.

<< Non-contact power supply device 2, power supply stage A >>
First, as a premise of the present invention, the non-contact power feeding device (WPT) 2 will be generally described with reference to FIGS. 1 (2), 3 (2), and the like.
In the power supply stage A, the non-contact power supply device 2 receives power from the power transmission coil L1 of the power transmission side circuit 3 provided with the high frequency power supply V to the power reception side circuit 4 provided with the battery of the load resistance R2 based on the mutual induction action of electromagnetic induction. An air gap G exists in the coil L2, and power is supplied while being in close contact with each other.
Such a non-contact power feeding device 2 will be described in more detail. First, the power transmission side circuit 3 on the primary side is stationaryly arranged on the ground, road surface, floor surface, and other ground 6 sides in the power supply area such as the power supply stand 5.
On the other hand, the power receiving side circuit 4 on the secondary side is mounted on the electric vehicle (EV), the electric mobile vehicle (AGV), the vehicle 7 such as the electric vehicle, and other moving bodies, and the load resistance battery R2 is installed. I have. In the power supply stage A, the power transmission coil L1 of the power transmission side circuit 3 and the power reception coil L2 of the power reception side circuit 4 are located opposite to each other with a slight air gap G of, for example, about 100 mm to 150 mm.
As shown in the figure, a stop power supply system in which the power receiving coil L2 is stopped at a position facing the power transmission coil L1 from above or the like is typical. In the case of the stop power supply system, the power receiving coil L2 and the power transmitting coil L1 have a symmetrical structure that is paired vertically or the like. On the other hand, a mobile power feeding system is also possible in which the power receiving coil L2 feeds power while traveling on the power transmitting coil L1 at a low speed.

The power transmission coil L1 of the power transmission side circuit 3 is connected to the high frequency power supply V1, and the high frequency power supply V1 directs high frequency alternating current of, for example, several kHz to several tens of kHz to several hundreds of kHz toward the power transmission coil L1 as an exciting voltage and an exciting current. And energize.
The output from the power receiving coil L2 of the power receiving side circuit 4 is rectified and supplied to the battery R2, and the charged battery R2 drives the traveling motor 8 in the example of FIG. 3 (2). In FIG. 3 (2), 9 is a rectifier that converts alternating current into direct current, and 10 is an inverter that converts direct current into direct current.
In FIG. 1 (2), C1, L3, and C2 are compensation circuit elements for the power transmission coil L1, and C3 and C4 are compensation circuit elements for the power reception coil L2. That is, C1 and L3 are buntpass (lowpass) filters, and C2 is a parallel capacitor for resonance. C3 is a parallel capacitor for resonance, and C4 is a series capacitor for resonance.

The mutual induction action of electromagnetic induction is as follows. When power is supplied in the power supply stage A, induced power is generated in the power receiving coil L2 by forming a magnetic flux in the power transmission coil L1, and the power is supplied from the power transmission coil L1 to the power receiving coil L2.
That is, by applying and energizing the power transmission coil L1 from the high frequency power supply V1 as a power feeding AC, an exciting voltage and an exciting current are generated, a self-induced electromotive force is generated, a magnetic field is formed around the power transmission coil L1, and a magnetic flux is generated on the coil surface. It is formed in the direction perpendicular to it. Then, the formed magnetic flux penetrates and crosses the power receiving coil L2 to generate an induced power and induce a magnetic field.
Then, by utilizing the induced magnetic field, it is possible to supply electric power of several kW or more to several tens of kW to several hundred kW. A magnetic flux magnetic circuit, that is, a magnetic path, is formed between the magnetic flux magnetic circuit on the transmission coil L1 side and the magnetic flux magnetic circuit on the power receiving coil L2 side, and is magnetically coupled with a total coefficient k. In the non-contact power feeding device 2, non-contact power feeding is performed based on such mutual induction action of electromagnetic induction.
The general explanation of the non-contact power supply device 2 and the power supply stage is as described above.

<< About Search Stage B, etc. >>
The search stage B will be described with reference to FIG. 1 (1) and the like.
In the non-contact power feeding device 2 of the present invention, the search stage B is performed for a short time prior to the above-mentioned power feeding stage A.
In the search stage B, a minute magnetic field D is formed around the power transmission coil L1, and based on the fact that the power receiving coil L2 is within the range of this minute magnetic field D, initial authentication information is obtained and the communication device 1 is started up and operated. Then, the initial authentication information can be sent and received.

Such a search stage B will be described in more detail. First, in the power transmission coil L1, a minute magnetic field D is formed around the search stage B by a search current, that is, by a search current which is a minute exciting current significantly reduced from the exciting current of the power feeding stage A.
The search current settings are as shown in a and b below. The excitation voltage and search current of the search stage B are first determined by a. The electromagnetic field formed by the power transmission coil L1 on the power transmission side and radiated in space is set small so as to be below a level at which deterioration of the surrounding electromagnetic environment can be suppressed. That is, the exciting voltage, the exciting current, and the search current are suppressed to a level sufficient for the minute magnetic field D to be formed in the power transmission coil L1.
Along with this, b. The exciting voltage, exciting current, and search current of the search stage B are equal to or higher than the level at which the induced power generated by the power receiving coil L2 on the power receiving side can secure the operating power of the communication device 1 and can be taken out. Is set to.
That is, the exciting voltage, the exciting current, and the search current are set so as to secure at least a level at which the induced power to be generated correspondingly by the power receiving coil L2 is sufficient to start up and operate the communication device 1.
In the illustrated example, as shown in FIG. 3 (1), the search current, which is the exciting current of the search stage B, is set to about 5 A. On the other hand, the exciting current of the power feeding stage A is a rated operating current of about 50 A.

In the search stage B, such a search current is sent to the power transmission coil L1, and a minute magnetic field D is formed around the power transmission coil L1 by the minute power (see the right side of FIG. 1 (1)).
That is, first, in the initial stage of the search stage B, the power transmission coil L1 and the power reception coil L2 are not yet in close proximity to each other. That is, the power receiving coil L2 on the moving vehicle 7 side is in a state of searching in order to face the power transmission coil L1 fixed on the ground 6 side in close proximity.
Then, in the final stage of the search stage B, when the power receiving coil L2 approaches the power transmission coil L1 and is positioned confronting the power transmission coil L1, the result is as follows.
Since the power receiving coil L2 falls within the range of the minute magnetic field D of the power transmission coil L1, induced power is generated based on the mutual induction action of electromagnetic induction (center of FIG. 1 (1) and FIG. 3 (2). ) See the figure).
The search stage B etc. are as described above.

<< Communication device 1 etc. >>
Next, the communication device 1 will be described with reference to FIG. 1 (1) and the like.
The communication device 1 is used in such a non-contact power supply device 2, and is provided as a pair on the power transmission side and the power reception side to transmit and receive power supply information.
Then, in the search stage B prior to the power feeding stage A, power is supplied by the induced power generated in the power receiving coil L2 to start up and operate, so that the power transmitting coil L1 and the power receiving coil L2 are confronted and positioned. It is possible to send and receive the initial authentication information of the receiving party.

Such a communication device 1 will be described in more detail. The power transmission side communication device 1 ₁ is provided in the power transmission side circuit 3, and the power reception side communication device 1 ₂ is provided in the power reception side circuit 4, and the power transmission side antenna 11 ₁ and the power reception side antenna _{112 2} are attached, respectively. There is.
Communication device 1 ₂ of the power receiving side, in the search stage B as described above, the induced electric power generated in the power receiving coil L2, a rectifier 9 is powered is converted into DC power by the launched with, is activated. In the search stage B, the communication devices 1 and ₂ are fed and operated by the electric power from the power transmission coil L1, the power reception coil L2, and the rectifier 9. And sends an initial authentication information, to the communication device 1 ₁ of the power transmission.
The initial authentication information received by the communication device 1 on the power transmission side is input to the control unit 12. Therefore, an instruction signal is output from the control unit 12 to the high frequency power supply V1 to switch the power supply output of the high frequency power supply V1.
Then, the exciting current to the power transmission coil L1 is switched to the rated operating current that is significantly higher than the search current of the search stage B (see FIG. 3 (1)), so that the power supply stage A is formed.
That is, in the power feeding stage A, the exciting voltage of the high frequency power supply V1 is significantly raised in the power transmitting side circuit 3, so that the DC voltage after rectification by the rectifier 9 is made higher than the voltage of the battery R2 in the power receiving side circuit 4 to make the battery. Power supply to R2 is started. It fed simultaneously to the power receiving side of the communication device 1 _2.
The communication device 1 etc. are as described above.

<< About load voltage and backflow prevention diode 13 >>
Next, the load voltage, the backflow prevention diode 13, and the like will be described with reference to FIGS. 1 (1) and 2 (1) of FIG.
First, in the power supply stage A, the operating frequency of the high frequency power supply V1 of the power transmission side circuit 3 is set to the constant voltage region frequency.
Even if the resistance value of the load resistance R2 of the power receiving side circuit 4 changes from the rated value R2'to 8 times SR', it is set to a constant voltage region frequency that converges to almost the same load voltage value. NS. The output voltage of the rectifier 9 of the power receiving side circuit 4 and the load voltage on the load resistance R2 of a battery or the like substantially equivalent thereto are constant values.
On the other hand, in the search stage B, as described above, the exciting current (that is, the search current) and the exciting voltage from the high-frequency power supply V1 of the power transmission side circuit 3 are narrowed down to minute values. Therefore, the output voltage of the rectifier 9 of the power receiving side circuit 4 and the load voltage on the load resistor R2 are also lowered to the corresponding values.

Note in the search stage B, the load resistor R2, the input resistance of the DC / DC power supply for voltage conversion, which is attached to the power receiving side of the communication device 1 ₂ (DC / DC converter), will point.
That is, in the power receiving side circuit 4, a backflow prevention diode 13 is provided between the rectifier 9 and the battery which is the load resistance R2 of the power feeding stage A. When the relationship of the rectifier 9 output voltage Va <battery voltage Vb is established, the backflow prevention diode 13 is in a switch-off state and is not conducted when the search stage B is in the search stage B (as will be described later in the illustrated example, Va120V <Vb315V). ..
In the search stage B has, for the power receiving side circuit 4, the rectifier 9 in a state in which only the communication device 1 ₂ are connected, the load resistor R2, is considered input resistance of the communication device 1 ₂ and.
The load resistance and the backflow prevention diode 13 are as described above.

<< About frequency change >>
Next, the frequency change will be described with reference to FIG. 1 (1), FIG. 2 (1), FIG. 3 (1), and the like.
In the power feeding stage A, the operating frequency of the high frequency power supply V1 is set to the constant voltage region frequency. In contrast search stage B, the operating frequency of the high frequency power source, the feeding stage to the constant voltage region frequency A is set to the constant current region frequencies differ, with and supply voltage to the power receiving side of the communication device 1 _2, constant It will be higher than if the voltage region frequency is left as it is.
Thus, as the range of variation of the supply voltage to the communication device 1 ₂ is narrowed.

Such a frequency change will be described in more detail. FIG. 2 (1) is a frequency characteristic diagram of the load voltage on the load resistance R2 with the load resistance R2 as a parameter. Here, the resistance value of the load resistance R2 is drawn by eight curves in which the resistance value of the load resistance R2 is arithmetically changed from the rated value R2'to 8 times R2'.
The figure shows a state in which the exciting voltage of the high-frequency power supply V1 is narrowed down from the rated value of 100% for the power feeding stage A to 10% for the search stage B. As described above, the exciting current is also narrowed down from the rated operating current of about 50 A for the power supply stage A to about 5 A of the surge current for the search stage B in the illustrated example (see FIG. 3 (1)).

In the figure, with respect to the high-frequency power supply V1 of the power transmission side circuit 3, the excitation voltage to the power transmission coil L1 is set to the rated value of the power supply stage A while the operating frequency is assumed to be the above-mentioned constant voltage region frequency (85 kHz in the illustrated example). When the search stage B is narrowed down to 10% with respect to 100%, the result is as follows.
In this case, in the power receiving side circuit 4 of the search stage B, the output voltage of the rectifier 9 and the load voltage on the load resistor R2 are also reduced to 10%. Therefore, the load resistor R2 and a communication device 1 ₂ of the DC / DC power supply, the power supply voltage variation in a wide range corresponding is required and respond to.
In the illustrated example, the load voltage is 315V in the power feeding stage A in which the exciting voltage to the power transmission coil L1 is rated at 100%, whereas the load voltage is 31.5V in the search stage B in which the exciting voltage is 10%. Become. That is, it is necessary to deal with voltage fluctuations in a wide range of 100% to 10%, 315V to 31.5V.
As for the DC / DC power supply device capable of supporting such a wide range, it is difficult to obtain a general-purpose product.

On the other hand, in the present invention, for the search stage B, the operating frequency of the high frequency power supply V1 of the power transmission side circuit 3 is changed to the constant current region frequency.
That is, the operating frequency is different from the constant voltage region frequency of the feeding stage A (85 kHz in the illustrated example), and the constant current (search current of 5 A in the illustrated example) region frequency (105 kHz higher than 85 kHz in the illustrated example, but lower than 85 kHz. It is also possible with frequency). Therefore, it becomes as follows.
In this case, in the power receiving side circuit 4 of the search stage B, when the resistance value of the load resistance R2 is increased, the load voltage becomes higher accordingly than when the constant voltage region frequency described above is maintained. At the same time, as shown in FIG. 2 (2), the power that can be taken out by the load resistance R2 also increases (in the illustrated example, it increases to about 53 W).

In the present invention, thus, the power receiving side circuit 4 of the search stage B, the load resistor is R2 communication device 1 ₂ of the DC / DC power supply through a rectifier 9, if corresponding to the voltage variation in a narrower range It will be good.
In the illustrated example, the load voltage is 315V in the power feeding stage A in which the excitation voltage to the power transmission coil L1 is 100% of the rated value, whereas in the search stage B, the resistance value of the load resistance R2 is set to the rated value R2. When it is set to 8 · R2', which is 8 times as much as', a voltage of 120 V can be obtained. That is, it suffices to correspond to a narrow voltage fluctuation range of 100% to 38%, 315V to 120V.
A DC / DC power supply device that can handle such a narrow range is easily available as a general-purpose product.
The frequency change is as described above.

<< Action, etc. >>
The communication device 1 of the non-contact power feeding device 2 of the present invention is configured as described above. Therefore, it becomes as follows.
(1) In the non-contact power feeding device 2, the search stage B is performed prior to the power feeding stage A.

(2) In the search stage B, first, in the power transmission side circuit 3, a search current, which is a minute exciting current, is applied and energized to the power transmission coil L1, and a minute magnetic field D is formed around the power transmission coil L1 (FIG. FIG. 1 (1) See the right side of the figure)

(3) Then, in the search stage B, the power receiving coil L2 of the power receiving side circuit 4 on the vehicle 7 side is positioned opposite to the power transmitting coil L1 on the ground 6 side by the subsequent search, and is within the range of the minute magnetic field D by the power transmitting coil L2. Upon entering, induced power is generated for the power receiving coil L2 based on the mutual induction action of electromagnetic induction (see the center of FIG. 1 (1) and FIG. 3 (2)).

(4) Therefore, in the search stage B, the power receiving side circuit 4, the power receiving side of the communication device 1 _2, is powered by the induced power generated in the power receiving coil L2, up, is activated.
Have been, the power receiving coil L2 to the power transmission coil L1 initial authentication information of the power receiving party indicating that the opposed positioning, to the communication device 1 ₁ of the power transmission (see (1) Figure 1).

(5) Based on the transmission / reception of such initial authentication information, the process proceeds from the search stage B to the power supply stage A. And based on the mutual induction effect of electromagnetic induction from the power transmission coil L1 of the power transmission circuit 3, power to the power receiving coil L2 of the power receiving side circuit 4 is supplied, the battery R2 and communication device 1 ₂ is fed (in FIG. 1 (1) See Fig. 3 and Fig. 3 (2)).

(6) In the present invention, as described above, when the power receiving coil L2 enters the minute magnetic field D formed around the power transmission coil L1 in the search stage B, an induced power is formed and the communication device 1 on the power receiving side is formed. ₂ is started and activated, and initial authentication information is transmitted and received.
Since such a search stage B is adopted prior to the power supply stage A, cold start and initial authentication of the power receiving partner can be performed even if the battery remaining capacity on the power receiving side is zero.

(7) And the present invention realizes these without adopting or newly installing new equipment and configurations. That is, it is realized by using the high frequency power supply V1, the power transmission coil L1, the power receiving coil L2, the battery R2, the communication device 1, etc. that have been used so far as they are.
Further, since the method is such that a minute magnetic field D is formed, it is not easily affected by the surrounding electromagnetic environment, sound source, light source, etc., and noise, errors, obstacles, etc. are prevented from occurring. Furthermore, there is no risk of adversely affecting the surrounding electromagnetic environment.

(8) The exciting current is as follows. Compared to the exciting current of the feeding stage A (rated operating current of about 50A in the illustrated example), the search current, which is the exciting current of the search stage B, consists of a significantly reduced minute value (about 5A in the illustrated example). (See Fig. 3 (1)).
That is, the search current is set to a level or less at which the minute magnetic field (electromagnetic field) generated by the power transmission coil L1 does not cause deterioration of the surrounding electromagnetic environment. However, the induced power receiving coil L ₂ is launched the communication device 1 _2, or the level sufficient to allowed to operate, is set.

(9) The operating frequency of the high-frequency power supply V1 of the power transmission side circuit 3 is as follows. In the feeding stage A, the constant voltage region frequency (85 kHz in the illustrated example) is set, whereas in the search stage B, the constant current region frequency (105 kHz in the illustrated example) is set (FIG. 2 of the search stage B). (1) Figure, (2) Figure).
That is, the communication device 1 ₂ of the DC / DC power supply of the power receiving side (DC / DC converter) is between the feed stage A and the search stage B, it will correspond to the variation of the different power supply voltages.
At that time, the feed voltage of the search stage B in which the exciting current is narrowed can be further increased based on the constant current region frequency as described above.
As a result, the power supply stage A and the search stage B can handle fluctuations in the power supply voltage in a narrower range, and general-purpose products can be used for the DC / DC power supply device.
The operation and the like of the present invention are as described above.

A Power supply stage B Search stage C1 Compensation circuit element C2 Compensation circuit element C3 Compensation circuit element C4 Compensation circuit element D Micromagnetic field G Air gap L1 Transmission coil L2 Power reception coil L3 Compensation circuit element R2 Load resistance (battery)
R2'Rated value V1 High frequency power supply 1 Communication device 1 ₁ Communication device (power transmission side)
1 ₂ Communication device (power receiving side)
2 Non-contact power feeding device 3 Transmission side circuit 4 Power receiving side circuit 5 Power supply stand 6 Ground 7 Vehicle 8 Motor 9 Rectifier 10 Inverter 11 ₁ Transmission side antenna 11 ₂ Power receiving side antenna 12 Control unit 13 Backflow prevention diode

Claims (1)

A communication device used in a non-contact power supply device, which is connected to a load battery from a power transmission coil on the power transmission side connected to a high-frequency power source based on the mutual induction action of electromagnetic induction in the power supply stage. There is an air gap in the power receiving coil on the power receiving side, and it is located in close proximity to each other in a non-contact manner to supply power.
The communication device is provided as a pair on the power transmission side and the power reception side to transmit and receive power supply information, and in the search stage prior to the power supply stage, initial authentication that the power transmission coil and the power reception coil are positioned facing each other. Information can be sent and received,
This initial authentication information is obtained based on the fact that a minute magnetic field is formed around the power transmission coil and the power receiving coil is within the range of the minute magnetic field in the search stage.
In the power transmission coil, the minute magnetic field is formed around the search stage by the search current, which is a minute exciting current that is significantly reduced from the exciting current of the feeding stage.
When the power receiving coil is positioned confronting the power transmission coil in the search stage and enters the range of the minute magnetic field, induced power is generated based on the mutual induction action of electromagnetic induction.
In the search stage, the communication device on the power receiving side transmits initial authentication information based on the fact that the power is supplied by the induced power generated in the power receiving coil to start up and operate.
Based on this initial authentication information, the power transmission coil has a rated operating current whose exciting current is significantly higher than the search current of the search stage, and thus serves as a power feeding stage.
In the power supply stage, the operating frequency of the high frequency power supply is set to the constant voltage region frequency, and in the search stage, the operating frequency of the high frequency power supply is set to a constant current region frequency different from the constant voltage region frequency of the power supply stage. Therefore, the power supply voltage to the communication device on the power receiving side becomes higher than when the constant voltage region frequency is left as it is.
As a result, the fluctuation range of the feeding voltage to the communication device is narrowed, and the communication device of the non-contact power feeding device is characterized.

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