Wireless power transfer system, program, and control method

Abstract

At least one of the power transmitter circuit (400) and the power receiver circuit (500) is configured so that the output characteristic can be switched. A processing unit of the wireless power transfer system acquires information on the output characteristic of the power transmitter circuit (400) and information on the output characteristic of the power receiver circuit (500), and determines a combination of the output characteristic of the power receiver circuit (500) with respect to the output characteristic of the power transmitter circuit (400) based on the acquired information. Before power is supplied from the power transmitter coil (22) to the power receiver coil (102), the output characteristic of the power transmitter circuit (400) or the power receiver circuit (500), which is configured to switch an output characteristic, are switched to an output characteristic according to the determined combination.

Description

WIRELESS POWER TRANSFER SYSTEM, PROGRAM, AND CONTROL METHODCross Reference

[0001] This application is based on Japanese Application No. 2025-019558 filed on February 07, 2025, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a wireless power transfer system, a program, and a control method.

[0003] In the related art, as described in, for example, Patent Literature 1, a wireless power transfer system is known, which includes a power transmitter circuit having a power transmitter coil disposed in a travel road of a vehicle, and a power receiver circuit having a power receiver coil and provided in the vehicle, for performing wireless power transfer from the power transmitter coil to the power receiver coil.

[0004] JP2024-122073A

[0005] When the combination of the output characteristic of the power receiver circuit with respect to the output characteristic of the power transmitter circuit is not an appropriate combination, there is a concern that a problem may arise. For example, during wireless power transfer, there is a concern that a large current may flow from the power receiver circuit to the in-vehicle battery.

[0006] The main object of the present disclosure is to provide a wireless power transfer system, a program, and a control method enables to make the combination of an output characteristic of a power receiver circuit with respect to an output characteristic of a power transmitter circuit an appropriate combination.

[0007] According to an aspect of the present disclosure, a wireless power transfer system, in which one of a ground side device on a road and a vehicle side device on a vehicle is a power transmitter device including a power transmitter circuit including a power transmitter antenna and an other of the ground side device and the vehicle side device is a power receiver device including a power receiver circuit including a power receiver antenna, is for transmission of electric power in a wireless manner from the power transmitter antenna to the power receiver antenna. The wireless power transfer system comprises: the power transmitter device; the power receiver device; and at least one processing unit. At least one of the power transmitter circuit and the power receiver circuit is configured to switch an output characteristic. The at least one processing unit is configured to acquire information on an output characteristic of the power transmitter circuit and information on an output characteristic of the power receiver circuit, and determine, based on the acquired information, a combination of the output characteristic of the power receiver circuit with respect to the output characteristic of the power transmitter circuit. Before the power transmitter antenna supplies power to the power receiver antenna, the at least one of the power transmitter circuit and the power receiver circuit, which is capable of switching the output characteristic, is configured to switch the output characteristic to an output characteristic according to the determined combination.

[0008] This allows the combination of the output characteristic of the power receiver circuit with respect to the output characteristic of the power transmitter circuit to be an appropriate combination.

[0009] The drawings described herein are intended to illustrate selected embodiments, do not depict all possible embodiments, and are not intended to limit the scope of the present disclosure.FIG. 1 is an overall configuration diagram of a wireless power transfer system according to a first embodiment.FIG. 2 is an overall configuration diagram of the wireless power transfer system.FIG. 3 is a diagram showing a power transmitter device and a power receiver device.FIG. 4 is a diagram showing a configuration of wide-area wireless communication between the power transmitter device and a vehicle.FIG. 5 is a diagram showing an example of an appropriate combination of an SS-mode power transmitter circuit and an SS-mode power receiver circuit.FIG. 6 is a diagram showing an example of an appropriate combination of a Double-LCC mode power transmitter circuit and a Double-LCC mode power receiver circuit.FIG. 7 is a diagram showing an example of a case in which a combination of a power transmitter circuit and a power receiver circuit is not an appropriate combination.FIG. 8 is a flowchart of a process executed by the power receiver device, the power transmitter device, and a server.FIG. 9 is a flowchart of a process executed by the power receiver device.FIG. 10 is a diagram showing a case in which a vehicle is about to enter a power transfer lane.FIG. 11 is a diagram showing a case in which a vehicle is about to enter a power transfer lane.FIG. 12 is a flowchart of a process executed by the power receiver device.FIG. 13 is a configuration diagram of the power receiver device.FIG. 14 is a configuration diagram of the power receiver device.FIG. 15 is a configuration diagram of the power receiver device.FIG. 16 is a configuration diagram of the power receiver device.FIG. 17 is a configuration diagram of the power receiver device.FIG. 18 is a configuration diagram of the power receiver device.FIG. 19 is a configuration diagram of the power receiver device.FIG. 20 is a flowchart of a process executed by a power receiver device, a power transmitter device, and a server according to a second embodiment.FIG. 21 is a flowchart of a process executed by the power transmitter device.FIG. 22 is a diagram showing a case in which power is supplied to first and second vehicles in a wireless manner.FIG. 23 is a configuration diagram of the power transmitter device.FIG. 24 is a diagram showing an example of a case in which a combination of the power transmitter circuit and the power receiver circuit is switched to an appropriate combination.FIG. 25 is a configuration diagram of the power transmitter device.FIG. 26 is a configuration diagram of the power transmitter device.FIG. 27 is a configuration diagram of the power transmitter device.FIG. 28 is a configuration diagram of the power transmitter device.FIG. 29 is a configuration diagram of the power transmitter device.FIG. 30 is a configuration diagram of the power transmitter device.FIG. 31 is a configuration diagram of the power transmitter device.FIG. 32 is a diagram showing the power transmitter device and the power receiver device.FIG. 33 is a configuration diagram of the power transmitter device.FIG. 34 is a flowchart of a process executed by a power receiver device, a power transmitter device, and a server according to a third embodiment.FIG. 35 is a flowchart of a process executed by a power receiver device and a power transmitter device according to a fourth embodiment.FIG. 36 is a diagram showing an in-vehicle device according to a modification example of the fourth embodiment.FIG. 37 is a flowchart of a process executed by a power transmitter device and a power receiver device according to a fifth embodiment.FIG. 38 is a flowchart of a process executed by a power transmitter device and a power receiver device according to a sixth embodiment.FIG. 39 is a flowchart of a process executed by a power transmitter device and a power receiver device according to a seventh embodiment.FIG. 40 is a diagram showing a power transmitter device, a power receiver device, and a disable command unit according to an eighth embodiment.FIG. 41 is a diagram showing a disposition of power transmitter side coil units according to another embodiment.

[0010] Multiple embodiments will be described with reference to the drawings. In the multiple embodiments, functionally and / or structurally corresponding and / or related portions may be labeled with the same reference numerals or with reference numerals that differ in the hundredth or higher digits. For corresponding and / or related portions, reference may be made to the description of other embodiments.

[0011] <First Embodiment> A first embodiment of a wireless power transfer system according to the present disclosure will be described below with reference to the drawings.

[0012] First, the overall configuration of the wireless power transfer system will be described. As shown in FIGS. 1, 2 and 3, a wireless power transfer system 10 includes a power transmitter device 20 and a power receiver device 100. The power receiver device 100 is a vehicle side device, which is mounted on a vehicle 11, as a moving object traveling on a road RS. The vehicle 11 is, for example, an electric vehicle or a hybrid vehicle. While the vehicle 11 is traveling or stopped, power is supplied from the power transmitter device 20 to the power receiver device 100. The wireless power transfer system 10 performs wireless power transfer from the power transmitter device 20 to the power receiver device 100 by magnetic field resonant coupling (magnetic field resonance). The wireless power transfer system 10 is also called a dynamic wireless power transfer (D-WPT) system.

[0013] The power transmitter device 20 is a device on the ground side including a power transmitter side coil unit 21 and a power transmitter side power source unit 51 that supplies power to the power transmitter side coil unit 21. The power transmitter device 20 is, for example, a stationary device. The power transmitter side coil unit 21 is installed (for example, buried) on the road RS, a parking lot, or the like. The power transmitter side power source unit 51 is installed, for example, at the side of the road RS. The power transmitter side coil unit 21 is connected to a power transmitter side power source unit 51. The power transmitter side power source unit 51 is connected to an AC power source 15 and supplies AC power from the AC power source 15 to the power transmitter side coil unit 21. The AC power source 15 is, for example, a commercial power source. Multiple power transmitter side coil units 21 are disposed along the traffic lanes of the road RS. FIG. 2 shows an example in which four power transmitter side coil units 21 disposed side by side along the road RS are connected to one power transmitter side power source unit 51. In other words, one power transmitter side power source unit 51 is provided for each of four power transmitter side coil units 21.

[0014] The configuration is not limited to one power transmitter side power source unit 51 being provided for each of the multiple power transmitter side coil units 21, but may also be one power transmitter side power source unit 51 being provided for one power transmitter side coil unit 21.

[0015] The power transmitter side power source unit 51 includes a PFC circuit 61, an inverter 60, and a filter circuit 52. The PFC circuit 61 includes an AC-DC converter and is connected to the AC power source 15. The switching elements (for example, IGBTs or MOSFETs) provided in the PFC circuit 61 are switched and controlled to convert the AC power input from the AC power source 15 to DC power while improving the power factor of the AC power. In the present embodiment, the PFC circuit 61 functions as a DC voltage source.

[0016] The inverter 60 is connected to the PFC circuit 61. The DC power input from the PFC circuit 61 is converted to AC power by controlling the switching of the switching elements (for example, IGBTs or MOSFETs) S1H, S1L, S2H, S2L provided in the inverter 60.

[0017] The filter circuit 52 removes noise contained in the AC current input from the inverter 60, and supplies the AC current from which the noise has been removed to the power transmitter side coil unit 21. The filter circuit 52 is, for example, an LC filter including a coil and a capacitor. As the filter circuit 52, circuits of various configurations are used, specifically, for example, a T-type filter circuit is used.

[0018] The power transmitter side coil unit 21 includes a power transmitter coil 22 (corresponding to a "power transmitter antenna"), a power transmitter side resonant circuit 30, and a power transmitter side communication coil 40. The power transmitter side resonant circuit 30 supplies the AC power supplied from the filter circuit 52 to the power transmitter coil 22. As the power transmitter side resonant circuit 30, various well-known resonant circuits such as a circuit including a resonance capacitor can be used.

[0019] In the present embodiment, the inverter 60, the filter circuit 52 and the power transmitter side resonant circuit 30 constitute a power transmitter circuit 400.

[0020] The power receiver device 100 includes a power receiver side coil unit 101 and a power receiver side power source unit 181. The power receiver side coil unit 101 includes a power receiver coil 102 (corresponding to a "power receiver antenna"). The power receiver side coil unit 101 is provided at the bottom of the vehicle body of the vehicle 11. The power receiver side coil unit 101 is provided at the bottom of the vehicle body to face the ground surface. When the vehicle 11 travels on the road RS in which the power transmitter coil 22 is buried, the power transmitter coil 22 on the ground side and the power receiver coil 102 provided on the vehicle 11 face each other in a vertical direction.

[0021] The power receiver device 100 includes a power receiver side resonant circuit 140. The power receiver coil 102 is connected to the power receiver side resonant circuit 140. Power is transmitted to the power receiver coil 102 from the power transmitter coil 22. The power receiver coil 102 supplies the received power to the power receiver side resonant circuit 140. As the power receiver side resonant circuit 140, various well-known resonant circuits such as a circuit including a resonance capacitor can be used.

[0022] The power receiver device 100 includes a filter circuit 182, a rectifier circuit 200 that functions as an AC-DC converter circuit, and a smoothing capacitor 210. The filter circuit 182 removes noise contained in the AC current input from the power receiver side resonant circuit 140, and supplies the AC current from which the noise has been removed to the rectifier circuit 200. The filter circuit 182 of the present embodiment is, for example, an LC filter including a reactor and a capacitor.

[0023] The rectifier circuit 200 converts the input AC current into a DC current and outputs the DC current. The rectifier circuit 200 is, for example, a full-bridge circuit including semiconductor switching elements, or a diode rectifier circuit. A first end of the smoothing capacitor 210 is connected to a high potential side output terminal of the rectifier circuit 200. A second end of the smoothing capacitor 210 is connected to the low potential side output terminal of the rectifier circuit 200. The rectifier circuit 200 is also referred to as an electronic rectification box (ERB).

[0024] In the present embodiment, the power receiver side resonant circuit 140, the filter circuit 182, and the rectifier circuit 200 constitute a power receiver circuit 500.

[0025] The vehicle 11 includes a high-potential side main switch 301H, a low-potential side main switch 301L, and a high-voltage power storage battery 300 as a power storage unit. The high-potential side main switch 301H and the low-potential side main switch 301L are, for example, relays (specifically, mechanical relays). The high potential side output terminal of the rectifier circuit 200 is connected to the positive-electrode terminal of the high-voltage power storage battery 300 via the high-potential side main switch 301H. The low potential side output terminal of the rectifier circuit 200 is connected to the negative terminal of the high-voltage power storage battery 300 via the low-potential side main switch 301L. The high-voltage power storage battery 300 is a secondary battery that can be charged and discharged, and has a rated voltage of, for example, several hundred volts. The high-voltage power storage battery 300 is, for example, a lithium-ion power storage battery or a nickel-metal hydride power storage battery.

[0026] The vehicle 11 includes a travel inverter 310 and a rotary electric machine 320. The travel inverter 310 is a three-phase inverter, and is connected to the high-voltage power storage battery 300 via the high-potential side main switch 301H and the low-potential side main switch 301L. An armature winding of the rotary electric machine 320 is connected to the upper and lower arm switches constituting the travel inverter 310. With the high-potential side main switch 301H and the low-potential side main switch 301L turned on, the switching of the upper and lower arm switches of the travel inverter 310 is controlled such that the travel inverter 310 converts the DC power supplied from the high-voltage power storage battery 300 into AC power and supplies the AC power to the armature winding. Therefore, the rotor of the rotary electric machine 320 rotates, and wheels 12 (drive wheels) of the vehicle 11 rotate by the rotational power of the rotor. As a result, the vehicle 11 travels. In the present embodiment, the high-voltage power storage battery 300 and the travel inverter 310 correspond to "power transfer target devices".

[0027] The power transmitter side power source unit 51 constituting the power transmitter device 20 includes a power transmitter side control unit 70. The power transmitter side control unit 70 includes a power transmitter side control device 71. The power transmitter side control device 71 is an electronic control unit (ECU) that performs various controls of the power transmitter device 20, and includes a processor as hardware, a storage unit, and a communication bus that connects the processor and the storage unit.

[0028] The storage unit includes memory and storage as hardware. The memory is a storage device for storing data used in a process of the power transmitter side control device 71. The memory provides the processor with, for example, a working area for temporary use when the processor performs the process. The memory includes, for example, a ROM or a RAM. The storage is a storage device that stores various programs and data to be read and executed by the processor, and is a non-transitory tangible storage medium. The storage includes, for example, a HDD or a flash memory. The storage stores program information and the like for the process described below.

[0029] The power receiver side power source unit 181 constituting the power receiver device 100 includes a power receiver side control device 231. The power receiver side control device 231 is an ECU that performs various controls of the power receiver device 100, and includes a processor as hardware, a storage unit, and a communication bus that connects the processor and the storage unit.

[0030] The storage unit includes memory and storage as hardware. The memory is a storage device for storing data used in the process of the power receiver side control device 231. The memory provides the processor with, for example, a working area for temporary use when the processor performs the process. The memory includes, for example, a ROM or a RAM. The storage is a storage device that stores various programs and data to be read and executed by the processor, and is a non-transitory tangible storage medium. The storage includes, for example, a HDD or a flash memory. The storage stores program information and the like for the process described below.

[0031] The power transmitter side control device 71 controls the switching of the PFC circuit 61 and the inverter 60. A high-frequency AC voltage is applied to the power transmitter coil 22 by controlling the switching of the inverter 60. Therefore, a high-frequency current flows through the power transmitter coil 22, and a magnetic field for power transmission is generated in the power transmitter coil 22.

[0032] In the present embodiment, the power transmitter side control device 71 controls the switching of the inverter 60 so that the frequency of the high-frequency voltage applied to the power transmitter coil 22 becomes a first specified frequency (specifically, 85 kHz) that is equal to or higher than 10 kHz and equal to or lower than 100 GHz. The resonance frequencies of the power transmitter side resonant circuit 30 and the power receiver side resonant circuit 140 are set to the same frequency as the first specified frequency or to a frequency close to the first specified frequency.

[0033] When the magnetic field generated in the power transmitter coil 22 interlinks with the power receiver coil 102 of the vehicle 11, a high-frequency current that fluctuates with the frequency of the high-frequency current flowing through the power transmitter coil 22 flows through the power receiver coil 102. The high-frequency current flowing through the power receiver coil 102 is supplied to the rectifier circuit 200 via the power receiver side resonant circuit 140 and the filter circuit 182. The rectifier circuit 200 converts the supplied AC current into a DC current and outputs the DC current. When the high-potential side main switch 301H and the low-potential side main switch 301L are turned on, the output current of the rectifier circuit 200 is supplied to the high-voltage power storage battery 300 and the travel inverter 310.

[0034] The vehicle 11 includes a low-voltage power storage battery 302. The rated voltage of the low-voltage power storage battery 302 is lower than the rated voltage of the high-voltage power storage battery 300. The low-voltage power storage battery 302 is, for example, a lead power storage battery. When power is supplied from the low-voltage power storage battery 302 to the power receiver side control device 231, the power receiver side control device 231 becomes operable.

[0035] The power receiver device 100 and the power transmitter device 20 have a configuration for communication between the power receiver device 100 and the power transmitter device 20. In detail, the power receiver side coil unit 101 constituting the power receiver device 100 includes a power receiver side communication coil 170 (corresponding to a "power receiver side communication antenna"). The power receiver side control unit 230 includes a transmitter 240.

[0036] The power transmitter side coil unit 21 constituting the power transmitter device 20 includes the power transmitter side communication coil 40 (corresponding to a "power transmitter side communication antenna"). The power transmitter side control unit 70 includes a receiver 80. The power receiver side communication coil 170 and the power transmitter side communication coil 40 are communication coils for performing short-range wireless communication. The short-range wireless communication is communication with a communication distance of less than 10 meters (for example, a maximum of 3 meters). The short-range wireless communication has a shorter communication distance than wide-area wireless communication.

[0037] As the short-range wireless communication, various near field communication methods can be used, and for example, communication conforming to any communication standard defined by IEEE, ISO, IEC, or the like is used. Specifically, for example, Wi-Fi (registered trademark), Bluetooth (registered trademark), ZigBee (registered trademark), radio frequency identification (RFID), or dedicated short-range communication (DSRC) is used as the short-range wireless communication.

[0038] The transmitter 240 is connected to the power receiver side control device 231. The power receiver side communication coil 170 is connected to the transmitter 240. The power receiver side control device 231 controls the transmitter 240 to supply a power transfer request signal COMM to the power receiver side communication coil 170. The power transfer request signal COMM is a signal that requests the power transmitter coil 22 near the vehicle 11 to transmit power to the power receiver coil 102.

[0039] The power receiver side control unit 230 supplies the power receiver side communication coil 170 with a vehicle side signal including the power transfer request signal COMM in one frame. Therefore, a high-frequency voltage is applied from the transmitter 240 to the power receiver side communication coil 170. As a result, a high-frequency current flows through the power receiver side communication coil 170, and a magnetic field for information communication is generated in the power receiver side communication coil 170. In the present embodiment, the power transfer request signal includes ID information that identifies the vehicle 11 and a requested power Weq, which is the requested value of power to be supplied to the vehicle 11.

[0040] When the power receiver side coil unit 101 of the vehicle 11 is close to the power transmitter side coil unit 21 on the ground side, when the magnetic field generated from the power receiver side communication coil 170 interlinks with the power transmitter side communication coil 40, a high-frequency current flows in the power transmitter side communication coil 40. This high-frequency current is input to the receiver 80. The receiver 80 recognizes the presence or absence of a power transfer request and the ID information based on the input signal from the power transmitter side communication coil 40. The receiver 80 acquires the requested power Weq of the vehicle 11 having the recognized ID information based on the signal from the power transmitter side communication coil 40. The information recognized by the receiver 80 and the requested power Weq are input to the power transmitter side control device 71.

[0041] In the present embodiment, the power receiver side control device 231 controls the transmitter 240 so that the frequency of the high-frequency voltage applied to the power receiver side communication coil 170 becomes a second specified frequency that is equal to or higher than 10 kHz and equal to or lower than 100 GHz. In the present embodiment, the second specified frequency is a frequency that is shifted from the first specified frequency, and specifically, is a frequency that is higher than the first specified frequency (specifically, 13.56 MHz).

[0042] The power transmitter side control device 71 determines whether to energize the power transmitter coil 22 based on an input signal from the receiver 80. In detail, on condition that it is determined that there is a power transfer request based on an input signal from the receiver 80, the power transmitter side control device 71 applies a high-frequency voltage to the power transmitter coil 22 by controlling the switching of the inverter 60 and the PFC circuit 61.

[0043] In detail, when it is determined that there is no power transfer request, the power transmitter side control device 71 stops controlling the switching of the PFC circuit 61 and the inverter 60. Therefore, the switching elements of the PFC circuit 61 and the inverter 60 are maintained off and the power transmitter coil 22 is not energized.

[0044] On the other hand, when it is determined that there is a power transfer request, the power transmitter side control device 71 applies a high-frequency voltage to the power transmitter coil 22 by controlling the switching of the PFC circuit 61 and the inverter 60 for a predetermined period of time. Therefore, a high-frequency current flows through the power transmitter coil 22 for a predetermined period of time. In this case, power is supplied in a wireless manner from the power transmitter coil 22 to the power receiver coil 102 that faces the power transmitter coil 22 in the vertical direction. After energizing the power transmitter coil 22 for a predetermined period of time, the power transmitter side control device 71 does not energize the power transmitter coil 22 until it is determined that there is a next power transfer request.

[0045] The power transmitter side control device 71 performs frequency control when applying a high-frequency voltage to the power transmitter coil 22. The frequency control is a control for adjusting an effective power Wact supplied from the inverter 60 to the filter circuit 52 by adjusting a frequency fout of the output voltage from the inverter 60 to the filter circuit 52. The power transmitter side control device 71 alternately turns on a set of a first upper arm switch S1H and a second lower arm switch S2L and a set of a first lower arm switch S1L and a second upper arm switch S2H to adjust the frequency fout of the output voltage based on the requested power Weq.

[0046] FIG. 4 is a schematic diagram for illustrating wide-area wireless communication in the wireless power transfer system 10. In the wireless power transfer system 10, each vehicle 11 is capable of communicating with each power transmitter device 20 via a communication network 16. The communication network 16 includes, for example, a wide area network (WAN), which is a public communication network such as the Internet, a telephone communication network for mobile phones, an information and communication network for ETC, and an information and communication network for the vehicle information and communication system (VICS (registered trademark)). The wide-area wireless communication has a longer communication distance than short-range wireless communication. The wide-area wireless communication is communication with a communication distance of, for example, 10 meters to 10 kilometers. Examples of wide-area wireless communication that can be used include 3GPP (registered trademark), 4G, LTE, 5G, and WiMAX (registered trademark) defined by IEEE.

[0047] The vehicle 11 includes a position sensor 330, a navigation device 331, and a communication unit 332. The position sensor 330 is a sensor that detects the current position of the vehicle, and is, for example, a GPS sensor. The storage unit (for example, storage) of the navigation device 331 stores map information including road information. The navigation device 331 receives current position information of the vehicle detected by the position sensor 330 and weather information. The power transmitter side control unit 70 of the power transmitter device 20 includes a communication unit 90. The communication unit 332 of the vehicle 11 and the communication unit 90 of the power transmitter side control unit 70 perform wide-area wireless communication via the communication network 16.

[0048] The wireless power transfer system 10 includes a server 410. A server 410 is, for example, a cloud server, and includes a server control device 411 and a communication unit 412. The server control device 411 is an electronic control unit (ECU) that performs various controls of the server 410 and includes a processor as hardware, a storage unit, and a communication bus connecting the processor and storage unit. The storage unit includes memory and storage as hardware. The memory is a storage device for storing data used in the process of the server control device 411. The memory provides the processor with, for example, a working area for temporary use when the processor performs the process. The memory includes, for example, a ROM or a RAM. The storage is a storage device that stores various programs and data to be read and executed by the processor, and is a non-transitory tangible storage medium. The storage includes, for example, a HDD or a flash memory. The storage stores program information and the like for the process described below.

[0049] The server control device 411 is connected to the communication unit 412. The server control device 411 performs wide-area wireless communication with the communication unit 332 of the vehicle 11 and the communication unit 90 of the power transmitter side control unit 70 via the communication unit 412 and the communication network 16.

[0050] For example, program information stored in a non-transitory tangible storage medium is installed in the storage units of the power receiver side control device 231, the power transmitter side control device 71 and the server control device 411. The storage medium is, for example, a USB memory, a CD-ROM, or a DVD. For example, program information transmitted via a communication network 16, such as over the air (OTA), is installed in the storage unit.

[0051] The output characteristic of the power receiver circuit 500 and the output characteristic of the power transmitter circuit 400 requested by the power receiver circuit 500 will be described. The output characteristic indicates the characteristics of the current or voltage at which power is supplied to a power transmitting target (such as a power transfer target device) that is the power transfer destination. The output characteristic includes, for example, current source characteristics that supply power at a constant current to a power transmitting target, which is the power transfer destination, and voltage source characteristics that supply power at a constant voltage to a power transmitting target. Although some characteristics are in between the current source characteristics and the voltage source characteristics, the characteristics are generally either close to the current source characteristics or close to the voltage source characteristics. In the present embodiment, current source characteristics and those having characteristics similar to the current source characteristics are collectively referred to as current source, and voltage source characteristics and those having characteristics similar to the voltage source characteristics are collectively referred to as voltage source.

[0052] By the way, the output characteristic can be identified by measuring the current and voltage while changing the load during power transfer. To identify the output characteristic of the power transmitter circuit 400, the current and voltage flowing from the power transmitter circuit 400 to the power transmitter coil 22 may be measured. The output characteristic of the power receiver circuit 500 can be identified by measuring the current and voltage flowing from the power transmitter circuit 400 to the high-voltage power storage battery 300. In some cases, the output characteristic can be identified from the circuit configuration. When the output characteristic of the power transmitter circuit 400 match the output characteristic of the power transmitter circuit 400 requested by the power receiver circuit 500, the combination of the power transmitter circuit 400 and the power receiver circuit 500 is appropriate, and the power receiver circuit 500 is compatible with the output characteristic of the power transmitter circuit 400. When the power receiver circuit 500 is compatible, the power receiver circuit 500 can receive power from the power transmitter circuit 400 appropriately.

[0053] Next, a combination of the output characteristic of the power receiver circuit 500 and the output characteristic of the power transmitter circuit 400 will be described. FIGS. 5 and 6 show examples of typical combinations.

[0054] FIG. 5 illustrates an example of an SS-mode wireless power transfer system. The power transmitter circuit 400 of this system includes a bandpass filter as the filter circuit 52. The bandpass filter includes a parallel capacitor 53A connected in parallel to the power transmitter coil 22, a series capacitor 53B connected in series to the power transmitter coil 22, and an inductor 53C connected in series to the series capacitor 53B. The power transmitter circuit 400 also includes two series capacitors 23 as the power transmitter side resonant circuit 30. A first end of each series capacitor 23 is connected to one end of power transmitter coil 22. A second end of each series capacitor 23 is connected by the parallel capacitor 53A of the bandpass filter. In the present embodiment, the output characteristic of the power transmitter circuit 400 refer to the combined output characteristic of the inverter 60, the filter circuit 52, the power transmitter side resonant circuit 30, and the power transmitter coil 22. In the present embodiment, the output characteristic of the power transmitter circuit 400 refer to the output characteristic from the power transmitter side resonant circuit 30 side when viewed from the power transmitter coil 22.

[0055] The power receiver circuit 500 of an SS-mode wireless power transfer system includes a bandpass filter as the filter circuit 182. The bandpass filter includes a parallel capacitor 183A connected in parallel to the power receiver coil 102, a series capacitor 183B connected in series to the power receiver coil 102, and an inductor 183C connected in series to the series capacitor 183B. The power receiver circuit 500 also includes two series capacitors 141 as the power receiver side resonant circuit 140. A first end of each series capacitor 141 is connected to one end of power receiver coil 102. A second end of each series capacitor 141 is connected by a bandpass filter parallel capacitor 183A. In the present embodiment, the output characteristic of the power receiver circuit 500 refer to the combined output characteristic of the power receiver coil 102, the power receiver side resonant circuit 140, the filter circuit 182, and the rectifier circuit 200.

[0056] In the SS mode wireless power transfer system, power is supplied to the inverter 60 from the PFC circuit 61, which functions as a voltage source, and the switching is controlled so that the output characteristic become those of the voltage source as they are when viewed from the filter circuit 52.

[0057] The power transmitter side resonant circuit 30 only includes two series capacitors 23. Therefore, when the output characteristic from the filter circuit 52 becomes those of a voltage source, the output characteristic of the power transmitter side resonant circuit 30 becomes those of the voltage source when viewed from the power transmitter coil 22 at the power receiving end.

[0058] In the present embodiment, the power transmitter coil 22 and the power receiver coil 102 function as an immittance converting unit, and therefore, when viewed from the power receiver side resonant circuit 140 at the power receiving end, the output characteristic become those of a current source. Immittance conversion is an impedance-admittance conversion, which in the present embodiment, converts the power source to a voltage source when the power transmitting source is a current source and converts the power source to a current source when the power transmitting source is a voltage source. In the present embodiment, the power receiver side resonant circuit 140 only includes two series capacitors 141. Therefore, when the output characteristic of the power receiver coil 102 become those of a current source, the output characteristic of the power receiver side resonant circuit 140 become those of the current source when viewed from the filter circuit 182 at the power receiving end.

[0059] The filter circuit 182 does not have a function as an immittance converting unit, and therefore, when viewed from the rectifier circuit 200 at the power receiving end, the output characteristic of the filter circuit 182 become those of a current source. As a result, the output characteristic with respect to the rectifier circuit 200 and the high-voltage power storage battery 300 become those of a current source. In the present embodiment, the rectifier circuit 200 controls the switching so that its output characteristic with respect to the high-voltage power storage battery 300 are not converted. In other words, when viewed from the high-voltage power storage battery 300, the output characteristic of the rectifier circuit 200 become those of a current source.

[0060] In the present embodiment, the output characteristic of the power transmitter circuit 400 requested by the power receiver circuit 500 are the output characteristic of the power transmitter circuit 400 that can be appropriately received by the current power receiver circuit 500, and are determined by the circuit configuration of the power receiver circuit 500, the control by the power receiver side control device 231, and a power transfer target device from the power receiver circuit 500. When the high-voltage power storage battery 300 is charged, the high-voltage power storage battery 300 requests a current source as the output characteristic of a power transfer source, and the power receiver circuit 500 shown in FIG. 5 converts the output characteristic of the power transmitter circuit 400 to supply power to the high-voltage power storage battery 300. Therefore, the output characteristic of the power transmitter circuit 400 requested by the power receiver circuit 500 shown in FIG. 5 are those of a voltage source. Whether the power receiver circuit 500 converts the output characteristic of the power transmitter circuit 400 and supplies power to a power transfer target device (such as the high-voltage power storage battery 300) depends on the circuit configuration of the power receiver circuit 500 and the control content of the power receiver side control unit 230 on the power receiver circuit 500.

[0061] In FIG. 5, the power transmitter circuit 400 may not include the filter circuit 52, and the power receiver circuit 500 may not include the filter circuit 182.

[0062] FIG. 6 shows an example of a Double-LCC mode wireless power transfer system. The power transmitter circuit 400 in this system includes an immittance filter as the filter circuit 52. The immittance filter includes a first inductor 54A connected in series to the power transmitter coil 22, a second inductor 54C connected in series to the first inductor 54A, and a capacitor 54B. The capacitor 54B is connected to the connection point between the first inductor 54A and the second inductor 54C. The power transmitter circuit 400 also includes two series capacitors 23 as the power transmitter side resonant circuit 30, similar to that shown in FIG. 5.

[0063] The power receiver circuit 500 of a Double-LCC mode wireless power transfer system includes an immittance filter as the filter circuit 182. The immittance filter includes a first inductor 184A connected in series to the power receiver coil 102, a second inductor 184C connected in series to the first inductor 184A, and a capacitor 184B. The capacitor 184B is connected to the connection point between the first inductor 184A and the second inductor 184C. The power receiver circuit 500 also includes two series capacitors 141 as the power receiver side resonant circuit 140, similar to that shown in FIG. 5.

[0064] In the Double-LCC mode wireless power transfer system 10, the filter circuit 52 functions as an immittance converting unit. Therefore, when the inverter 60 serves as a voltage source, the output characteristic of the filter circuit 52 become those of a current source when viewed from the power transmitter side resonant circuit 30 at the power receiving end.

[0065] The power transmitter side resonant circuit 30 only includes two series capacitors 23. Therefore, when the output characteristic of the filter circuit 52 become those of a current source, the output characteristic from the power transmitter side resonant circuit 30 become those of a current source when viewed from the power transmitter coil 22 at the power receiving end.

[0066] In the present embodiment, the power transmitter coil 22 and the power receiver coil 102 function as an immittance converting unit. Therefore, when the power transmitter coil 22 and the power receiver coil 102 are viewed from the power receiver side resonant circuit 140 at the power receiving end, the output characteristic of the power receiver coil 102 become those of a voltage source. In the present embodiment, the power receiver side resonant circuit 140 only includes two series capacitors 141. Therefore, when the output characteristic of the power receiver coil 102 become those of a voltage source, the output characteristic of the power receiver side resonant circuit 140 become those of the voltage source when viewed from the filter circuit 182 at the power receiving end.

[0067] The filter circuit 182 has a function as an immittance converting unit, and therefore, when viewed from the rectifier circuit 200 at the power receiving end, the output characteristic from the filter circuit 182 become those of a current source. As a result, the power transfer for the rectifier circuit 200 and the high-voltage power storage battery 300 becomes those of a current source. The rectifier circuit 200 controls the switching so that the output characteristic of the high-voltage power storage battery 300 are not converted.

[0068] When the high-voltage power storage battery 300 is charged, the high-voltage power storage battery 300 requests a current source as a power transfer source, and the power receiver circuit 500 shown in FIG. 6 transmits the output characteristic of the power transmitter circuit 400 to the high-voltage power storage battery 300 as they are. Therefore, the output characteristic of the power transmitter circuit 400 requested by the power receiver circuit 500 shown in FIG. 6 are those of a current source.

[0069] In FIG. 6, the filter circuit 52 of the power transmitter circuit 400 does not need to be provided with the first inductor 54A on the power transmitter coil 22 side, and the function of the first inductor 54A may be substituted by the inductance of the power transmitter coil 22. The filter circuit 182 of the power receiver circuit 500 may not be provided with the first inductor 184A on the power receiver coil 102 side, and the function of the first inductor 184A may be substituted by the inductance of the power receiver coil 102.

[0070] As illustrated in FIGS. 5 and 6, when viewed from the high-voltage power storage battery 300, the output characteristic of the power receiver circuit 500 become those of a current source. On the other hand, there may be multiple specifications for the power transmitter circuit 400 available on the market. There may be multiple specifications for the power receiver circuit 500 available on the market. In this case, the combination of the output characteristic of the power receiver circuit 500 with the output characteristic of the power transmitter circuit 400 will no longer be an appropriate combination, and the output characteristic of the power transmitter circuit 400 requested by the power receiver circuit 500 may not match the output characteristic of the power transmitter circuit 400. FIG. 7 shows an example of an inappropriate combination in which the power transmitter circuit 400 is a Double-LCC mode circuit and the filter circuit 182 of the power receiver circuit 500 is a bandpass filter instead of an immittance filter.

[0071] In the case shown in FIG. 7, the output characteristic of the power transmitter circuit 400 are those of a current source, and the output characteristic of the power transmitter circuit 400 requested by the power receiver circuit 500 are those of a voltage source, so the combination is not appropriate. When the combination is not appropriate, the power source for the high-voltage power storage battery 300 becomes a voltage source, and there is a concern that a problem may arise. Specifically, when the output voltage of the rectifier circuit 200 is higher than that of the high-voltage power storage battery 300 during wireless power transfer, there is a concern that a large current will flow from the rectifier circuit 200 to the high-voltage power storage battery 300. When the output voltage of the rectifier circuit 200 is lower than that of the high-voltage power storage battery 300 during wireless power transfer, there is a concern that the rectifier circuit 200 may not be able to supply current to the high-voltage power storage battery 300.

[0072] To address this problem, the power receiver circuit 500 is configured to have switchable output characteristic. Before wireless power transfer is performed, the server 410 acquires information on the output characteristic of the power receiver circuit 500 and information on the output characteristic of the power transmitter circuit 400 provided in the vehicle 11, and based on information on the acquired output characteristic, instructs the power receiver side control device 231 to switch the output characteristic of the power receiver circuit 500.

[0073] FIG. 8 is a flowchart of a process executed by the server 410, the power receiver side control device 231 mounted on each vehicle 11, and the power transmitter side control device 71 of each power transmitter side power source unit 51.

[0074] In step S10, the power receiver side control device 231 transmits power receiver side information of the vehicle 11 on which the power receiver side control device 231 is mounted to the server 410 by wide-area wireless communication. The power receiver side information is information that includes power receiver side identification information that identifies the power receiver circuit 500 (specifically, vehicle ID information that identifies the vehicle on which the power receiver circuit 500 is mounted) and information associated with this power receiver side identification information, which is information on the output characteristic of the power receiver circuit 500.

[0075] In step S20, the server 410 receives the power receiver side information transmitted from the power receiver side control device 231.

[0076] In step S30, the power transmitter side control device 71 transmits power transmitter side information of the power transmitter circuit 400 that is the control target of the power transmitter side control device 71 to the server 410 by wide-area wireless communication. The power transmitter side information includes power transmitter side identification information that identifies the power transmitter circuit 400 and information associated with this power transmitter side identification information, which is information on the output characteristic of the power transmitter circuit 400.

[0077] In step S21, the server 410 receives the power transmitter side information transmitted from the power transmitter side control device 71. Every time the server 410 receives information transmitted from the power transmitter side control device 71 and the power receiver side control device 231, the power transmitter side information and the power receiver side information stored in the storage unit of the server 410 are updated.

[0078] In step S22, the server 410 determines a combination of the output characteristic of the power receiver circuit 500 with the output characteristic of the power transmitter circuit 400 based on the information on the output characteristic of the power receiver circuit 500 and the information on the output characteristic of the power transmitter circuit 400, which are received. Specifically, for example, the server 410 may determine a combination in which the number of immittance converting units included in the power receiver circuit 500 and the power transmitter circuit 400 is an odd number in total. For example, the server 410 may determine a combination based on the efficiency of power transmission from the power transmitter circuit 400 to the power receiver circuit 500 before and after the switching, or the adjustment range of the current and voltage.

[0079] In step S23, the server 410 transmits the information on the combination determined in step S22 to the power receiver side control device 231 by wide-area wireless communication, which is associated with the power transmitter side identification information received in step S21. With the information associated with the power transmitter side identification information, the vehicle 11 can grasp which of the many power transmitter side coil units 21 the vehicle 11 is about to pass over.

[0080] In step S11, the power receiver side control device 231 switches the output characteristic of the power receiver circuit 500 to output characteristic according to the determined combination based on the combination information and power transmitter side identification information, which are received. Specifically, the power receiver side control device 231 switches the output characteristic of the power receiver circuit 500 before the traveling vehicle 11 on which the power receiver side control device 231 is mounted is supplied with power in a wireless manner from the power transmitter coil 22 of the power transmitter circuit 400 identified by the received power transmitter side identification information.

[0081] FIG. 9 is a flowchart of a process executed by the power receiver side control device 231.

[0082] In step S40, the power receiver side control device 231 determines whether it is necessary to switch the output characteristic of the power receiver circuit 500 based on the combination information and the power transmitter side identification information received in step S11.

[0083] When it is determined that switching is not necessary, the power receiver side control device 231 leaves the output characteristic of the power receiver circuit 500 as they are. On the other hand, when it is determined that switching is necessary, the power receiver side control device 231 proceeds to step S41 and performs a switching process to switch the output characteristic of the power receiver circuit 500 to the output characteristic according to the combination information received in step S11.

[0084] In detail, the power receiver side control device 231 determines whether the vehicle is about to enter a target power transfer lane, for example, based on the power transmitter side identification information received in step S11 and the map information stored in the storage unit of the navigation device 331 (see FIG. 10). The target power transfer lane is a power transfer lane in which the power transmitter side coil unit 21 of the power transmitter circuit 400 identified by the received power transmitter side identification information is embedded. When it is determined that the vehicle is about to enter the target power transfer lane, the power receiver side control device 231 switches the output characteristic of the power receiver circuit 500 based on the combination information. This allows the output characteristic of the power receiver circuit 500 to be switched before the vehicle 11 enters the target power transfer lane.

[0085] The power receiver side control device 231 may determine whether the vehicle 11 is about to enter the target lane based on image information from an in-vehicle camera that captures images of the surroundings of the vehicle 11.

[0086] When a negative determination is made in step S40 or when the process of step S41 is completed, the power receiver side control device 231 proceeds to step S42 and transmits a vehicle side signal including vehicle ID information and information on the requested power Weq via short-range wireless communication using the power receiver side communication coil 170.

[0087] As shown in FIG. 11, when there is an (N+1)th target power transfer lane located away from an Nth target power transfer lane, the output characteristic of the power transmitter circuit 400 in the Nth target power transfer lane may differ from the output characteristic of the power transmitter circuit 400 in the (N+1)th target power transfer lane. In this case, after the vehicle 11 passes on the target power transfer lane of an Nth circuit, the output characteristic of the power receiver circuit 500 may be switched before the vehicle 11 enters the (N+1)th target power transfer lane.

[0088] As described above, in the present embodiment, information is collected in the server 410 by wide-area wireless communication, and a combination is determined in the server 410. Information on the determined combination is transmitted to the power receiver side control device 231 by wide-area wireless communication. Therefore, the power receiver side control device 231 can obtain the combination information in advance before the vehicle 11 enters the target power transfer lane. As a result, the power receiver side control device 231 can quickly switch the output characteristic of the power receiver circuit 500 in a situation in which the output characteristic should be switched.

[0089] The process shown in FIG. 9 can also be modified to the process shown in FIG. 12. FIG. 12 is a flowchart of a process executed by the power receiver side control device 231.

[0090] When a positive determination is made in step S40, the power receiver side control device 231 proceeds to step S43 and determines whether a first condition or a second condition is met before the vehicle 11 enters the target power transfer lane. The first condition is that the output characteristic of the power receiver circuit 500 cannot be switched to the output characteristic according to the received combination information. The second condition is that an abnormality related to wireless power transfer occurs. An abnormality related to wireless power transfer is, for example, an abnormality in a component of the power receiver circuit 500.

[0091] When it is determined that neither the first condition nor the second condition is met, the power receiver side control device 231 proceeds to step S41. On the other hand, when it is determined that the first condition or the second condition is met, the power receiver side control device 231 proceeds to step S44 and prohibits transmission of a vehicle side signal. This reduces the occurrence of a situation in which wireless power transfer is started when the combination of output characteristics of the power receiver circuit 500 and the power transmitter circuit 400 is not the combination received in step S11 of FIG. 8, or when an abnormality related to wireless power transfer occurs.

[0092] An example of the power receiver circuit 500 capable of switching output characteristic will now be described.

[0093] (A1) As shown in FIG. 13, in the power receiver circuit 500, a DC-DC converter 201 is provided between the rectifier circuit 200 and the high-voltage power storage battery 300. The DC-DC converter 201 is configured to transform the DC voltage input from the rectifier circuit 200 and output the transformed voltage to the high-voltage power storage battery 300. The DC-DC converter 201 is controlled by the power receiver side control device 231.

[0094] The power receiver side control device 231 adjusts the output voltage (for example, the output voltage effective value) of the DC-DC converter 201 in order to change the output characteristic of the power receiver circuit 500. For example, the power receiver side control device 231 adjusts the output voltage so that a constant current flows through the high-voltage power storage battery 300.

[0095] (A2) The output characteristic of the power receiver circuit 500 are changed by changing the control in the rectifier circuit 200 without providing the DC-DC converter 201. The power receiver side control device 231 switches the control of the rectifier circuit 200 from frequency control to duty control. For example, the power receiver side control device 231 adjusts the duty ratio so that a constant current flows through the high-voltage power storage battery 300.

[0096] (A3) The power receiver circuit 500 shown in FIG. 14 is a Double-LCC mode circuit. The power receiver circuit 500 includes a characteristic changeover switch SA. The characteristic changeover switch SA is a switch that cuts off the current flow through the bypass path that connects the output unit of the power receiver side resonant circuit 140 and the input unit of the rectifier circuit 200. When the characteristic changeover switch SA is turned off, the output unit of the power receiver side resonant circuit 140 and the input unit of the rectifier circuit 200 are connected via the filter circuit 182 (specifically, an immittance filter) that functions as an immittance converting unit. On the other hand, when the characteristic changeover switch SA is turned on, the output unit of the power receiver side resonant circuit 140 and the input unit of the rectifier circuit 200 are connected to each other without going through the filter circuit 182.

[0097] For example, the power receiver side control device 231 turns off the characteristic changeover switch SA in a normal state in which the power transmitter circuit 400 is a Double-LCC mode circuit. On the other hand, the power receiver side control device 231 switches the characteristic changeover switch SA on. When the characteristic changeover switch SA is turned on, the number of immittance converting units in the power receiver circuit 500 is reduced by one, and the output characteristic is changed.

[0098] (A4) The power receiver circuit 500 shown in FIG. 15 is an SS-mode circuit. The power receiver circuit 500 includes characteristic changeover switches SB connected in parallel to respective series capacitors 183B. When the characteristic changeover switch SB is turned off, the filter circuit 182 functions as a normal bandpass filter and does not function as an immittance converter. On the other hand, when the characteristic changeover switch SB is turned on, the series capacitor 183B is bypassed by a characteristic changeover switch SWB. As a result, the filter circuit 182 becomes an immittance filter and functions as an immittance converter. As a result, one more immittance converting unit is added to the power receiver circuit 500, and the output characteristic is changed.

[0099] For example, the power receiver side control device 231 turns off the characteristic changeover switch SB in a normal state in which the power transmitter circuit 400 is an SS-mode circuit. On the other hand, the power receiver side control device 231 turns on the characteristic changeover switch SB. As a result, the output characteristic is changed by the filter circuit 182, and as a result, when viewed from the high-voltage power storage battery 300, the output characteristic of the power receiver circuit 500 (rectifier circuit 200) become those of a current source.

[0100] According to the configuration shown in FIG. 15, the bandpass filter is effectively used to enable switching of the circuit system so that the number of elements to be added for changing the output characteristic can be reduced.

[0101] (A5) The power receiver circuit 500 shown in FIG. 16 is a Double-LCC mode circuit. In the configuration shown in FIG. 16, the capacitor 184B is referred to as a first capacitor 184B.

[0102] The filter circuit 182 includes a second capacitor 184D connected in parallel to the power receiver coil 102, and a characteristic changeover switch SC. The series connection of the second capacitor 184D and the characteristic changeover switch SC connects the power receiver side resonant circuit 140 side of both ends of each first inductor 184A.

[0103] For example, the power receiver side control device 231 turns off the characteristic changeover switch SC in a normal state in which the power transmitter circuit 400 is a Double-LCC mode circuit. On the other hand, the power receiver side control device 231 turns on the characteristic changeover switch SC. As a result, one more immittance converting unit is added to the power receiver circuit 500, and the output characteristic is no longer converted by the filter circuit 182. As a result, when viewed from the high-voltage power storage battery 300, the output characteristic of the power receiver circuit 500 (rectifier circuit 200) become those of a current source.

[0104] The characteristic changeover switch SC may be connected in series to the first capacitor 184B instead of the second capacitor 184D.

[0105] (A6) The power receiver circuit 500 shown in FIG. 17 is a Double-LCC mode circuit. The capacitance of the first capacitor 184B and the capacitance of the second capacitor 184D are the same. The power receiver circuit 500 includes a characteristic changeover switch SD. The series connection of the second capacitor 184D and the characteristic changeover switch SD connects the rectifier circuit 200 side of both ends of each first inductor 184A.

[0106] For example, the power receiver side control device 231 turns off the characteristic changeover switch SD in a normal state in which the power transmitter circuit 400 is a Double-LCC mode circuit. On the other hand, the power receiver side control device 231 turns on the characteristic changeover switch SD. As a result, one more immittance converting unit is added to the power receiver circuit 500, and the output characteristic is no longer converted by the filter circuit 182. As a result, when viewed from the high-voltage power storage battery 300, the output characteristic of the power receiver circuit 500 (rectifier circuit 200) become those of a current source.

[0107] (A7) The power receiver circuit 500 shown in FIG. 18 is configured to be switchable between an S-mode and a P mode. The power receiver side resonant circuit 140 includes a parallel capacitor 142, a first switch S1, and a second switch S2. The series connection of the parallel capacitor 142 and the first switch S1 is connected in parallel to the power receiver coil 102. The second switch S2 is connected in parallel to each series capacitor 141.

[0108] For example, in a normal state in which the power transmitter circuit 400 is the SS-mode circuit shown in FIG. 5, the power receiver side control device 231 turns off the first switch S1 and the second switch S2. On the other hand, when the first switch S1 and the second switch S2 are turned on, the power receiver side resonant circuit 140 is configured in the P mode in which the parallel capacitor 142 is connected in parallel to the power receiver coil 102. As a result, the output characteristic of the power receiver side resonant circuit 140 are changed, and the output characteristic of the power receiver circuit 500 become those of a current source.

[0109] (A8) In the power receiver circuit 500 shown in FIG. 19, a resonant coil 25 that resonates with the power receiver coil 102 is provided. The output characteristic of the power receiver circuit 500 are thus configured to be switchable. The power receiver circuit 500 includes a resonant coil 27 that is magnetically coupled to the power receiver coil 102, a sub-capacitor 28, and a switch SW. The series connection of the sub-capacitor 28 and the switch SW is connected in parallel to the resonant coil 27.

[0110] For example, in a normal state in which the power transmitter circuit 400 is the SS-mode circuit shown in FIG. 5, the power receiver side control device 231 turns off the switch SW. On the other hand, when the switch SW is turned on, a current flows through the closed circuit including the resonant coil 27 and the sub-capacitor 28, causing resonance with the power receiver coil 102. As a result, the output characteristic do not change between the power transmitter coil 22 and the power receiver coil 102. As a result, the output characteristic of the power receiver circuit 500 become those of a current source.

[0111] <Modification Example of First Embodiment> The power transmitter side control device 71 may transmit the power transmitter side information to the server 410 using, for example, road-to-vehicle communication or wired communication (for example, the wired Internet) instead of wide-area wireless communication.

[0112] <Second Embodiment> Hereinafter, a second embodiment will be described with reference to the drawings, focusing on differences from the first embodiment. In the present embodiment, the output characteristic of the power transmitter circuit 400 as well as the power receiver circuit 500 are configured to be switchable.

[0113] FIG. 20 is a flowchart of a process executed by the server 410, the power receiver side control device 231 mounted on each vehicle 11, and the power transmitter side control device 71 of each power transmitter side power source unit 51.

[0114] In step S24, the server 410 associates the information on the combination determined in step S22 with the power receiver side identification information and transmits the information to each power transmitter side control device 71 by wide-area wireless communication.

[0115] In step S31, the power transmitter side control device 71 receives the combination information associated with the power receiver side identification information.

[0116] FIG. 21 is a flowchart of a process executed by the power transmitter side control device 71.

[0117] In step S50, the power transmitter side control device 71 receives the vehicle side signal transmitted by short-range wireless communication.

[0118] In step S51, the power transmitter side control device 71 determines the output characteristic of the power transmitter circuit 400 according to the combination information based on the vehicle ID information contained in the received vehicle side signal and the power receiver side identification information and combination information received in step S31 of FIG. 20.

[0119] In step S52, the power transmitter side control device 71 determines whether it is necessary to switch the output characteristic of the power transmitter circuit 400 based on information on the current output characteristic of the power transmitter circuit 400 and the output characteristic determined in step S51.

[0120] When it is determined that switching is not necessary, the power transmitter side control device 71 leaves the output characteristic of the power transmitter circuit 400 as they are. On the other hand, when it is determined that switching is necessary, the power transmitter side control device 71 proceeds to step S53 and performs a switching process of switching the output characteristic of the power transmitter circuit 400 to the output characteristic determined in step S51.

[0121] When a negative determination is made in step S52 or when the process of step S53 is completed, the power transmitter side control device 71 proceeds to step S54 and determines whether there is a power transfer request based on the vehicle side signal received in step S50. When it is determined that there is a power transfer request, the power transmitter side control device 71 proceeds to step S55 and energizes the power transmitter coil 22. On the other hand, when it is determined that there is no power transfer request, the power transmitter side control device 71 proceeds to step S56 and stops the energization of the power transmitter coil 22.

[0122] Information is collected in the server 410 by wide-area wireless communication, and a combination is determined in the server 410. Information on the determined combination is transmitted to each power transmitter side control device 71 on the ground side by wide-area wireless communication. Therefore, the power transmitter side control device 71 can obtain the combination information in advance before the vehicle 11 enters the target power transfer lane. As a result, the power transmitter side control device 71 can quickly switch the output characteristic of the power transmitter circuit 400 in a situation in which the output characteristic should be switched.

[0123] As shown in FIG. 22, the power transmitter side control device 71 can combine the output characteristic of the power receiver circuit 500 of the first vehicle 11A traveling near the first unit 21A among the multiple power transmitter side coil units 21 arranged in a vehicle traveling direction with the output characteristic of the power transmitter circuit 400 provided in the first unit 21A according to the combination information. The power transmitter side control device 71 can combine the output characteristic of the power receiver circuit 500 of the second vehicle 11B traveling near a second unit 21B, which is different from the first unit 21A among the multiple power transmitter side coil units 21, with the output characteristic of the power transmitter circuit 400 provided in the second unit 21B according to the combination information. As a result, the combination of the output characteristic of the power receiver circuit 500 and the output characteristic of the power transmitter circuit 400 can be appropriately set for each of the vehicles 11A and 11B.

[0124] An example of the power transmitter circuit 400 capable of switching output characteristic will now be described.

[0125] (B1) The power transmitter circuit 400 shown in FIG. 23 is configured so that the circuit mode can be switched so that the number of immittance converting units included in the power receiver circuit 500 and the power transmitter circuit 400 is an odd number when wireless power transfer is performed. The power transmitter circuit 400 shown in FIG. 23 is a Double-LCC mode circuit.

[0126] The power transmitter circuit 400 includes a characteristic changeover switch SWA. The characteristic changeover switch SWA connects the output unit of the inverter 60 and the input unit of the power transmitter side resonant circuit 30. The output unit of the inverter 60 is specifically the source which is the low potential side terminal of the second upper arm switch S2H and the drain which is the high potential side terminal of the second lower arm switch S2L.

[0127] When the characteristic changeover switch SWA is turned off, the inverter 60 and the power transmitter side resonant circuit 30 are connected via the filter circuit 52 (specifically, an immittance filter) that functions as an immittance converting unit. On the other hand, when the characteristic changeover switch SWA is turned on, the inverter 60 and the power transmitter side resonant circuit 30 are connected to each other without passing through the filter circuit 52.

[0128] The power transmitter side control device 71 turns off the characteristic changeover switch SWA in a normal state in which the power receiver circuit 500 is a Double-LCC mode circuit. As a result, when wireless power transfer is performed, the number of immittance converting units included in the power receiver circuit 500 and the power transmitter circuit 400 becomes an odd number in total. By turning on the characteristic changeover switch SWA, an immittance filter is interposed between the inverter 60 and the power transmitter side resonant circuit 30. As a result, harmonics can be reduced.

[0129] On the other hand, when the characteristic changeover switch SWA is turned on, the filter circuit 52, which is an immittance filter, is bypassed, and the number of immittance converting units is reduced by one, as shown in FIG. 24. As a result, even when the power receiver circuit 500 is the circuit shown in FIG. 7, the total number of immittance converting units included in the power receiver circuit 500 and the power transmitter circuit 400 can be an odd number. Therefore, in the power receiver circuit 500, the power sources of the rectifier circuit 200 and the high-voltage power storage battery 300 can be used as current sources.

[0130] (B2) The power transmitter circuit 400 shown in FIG. 25 includes the characteristic changeover switch SWB that short-circuits the output unit of the filter circuit 52. The characteristic changeover switch SWB connects the power transmitter side resonant circuit 30 side of both ends of each first inductor 54A. When the characteristic changeover switch SWB is turned on, the number of immittance converting units in the power transmitter circuit 400 is reduced by one compared to when the characteristic changeover switch SWB is turned off.

[0131] (B3) The power transmitter circuit 400 shown in FIG. 26 is a SS-mode circuit. The power transmitter circuit 400 includes characteristic changeover switches SWC connected in parallel to respective series capacitors 53B.

[0132] When the characteristic changeover switch SWC is turned off, the filter circuit 52, which is a bandpass filter, does not function as an immittance converter, as shown in (A) of FIG. 26. On the other hand, when the characteristic changeover switch SWC is turned on, each parallel capacitor 53A is bypassed by the characteristic changeover switch SWC as shown in (B) of FIG. 26. As a result, the filter circuit 52 functions as an immittance converter. This increases the number of immittance converting units in the power transmitter circuit 400 by one. The power transmitter side control device 71 turns on or off the characteristic changeover switch SWC based on the output characteristic determined in step S51 of FIG. 21.

[0133] According to the configuration shown in FIG. 26, the bandpass filter is effectively used to enable switching of the circuit system so that the number of elements to be added for changing the output characteristic can be reduced.

[0134] (B4) The power transmitter circuit 400 shown in FIG. 27 is a Double-LCC mode circuit. In the embodiment shown in FIG. 27, the capacitor 54B is referred to as a first capacitor 54B.

[0135] The filter circuit 52 includes a second capacitor 54D connected in parallel to the power transmitter coil 22 and a characteristic changeover switch SWD. The series connection of the second capacitor 54D (corresponding to a "target capacitor") and the characteristic changeover switch SWD connects the power transmitter side resonant circuit 30 side of both ends of each first inductor 54A. The power transmitter side control device 71 turns on or off the characteristic changeover switch SWD based on the output characteristic determined in step S51. When the characteristic changeover switch SWD is turned on, the filter circuit 52 functions as a fourth-order filter.

[0136] When the characteristic changeover switch SWD is switched from off to on, the number of immittance converting units in the power transmitter circuit 400 is reduced by one, and the filter circuit 52 is switched from a current source to a voltage source.

[0137] The characteristic changeover switch SWD may be connected in series to the first capacitor 54B instead of the second capacitor 54D.

[0138] (B5) The power transmitter circuit 400 shown in FIG. 28 is a Double-LCC mode circuit. The capacitance of the first capacitor 54B and the capacitance of the second capacitor 54D are the same. The power transmitter circuit 400 includes a characteristic changeover switch SWE. The series connection of the second capacitor 54D and the characteristic changeover switch SWE connects the inverter 60 side of both ends of each first inductor 54A. The power transmitter side control device 71 turns on or off the characteristic changeover switch SWE based on the output characteristic determined in step S51.

[0139] When the characteristic changeover switch SWE is switched from off to on, the number of immittance converting units in the power transmitter circuit 400 is reduced by one, and the filter circuit 52 is switched from a current source to a voltage source.

[0140] (B6) The power transmitter side resonant circuit 30 of the power transmitter circuit 400 shown in FIG. 29 is configured so that it is possible to switch between having and not having an immittance converting function. The power transmitter side resonant circuit 30 includes a parallel capacitor 24, a first switch SW1, and a second switch SW2. The series connection of the parallel capacitor 24 and the first switch SW1 is connected in parallel to the power transmitter coil 22. The second switch SW2 is connected in parallel to each series capacitor 23. The power transmitter side control device 71 turns on or off the first switch SW1 and the second switch SW2 based on the output characteristic determined in step S51.

[0141] As shown in (A) of FIG. 29, when the first switch SW1 and the second switch SW2 are turned off, the power transmitter side resonant circuit 30 is set to the S mode in which each series capacitor 23 is connected in series to the power transmitter coil 22. On the other hand, as shown in (B) of FIG. 29, when the first switch SW1 and the second switch SW2 are turned on, the power transmitter side resonant circuit 30 is set to the P mode in which the parallel capacitor 24 is connected in parallel to the power transmitter coil 22. By using the P mode, it is possible to reduce the number of immittance converting units in the power transmitter circuit 400 by one compared to when the S mode is used.

[0142] (B7) The power transmitter side resonant circuit 30 of the power transmitter circuit 400 shown in FIG. 30 is configured so that it is possible to switch between having and not having an immittance converting function. The power transmitter side resonant circuit 30 includes a resonant coil 25 magnetically coupled to the power transmitter coil 22, a sub-capacitor 26, and a third switch SW3. The series connection of the sub-capacitor 26 and the third switch SW3 is connected in parallel to the resonant coil 25. The power transmitter side control device 71 turns on or off the first switch SW1, the second switch SW2, and the third switch SW3 based on the output characteristic determined in step S51.

[0143] As shown in (A) of FIG. 30, when the first switch SW1, the second switch SW2, and the third switch SW3 are turned off, the power transmitter side resonant circuit 30 is switched to the S mode and the closed circuit including the resonant coil 25 and the sub-capacitor 26 is cut off. On the other hand, as shown in (B) of FIG. 30, when the first switch SW1 and the second switch SW2 are turned on, the power transmitter side resonant circuit 30 is set to the P mode and the closed circuit is formed. This allows one more immittance converting unit to be added to the power transmitter circuit 400 compared to the case of (A) of FIG. 30.

[0144] (B8) As shown in FIG. 31, the output characteristic of the power transmitter circuit 400 can be switched by controlling the inverter 60 provided in the power transmitter circuit 400 without switching the circuit mode of the power transmitter circuit 400. The power transmitter side control device 71 switches the control of the inverter 60 from frequency control to duty control. In the duty control, a set of the first upper arm switch S1H and the second lower arm switch S2L and a set of the first lower arm switch S1L and the second upper arm switch S2H are alternately turned on at a predetermined switching period Tsw.

[0145] In duty control, the duty ratio (= Ton / Tsw), which is the ratio of the on period Ton of the set of the first upper arm switch S1H and the second lower arm switch S2L (or the set of the first lower arm switch S1L and the second upper arm switch S2H) to the switching period Tsw, is adjusted. The larger the duty ratio, the larger the effective power Wact output from the inverter 60 to the filter circuit 52.

[0146] (B9) As shown in FIG. 32, the power transmitter circuit 400 includes a DC-DC converter 62. The DC-DC converter 62 is connected to the PFC circuit 61. The DC-DC converter 62 transforms the DC voltage input from the PFC circuit 61 and outputs the transformed voltage to the inverter 60.

[0147] As a switching process, the power transmitter side control device 71 performs a process of controlling an output voltage Vout (specifically, the output voltage effective value) of the DC-DC converter 62 in order to adjust the effective power Wact output from the inverter 60 to the filter circuit 52, as shown in FIG. 33.

[0148] <Modification Example of Second Embodiment> The server 410 may transmit the combination information associated with the power receiver side identification information to each power transmitter side control device 71 using, for example, road-to-vehicle communication or wired communication (for example, the wired Internet) instead of wide-area wireless communication.

[0149] <Third Embodiment> Hereinafter, a third embodiment will be described with reference to the drawings, focusing on differences from the second embodiment. In the present embodiment, among the power transmitter circuit 400 and the power receiver circuit 500, only the power transmitter circuit 400 is configured to switch an output characteristic.

[0150] FIG. 34 is a flowchart of a process executed by the server 410, the power receiver side control device 231 mounted on each vehicle 11, and the power transmitter side control device 71 of each power transmitter side power source unit 51. The process of FIG. 34 does not include the processes of steps S23 and S11 of FIG. 20.

[0151] <Modification Example of Third Embodiment> The server 410 may transmit the combination information associated with the power receiver side identification information to each power transmitter side control device 71 using, for example, road-to-vehicle communication or wired communication (for example, the wired Internet) instead of wide-area wireless communication.

[0152] <Fourth Embodiment> Hereinafter, a fourth embodiment will be described with reference to the drawings, focusing on differences from the second embodiment. In the present embodiment, the combination information is determined not by the server 410 but by the power receiver side control device 231 of the vehicle 11. Among the power transmitter circuit 400 and the power receiver circuit 500, only the power receiver circuit 500 is configured to switch an output characteristic.

[0153] FIG. 35 is a flowchart of a process executed by the power receiver side control device 231 mounted on each vehicle 11 and the power transmitter side control device 71 of each power transmitter side power source unit 51.

[0154] In step S130, the power transmitter side control device 71 transmits the power transmitter side information of the power transmitter circuit 400 that is the control target of power transmitter side control device 71 to the power receiver side control device 231 of each vehicle 11 by wide-area wireless communication.

[0155] In step S100, the power receiver side control device 231 receives the power transmitter side information transmitted from the power transmitter side control device 71.

[0156] In step S101, the power receiver side control device 231 determines a combination of the output characteristic of the power receiver circuit 500 with the output characteristic of the power transmitter circuit 400 based on the received information on the output characteristic of the power transmitter circuit 400 and the information on the output characteristic of the power receiver circuit 500 that is the control target of the power receiver side control device 231. Specifically, for example, the server 410 may determine a combination in which the number of immittance converting units included in the power receiver circuit 500 and the power transmitter circuit 400 is an odd number in total. For example, the server 410 may determine a combination based on the efficiency of power transmission from the power transmitter circuit 400 to the power receiver circuit 500 before and after the switching, or the adjustment range of the current and voltage. Information on the determined combination is used in determining whether it is necessary to switch the output characteristic of the power receiver circuit 500 in step S40 of FIG. 9.

[0157] Information is collected in the power receiver side control device 231 by wide-area wireless communication, and the power receiver side control device 231 determines a combination. Therefore, the power receiver side control device 231 can obtain the combination information in advance before the vehicle 11 enters the target power transfer lane. As a result, the power receiver side control device 231 can quickly switch the output characteristic of the power receiver circuit 500 in a situation in which the output characteristic should be switched.

[0158] <Modification Example of Fourth Embodiment> The power receiver side control device 231 may acquire the power transmitter side information by the following method, instead of wide-area wireless communication.

[0159] (C1) The power receiver side control device 231 may use vehicle-to-vehicle communication to perform wireless communication between the vehicle 11 (the host vehicle) and other vehicles in the vicinity of the host vehicle 11. In detail, as shown in FIG. 36, the host vehicle 11 may be provided with a vehicle-to-vehicle communication unit 91 that acquires, from other vehicles by vehicle-to-vehicle communication, information acquired by the other vehicles, about the power transmitter side information of the power transmitter side coil unit 21 that the host vehicle 11 is scheduled to pass over next. The present invention is not limited to vehicle-to-vehicle communication, and wireless communication such as VICS (registered trademark), FM, or DSRC may also be used. The information is not limited to wireless communication, and for example, information from the navigation device 331 may be used.

[0160] (C2) The power receiver side control device 231 may acquire the power transmitter side information of the power transmitter side coil unit 21 that the host vehicle 11 is scheduled to pass over next from the power transmitter side control device 71 corresponding to this power transmitter side information by short-range wireless communication. In this case, the power receiver side control device 231 may transmit the acquired power transmitter side information from the host vehicle 11 in which the power receiver side control device 231 is provided to another vehicle, for example, by wide-area wireless communication or vehicle-to-vehicle communication. This allows the power transmitter side information to be shared among the vehicles.

[0161] (C3) The power receiver side control device 231 may be provided with a position information acquisition unit 92 that acquires current position information of the vehicle 11 using the position sensor 330 and acquires power transmitter side information of the power transmitter side coil unit 21 that the host vehicle 11 is scheduled to pass over next based on the acquired current position information. For example, the power transmitter side information associated with each current position information may be stored in a storage unit of the power receiver side control device 231, and the power receiver side control device 231 may read out the power transmitter side information based on the acquired current position information of the vehicle 11 and the information stored in the storage unit. The power receiver side control device 231 may acquire power transmitter side information corresponding to the acquired current position information of the vehicle 11 from the server 410 using wide-area wireless communication or the like.

[0162] (C4) The imaging device provided on the vehicle 11 captures images of road signs (for example, signs, bulletin boards, or electric bulletin boards that can change the display information) provided on the road RS on which the vehicle 11 passes, the road surface color of the road RS, letters and figures painted on the road RS, or unevenness formed on the road RS. The road sign, color, or unevenness is information associated with the power transmitter side information. The vehicle 11 may be provided with an image recognition unit 93 that performs image recognition on the captured sign information to acquire power transmitter side information of the power transmitter side coil unit 21 that the vehicle 11 is scheduled to pass over next. In other words, the power receiver side control device 231 may acquire the power transmitter side information displayed on the recognized sign, or may read out the power transmitter side information that is pre-stored in the storage unit in association with the sign information.

[0163] (C5) The vehicle 11 may be provided with a marker recognition unit 94. The marker recognition unit 94 recognizes markers provided on the road RS on which the vehicle 11 passes, and based on the recognized markers, acquires power transmitter side information of the power transmitter side coil unit 21 that the vehicle 11 is scheduled to pass over next. The marker recognition unit 94 may acquire the power transmitter side information by, for example, recognizing a signal (for example, an electrical signal, an optical signal, or a magnetic signal) emitted from a marker. In this case, the emitted signal may or may not directly include the power transmitter side information. When the power transmitter side information is not included, the marker recognition unit 94 may acquire information about the marker, such as the type of marker and position information, based on the signal emitted from the marker, and acquire power transmitter side information based on the acquired information about the marker.

[0164] The above methods (C1) to (C5) can be used in any of the following embodiments where applicable.

[0165] The above methods (C1) to (C5) may be used alone or in combination of two or more.

[0166] The acquired information may also be reflected in the road information of the navigation device 331.

[0167] <Fifth Embodiment> Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the fourth embodiment. In the present embodiment, the output characteristic of the power transmitter circuit 400 as well as the power receiver circuit 500 are configured to be switchable.

[0168] FIG. 37 is a flowchart of a process executed by the power receiver side control device 231 mounted on each vehicle 11 and the power transmitter side control device 71 of each power transmitter side power source unit 51.

[0169] After completing the process of step S101, in step S101, the power receiver side control device 231 associates the information of the combination determined in step S101 with the power receiver side identification information and transmits the information to each power transmitter side control device 71 by wide-area wireless communication.

[0170] In step S131, the power transmitter side control device 71 receives the combination information associated with the power receiver side identification information.

[0171] In the present embodiment, the process of step S51 in FIG. 21 is not executed. In step S52, the power transmitter side control device 71 uses the received combination information to determine whether it is necessary to switch the output characteristic of the power transmitter circuit 400.

[0172] <Modification Example of Fifth Embodiment> Among the power transmitter circuit 400 and the power receiver circuit 500, only the power transmitter circuit 400 may be configured to switch an output characteristic.

[0173] <Sixth Embodiment> Hereinafter, a sixth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment. In the present embodiment, the combination information is determined not by the server 410 but by the power transmitter side control device 71 on the ground side. Among the power transmitter circuit 400 and the power receiver circuit 500, only the power receiver circuit 500 is configured to switch an output characteristic.

[0174] FIG. 38 is a flowchart of a process executed by the power receiver side control device 231 mounted on each vehicle 11 and the power transmitter side control device 71 of each power transmitter side power source unit 51.

[0175] In step S200, the power receiver side control device 231 transmits power receiver side information of the vehicle 11 on which the power receiver side control device 231 is mounted to each power transmitter side control device 71 by wide-area wireless communication.

[0176] In step S230, the power transmitter side control device 71 receives the power receiver side information transmitted from the power receiver side control device 231.

[0177] In step S231, the power transmitter side control device 71 determines a combination of the output characteristic of the power receiver circuit 500 with the output characteristic of the power transmitter circuit 400 based on the received information on the output characteristic of the power receiver circuit 500 and the information on the output characteristic of the power transmitter circuit 400 that is the control target of the power transmitter side control device 71. Specifically, for example, the power transmitter side control device 71 determines a combination such that the number of immittance converting units included in the power receiver circuit 500 and the power transmitter circuit 400 is an odd number in total.

[0178] In step S232, the power transmitter side control device 71 associates the information on the combination determined in step S231 with the own power transmitter side identification information of the power transmitter side control device 71 and transmits the information to the power receiver side control device 231 by wide-area wireless communication.

[0179] In step S201, the power receiver side control device 231 receives the combination information and the power transmitter side identification information. The received combination information is used in step S40 of FIG. 9 to determine whether it is necessary to switch the output characteristic of the power receiver circuit 500.

[0180] Information is collected in the power transmitter side control device 71 by wide-area wireless communication, and the power transmitter side control device 71 determines a combination. Information on the determined combination is transmitted to the power receiver side control device 231 by wide-area wireless communication. Therefore, the power receiver side control device 231 can obtain the combination information in advance before the vehicle 11 enters the target power transfer lane. As a result, the power receiver side control device 231 can quickly switch the output characteristic of the power receiver circuit 500 in a situation in which the output characteristic should be switched.

[0181] <Modification Example of Sixth Embodiment> The output characteristic of the power transmitter circuit 400 may also be configured to be switchable. In this case, the power transmitter side control device 71 may use the received combination information in step S52 of FIG. 21 to determine whether it is necessary to switch the output characteristic of the power transmitter circuit 400. In this case, the process of step S51 is not executed.

[0182] <Seventh Embodiment> Hereinafter, a seventh embodiment will be described with reference to the drawings, focusing on differences from the sixth embodiment. In the present embodiment, among the power transmitter circuit 400 and the power receiver circuit 500, only the power transmitter circuit 400 is configured to switch an output characteristic.

[0183] FIG. 39 is a flowchart of a process executed by the power receiver side control device 231 mounted on each vehicle 11 and the power transmitter side control device 71 of each power transmitter side power source unit 51. The process of FIG. 39 does not include the process of step S201 of FIG. 38.

[0184] <Eighth Embodiment> Hereinafter, an eighth embodiment will be described with reference to the drawings focusing on differences from each of the above-described embodiments. The power transmitter side control device 71 shown in FIG. 40 has a first control function to control the switching (for example, the above-mentioned frequency control) of the inverter 60 so that the received power of the power receiver coil 102 becomes the requested power Weq. The power receiver side control device 231 also has a second control function to control the switching of the rectifier circuit 200 so that the received power of the power receiver coil 102 becomes the requested power Weq.

[0185] When the power transmitter coil 22 and the power receiver coil 102 are magnetically coupled, when both the first control function and the second control function are exerted, there is a concern that the controllability of the received power will decrease and the received power will deviate from the requested power Weq.

[0186] Therefore, the wireless power transfer system 10 includes a disable command unit 700 that disables either the first control function or the second control function. The disable command unit 700 transmits a disable command to either the power transmitter side control device 71 or the power receiver side control device 231. The disable command unit 700 may be provided in, for example, the server 410, the power transmitter side control device 71, or the power receiver side control device 231.

[0187] According to the present embodiment described above, it is possible to reduce the occurrence of a situation in which the controllability of received power is reduced.

[0188] <Other Embodiments> The above embodiments may be changed and carried out as follows.

[0189] The information on the output characteristic of the power receiver circuit 500 may be acquired by the following method, instead of the above-described method.

[0190] Code information (for example, a two-dimensional code such as a QR code (registered trademark)) associated with the output characteristic of the power receiver circuit 500 and the power receiver side identification information is attached in a position that can be seen from the outside of the vehicle 11. The imaging device provided in the wireless power transfer system 10 captures an image of the code information attached to the vehicle 11. The imaging device is provided as a device on the ground side. For example, the imaging device captures an image of the vehicle 11 passing through an entrance gate such as a toll booth. The imaging device transmits image information to, for example, the server 410 or each power transmitter side control device 71. The server 410 or the power transmitter side control device 71 acquires information on the output characteristic of the power receiver circuit 500 associated with the power receiver side identification information based on the received image information.

[0191] The present disclosure is not limited to travel roads such as ordinary roads or expressways without traffic lights, but can also be applied to roads including intersections, as shown in FIG. 41, for example. In FIG. 41, 600 indicates a center line and 601 indicates a crosswalk. FIG. 41 shows an example in which the power transmitter side coil unit 21 is provided just before a crosswalk 601 in a traffic lane.

[0192] The present disclosure can also be applied to a travel road located immediately adjacent to a parking space in which the power receiver side coil unit 101 is buried. In this case, for example, the combination determination process and the output characteristic switching process may be performed on the travel road leading to the parking space.

[0193] The present disclosure can also be applied to vehicles, such as large vehicles, that are provided with multiple power receiver coils. In this case, for example, among the power receiver circuits corresponding to the respective power receiver coils, the power receiver circuit having the highest power transmission efficiency in relation to the output characteristic of the power transmitter circuit may be used.

[0194] The wireless power transfer system may have a second function of supplying power in a wireless manner from a vehicle side device to a device on the ground side, in addition to a first function of supplying power in a wireless manner from a device on the ground side to a vehicle side device. In this case, the power receiver device 100 on the vehicle side has a power transmitting function in addition to a power receiving function. The power transmitter device 20 on the ground side has a power receiving function in addition to a power transmitting function. The second function will be described below with reference to FIG. 3.

[0195] The power receiver side control device 231 applies a high-frequency AC voltage to the power receiver coil 102 by controlling the switching of the rectifier circuit 200. Therefore, a high-frequency current flows through the power receiver coil 102, and a magnetic field for power transmission is generated in the power receiver coil 102.

[0196] When the magnetic field generated in the power receiver coil 102 interlinks with the power transmitter coil 22, a high-frequency current that fluctuates with the frequency of the high-frequency current flowing through the power receiver coil 102 flows through the power transmitter coil 22. The high-frequency current flowing through the power transmitter coil 22 is supplied to the AC power source 15 via the power transmitter side resonant circuit 30, the filter circuit 52, the inverter 60, and the PFC circuit 61. In this case, the power transmitter side control device 71 controls the switching of the inverter 60 and the PFC circuit 61.

[0197] In the wireless power transfer system having the second function, for example, the power transmitter device 20 may include a transmitter that supplies a power transfer request signal to the power transmitter side communication coil 40. The power receiver device 100 may include a receiver that receives the power transfer request signal received by the power receiver side communication coil 170 and inputs the signal to the power receiver side control device 231.

[0198] The wireless power transfer system may have a function of supplying power in a wireless manner from a vehicle side device to a device on the ground side, instead of the function of supplying power in a wireless manner from a device on the ground side to a vehicle side device.

[0199] The power receiver side communication antenna and the power transmitter side communication antenna are not limited to communication coils, and various antennas may be used. For example, the communication antenna is a dipole antenna or a monopole antenna.

[0200] The method of wireless power transfer by the power transmitter antenna and the power receiver antenna is not limited to the magnetic field resonance method, and may be an electric field coupling method. In this case, a power transmitter antenna and a power receiver antenna that are different in form from coils and that use an electric field coupling method may be used.

[0201] The power receiver side identification information of the vehicle used in the process of the above embodiments is not limited to vehicle ID information, and may be, for example, a token or credit card information of a vehicle user.

[0202] The vehicle on which the power receiver device 100 is mounted is not limited to a vehicle that travels on the road RS, and may be, for example, an automated guided vehicle (AGV) or a traveling robot. In this case, the power transmitter side coil unit 21 does not need to be buried in the road RS, but may be installed on a sidewalk adjacent to the road RS, in a parking lot, or on a route on which the AGV travels.

[0203] The control units and methods thereof described in the present disclosure may be implemented by a dedicated computer including a processor programmed to execute multiple functions embodied by a computer program and a memory. Alternatively, the control units and the methods thereof described in the present disclosure may be implemented by a dedicated computer including a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be implemented by one or more dedicated computers including a combination of a processor and a memory programmed to execute one or multiple functions and a processor including one or more hardware logic circuits. The computer program may be stored in a computer-readable non-transient tangible storage medium, as an instruction executed by a computer.

[0204] While the present disclosure has been described with reference to embodiments thereof, it is to be understood that the disclosure is not limited to the embodiments and constructions. To the contrary, the present disclosure is intended to cover various modification and equivalent arrangements. Furthermore, although various combinations and modes are described in the present disclosure, the scope and idea of the present disclosure further include other combinations and modes including only one element, more elements, or less elements in these.

Claims

1. A wireless power transfer system (10), in which one of a ground side device on a ground and a vehicle side device on a vehicle (11) is a power transmitter device (20) including a power transmitter circuit (400) including a power transmitter antenna (22) and an other of the ground side device and the vehicle side device is a power receiver device (100) including a power receiver circuit (500) including a power receiver antenna (102), for transmission of electric power in a wireless manner from the power transmitter antenna to the power receiver antenna, the wireless power transfer system comprising: the power transmitter device; the power receiver device; and at least one processing unit (410, 230, 70), wherein at least one of the power transmitter circuit and the power receiver circuit is configured to switch an output characteristic, the at least one processing unit is configured to acquire information on an output characteristic of the power transmitter circuit and information on an output characteristic of the power receiver circuit, and determine, based on the acquired information, a combination of the output characteristic of the power receiver circuit with respect to the output characteristic of the power transmitter circuit, and before the power transmitter antenna supplies power to the power receiver antenna, the at least one of the power transmitter circuit and the power receiver circuit, which is capable of switching the output characteristic, is configured to switch the output characteristic to an output characteristic according to the determined combination.

2. The wireless power transfer system according to claim 1, wherein the power receiver circuit is capable of switching the output characteristic, the wireless power transfer system further comprising: a server (410) including the at least one processing unit, wherein the power receiver device includes a power receiver side control unit (230) configured to transmit the information on the output characteristic of the power receiver circuit, which is associated with power receiver side identification information for identifying the power receiver circuit, to the server, the power transmitter device includes a power transmitter side control unit (70) configured to transmit the information on the output characteristic of the power transmitter circuit, which is associated with power transmitter side identification information for identifying the power transmitter circuit, to the server, the server is configured to determine the combination based on the received information on the output characteristic of the power receiver circuit and the received information on the output characteristic of the power transmitter circuit, and transmit information on the determined combination, which is associated with the power transmitter side identification information, to the power receiver side control unit, and the power receiver side control unit is configured to switch the output characteristic of the power receiver circuit to an output characteristic according to the determined combination, based on the received information on the combination and the received power transmitter side identification information.

3. The wireless power transfer system according to claim 2, wherein the power transmitter circuit is capable of switching the output characteristic, the server is configured to transmit information on the determined combination, which is associated with the power receiver side identification information, to the power transmitter side control unit, and the power transmitter side control unit is configured to switch the output characteristic of the power transmitter circuit to an output characteristic according to the determined combination, based on the received information on the combination and the received power receiver side identification information.

4. The wireless power transfer system according to claim 1, wherein the power transmitter circuit is capable of switching the output characteristic, the wireless power transfer system further comprising: a server (410) including the at least one processing unit, wherein the power receiver device includes a power receiver side control unit (230) configured to transmit the information on the output characteristic of the power receiver circuit, which is associated with power receiver side identification information for identifying the power receiver circuit, to the server, the power transmitter device includes a power transmitter side control unit (70) configured to transmit the information on the output characteristic of the power transmitter circuit, which is associated with power transmitter side identification information for identifying the power transmitter circuit, to the server, the server is configured to determine the combination based on the received information on the output characteristic of the power receiver circuit and the received information on the output characteristic of the power transmitter circuit, and transmit information on the determined combination, which is associated with the power receiver side identification information, to the power transmitter side control unit, and the power transmitter side control unit is configured to switch the output characteristic of the power transmitter circuit to an output characteristic according to the determined combination, based on the received information on the combination and the received power receiver side identification information.

5. The wireless power transfer system according to claim 1, wherein the power receiver circuit is capable of switching the output characteristic, the at least one processing unit is included in a power receiver side control unit (230) provided to the power receiver device, the power receiver side control unit is configured to acquire the information on the output characteristic of the power transmitter circuit and power transmitter side identification information for identifying the power transmitter circuit, determine the combination based on the acquired information on the output characteristic of the power transmitter circuit and the acquired power transmitter side identification information, and switch the output characteristic of the power receiver circuit to an output characteristic according to the determined combination, based on the information on the determined combination and the power transmitter side identification information.

6. The wireless power transfer system according to claim 5, wherein the power transmitter circuit is capable of switching the output characteristic, the power receiver side control unit is configured to transmit information on the determined combination, which is associated with power receiver side identification information for identifying the power receiver circuit, to a power transmitter side control unit (70) provided to the power transmitter device, and the power transmitter side control unit is configured to switch the output characteristic of the power transmitter circuit to an output characteristic according to the determined combination, based on the received information on the combination and the received power receiver side identification information.

7. The wireless power transfer system according to claim 1, wherein the power transmitter circuit is capable of switching the output characteristic, the at least one processing unit is included in a power receiver side control unit (230) provided to the power receiver device, the power receiver side control unit is configured to acquire the information on the output characteristic of the power transmitter circuit and power transmitter side identification information for identifying the power transmitter circuit, determine the combination based on the acquired information on the output characteristic of the power transmitter circuit and the acquired power transmitter side identification information, and transmit information on the determined combination, which is associated with power receiver side identification information for identifying the power receiver circuit, to a power transmitter side control unit (70) provided to the power transmitter device, and the power transmitter side control unit is configured to switch the output characteristic of the power transmitter circuit to an output characteristic according to the determined combination, based on the received information on the combination and the received power receiver side identification information.

8. The wireless power transfer system according to any one of claims 5 to 7, wherein the power receiver side control unit is configured to acquire the information on the output characteristic of the power transmitter circuit and the power transmitter side identification information for identifying the power transmitter circuit, based on wireless communication, information from a navigation device (331) mounted on the vehicle, road surface information shown on a road surface on which the vehicle travels, the road surface information associated with the output characteristic of the power transmitter circuit and the power transmitter side identification information, road sign information associated with the output characteristic of the power transmitter circuit and the power transmitter side identification information, or marker information provided on a travel road of the vehicle, the marker information associated with the output characteristic of the power transmitter circuit and the power transmitter side identification information.

9. The wireless power transfer system according to claim 1, wherein the power receiver circuit is capable of switching the output characteristic, the at least one processing unit is included in a power transmitter side control unit (70) provided to the power transmitter device, the power receiver device includes a power receiver side control unit (230) configured to transmit the information on the output characteristic of the power receiver circuit, which is associated with power receiver side identification information for identifying the power receiver circuit, to the power transmitter side control unit, the power transmitter side control unit is configured to determine the combination based on the received information, and transmit information on the determined combination, which is associated with power transmitter side identification information for identifying the power transmitter circuit, to the power receiver side control unit, and the power receiver side control unit is configured to switch the output characteristic of the power receiver circuit to an output characteristic according to the determined combination, based on the received information on the combination and the received power transmitter side identification information.

10. The wireless power transfer system according to claim 9, wherein the power transmitter circuit is capable of switching the output characteristic, and the power transmitter side control unit is configured to switch the output characteristic of the power transmitter circuit to an output characteristic according to the determined combination, based on the information on the determined combination and the power receiver side identification information.

11. The wireless power transfer system according to claim 1, wherein the power transmitter circuit is capable of switching the output characteristic, the at least one processing unit is included in a power transmitter side control unit (70) provided to the power transmitter device, the power receiver device includes a power receiver side control unit (230) configured to transmit the information on the output characteristic of the power receiver circuit, which is associated with power receiver side identification information for identifying the power receiver circuit, to the power transmitter side control unit, and the power transmitter side control unit is configured to determine the combination based on the received information, and switch the output characteristic of the power transmitter circuit to an output characteristic according to the determined combination, based on the information on the determined combination and the power receiver side identification information.

12. The wireless power transfer system according to any one of claims 3, 4, 6, 7, 10, and 11, wherein the power receiver side control unit is configured to transmit, to the power transmitter device by short-range wireless communication, a power transfer request signal, which indicates a power transfer request to the power transmitter antenna, and the power receiver side identification information, and the power transmitter side control unit is configured to energize the power transmitter antenna by performing energization control of the power transmitter circuit when receiving the power transfer request signal transmitted by short-range wireless communication, switch the output characteristic of the power transmitter circuit to an output characteristic according to the determined combination, based on the power receiver side identification information transmitted by short-range wireless communication, and the power receiver side identification information and information on the combination transmitted by wide-area wireless communication.

13. The wireless power transfer system according to claim 12, wherein the power receiver side control unit is configured to prohibit transmission of the power transfer request signal, when determining, before the vehicle enters a power transfer lane provided with the power transmitter antenna, that the output characteristic cannot be switched to an output characteristic according to the combination, or when determining that an abnormality related to wireless power transfer occurs.

14. The wireless power transfer system according to any one of claims 1 to 7 and 9 to 11, wherein the at least one of the power transmitter circuit and the power receiver circuit, which is capable of switching the output characteristic, is configured to switch the output characteristic to an output characteristic according to the determined combination, before the vehicle enters a power transfer lane provided with the power transmitter antenna.

15. The wireless power transfer system according to any one of claims 3, 4, 6, 7, 10, and 11, wherein the power transmitter antenna includes a plurality of power transmitter antennas arranged in a vehicle traveling direction, the power transmitter circuit is configured to switch the output characteristic of the power transmitter circuit including a first power transmitter antenna among the power transmitter antennas to an output characteristic according to a combination with the power receiver circuit of a first vehicle, which travels near the first power transmitter antenna, and switch the output characteristic of the power transmitter circuit including a second power transmitter antenna among the power transmitter antennas to an output characteristic according to a combination with the power receiver circuit of a second vehicle, which travels near the second power transmitter antenna, and the second power transmitter antenna is different from the first power transmitter antenna.

16. The wireless power transfer system according to any one of claims 1 to 7 and 9 to 11, wherein the power transmitter device has a first control function configured to control received power of the power receiver antenna to a requested power, the power receiver device has a second control function configured to control the received power of the power receiver antenna to the requested power, and the wireless power transfer system further comprising: a disable command unit (700) configured to disable either the first control function or the second control function.

17. A program applicable to a wireless power transfer system (10), in which one of a ground side device on a ground and a vehicle side device on a vehicle (11) is a power transmitter device (20) including a power transmitter circuit (400) including a power transmitter antenna (22) and an other of the ground side device and the vehicle side device is a power receiver device (100) including a power receiver circuit (500) including a power receiver antenna (102), for transmission of electric power in a wireless manner from the power transmitter antenna to the power receiver antenna, at least one of the power transmitter circuit and the power receiver circuit configured to switch an output characteristic, the program configured to cause at least one processor to execute a process to acquire information on an output characteristic of the power transmitter circuit and information on an output characteristic of the power receiver circuit, and determine, based on the acquired information, a combination of the output characteristic of the power receiver circuit with respect to the output characteristic of the power transmitter circuit, and a process to, before the power transmitter antenna supplies power to the power receiver antenna, cause the at least one of the power transmitter circuit and the power receiver circuit, which is capable of switching the output characteristic, to switch the output characteristic to an output characteristic according to the determined combination.

18. A control method applicable to a wireless power transfer system (10), in which one of a ground side device on a ground and a vehicle side device on a vehicle (11) is a power transmitter device (20) including a power transmitter circuit (400) including a power transmitter antenna (22) and an other of the ground side device and the vehicle side device is a power receiver device (100) including a power receiver circuit (500) including a power receiver antenna (102), for transmission of electric power in a wireless manner from the power transmitter antenna to the power receiver antenna, at least one of the power transmitter circuit and the power receiver circuit configured to switch an output characteristic, the method comprising: acquiring information on an output characteristic of the power transmitter circuit and information on an output characteristic of the power receiver circuit, and determining, based on the acquired information, a combination of the output characteristic of the power receiver circuit with respect to the output characteristic of the power transmitter circuit, by at least one processor in a process, and before the power transmitter antenna supplies power to the power receiver antenna, causing the at least one of the power transmitter circuit and the power receiver circuit, which is capable of switching the output characteristic, to switch the output characteristic to an output characteristic according to the determined combination, by the at least one processor in a process.

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