In-vehicle power receiving system and wireless power transfer system

Abstract

In a wireless power transfer system, a power transmitter coil is provided at a travel path, and wireless power transfer is performed between the power transmitter coil at the travel path and an in-vehicle power receiver coil (102) when a vehicle (400) travels on the travel path. Two or more power receiver coils (power receivers 100) can be mounted on the vehicle. An ECU (430) includes a recognition unit that recognizes power receiving capability information indicating a power receiving capability of the vehicle by the power receiver coil mounted on the vehicle, and a power receiving control unit that performs power receiving control based on the power receiving capability information recognized by the recognition unit.

Description

IN-VEHICLE POWER RECEIVING SYSTEM AND WIRELESS POWER TRANSFER SYSTEMCross Reference

[0001] This application is based on Japanese Patent Application No. 2024-208008 filed on November 29, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to an in-vehicle power receiving system and a wireless power transfer system.

[0003] Patent Literature 1 discloses a system for performing wireless power transfer from a ground power transmitter to a power receiver mounted on an electric vehicle. The power transmitter includes a power transmitter coil and a control unit that energizes the power transmitter coil. The power receiver includes a power receiver coil to which power is supplied from the power transmitter coil in a wireless manner.

[0004] JP 2024-008088 A

[0005] For example, in a vehicle such as a truck or a bus having a larger overall length than a passenger car, it is conceivable that a plurality of power receiver coils is provided so as to be disposed in the vehicle front-rear direction. In addition, in such a vehicle such as a truck or a bus, it is conceivable that the number of power receiver coils that can be mounted varies according to the difference in overall length dimension. In this case, assuming that the number of power receiver coils in the entire vehicle is not uniform and can be appropriately changed, a form of power reception in each power receiver coil also changes. In addition, the power receiving capability in the vehicle changes. Therefore, it is conceivable that there is room for technical improvement in consideration of this point.

[0006] An object of the present disclosure is to provide an in-vehicle power receiving system and a wireless power transfer system, which are capable of appropriately receiving power in a vehicle from a power transmission side.

[0007] According to an aspect of the present disclosure, an in-vehicle power receiving system for a wireless power transfer system. The wireless power transfer system includes a power transmitting antenna provided at a travel path and an in-vehicle power receiving antenna. The wireless power transfer system performs wireless power transfer between the power transmitting antenna at the travel path and the in-vehicle power receiving antenna when a vehicle travels on the travel path. The power receiving antenna is one of two or more power receiving antennas mountable on the vehicle. The in-vehicle power receiving system includes a recognition unit and a power receiving control unit. The recognition unit is configured to recognize power receiving capability information indicating a power receiving capability of the vehicle by the power receiving antennas mounted on the vehicle. The power receiving control unit is configured to perform power receiving control based on the power receiving capability information recognized by the recognition unit.

[0008] According to the above configuration, for example, even when there occurs a case where the power receiving capability of the vehicle is changed due to a difference in the number of power receiving antennas mounted on the vehicle in a vehicle having a long overall length dimension, the power receiving capability can be appropriately grasped. In addition, in the vehicle, the power reception state of the entire vehicle can be suitably controlled according to the power receiving capability of the vehicle. As a result, power reception from the power transmission side can be appropriately performed in the vehicle.

[0009] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.FIG. 1 is an overall configuration diagram of the wireless power transfer system according to the embodiment.FIG. 2 is an overall configuration diagram of the wireless power transfer system.FIG. 3 is a diagram illustrating the power transmitter and the power receiver.FIG. 4 is a diagram showing a schematic configuration of a vehicle including a tractor and a trailer.FIG. 5 is a diagram illustrating a configuration of a trailer.FIG. 6 is a diagram illustrating a configuration of the in-vehicle power receiving system.FIG. 7 is a diagram illustrating a configuration of the in-vehicle power receiving system.FIG. 8 is a diagram illustrating a configuration of the in-vehicle power receiving system.FIG. 9 is a diagram illustrating a relationship between an SOC of a battery and the number of power receivers.FIG. 10 is a diagram illustrating a relationship between a battery temperature and the number of power receivers.FIG. 11 is a diagram illustrating a relationship between a battery temperature and the number of power receivers.FIG. 12 is a diagram illustrating a relationship between a travel distance of a vehicle and the number of power receivers.FIG. 13 is a diagram illustrating a relationship between a power consumption and the number of power receivers.FIG. 14 is a flowchart showing a processing procedure of power receiving control in a vehicle.FIG. 15 is a diagram illustrating a configuration of the in-vehicle power receiving system.FIG. 16 is a diagram illustrating a configuration of the in-vehicle power receiving system.FIG. 17 is a diagram illustrating a configuration of the in-vehicle power receiving system.FIG. 18 is a flowchart showing a processing procedure of power receiving control in another example.FIG. 19 is a flowchart showing a processing procedure of power receiving control in another example.FIG. 20 is a flowchart showing a processing procedure of power receiving control in another example.FIG. 21 is a flowchart showing a processing procedure of power receiving control in another example.FIG. 22 is a flowchart showing a processing procedure of power receiving control in another example.FIG. 23 is a flowchart showing a processing procedure of power receiving control in another example.FIG. 24 is a view illustrating another form of the vehicle.FIG. 25 is a view illustrating another form of the vehicle.FIG. 26 is a view illustrating another form of the vehicle.

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In embodiments, functionally and / or structurally corresponding and / or associated portions may be provided with the same reference numerals or reference numerals differing in one hundred or more places. For a corresponding portion and / or an associated portion, reference may be made to descriptions of other embodiments.

[0011] Hereinafter, the embodiments embodying a wireless power transfer system according to the present disclosure will be described with reference to the drawings.

[0012] First, an overall configuration of a wireless power transfer system will be described. As illustrated in FIGS. 1, 2, and 3, a wireless power transfer system 10 includes a power transmitter 20 and a power receiver 100. The power receiver 100 is mounted on a vehicle 11 as a mobile body traveling on a road RS. The vehicle 11 is, for example, an electric car or a hybrid car. Power is supplied from the power transmitter 20 to the power receiver 100 while the vehicle 11 is traveling or stopped. The wireless power transfer system 10 performs wireless power transmission from the power transmitter 20 to the power receiver 100 by magnetic field resonance coupling (magnetic field resonance). The wireless power transfer system 10 is also referred to as a dynamic wireless power transmission (D-WPT) system.

[0013] The power transmitter 20 is a ground device including a power-transmitter coil unit 21 and a power-transmitter power supply unit 51 that supplies power to the power-transmitter coil unit 21. The power transmitter 20 is, for example, a stationary device. The power-transmitter coil unit 21 is installed (for example, embedding) on the road RS, a parking lot, or the like. The power-transmitter power supply unit 51 is installed, for example, beside the road RS. The power-transmitter coil unit 21 is connected to the power-transmitter power supply unit 51. The power-transmitter power supply unit 51 is connected to an AC power supply 15, and supplies AC power of the AC power supply 15 to the power-transmitter coil unit 21. The AC power supply 15 is, for example, a commercial power supply. A plurality of power-transmitter coil units 21 is disposed along the lane of the road RS. FIG. 2 illustrates an example in which four power-transmitter coil units 21 disposed side by side along the road RS are connected to one power-transmitter power supply unit 51. That is, one power-transmitter power supply unit 51 is provided for every four power-transmitter coil units 21. The plurality of power-transmitter coil units 21 is disposed side by side at predetermined intervals in the vehicle travel direction. Regarding the installation interval of the power-transmitter coil units 21, the interval between the center positions of the power-transmitter coil units 21 in the vehicle travel direction is, for example, about 1.5 to 2 m, and the separation interval between the power-transmitter coil units 21 is, for example, about 0.5 to 0.8 m.

[0014] The configuration is not limited to the configuration in which one power-transmitter power supply unit 51 is provided for the plurality of power-transmitter coil units 21, and one power-transmitter power supply unit 51 may be provided for one power-transmitter coil unit 21.

[0015] The power-transmitter power supply unit 51 includes a PFC (Power Factor Correction) 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 supply 15. Switching control of a switching element (for example, IGBTs or MOSFETs) included in the PFC circuit 61 improves the power factor of the AC power input from the AC power supply 15, and converts the input AC power into DC power. IGBT is an abbreviation of Insulated Gate Bipolar Transistor. MOSFET is an abbreviation of Metal-Oxide-Semiconductor Field-Effect Transistor.

[0016] The inverter 60 is connected to the PFC circuit 61. The switching element (for example, IGBTs or MOSFETs) included in the inverter 60 are subjected to switching control, whereby the DC power input from the PFC circuit 61 is converted into AC power.

[0017] The filter circuit 52 removes noise included 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 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 having various configurations are used, and specifically, for example, a T-type filter circuit is used.

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

[0019] The power receiver 100 includes a power-receiver coil unit 101 and a power-receiver power supply unit 181. The power-receiver coil unit 101 includes a power receiver coil 102 (corresponding to a "power receiving antenna"). The power-receiver coil unit 101 is provided at the bottom of the vehicle body of the vehicle 11. The power-receiver coil unit 101 is provided at the bottom of the vehicle body so as to face the ground face. When the vehicle 11 travels on the road RS in which the power transmitter coil 22 is embedded, the ground power transmitter coil 22 and the power receiver coil 102 included in the vehicle 11 face each other in the vertical direction.

[0020] The power receiver 100 includes a power-receiver resonant circuit 140. The power receiver coil 102 is connected to the power-receiver resonant circuit 140. Power is transmitted from the power transmitter coil 22 to the power receiver coil 102. The power receiver coil 102 supplies the received power to the power-receiver resonant circuit 140. As the power-receiver resonant circuit 140, various known resonant circuits such as a circuit including a resonant capacitor can be used.

[0021] The power receiver 100 includes a filter circuit 182, a rectifier circuit 200 functioning as a DC / AC conversion circuit, and a smoothing capacitor 210. The filter circuit 182 removes noise included in the AC current input from the power-receiver 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.

[0022] The rectifier circuit 200 converts the input alternating current into a direct current to output the direct current. The rectifier circuit 200 is, for example, a full-bridge circuit including a semiconductor switching element or a diode rectifier circuit. The first end of the smoothing capacitor 210 is connected to the high potential output terminal of the rectifier circuit 200. The second end of the smoothing capacitor 210 is connected to the low potential output terminal of the rectifier circuit 200. The rectifier circuit 200 is also referred to as an electronic rectification box (ERB).

[0023] The vehicle 11 includes a high potential main switch 301H, a low potential main switch 301L, and a high-voltage storage battery 300(corresponding to a power supply target device and a battery) as a power storage unit. The high potential main switch 301H and the low potential main switch 301L are relays (specifically, the mechanical relay), for example. A positive electrode terminal of the high-voltage storage battery 300 is connected to a high potential output terminal of the rectifier circuit 200 via the high potential main switch 301H. A negative electrode terminal of the high-voltage storage battery 300 is connected to the low potential output terminal of the rectifier circuit 200 via the low potential main switch 301L. The high-voltage storage battery 300 is a secondary battery that can be charged and discharged, and has a rated voltage of, for example, several hundred V. The high-voltage storage battery 300 is, for example, a lithium ion storage battery or a nickel-metal hydride storage battery.

[0024] The vehicle 11 includes a traveling inverter 310 and a rotation electrical machine 320. The traveling inverter 310 is a three-phase inverter, and is connected to the high-voltage storage battery 300 via the high potential main switch 301H and the low potential main switch 301L. The armature winding of the rotation electrical machine 320 is connected to the higher and lower arm switches constituting the traveling inverter 310. When the higher and lower arm switches of the traveling inverter 310 are subjected to switching control in a state where the high potential main switch 301H and the low potential main switch 301L are turned on, the traveling inverter 310 converts DC power supplied from the high-voltage storage battery 300 into AC power and supplies the AC power to the armature winding. As a result, the rotor of the rotation electrical machine 320 rotates, and the driving wheels of the vehicle 11 rotate by the rotational power of the rotor. As a result, the vehicle 11 travels.

[0025] As illustrated in FIG. 3, the power-transmitter power supply unit 51 constituting the power transmitter 20 includes a power-transmitter control unit 70. The power-transmitter control unit 70 includes a power-transmitter controller 71. The power-transmitter controller 71 is an electronic control unit (ECU) that performs various kinds of control of the power transmitter 20, and includes a processor as hardware, a storage unit, and a communication bus that connects the processor and the storage unit.

[0026] The storage unit includes a memory and a storage as hardware. The memory is a storage device for storing data used for processing of power-transmitter controller 71. The memory provides, for example, a work area for the processor to temporarily use when the processor performs processing. 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, an HDD or a flash memory. The storage stores program information and the like for processing to be described later.

[0027] The power-receiver power supply unit 181 constituting the power receiver 100 includes a power-receiver controller 231. The power-receiver controller 231 is an ECU that performs various types of control of the power receiver 100, 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 a memory and a storage as hardware. The memory is a storage device for storing data used for processing of the power-receiver controller 231. The memory provides, for example, a work area for the processor to temporarily use when the processor performs processing. 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, an HDD or a flash memory. The storage stores program information and the like for processing to be described later.

[0029] For example, program information stored in a non-transitory tangible storage medium is installed in the storage units of the power-receiver controller 231 and the power-transmitter controller 71. The storage medium is, for example, a USB memory, a CD-ROM, or a DVD. Furthermore, for example, program information transmitted via a communication network such as over the air (OTA) is installed in the storage unit.

[0030] The power-transmitter controller 71 performs switching control of the PFC circuit 61 and switching control of the inverter 60. By switching control of the inverter 60, a high-frequency AC voltage is applied to the power transmitter coil 22. As a result, 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.

[0031] In the present embodiment, the power-transmitter controller 71 performs the switching control of the inverter 60 so that the frequency of the high-frequency voltage applied to the power transmitter coil 22 is a first specified frequency (specifically, 85 kHz) of 10 kHz or more and 100 GHz or less. The resonance frequency of the power-transmitter resonant circuit 30 and the power-receiver resonant circuit 140 is set to the frequency same as the first specified frequency or a frequency close to the first specified frequency.

[0032] When the magnetic field generated in the power transmitter coil 22 is interlinked with the power receiver coil 102 of the vehicle 11, a high-frequency current that fluctuates at 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 resonant circuit 140 and the filter circuit 182. The rectifier circuit 200 converts the supplied alternating current into a direct current to output the direct current. In a state where the high potential main switch 301H and the low potential main switch 301L are turned on, the output current of the rectifier circuit 200 is supplied to the high-voltage storage battery 300 and the traveling inverter 310.

[0033] The vehicle 11 includes a low-voltage storage battery 302. The rated voltage of the low-voltage storage battery 302 is lower than the rated voltage of the high-voltage storage battery 300. The low-voltage storage battery 302 is, for example, a lead-acid battery. Power is supplied from the low-voltage storage battery 302 to the power-receiver controller 231, whereby the power-receiver controller 231 is operable.

[0034] The power receiver 100 and the power transmitter 20 have a configuration for communication between the power receiver 100 and the power transmitter 20. Specifically, the power-receiver coil unit 101 constituting the power receiver 100 includes a power-receiver communication coil 170. A power-receiver control unit 230 includes a signal transmitter 240. The power-receiver communication coil 170 is a planar coil formed by winding a conductive wire in a planar shape. The power-receiver communication coil 170 is provided at the bottom of the vehicle body with the plane direction of the planar coil facing the ground face. In the power receiver 100, the power receiver coil 102 is also preferably configured by a planar coil in the same manner. The same applies to the power transmitter coil 22 and the power-transmitter communication coil 40 of power transmitter 20.

[0035] The power-transmitter coil unit 21 constituting the power transmitter 20 includes the power-transmitter communication coil 40. The power-transmitter control unit 70 includes a signal receiver 80. The power-receiver communication coil 170 and the power-transmitter communication coil 40 are communication coils for performing narrow-area wireless communication. The narrow-area wireless communication is communication with a communication distance of less than 10 meters (for example, up to about 3 meters). The narrow-area wireless communication is communication having a shorter communication distance than wide-area wireless communication.

[0036] Various types of short-range wireless communication can be used as the narrow-area wireless communication, and for example, communication conforming to any communication standard formulated 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 narrow-area wireless communication.

[0037] The signal transmitter 240 is connected to the power-receiver controller 231. The power-receiver communication coil 170 is connected to the signal transmitter 240. The power-receiver controller 231 controls the signal transmitter 240 in order to supply a power supply request signal COMM to the power-receiver communication coil 170. The power supply request signal COMM is a signal requesting the power transmitter coil 22 near the vehicle 11 to transmit power to the power receiver coil 102.

[0038] The power-receiver control unit 230 supplies the power-receiver communication coil 170 with the power supply request signal COMM and the vehicle signal including the traveling speed of the vehicle 11 included in one frame. In the present embodiment, the power supply request signal COMM includes ID information about the vehicle 11 and a required power Weq that is a required value of the power supply to the vehicle 11. As a result, a high-frequency voltage is applied from the signal transmitter 240 to the power-receiver communication coil 170. As a result, a high-frequency current flows through the power-receiver communication coil 170, and a magnetic field for information communication is generated in the power-receiver communication coil 170.

[0039] When the magnetic field generated from the power-receiver communication coil 170 interlinks the power-transmitter communication coil 40 in a state where the power-receiver coil unit 101 of the vehicle 11 approaches the ground power-transmitter coil unit 21, a high-frequency current flows through the power-transmitter communication coil 40. The high-frequency current is input to the signal receiver 80. The signal receiver 80 recognizes the presence or absence of the power supply request and the ID information based on the input signal of the power-transmitter communication coil 40. In addition, the signal receiver 80 acquires the required power Weq of the vehicle 11 having the recognized ID information based on the signal of the power-transmitter communication coil 40. The information recognized by the signal receiver 80 and the required power Weq are input to the power-transmitter controller 71.

[0040] In the present embodiment, the power-receiver controller 231 controls the signal transmitter 240 so that the frequency of the high-frequency voltage applied to the power-receiver communication coil 170 is a second specified frequency of 10 kHz or more and 100 GHz or less. In the present embodiment, the second specified frequency is a frequency deviated from the first specified frequency, specifically, a frequency (specifically, 13.56 MHz) higher than the second specified frequency.

[0041] The power-transmitter controller 71 determines whether to energize the power transmitter coil 22 based on the input signal from the signal receiver 80. Specifically, when determining that there is a power supply request based on the input signal from the signal receiver 80, the power-transmitter controller 71 applies a high-frequency voltage to the power transmitter coil 22 by controlling the inverter 60 and the PFC circuit 61. Accordingly, power is transmitted from the power transmitter coil 22 to the power receiver coil 102 in a wireless manner.

[0042] Incidentally, when the wireless power transfer system 10 is constructed in a towing vehicle having a towing unit and a towed unit, such as a coupled truck to which a tractor and a trailer are coupled, it is conceivable that the power receiver 100 is provided in each of the towing unit and the towed unit in the vehicle. In addition, in the vehicle having such a towing structure, it is assumed that only the towing unit (tractor) is operated and the towing unit (tractor) and the towed unit (trailer) are coupled, and it is conceivable that the length of the towed unit and the number of coupling of towed units change behind the towing unit.

[0043] In this case, assuming that the number of power receiver coils 102 in the entire vehicle can be changed in the configuration in which the power receiver coil 102 is provided in each of the towing unit and the towed unit, a desirable power supply form at the time of power transmission from the power transmitter coil 22 is changed. Hereinafter, an application example of a vehicle 400 including a tractor and a trailer and on which a plurality of power receivers 100 is mounted will be described.

[0044] FIG. 4 is a diagram illustrating a schematic configuration of the vehicle 400. The vehicle 400 is a battery electric vehicle (BEV) electric truck including a tractor 401 as a towing unit and a trailer 402 as a towed unit. The tractor 401 is a towing vehicle that tows the trailer 402, and the trailer 402 is a towed vehicle towed by the tractor 401. The tractor 401 is also referred to as a head.

[0045] The tractor 401 includes a chargeable / dischargeable battery 411, a motor 412 driven by power supply from the battery 411, and a plurality of driving wheels 413. The battery 411 is charged by the wireless power transfer of the wireless power transfer system 10. The battery 411 can be charged by regenerative power generation of the motor 412. The motor 412 is a rotation electrical machine capable of performing powering drive and regenerative power generation. The motor 412 is a traveling drive source of the tractor 401, and driving wheels 413 are rotated by driving of the motor 412, and the tractor 401 travels. In comparison with the configuration illustrated in FIG. 3, the battery 411 corresponds to the high-voltage storage battery 300, and the motor 412 corresponds to the rotation electrical machine 320. The motor 412 can also be driven by power given by the wireless power transfer of the wireless power transfer system 10.

[0046] The tractor 401 can travel alone without coupling the trailer 402 and travel with the trailer 402 coupled. In addition, the tractor 401 has an external charging port 414 that is capable of charging from an external charging device (not illustrated), and can charge the battery 411 from the external charging device in a state where a charging cable is connected to the external charging port 414.

[0047] The tractor 401 also includes an ECU 430 (corresponding to "power receiving control device") that controls charging of the battery 411 and driving of the motor 412. The ECU 430 executes control of a traveling driving force by the motor 412, control of charging and discharging of the battery 411, and the like during traveling of the tractor 401. The ECU 430 is a controller that integrally controls power reception by each power receiver 100 of the vehicle 400. Further, the ECU 430 can perform wireless communication with the power transmitter 20.

[0048] The trailer 402 includes a coupling portion 421 coupled to the tractor 401 and a plurality of driven wheels 422. The coupling portion 421 has a coupling mechanism that allows the trailer 402 to be connected to and detached from the tractor 401. The coupling portion 421 allows the trailer 402 to rotate in the yaw direction relative to the tractor 401. The trailer 402 can travel accompanying the tractor 401 in a state of being coupled to the tractor 401 by the coupling portion 421.

[0049] The illustrated trailer 402 is a semi-trailer in which the weight is supported by the tractor 401 at the coupling portion 421, but may be a full trailer in which the weight is supported by the trailer itself.

[0050] The power receiver 100 is mounted on each of the tractor 401 and the trailer 402. One or a plurality of power receivers 100 is mounted on the tractor 401. In the illustrated configuration, two power receivers 100 are mounted on the tractor 401. When the plurality of power receivers 100 is mounted on the tractor 401, the power receivers 100 are disposed at predetermined intervals in the vehicle front-rear direction. In the tractor 401, each power receiver 100 is electrically connected to the battery 411 and the motor 412 via a power line 403A.

[0051] One or a plurality of power receivers 100 is mounted on the trailer 402. In the illustrated configuration, three power receiver coils 102 are mounted on the trailer 402. When the plurality of power receivers 100 is mounted on the trailer 402, the power receivers 100 are disposed at predetermined intervals in the vehicle front-rear direction. In the trailer 402, each power receiver 100 is electrically coupled to a connector 404 provided in the coupling portion 421 via a power line 403B.

[0052] The connector 404 is a relay member that electrically connects a power receiving device of the tractor 401 and a power receiving device of the trailer 402. The connector 404 actually includes a connector member of the tractor 401 and a connector member of the trailer 402, and allows coupling and separation of the connector members. Here, the configurations of the connector members of the tractor 401 and the trailer 402 are collectively referred to as the connector 404. When the trailer 402 is mechanically coupled to the tractor 401 by the coupling portion 421, the power lines 403A and 403B are electrically coupled to each other by the connector 404, that is, the battery 411 and the motor 412 of the tractor 401 are electrically coupled to the power receiver coils 102 of the trailer 402.

[0053] Rated power receiving capabilities (rated capacities) of the power receivers 100 mounted on the tractor 401 and the trailer 402 may be the same or different from each other. In this case, when the rated capacities of the power receivers 100 mounted on the tractor 401 and the trailer 402 are different from each other, the rated capacity of the power receiver 100 of the tractor 401 may be higher or lower.

[0054] A plurality of trailers 402 having different configurations can be coupled to the rear of the tractor 401. For example, a trailer 402B illustrated in FIG. 5 can be coupled instead of the trailer 402A illustrated in FIG. 4.

[0055] The trailer 402B is different from the trailer 402A in the overall length dimension and the number of power receivers 100. Specifically, the number of power receivers 100 of the trailer 402A is 3, whereas the number of power receivers 100 of the trailer 402B is 2. Therefore, in a state where the trailer 402A is coupled to the tractor 401, the total number of power receivers 100 of the vehicle 400 is five, and in a state where the trailer 402B is coupled to the tractor 401, the total number of power receivers 100 of the vehicle 400 is 4. The number of power receivers 100 of the tractor 401 is arbitrary, and the total number of power receivers 100 of the vehicle 400 is arbitrarily changed.

[0056] Next, the in-vehicle power receiving system that is a configuration related to power reception of the vehicle 400 in the wireless power transfer system 10 will be described with reference to FIG. 6.

[0057] In the vehicle 400, the tractor 401 includes two power receivers 100. The trailer 402 includes three power receivers 100. Each of the power receivers 100 has the configuration described in FIG. 3, and FIG. 6 illustrates the power receiver coil 102 and the power-receiver power supply unit 181 connected to the power receiver coil 102 for each power receiver 100. As described with reference to FIG. 3, the power-receiver power supply unit 181 includes the filter circuit 182, the rectifier circuit 200 functioning as a DC / AC conversion circuit, and the power-receiver control unit 230. The power-receiver power supply unit 181 corresponds to a "power converter". The configuration of the in-vehicle power receiving system illustrated in FIG. 6 is merely an example, and the tractor 401 may be provided with one power receiver 100, and the trailer 402 may be provided with four or more power receivers 100 according to the overall length of the trailer. In the following description, the power-receiver power supply unit 181 is simply referred to as a power supply unit 181.

[0058] In FIG. 6, the power receivers 100 disposed in the front-rear direction in the vehicle 400 are illustrated in the arrangement order, and the left side of the drawing represents the front of the vehicle and the right side of the drawing represents the rear of the vehicle. In the following description, for convenience of description, the power receiver 100 mounted on the tractor 401 is also referred to as a "first power receiver 100A", and the power receiver 100 mounted on the trailer 402 is also referred to as a "second power receiver 100B".

[0059] The first power receiver 100A of the tractor 401 and the second power receiver 100B of the trailer 402 are connected to each other by the power line 403 and the connector 404, and are connected to the battery 411 and the motor 412.

[0060] In addition, in the tractor 401 and the trailer 402, the power supply unit 181 of each power receiver 100 can exchange various types of information with the ECU 430 using a communication means such as a controller area network (CAN). In the illustrated configuration, the power supply units 181 of the power receivers 100 are connected in series in the arrangement order of the power receiver coils 102 in the vehicle front-rear direction by a communication line 405 capable of CAN communication. Specifically, in each power supply unit 181, the power-receiver controller 231 of the power-receiver control unit 230 is connected in series by the communication line 405.

[0061] In the present embodiment, the connection of the power supply units 181 is a daisy chain connection in which the power supply units 181 are connected in a row, and signal transmission is performed between the adjacent power supply units 181 connected in a row. In this case, the power supply unit 181 at the frontmost of the vehicle 400 can directly transmit a signal to the ECU 430 via the communication line 405, and the other power supply units 181 can indirectly transmit a signal to the ECU 430 through the power supply units 181 other than the foremost power supply unit and the communication line 405. The communication line 405A of the tractor 401 and the communication line 405B of the trailer 402 are connected by a connector 406. The communication line connector 406 is preferably provided in the coupling portion 421 as in the power line connector 404.

[0062] <Recognition of the number of power receiver coils in vehicle> In the vehicle 400, it is possible to travel by the tractor 401 alone and travel with the trailer 402 coupled to the rear of the tractor 401, and it is possible to appropriately change the trailer 402 coupled to the tractor 401. Therefore, it is conceivable that the number of power receivers 100 (power receiver coils 102) mounted on the vehicle 400 may change each time. When the number of power receivers 100 mounted on the vehicle 400 changes, the maximum power receiving amount in the vehicle 400 changes and affects the traveling state and the traveling plan of the vehicle 400. Therefore, it is desirable to grasp the number of power receivers 100 of the vehicle 400. Therefore, in the present embodiment, the number of power receivers 100 (power receiver coils 102) mounted on the vehicle 400 is recognized, and power receiving control in the vehicle 400 is performed based on the number of power receivers 100. The number of power receivers 100 (power receiver coils 102) mounted on the vehicle 400 corresponds to "power receiving capability information" indicating the power receiving capability of the vehicle 400.

[0063] In addition, when an abnormality occurs in some power receivers of the plurality of power receivers 100 mounted on the vehicle 400, it is conceivable that the number of power receivers 100 that can be used in the vehicle 400 changes. In the present embodiment, in consideration of this point, the number of power receivers 100 that can be used in the vehicle 400 is grasped. The ECU 430 corresponds to a "recognition unit" and a "power receiving control unit".

[0064] Incidentally, in the ECU 430, when the number of power receivers 100 used for wireless power transfer, that is, the number of active power receivers capable of receiving power can be grasped, the number of active power receivers can be notified to the power transmitter 20. Therefore, for example, in a case where billing is performed according to the number of active power receivers of the vehicle 400 at the power transmitter 20, billing calculation can be performed according to the number of active power receivers.

[0065] A specific recognition method of the number of power receiver coils will be described below. In the present embodiment, the number of power receivers 100 and the number of power receiver coils are the same.

[0066] In the present embodiment, each power supply unit 181 of the in-vehicle power receiving system outputs a signal corresponding to the presence or absence of connection of a power supply unit 181 that is at a lower stage by one than itself in the arrangement order in which a tractor 401 (vehicle front) side power supply unit is at a higher stage and a trailer 402 (vehicle rear side) side power supply unit is at a lower stage. The signal output of each power supply unit 181 is preferably performed by the power-receiver controller 231. The ECU 430 recognizes the number of power receiver coils in the vehicle 400 based on the signal output from the power supply unit 181.

[0067] Specifically, the ECU 430 inquires the power supply units 181 of the respective power receivers 100 disposed in the vehicle front-rear direction, starting from the higher position, whether another power supply unit 181 is connected at a lower stage by one than itself (each individual power supply unit), and receives a signal indicating a response to the inquiry. In this case, in the configuration shown in FIG. 6, a signal indicating that a power supply unit 181 is connected at a lower stage is output each from the first to fourth higher power supply units 181 in the order, whereas a signal indicating that a power supply unit 181 is connected at a lower stage is not output from the fifth (lowest) power supply unit 181. Therefore, the ECU 430 recognizes that the fifth power supply unit 181 is at the lowest stage, that is, the number of power receiver coils 102 is five, from the signal from each power supply unit 181.

[0068] The ECU 430 may sequentially assign IDs (identification numbers) from the power supply unit 181 at the highest stage, and recognize the number of power receiver coils 102 in the vehicle 400 based on the response signals from the power supply units 181 and the IDs. The ID of each power supply unit 181 may be given from the ECU 430 in the power supply unit 181 at the highest stage, and may be incremented by a predetermined rule (for example, by 1) in each power supply unit 181 at the stage lower than the highest stage.

[0069] In the vehicle 400, it is also possible to recognize the number of power receiver coils by the following method.

[0070] Each power supply unit 181 of the in-vehicle power receiving system sequentially outputs, to the next higher power supply unit 181, starting from the lower power supply unit 181, a signal indicating the total number of power supply units 181, including itself and all units lower than itself, that is, the number of installed power supply units 181. In this case, for the x-th power supply unit 181 from the lowest position, the total number of units 181, including itself and all units lower than itself, is "x", and this information of x is output to the next higher power supply unit 181. Mutual signal transmission between the power supply units 181 is performed via the communication line 405. In the present configuration, each power supply unit 181 outputs a signal indicating a different numerical value corresponding to the presence or absence of connection of the next lower power supply unit 181. In other words, the signal output from each power supply unit 181 corresponds to a signal corresponding to the presence or absence of connection of the next lower power supply unit 181.

[0071] More specifically, in the lowest power supply unit 181 (that is, the power supply unit 181 of the power receiver 100 at the vehicle rearmost end), "1" is output to the higher as the information indicating the number of power supply units 181, and in the second lowest power supply unit 181, "2" is output to the higher as the information indicating the number of power supply units 181. The same applies to the third lowest and subsequent power supply units 181. With such signal transmission, in the highest power supply unit 181 (that is, the power supply unit 181 of the power receiver 100 at the vehicle most front end), the actual total number of power receiver coils 102 (five in the present embodiment) in the vehicle 400 is output to the ECU 430 as information indicating the number of power supply units 181. The ECU 430 recognizes the total number of power receiver coils 102 in the vehicle 400 based on the number indicated by the signal output from the highest power supply unit 181 in the daisy chain.

[0072] In addition, the ECU 430 performs power receiving control in the vehicle 400 based on the number of power receiver coils 102. At this time, the ECU 430 grasps the maximum power receiving amount in the vehicle 400 according to the number of power receiver coils 102, controls the traveling state of the vehicle 400 based on the maximum power receiving amount, and sets a traveling plan such as a travel route.

[0073] Part of the configuration of FIG. 6 may be changed to the configuration of FIG. 7. FIG. 7 is a modification of the configuration in which the power supply unit 181 is connected by daisy chain.

[0074] In FIG. 7, in the tractor 401 of the vehicle 400, the power supply unit 181 of each power receiver coil 102 is connected to the ECU 430 via a communication line 405A. One power supply unit 181 of the tractor 401 and all the plurality of power supply units 181 of the trailer 402 are connected in series via a communication line 405B. In this case, each power supply unit 181 is connected to the CAN bus in the trailer 402, and each power supply unit 181 is connected to the daisy chain in the trailer 402.

[0075] In the power supply units 181 of the trailer 402, starting from a lower power supply unit 181, signals are sequentially output to a next higher power supply unit 181 in an arrangement order where a side closer to the tractor 401 (vehicle front side) is a higher stage and a side farther from the tractor 401 (vehicle rear side) is a lower stage. Each of the signals indicates the total number of power supply units 181, including itself and those lower than itself. As a result, the number of power supply units 181 installed in the trailer 402 is output. In the power supply unit 181 of the tractor 401, which is at the highest stage in the daisy chain, the actual number of power receiver coils 102 (three in the present embodiment) in the trailer 402 is output to the ECU 430 as information indicating the number of power supply units 181.

[0076] The ECU 430 recognizes the total number of power receiver coils 102 in the vehicle 400 based on the number of power receiver coils 102 of the tractor 401 and the number indicated by the signal output from the highest power supply unit 181 in the arrangement order in the trailer 402.

[0077] In the above configuration, the ECU 430 is provided in the tractor 401, and the number of power receiver coils 102 of the tractor 401 is known in the ECU 430. In addition, although the number of power receiver coils 102 of the trailer 402 is unknown, it is possible to grasp the total number of power receiver coils 102 in the vehicle 400 by grasping the number of power receiver coils 102 in the trailer 402.

[0078] The configuration of FIG. 8 can also be used. The configuration in FIG. 8 is different from the configuration in FIG. 7 in that in the trailer 402, all the plurality of power supply units 181 is connected in series by the communication line 405B, and information (the number of power receiver coils of the trailer 402) indicating the number of power supply units 181 of the trailer 402 is output from the power supply unit 181, which is at the highest stage in the daisy chain, to the ECU 430. In the trailer 402, the power supply unit 181 at the highest stage in the daisy chain and the ECU 430 are connected via the connector 406.

[0079] <Determination of power receiver to be used> As described above, in the vehicle 400 including the plurality of power receivers 100, it is conceivable that the situation as to whether it is desirable to perform the wireless power transfer using all the power receivers 100 among the plurality of power receivers 100 may change. That is, it is conceivable that which power receiver 100 among the plurality of power receivers 100 mounted on the vehicle 400 is used is changed according to each situation. Therefore, in the present embodiment, the ECU 430 determines the power receiver 100 to be used for the wireless power transfer among the plurality of power receivers 100, and performs the wireless power transfer using the determined power receiver 100. The ECU 430 corresponds to a "determination unit" and a "power receiving control unit". Details thereof will be described below.

[0080] When any of the plurality of power receivers 100 mounted on the vehicle 400 is in an abnormality state, there is a concern that even when power is transmitted from the power transmitter 20, the power receiver 100 cannot receive power and transmission power is wasted. Therefore, abnormality information about each power receiver 100 may be acquired in the vehicle 400, and the power receiver 100 other than the power receiver to which the abnormality information indicative of abnormal is associated among the power receivers 100 may be determined as the power receiver 100 used for the wireless power transfer.

[0081] The ECU 430 may acquire the abnormality information about the power receiver 100 by any of the following methods.

[0082] For each power receiver 100, it is determined whether there is disconnection in the power-receiver coil unit 101 and the power-receiver power supply unit 181, and when it is determined that there is disconnection in any of the power receivers 100, a disconnection signal is transmitted to the ECU 430. Transmission of an abnormality signal (disconnection signal or the like) from each power receiver 100 to the ECU 430 is preferably performed using the communication line 405. When it is determined that the disconnection abnormality has occurred, the ECU 430 stores the abnormality history in association with the arrangement order of the power receivers 100 in the vehicle 400.

[0083] In addition, at the time of wireless power transfer by each power receiver 100, the current output to the power line 403 is detected for each power receiver 100, and when the detected current does not fall within the predetermined range in any of the power receivers 100, an abnormality signal indicating that a current abnormality has occurred is transmitted to the ECU 430. In the in-vehicle power receiving system illustrated in FIG. 6, a current sensor 441 that detects the current flowing from the power receiver 100 to the power line 403 is provided for each power receiver 100, and the presence or absence of the current abnormality is determined based on the detection value of the current sensor 441. For example, a specified current flowing from the power receiver 100 to the power line 403 at the time of wireless power transfer is determined in advance, and when the detected current of the current sensor 441 does not fall within a predetermined range including the identified current, it is determined that a current abnormality has occurred. The ECU 430 stores an abnormality history in association with the arrangement order of the power receivers 100 in the vehicle 400 for the power receiver 100 determined to have a current abnormality.

[0084] At the time of wireless power transfer by each power receiver 100, the temperature is detected for each power receiver 100, and when the detected temperature is not within a predetermined range in any of the power receivers 100, an abnormality signal indicating that a temperature abnormality has occurred is transmitted to the ECU 430. In the in-vehicle power receiving system illustrated in FIG. 6, a temperature sensor 442 is provided for each power receiver 100, and the presence or absence of a temperature abnormality is determined based on a detection value of the temperature sensor 442. The temperature sensor 442 may detect the temperature of the power supply unit 181 or may detect the temperature of the power receiver coil 102. For example, an allowable temperature of the power receiver 100 at the time of wireless power transfer is determined in advance, and when the temperature detected by the temperature sensor 442 is higher than the allowable temperature, it is determined that a temperature abnormality has occurred. The ECU 430 stores an abnormality history of the power receiver 100 determined to have a temperature abnormality in association with the arrangement order of the power receivers 100 in the vehicle 400.

[0085] When it is determined that there is an abnormality in any of the power receivers 100, the ECU 430 determines the power receiver 100 having the abnormality as the power receiver 100 not to be used for the wireless power transfer, and determines the power receiver 100 other than the power receiver 100 having the abnormality as the power receiver 100 to be used for the wireless power transfer.

[0086] When it is determined that there is an abnormality in any of the power receivers 100, the ECU 430 may stop the power reception of all the power receivers 100 including the abnormal power receiver 100 according to the situation of occurrence of the abnormality. For example, when the temperature is excessively increased in the plurality of power receivers 100 or when the voltage is excessively increased in the plurality of power receivers 100, the power reception of all the power receivers 100 may be stopped.

[0087] As described above, each power receiver 100 acquires state information such as current and temperature in the power receiver 100 including the power receiver coil 102. The ECU 430 receives the state information from each power receiver 100, and determines whether to perform power reception for power transmission from the power transmitter 20, that is, whether to perform wireless power transfer, for each power receiver 100 based on the state information (power receiving determination unit).

[0088] When the state of the battery 411 is different, the amount of power to be supplied to the battery 411 is different. For example, when the state of charge (SOC), which is the state of charge of the battery 411, is different, the amount of power required in the battery 411 is different. In this case, when the battery 411 is in the high SOC, the amount of power supplied to the battery 411 may be relatively small, and when the battery is in the low SOC, the amount of power supplied to the battery 411 is relatively large. Therefore, the SOC of the battery 411 may be acquired, and the power receiver 100 used for the wireless power transfer may be determined based on the SOC.

[0089] When the SOC of the battery 411 is large, the ECU 430 reduces the number of power receivers 100 (the number of active power receivers) used for the wireless power transfer, as compared with the case where the SOC is small. Specifically, as illustrated in FIG. 9, when the SOC is greater than or equal to a predetermined value K1, the number of active power receivers is set to X1, and when the SOC is less than the predetermined value K1, the number of active power receivers is set to X2 (X1 < X2). For example, when the SOC is greater than or equal to the predetermined value K1, the number of active power receivers is set to three, and when the SOC is less than the predetermined value K1, the number of active power receivers is set to five. In FIG. 9, the number of active power receivers (X1, X2) may be determined according to the total number of power receivers 100 in the vehicle 400. The number of active power receivers can be switched in three or more stages according to the SOC. As a parameter indicating the state of charge of the battery 411, it is also possible to use a terminal voltage (for example, an open-circuit voltage) of the battery 411 instead of the SOC.

[0090] When the temperature of the battery 411 is different, the allowable amount of power of the battery 411 is different. In this case, when the battery 411 is not in a high temperature state, the allowable amount of power of the battery 411 is relatively large, and when the battery is in a high temperature state, the allowable amount of power of the battery 411 is relatively small. That is, when the battery temperature is high, it is desirable to reduce the number of active power receivers to reduce the power receiving amount per unit time. Therefore, the battery temperature may be acquired, and the active power receiver may be determined based on the battery temperature.

[0091] When the battery temperature is high, the ECU 430 reduces the number of active power receivers as compared with the case where the battery temperature is low. Specifically, as illustrated in FIG. 10, when the battery temperature is greater than or equal to a predetermined value K2, the number of active power receivers is set to X1, and when the battery temperature is less than the predetermined value K2, the number of active power receivers is set to X2. For example, when the battery temperature is greater than or equal to the predetermined value K2, the number of active power receivers is set to three, and when the battery temperature is lower than the predetermined value K2, the number of active power receivers is set to five. The number of active power receivers can be switched in three or more stages according to the battery temperature. The state of charge and the battery temperature of the battery 411 correspond to "battery information".

[0092] The relationship between the battery temperature and the number of power receivers 100 can also be as illustrated in FIG. 11. In FIG. 11, when the battery temperature is less than the predetermined value K21, the number of active power receivers is set to X2, when the battery temperature is the predetermined value K21 to K22, the number of active power receivers is set to X1, and when the battery temperature is greater than or equal to the predetermined value K22, the number of active power receivers is set to 0. As a result, when the battery temperature excessively rises and exceeds the allowable temperature, charging of the battery 411 can be stopped.

[0093] When the travel destinations of the vehicle 400 are different, the travel distance of the vehicle 400, the type of road scheduled to travel, and the like are different, and the amount of power (electric energy) required for traveling to the travel destination is different. Therefore, it is preferable to acquire destination information about a travel destination in the vehicle 400, and determine the power receiver 100 to be used for wireless power transfer among the plurality of power receivers 100 based on the destination information.

[0094] The ECU 430 acquires, as destination information about the vehicle 400, a travel distance to a destination and road type information about a travel route based on map information and the like. For example, the destination information may be acquired using map information of an in-vehicle navigation device or map application software. Further, the travel distance to the destination and the road type information may be acquired from the route search result by the navigation device or the map application. The road type information includes information about whether the road is a general road or an expressway, information about a speed limit, and the like.

[0095] The ECU 430 performs the wireless power transfer by selectively using each power receiver 100 based on the destination information. For example, when the travel distance to the destination is short, the number of active power receivers is reduced as compared with the case where the travel distance to the destination is long. Specifically, as illustrated in FIG. 12, when the travel distance to the destination is less than the predetermined value K3, the number of active power receivers is set to X1, and when the travel distance to the destination is greater than or equal to the predetermined value K3, the number of active power receivers is set to X2. For example, when the travel distance is less than the predetermined value K3, the number of active power receivers is set to three, and when the travel distance is greater than or equal to the predetermined value K3, the number of active power receivers is set to five. The number of active power receivers can be switched in three or more stages. In a case where the ratio of the expressway is high in all the travel routes, it is conceivable that the frequency of acceleration / deceleration decreases and the energy efficiency increases as compared with a case where the ratio of the expressway is low. Therefore, when the ratio of the expressway in the entire travel route is high, the determination that the active power receiver is reduced may be made.

[0096] When the power consumption accompanying the driving of various electric loads in the vehicle 400 increases, the amount of power required in the vehicle 400 increases. The electric load is, for example, the motor 412 as a traveling drive source, a compressor for air conditioning, or the like. In the vehicle 400, the power consumption of the motor 412 increases during high-load traveling such as acceleration by accelerator-on and climbing. Each electric load can be driven by the received power of the power receiver 100. Each electric load can be driven by power supply from the battery 411 after the battery 411 is charged by the received power of the power receiver 100, and can be driven by direct supply of the received power of the power receiver 100.

[0097] The ECU 430 grasps various electric loads in the driving state in the vehicle 400, and acquires the sum of the power consumptions of the respective electric loads as the power consumption information. Based on the power consumption information, the ECU 430 selectively uses the power receivers 100 to perform wireless power transfer. Specifically, as illustrated in FIG. 13, when the power consumption is greater than or equal to the predetermined value K4, the number of active power receivers is increased as compared with the case where the power consumption is less than the predetermined value K4. For example, when the power consumption is greater than or equal to the predetermined value K4, the number of active power receivers is set to five, and when the power consumption is less than the predetermined value K4, the number of active power receivers is set to three. The number of active power receivers can be switched in three or more stages.

[0098] In a case where some power receivers of the plurality of power receivers 100 mounted on the vehicle 400 are not used, that is, in a case where power receivers 100 whose number is smaller than the total number of power receivers 100 in the vehicle 400 are determined as active power receivers, the ECU 430 may determine which power receiver 100 is to be put on standby (standby device setting unit).

[0099] Specifically, the ECU 430 may cause a power receiver 100 at an intermediate position in the vehicle front-rear direction among the power receivers 100 disposed in the vehicle front-rear direction to become standby. Here, in the vehicle 400, the power receivers 100 excluding the frontmost power receiver 100 and the rearmost power receiver 100 correspond to the power receiver 100 at the intermediate position in the vehicle front-rear direction. For example, in the vehicle 400, when the number of the power receivers 100 used for the wireless power transfer is reduced from five to three, the second power receiver 100 and the fourth power receiver 100 from the front may be put on standby. In this case, since the power receivers 100 in the operating state are spaced apart from each other, erroneous reception of the power supply request signal transmitted from the power receiver 100 is suppressed in the power transmitter 20. In addition, it is possible to reduce the influence of mutual heat of the power receiver 100 in the vehicle 400.

[0100] In the vehicle 400, the battery 411 and the traveling motor 412 are provided in the tractor 401 which is a vehicle front portion. In the vehicle 400 having such a configuration, the power receiver 100 of the trailer 402 which is the vehicle rear portion may be to be put on standby. In this case, in the vehicle 400, the power receiver 100 at the vehicle rear end may be prioritized to be put on standby. For example, when there is one power receiver 100 to be put on standby, the power receiver 100 at the rearmost part of the vehicle is put on standby, and when there are two power receivers 100 to be put on standby, the two power receivers 100 from the rearmost part of the vehicle are put on standby. In this case, the power receiver 100 mounted on the tractor 401 may be prioritized to be determined as the power receiver 100 used for the wireless power transfer. In the present configuration, since the power receiver 100 at a position away from the battery 411 and the motor 412 is put on standby, it is possible to reduce a loss caused by an increase in the length of the power line 403.

[0101] In addition, the ECU 430 may determine the power receiver 100 determined to have abnormality, the power receiver 100 showing a sign of abnormality, or the power receiver 100 having the highest temperature in the vehicle 400 as the power receiver 100 to be put on standby.

[0102] <Vehicle travel control according to power reception rate> In the vehicle 400 in which the wireless power transfer is performed, it is conceivable that the power receiving amount per unit time by each in-vehicle power receiver 100 changes due to various factors. The power receiving amount per unit time can be rephrased as a power reception rate, and hereinafter, this is also referred to as a power reception rate. For example, it is conceivable that the number of power receivers 100 is different between a state in which the tractor 401 travels alone and a state in which the tractor 401 travels towing the trailer 402, and the power reception rate in the vehicle 400 is changed by the difference in the number of power receivers 100. In addition, in the vehicle 400, when the total number of power receivers 100 changes due to replacement of the trailer 402, the power reception rate in the vehicle 400 changes. When the number of power receivers 100 used for wireless power transfer in the vehicle 400 changes due to other factors, it is conceivable that the power reception rate also changes. In this case, when the power reception rate of the vehicle 400 changes, the power energy that can be consumed by the motor 412 for traveling changes, and the traveling state and the traveling plan of the vehicle 400 may be affected.

[0103] Therefore, the ECU 430 acquires power receiving amount information indicating a power reception rate by the power receiver 100 in the vehicle 400, and executes control related to vehicle travel based on the power receiving amount information. The power receiving amount information is, for example, the number of power receivers 100 that can be used for wireless power transfer in the vehicle 400. The number of power receivers 100 in the vehicle 400 is, for example, the total number of power receivers 100 in the tractor 401 and the trailer 402. The ECU 430 corresponds to an "acquisition unit" and a "travel control unit".

[0104] When indicating that the power reception rate is small, the ECU 430 increases the output restriction degree for restricting the output of the motor 412, compared with when indicating that the power reception rate is large. Specifically, for example, the output restriction degree of the motor 412 may be increased by decreasing the maximum speed limit of the vehicle 400 or restricting the acceleration of the vehicle 400. As a result, even under a situation where the power reception rate is small in the vehicle 400, appropriate vehicle travel is possible.

[0105] Further, the ECU 430 may instruct to change at least one of the destination and the travel route when the actual power reception rate is different from the assumed power reception rate assumed in advance. The vehicle 400 has a navigation function of setting a travel route to a destination and presenting the travel route as navigation information about the vehicle. The navigation function is a function of performing route guidance of the vehicle 400 based on map information, position information about the vehicle 400, and the like. In the vehicle 400, route guidance according to the travel route is provided by, for example, display or voice. The navigation function may be realized by a vehicle travel controller (navigation ECU) in the vehicle 400.

[0106] In the vehicle 400, the number of power receivers 100 used for wireless power transfer is set to a specified value (for example, five), and then a travel route to a destination is set. The specified value is a predetermined value (specified number). The specified value may be the total number of power receivers 100 recognized at the time of activation of the vehicle 400. In this case, the assumed power reception rate is grasped according to the specified number of power receivers 100. The ECU 430 instructs the navigation ECU to change the destination or the travel route when the number of power receivers 100 actually used for the wireless power transfer is different from the specified number of the initial power receivers 100 at the time of vehicle travel.

[0107] For example, in a case where the specified number of initial power receivers 100 is five, and the number of power receivers 100 actually used for the wireless power transfer is three, the power reception rate in the vehicle 400 is smaller than the initial assumption. In this case, the ECU 430 outputs a command to the navigation ECU so as to change to another destination having a travel distance smaller than the initial destination. Alternatively, the ECU 430 outputs a command to the navigation ECU so as to change the travel route to another route with a small power burden. For example, it is preferable to instruct to reduce intermediate stopping points on the travel route.

[0108] In the vehicle 400, when the specified number of power receivers 100 used for the wireless power transfer is set to a relatively small value (for example, two), it is conceivable that the actual power reception rate is larger than the assumed power reception rate assumed in advance. For example, when it is initially assumed that only the tractor 401 travels, and the vehicle travels in a state where the trailer 402 is towed by the tractor 401 in practice, it is conceivable that the actual power reception rate is larger than the assumed power reception rate because the total number of power receivers 100 is larger than assumed. In such a case, it is preferable that a permission to change the destination to a distant place or a permission to change the travel route so as to increase the number of intermediate stopping points is given.

[0109] Both the destination and the travel route may be changed based on the power receiving amount information (power reception rate).

[0110] Both the processing of restricting the output of the motor 412 based on the power receiving amount information and the processing of changing the destination or the travel route of the vehicle 400 based on the power receiving amount information may be performed.

[0111] In addition, in the vehicle 400, when any of the power receivers 100 is in an abnormal state, the power receiver 100 in the abnormal state set to a standby mode. In this case, the ECU 430 acquires the number of power receivers 100 other than the standby power receivers among the power receivers 100 as the power receiving amount information, and executes control related to vehicle travel based on the power receiving amount information. As a result, it is possible to optimize the vehicle travel state while grasping the standby situation of the power receiver 100.

[0112] In addition, it is conceivable that the power reception rate of the vehicle 400 changes due to a change in the power transmission mode of the power transmitter coil 22 of the power transmitter 20 in the travel path. For example, when the transmission power level from the power transmitter coil 22 of the power transmitter 20 changes or the installation interval of the power-transmitter coil unit 21 at the travel path changes, it is conceivable that the power reception rate of the vehicle 400 changes. Therefore, the ECU 430 acquires information about the power transmission mode of the power transmitter 20 as the power receiving amount information about the vehicle 400, and executes control related to vehicle travel based on the information. The information about the power transmission mode of the power transmitter 20 is, for example, information about a transmission power level and an installation interval of the power-transmitter coil units 21. When the transmission power level indicates a predetermined level or less, or when the installation interval of the power-transmitter coil units 21 indicates a predetermined level or more, the ECU 430 reduces the maximum speed limit of the vehicle 400 or limits the acceleration of the vehicle 400, for example, in order to increase the output restriction degree of the motor 412.

[0113] <Power receiving control procedure by ECU> FIG. 14 is a flowchart illustrating a processing procedure of the power receiving control in the vehicle 400. This process is repeatedly executed by the ECU 430 at a predetermined cycle.

[0114] In FIG. 14, in step S101, it is determined whether a recognition condition for recognizing the number of power receivers 100 is satisfied in the vehicle 400. The recognition condition includes, for example, a condition that the ECU 430 is initialized as the power switch (IG switch) of the vehicle 400 is turned on, a condition that wireless power transfer is performed after the current point in time in the vehicle 400, and a condition that separation or coupling of the trailer 402 is performed in the vehicle 400. In a case where at least one of these conditions is satisfied, the recognition condition is considered to be satisfied. When step S101 is positive, the process proceeds to subsequent step S102.

[0115] In step S102, the total number of power receivers 100 (the total number of power receiver coils 102) in the vehicle 400 is recognized. At this time, for example, in the in-vehicle power receiving system having the configuration of FIG. 6, the total number of power receivers 100 is recognized based on a signal transmitted from the highest power receiver 100 among the plurality of power receivers 100 mounted on the vehicle 400 to the ECU 430. The in-vehicle power receiving system may have the configuration of FIG. 7 or FIG. 8.

[0116] In step S102, it is also possible to individually recognize the number of power receivers 100 provided in the tractor 401 and the number of power receivers 100 provided in the trailer 402 based on a signal transmitted from each power receiver 100 in the vehicle 400.

[0117] In step S103, abnormality information indicating an abnormality state of each power receiver 100 is acquired from each power receiver 100. The power receiver 100 preferably has an abnormality determination function. Specifically, information about a disconnection abnormality indicating the presence or absence of a disconnection in each of the power receivers 100, information about a current abnormality indicating that an abnormality current is flowing through each of the power receivers 100, and information about a temperature abnormality indicating that the temperature of each of the power receivers 100 is excessively increased are acquired. In this case, the ECU 430 recognizes from which power receiver 100 the abnormality information is transmitted in the vehicle 400.

[0118] In step S104, a battery state indicating the state of the battery 411 is acquired. Specifically, as the battery information, the SOC or the open-circuit voltage of the battery 411, which is the state of charge information of the battery 411, is acquired. Alternatively, the battery temperature is acquired as the battery information.

[0119] In step S105, destination information about the vehicle 400 is acquired. Specifically, a travel distance to a destination and road type information about a travel route are acquired as the destination information.

[0120] In step S106, the power consumption information about the vehicle 400 is acquired. Specifically, as the power consumption information, various electric loads in the driving state in the vehicle 400 are grasped, and a total value of the power consumptions of the respective electric loads is acquired.

[0121] Thereafter, in step S107, the number of power receivers 100 (the number of active power receivers) used for the wireless power transfer among the plurality of power receivers 100 of the vehicle 400 is determined based on the information acquired in steps S103 to S106. The ECU 430 determines the number of active power receivers using, for example, the relationships in FIGS. 9 to 13. At this time, when the number of active power receivers is determined by a plurality of relationships, the smallest number may be determined as the number of active power receivers.

[0122] In step S107, when there is abnormality information indicating that there is an abnormality, the power receiver 100 to be used for the wireless power transfer may be determined by prioritizing use of the abnormality information. At this time, the power receiver 100 other than the power receiver to which the abnormality information is associated among the power receivers 100 is determined as the active power receiver. That is, the number of active power receivers is determined except for the power receiver 100 with abnormality. In addition, among the power receivers 100, the power receiver to which the information indicative of abnormal is associated may be subjected to power reception restriction with a reduced power receiving amount instead of power reception stop.

[0123] In addition, when there is no abnormality information indicative of abnormal, the power receiver 100 to be used for the wireless power transfer may be determined using any of the battery information (state of charge information or battery temperature), the destination information about the vehicle 400, and the power consumption information. At this time, the number of active power receivers is determined based on the SOC or the battery temperature of the battery 411 using any of the relationships illustrated in FIGS. 9 to 11. In addition, the number of active power receivers is determined based on the travel distance to the destination using the relationship illustrated in FIG. 12. In addition, the number of active power receivers is determined based on the power consumption of the electric load using the relationship illustrated in FIG. 13. In a case where it is determined to reduce the power receiver 100 based on each of the above information, the power receiver 100 used for the wireless power transfer is reduced according to the determination.

[0124] Thereafter, in step S108, it is determined whether some power receivers 100 of the plurality of power receivers 100 in the vehicle 400 are to be put on standby, based on the determination result in step S107. When step S108 is positive, the process proceeds to step S109.

[0125] In step S109, the power receiver 100 to be put on standby is determined. In this step, when there is the power receiver 100 to which the abnormality information is attached, the power receiver 100 to which the abnormality information is attached is put on standby. Alternatively, among the power receivers 100 disposed in the vehicle front-rear direction, the power receiver 100 at the intermediate position in the vehicle front-rear direction may be put on standby, or the power receiver 100 of the trailer 402 away from the battery 411 may be put on standby. It is also possible to switch the power receiver 100 on standby at a predetermined cycle.

[0126] Thereafter, in step S110, power receiving amount information about the vehicle 400 is acquired in the current wireless power transfer. At this time, the number of power receivers 100 that can be used for wireless power transfer in the vehicle 400 (i.e., the number of power receivers 100 excluding power receivers to be put on standby) is acquired as power receiving amount information. The number of power receivers 100 that can be used for wireless power transfer is information correlated with the power reception rate of the vehicle 400, and the larger the number of power receivers 100, the larger the power reception rate. As the power receiving amount information, information about the number of power receivers other than the power receiver that has been put on standby due to abnormality and information about the power transmission mode of the power transmitter 20 may be acquired.

[0127] In step S111, control related to vehicle travel is executed based on the power receiving amount information about the vehicle 400. At this time, the output of the motor 412 is restricted based on the power receiving amount information. More specifically, when the power reception rate is small, the maximum speed limit of the vehicle 400 may be reduced, or the acceleration of the vehicle 400 may be limited.

[0128] In step S111, instead of or in addition to the processing of restricting the output of the motor 412 based on the power receiving amount information, processing of changing the destination or the travel route of the vehicle 400 based on the power receiving amount information may be performed.

[0129] According to the present embodiment described in detail above, the following effects can be obtained.

[0130] The number of power receivers 100 (power receiver coils 102) mounted on the vehicle 400 is recognized, and power receiving control is performed based on the number of power receivers 100. As a result, even when there occurs a case where the number of power receivers 100 mounted on the vehicle 400 is different, the number of power receivers 100 can be appropriately grasped. In addition, in the vehicle 400, the power reception state by the power receiver 100 of the entire vehicle can be suitably controlled according to the number of power receivers 100. As a result, the power reception from the power transmission side can be appropriately performed in the vehicle 400.

[0131] In a vehicle 400 including tractor 401 (towing unit) and trailer 402 (towed unit), the total number of power receivers 100 of the tractor 401 and the trailer 402 is recognized, and a power supply request is output to the power transmission based on the total number of power receivers 100. As a result, even when the coupling state of the trailer 402 to the tractor 401 changes, it is possible to appropriately control the power reception of each power receiver 100 while appropriately grasping the total number of power receivers 100 in the vehicle 400.

[0132] The power supply units 181 of the power receivers 100 are connected in series, and each power supply unit 181 is configured to output a signal corresponding to the presence or absence of the next lower power supply unit 181 via the communication line 405 (see FIG. 6). The number of power receivers 100 in the vehicle 400 is recognized based on the signal output from the power supply unit 181. In this case, it is possible to appropriately grasp the total number of power receivers 100 mounted on the vehicle 400.

[0133] Each of the power supply units 181 of the trailer 402 is configured to output a signal corresponding to the presence or absence of the next lower power supply unit 181 via the communication line 405 in an arrangement order in which a power supply unit close to the tractor 401 is at the higher stage and a power supply unit away from the tractor 401 is at the lower stage (see FIGS. 7 and 8). The number of power receivers 100 in the vehicle 400 is recognized based on the number (known number) of power receivers 100 of the tractor 401 and a signal output from the power supply unit 181 of the trailer 402. As a result, in a case where the number of power receivers 100 of the tractor 401 is known while the number of power receivers 100 of the trailer 402 is unknown, it is possible to appropriately grasp the number of power receivers 100 in the trailer 402 and to appropriately grasp the total number of power receivers 100 in the vehicle 400.

[0134] In a case where a plurality of power receivers 100 is mounted on the vehicle 400, it is conceivable that the states of the power receivers 100 are not equal, and include an abnormality or an excessive temperature rise. In consideration of this point, state information indicating the state of each power receiver 100 is received from each power supply unit 181, and whether to perform wireless power transfer is determined for each power receiver 100 based on the state information. As a result, it is possible to perform appropriate wireless power transfer while suppressing a decrease in power supply efficiency and protecting components.

[0135] In a vehicle 400 including a plurality of power receivers 100, the power receiver 100 to be used for wireless power transfer is determined among the plurality of power receivers 100, and the power receiver 100 is used to perform wireless power transfer. As a result, it is possible to appropriately perform power reception in each power receiver 100 by selectively using each power receiver 100 while coping with the situation of whether it is desirable to perform the wireless power transfer using all the power receivers 100 among the in-vehicle power receivers 100. As a result, it is possible to appropriately perform the wireless power transfer in the vehicle 400 including the plurality of power receivers 100.

[0136] When any of the plurality of power receivers 100 mounted on the vehicle 400 is in an abnormality state, there is a concern that even when power is transmitted from the power transmitter 20, power cannot be received by the power receiver 100 and power is wasted. Therefore, abnormality information about each power receiver 100 in the vehicle 400 is acquired, and among the power receivers 100, the power receiver 100 other than the power receiver to which the abnormality information indicative of abnormal is associated is determined as the power receiver 100 used for the wireless power transfer. As a result, it is possible to suppress an inconvenience that power is unnecessarily transmitted to the power receiver 100 in the abnormality state.

[0137] Based on battery information including the state of charge of the battery 411 and the battery temperature, the power receivers 100 are selectively used to perform wireless power transfer. As a result, for example, even in a state where the SOC of the battery 411 or the battery temperature changes, the efficiency of the wireless power transfer can be enhanced.

[0138] Based on destination information about a travel destination of the vehicle 400, wireless power transfer is performed by selectively using the power receivers 100. For example, when the travel distance to the destination is different, the amount of power required for traveling to the destination is different. By determining the power receiver 100 to be used for the wireless power transfer among the plurality of power receivers 100 based on the destination information, it is possible to obtain a necessary amount of power in the vehicle 400 by the wireless power transfer.

[0139] In the vehicle 400, wireless power transfer is performed by selectively using the power receivers 100 based on power consumption information by an electric load. As a result, in a case where the motor 412 is operated under a high load or an air conditioner load is generated in the vehicle 400, it is possible to perform appropriate wireless power transfer.

[0140] In a case where the wireless power transfer is performed using the power receivers 100 whose number is smaller than the total number of the power receivers 100 of the vehicle 400, the power receiver 100 at the intermediate position among the power receivers 100 disposed in the vehicle front-rear direction is configured to be put on standby. In this case, by separating the power receivers 100 in the operating state from each other, erroneous reception of the power supply request signal transmitted by the power receiver 100 by the power transmitter 20 is suppressed. In addition, it is possible to reduce the influence of mutual heat of the power receiver 100 in the vehicle 400.

[0141] In the vehicle 400 having the tractor 401 and the trailer 402 that can be separated from each other, the total number of power receivers 100 mounted on the vehicle 400 is recognized, and the power receiver 100 to be used for the wireless power transfer is determined among the number of power receivers 100. In this case, even when the towing situation of the trailer 402 with respect to the tractor 401 changes, it is possible to appropriately perform the wireless power transfer using the desired number of power receivers 100 after appropriately grasping the number of power receivers 100 disposed in the front-rear direction in the vehicle 400.

[0142] When wireless power transfer is performed using the power receivers 100 whose number is smaller than the total number of the power receivers 100 mounted on the vehicle 400, the power receiver 100 mounted on the tractor 401 is preferentially determined as the power receiver 100 used for wireless power transfer. As a result, in a case where power reception is performed using the power receiver 100 of part of the vehicle 400, the charging efficiency for the in-vehicle battery 411 can be enhanced.

[0143] In the vehicle 400, when the power receiving amount (power reception rate) per unit time changes, the power energy consumable by the motor 412 for vehicle travel changes. In view of this point, power receiving amount information indicating a power receiving amount per unit time received by the power receiver 100 in the vehicle 400 is acquired, and control related to vehicle travel is executed based on the power receiving amount information. As a result, the vehicle 400 can be properly driven while corresponding to the power reception state of the power receiver 100 of the vehicle 400.

[0144] When the power reception rate of the vehicle 400 is small, the output restriction degree of the motor 412 is increased as compared with the case where the power reception rate is large. As a result, even in a situation where the power reception rate is small in the vehicle 400, proper vehicle travel can be continued.

[0145] In the vehicle 400 having a navigation function, when the power reception rate of the vehicle 400 is different from the assumed power reception rate assumed at the time of setting the travel route, at least one of the destination and the travel route of the vehicle 400 is changed. As a result, even under a situation where the power reception rate is small in the vehicle 400, proper route guidance can be realized.

[0146] In the vehicle 400 including the plurality of power receivers 100, when the number of power receivers 100 used for wireless power transfer changes, the power reception rate of the vehicle 400 may change. That is, when the state of performing the wireless power transfer using all the power receivers 100 and the state of performing the wireless power transfer using some of the power receivers 100 are switched, the power reception rate of the vehicle 400 can be changed by performing the state switching. In view of this point, power receivers 100 to be used for wireless power transfer among the plurality of power receivers 100 are determined, and the determined number of power receivers 100 is acquired as power receiving amount information. As a result, it is possible to optimize the vehicle travel state while grasping the power reception state by the power receiver 100 of the vehicle 400.

[0147] In the vehicle 400 in which the power receiver 100 is provided in each of the tractor 401 and the trailer 402, the power reception rate of the vehicle 400 decreases due to separation of the trailer 402 from the tractor 401. In addition, it is also conceivable that the total number of power receivers 100 in the vehicle 400 changes due to replacement of the trailer 402. In view of this point, the number of power receivers 100 in the vehicle 400 is recognized, and the number of power receivers 100 is acquired as power receiving amount information. As a result, it is possible to optimize the vehicle travel state while grasping the power reception state by the power receiver 100 of the vehicle 400.

[0148] In the vehicle 400, when some of the power receivers 100 are in an abnormality state, the power receivers 100 in the abnormality state are put in a standby mode. Then, the number of power receivers 100 other than the power receivers that have been put on standby among the power receivers 100 is acquired as the power receiving amount information. As a result, it is possible to optimize the vehicle travel state while grasping the standby situation of the power receiver 100.

[0149] Information about the power transmission mode of the power transmitter 20 is acquired as power receiving amount information, and vehicle travel is controlled based on the power receiving amount information. As a result, it is possible to optimize the vehicle travel state while considering that the power reception rate of the vehicle 400 changes according to the power transmission mode on the power transmission.

[0150] <Modification regarding power receiving capability information> In the above embodiment, the number of power receivers 100 (power receiver coils 102) mounted on the vehicle 400 is acquired as the power receiving capability information indicating the power receiving capability of the vehicle 400, but this may be changed. For example, the sum of the rated power receiving amounts of the power receivers 100 (power receiver coils 102) mounted on the vehicle 400 may be acquired as the power receiving capability information.

[0151] For example, in the in-vehicle power receiving system illustrated in FIG. 6, each power supply unit 181 outputs a signal corresponding to the rated power receiving amount of the power receiver coil 102 associated with the next lower power supply unit 181 to the higher stage via the communication line 405. The ECU 430 recognizes the total amount (total rated power receiving amount) of the rated power receiving amounts of the power receiver coils 102 in the vehicle 400 as the power receiving capability information based on the signal output from the power supply unit 181.

[0152] The ECU 430 recognizes the total rated power receiving amount as the maximum power receiving amount in the vehicle 400, and monitors the state of each power receiver 100 by the actual power receiving amount with respect to the total rated power receiving amount. In this case, the ECU 430 calculates the divergence amount of the actual power receiving amount with respect to the total rated power receiving amount, and when the actual power receiving amount is smaller than the total rated power receiving amount and the divergence amount is greater than or equal to a predetermined value, the ECU determines that the power reception efficiency is reduced in any of the power receivers 100. For example, the power receiving amount is restricted for the power receiver 100 in which the power reception efficiency is deteriorated. In addition, the ECU 430 controls the travel state of the vehicle 400 based on the total rated power receiving amount (maximum power receiving amount) and sets a travel plan such as a travel route.

[0153] Further, in the in-vehicle power receiving system illustrated in FIG. 7, each power supply unit outputs a signal corresponding to the power receiving amount of the power receiver coil 102 associated with the next lower power supply unit 181, via the communication line 405 to the higher stage, in the arrangement order where the power supply unit 181 of the trailer 402 are ordered with the side closer to the tractor 401 being the higher stage and the side farther from the tractor 401 being the lower stage. The ECU 430 recognizes the total amount (total rated power receiving amount) of the rated power receiving amounts of the power receiver coils 102 in the vehicle 400 as the power receiving capability information based on the known rated power receiving amount of the power receiver coil 102 in the tractor 401 and the rated power receiving amount of the power receiver coil 102 recognized from the signal output from the power supply unit 181 of the trailer 402. The same applies to the in-vehicle power receiving system illustrated in FIG. 8.

[0154] <Modification of in-vehicle power receiving system> The configuration of the in-vehicle power receiving system may be changed as follows.

[0155] <First modification> The configuration illustrated in FIG. 15 is different from the configuration of FIG. 6 described above in that the power supply unit 181 of each power receiver 100 is connected to the ECU 430 by a communication line 405 which is a bus line, is connected in series by a connection line 407 which is a Zika line capable of transmitting one specific signal, and the connection line 407 is connected to the ECU 430. Each power supply unit 181 outputs, via the connection line 407, a signal corresponding to the presence or absence of connection of the next lower power supply unit 181 in the arrangement order where the front side of the vehicle 400 represents a higher stage and the rear side represents a lower stage. Each power supply unit 181 outputs a voltage signal indicating presence or absence of the connection between the power supply units 181 at the lower stage to the ECU 430 via the connection line 407. The ECU 430 recognizes the number of power receiver coils 102 in the vehicle 400 as the power receiving capability information based on the signal output from the power supply unit 181. As a method of recognizing the number of power receiver coils, the method described with reference to FIG. 6 may be used, and the description thereof will be omitted here.

[0156] According to the above configuration, while the presence or absence of the connection between power supply units 181 is determined by the simple configuration in which the voltage signal of the connection line 407 (Zika line) is switched, the total number of power receiver coils 102 in vehicle 400 can properly be grasped.

[0157] <Second modification> The configuration illustrated in FIG. 16 is different from the configuration of FIG. 6 described above in that the power supply unit 181 of each power receiver 100 is connected to the ECU 430 by the communication line 405 which is a bus line. The power supply unit 181 outputs a predetermined response signal in response to a request from the ECU 430. The ECU 430 recognizes the number of power receiver coils 102 in the vehicle 400 as the power receiving capability information based on the number of power supply units 181 that output the response signal. The response signal output from each power supply unit 181 may be 1D (identification number) defined for each power supply unit 181.

[0158] According to the above configuration, the total number of power receiver coils 102 mounted on vehicle 400 can properly be grasped based on the number of response signals for each power receiver coil 102.

[0159] <Third modification> The configuration illustrated in FIG. 17 is different from the configuration of FIG. 6 described above in that the power supply units 181 of the power receivers 100 are connected in series and in a ring shape via the communication line 405. In this configuration, the power supply units 181 are connected using the token ring method. Each power supply unit 181 outputs a signal indicating its own presence in an arrangement order in which the front side of the vehicle 400 is higher and the rear side is lower. The ECU 430 recognizes the number of power receiver coils 102 in the vehicle 400 as the power receiving capability information based on the signal output from the highest or lowest power supply unit 181.

[0160] In FIG. 17, the communication line 405 is connected in a loop by turning back the rearmost communication line 405 of the trailer 402. When only the tractor 401 is used in the vehicle 400, a return cap may be attached to a connector member of the tractor 401 at the connector 406 in order to connect the communication line 405 of the tractor 401 in a loop.

[0161] According to the above configuration, it is possible to appropriately grasp the total number of power receiver coils 102 mounted on vehicle 400 by the output signal of the highest or the lowest power supply unit 181. In addition, in the configuration in which the power supply units 181 are connected in a ring shape, even when part of the ring-shaped transmission path is cut off, the number of coils can be continuously grasped by switching the order of signal transmission.

[0162] Other embodiments The above embodiments may be modified as follows, for example.

[0163] In the determination process of determining the power receivers 100 to be used for the wireless power transfer among the plurality of power receivers 100 (step S107 in FIG. 14), the load weight of the vehicle 400 (actually, the load weight of the trailer 402) may be acquired, and the number of power receivers 100 to be used for the wireless power transfer may be determined based on the load weight. In this case, when the load weight of the vehicle 400 is small (if the load weight is equal to or less than a predetermined value), the number of power receivers 100 to be used for wireless power transfer may be reduced.

[0164] Alternatively, in the determination process of determining the power receiver 100 to be used for the wireless power transfer among the plurality of power receivers 100 (step S107 in FIG. 14), the maximum input power Win of the vehicle 400 may be acquired, and the number of power receivers 100 to be used for the wireless power transfer may be determined based on the maximum input power Win. In this case, when the maximum input power Win is small (equal to or less than a predetermined value), the number of power receivers 100 to be used for wireless power transfer may be reduced.

[0165] When the power transmission mode of the ground power transmitter 20 is different, it is conceivable that a desirable power reception mode of the vehicle 400 may change. For example, it is conceivable that the installation interval of the ground power-transmitter coil unit 21 differs or the magnitude of the transmission power by the power transmitter 20 differs according to the travel path. In this case, in the vehicle 400, power reception (wireless power transfer) by the power receiver 100 may be performed while coping with the power transmission mode of the power transmitter 20. In consideration of this point, the power receiver 100 to be used for the wireless power transfer may be determined based on the information about the power transmission mode of the power transmitter 20. Specifically, the ECU 430 executes the process illustrated in FIG. 18. The process of FIG. 18 may be incorporated into the process of FIG. 14.

[0166] In FIG. 18, in step S201, information (power transmission information) about the power transmission mode of the power transmitter 20 is acquired. At this time, the installation interval of the power-transmitter coil unit 21 or the transmission power level of the power transmitter 20 is acquired as the power transmission information. In subsequent step S202, the power receiver 100 to be used for the wireless power transfer is determined based on the information about the power transmission mode of the power transmitter 20. At this time, when the installation interval of the power-transmitter coil unit 21 is narrow, the number of power receivers 100 (the number of active power receivers) to be used for wireless power transfer is reduced as compared with the case where the installation interval is wide. For example, when the installation interval is less than a predetermined value, the number of active power receivers is set to three, and when the installation interval is greater than or equal to the predetermined value, the number of active power receivers is set to five.

[0167] In this case, in a case where the installation interval of the power-transmitter coil unit 21 is narrow, when the power supply request signal is transmitted from the power-receiver communication coil 170 of the vehicle 400, there is a concern that the power supply request signal is unintentionally received by the plurality of power-transmitter communication coils 40 disposed in the vehicle front-rear direction, and the plurality of power transmitter coils 22 unnecessarily perform transmission. In this regard, unnecessary transmission by the plurality of power transmitter coils 22 is suppressed by reducing the number of power receivers 100 used for wireless power transfer, more specifically, by thinning out some of the plurality of power receivers 100.

[0168] Alternatively, when the transmission power level of the power transmitter 20 is large, the number of power receivers 100 used for the wireless power transfer is reduced as compared with the case where the transmission power level is small. For example, when the transmission power level is greater than or equal to a predetermined value, the number of active power receivers is set to three, and when the transmission power level is less than the predetermined value, the number of active power receivers is set to five. That is, when the transmission power level is large, a desired power receiving amount is realized by reducing the active power receiver 100, and when the transmission power level is small, a desired power receiving amount is realized by increasing the active power receiver 100.

[0169] As described above, for example, even when the power transmission mode of the power transmitter 20 changes according to the travel path, it is possible to appropriately perform the wireless power transfer of the vehicle 400.

[0170] It is conceivable that the required power receiving amount in the vehicle 400 is different between the powering state and the regeneration state of the motor 412. In consideration of this point, the power receiver 100 to be used for the wireless power transfer may be determined according to whether the motor 412 is in the powering state or the regeneration state. Specifically, the ECU 430 executes the process illustrated in FIG. 19. The process of FIG. 19 may be incorporated into the process of FIG. 14.

[0171] In FIG. 19, in step S301, information indicating whether the motor 412 is in the powering state or the regeneration state is acquired. In subsequent step S302, the power receiver 100 to be used for wireless power transfer is determined according to whether the motor 412 is in the powering state or the regeneration state. At this time, when the motor 412 is in the regeneration state, the number of active power receivers is reduced as compared with the case where the motor 412 is in the powering state. For example, in the regenerative state, the number of active power receivers is set to three, and in the powering state, the number of active power receivers is set to five.

[0172] As described above, appropriate wireless power transfer can be performed in both the powering state and the regeneration state of the motor 412.

[0173] When the power receiving amount in the vehicle 400 is changed, it is conceivable that the transmission power level of the power transmitter 20 is changed to cope with the change, and the number of power receivers 100 (the number of active power receivers) used for the wireless power transfer in the vehicle 400 is changed to cope with the change. In this case, comparing these two methods, for example, there is a difference in responsiveness at the time of changing the power receiving amount, and it is conceivable that switching of the power receiver 100 of the vehicle 400 is more responsive. In consideration of this point, when the power receiving amount of the vehicle 400 is changed, either the first change process of instructing the power transmitter 20 to change the transmission power level or the second change process of changing the number of active power receivers in the vehicle 400 may be selectively performed. Specifically, the ECU 430 executes the process illustrated in FIG. 20. The process of FIG. 20 may be incorporated into the process of FIG. 14.

[0174] In FIG. 20, in step S401, it is determined whether to change the power receiving amount in the vehicle 400. In a case where the power receiving amount is changed to increase or in a case where the power receiving amount is changed to decrease, step S401 is positive. When positive determination is made in step S401, the process proceeds to step S402.

[0175] In step S402, according to whether the power receiving amount is changed to increase or the power receiving amount is changed to decrease, the first change process of instructing the change of the transmission power level or the second change process of changing the number of active power receivers is selectively executed. An example thereof will be described below. At the present time, in a case where the number of active power receivers is the maximum number (for example, five), when the power receiving amount is changed to increase, the transmission power level is increased in the first change process, and when the power receiving amount is changed to decrease, the active power receivers are reduced in the second change process. In addition, in a case where the number of active power receivers is less than the maximum number (for example, three), when the power receiving amount is changed to increase, the number of active power receivers is increased in the second change process, and when the power receiving amount is changed to decrease, the transmission power level is lowered in the first change process.

[0176] Alternatively, the first change process and the second change process may be selectively executed according to the travel path. For example, in the case of a general road, when the power receiving amount in the vehicle 400 is changed, the second change process of changing the number of power receivers 100 is executed, and in the case of a motor way such as an expressway, the first change process of giving an instruction to change the transmission power level is executed.

[0177] As described above, by selectively executing the first change process and the second change process, it is possible to appropriately perform the wireless power transfer according to each situation.

[0178] When the plurality of power receivers 100 is mounted on the vehicle 400, a state (first state) in which some of the plurality of power receivers 100 are used for the wireless power transfer and a state (second state) in which all of the plurality of power receivers 100 are used for the wireless power transfer are assumed. In this case, comparing these two states, in the first state, it is possible to cause the power receiver 100 to perform power reception with high efficiency as a state close to 100% of the rated capacity. On the other hand, in each of these states, the degree of temperature rise of the power receivers 100 in the power reception state is different, and in the first state, heat may concentrate on some of the power receivers 100.

[0179] In consideration of this point, the first state in which some of the plurality of power receivers 100 are set to the power receivers 100 used for the wireless power transfer and the second state in which all of the plurality of power receivers 100 are set to the power receivers 100 used for the wireless power transfer may be switched based on the temperature information about the power receiver 100 in the vehicle 400. In this case, the first state can be said to be a state of full load operation since wireless power transfer is performed using all the power receivers 100 of the vehicle 400, and the second state can be said to be a state of partial load operation since wireless power transfer is performed using some of all the power receivers 100 of the vehicle 400. Specifically, the ECU 430 executes the process illustrated in FIG. 21. The process of FIG. 21 may be incorporated into the process of FIG. 14.

[0180] In FIG. 21, in step S501, temperature information about the power receiver 100 in the vehicle 400 is acquired. This temperature information is information indicating that the temperature of the power receiver 100 has risen or the power receiver 100 is in a situation where the temperature rises. The temperature information includes, for example, information about the temperature detected by the temperature sensor 442 in each power receiver 100 and information indicating that the temperature detected by the temperature sensor 442 has increased to a predetermined value or more. In addition, the temperature information may include information indicating that the state of high-speed traveling of the vehicle 400 is continued, and the temperature is in a situation in which temperature rise occurs due to high frequency of energization of each power receiver 100.

[0181] Thereafter, in step S502, it is determined whether the temperature of the power receiver 100 rises. When the temperature of the power receiver 100 does not rise, the process proceeds to step S503, and the in-vehicle power reception system is brought into a state (first state) in which some of the plurality of power receivers 100 are used for the wireless power transfer. When the temperature of the power receiver 100 has risen, the process proceeds to step S504, and the in-vehicle power reception system is brought into a state (second state) in which all of the plurality of power receivers 100 are used for wireless power transfer.

[0182] With this configuration, it is possible to perform appropriate wireless power transfer while considering the power reception efficiency and the temperature state of the power receiver 100.

[0183] When some power receivers of all the power receivers 100 mounted on the vehicle 400 have been put on standby due to factors such as abnormality information, battery information, destination information, and power consumption information, power receivers 100 except for the power receivers 100 that have been put on standby may be switched between the first state and the second state. Alternatively, when some power receivers 100 among all the power receivers 100 mounted on the vehicle 400 have been put on standby due to factors such as abnormality information, battery information, destination information, and power consumption information, power receivers 100 except for the power receivers 100 that have been put on standby may be constantly set to the second state (a state in which all the power receivers are used for wireless power transfer).

[0184] When a number of the power receivers 100, which is less than the total number of the power receivers 100 of the vehicle 400, is determined as the active power receivers (the power receiver used for the wireless power transfer), the ECU 430 sets a power receiver 100 to be put on standby (standby device setting unit). At this time, among the power receivers 100, the power receiver 100 to be put on standby may be changed every predetermined time. Specifically, the ECU 430 executes the process illustrated in FIG. 22. The process of FIG. 22 may be incorporated into the process of FIG. 14.

[0185] In FIG. 22, in step S601, it is determined whether some of the plurality of power receivers 100 mounted on the vehicle 400 are to be put on standby. When some of the plurality of power receivers 100 are to be put on standby, the process proceeds to step S602, and the power receivers 100 to be put on standby from power reception among the plurality of power receivers are switched in a predetermined order at predetermined time intervals. For example, when the number of power receivers 100 is four and the number of standby power receivers 100 is one, the standby power receivers 100 are switched in the order of first → second → third →... from the front of the vehicle 400. When there are two standby power receivers 100, the standby power receivers 100 are switched in order from the front of the vehicle 400, from the first and third to the second and fourth, and so on. This ensures equalization of heat generation among the power receivers 100.

[0186] When a plurality of power receivers 100 is mounted on the vehicle 400, it is conceivable that the plurality of power receivers 100 may include power receivers having different rated power receiving capabilities. For example, it is conceivable that the rated power receiving capability of the power receiver 100 mounted on the tractor 401 and the rated power receiving capability of the power receiver 100 mounted on the trailer 402 are different from each other. In consideration of this point, when wireless power transfer is performed using a smaller number of power receivers than the total number of power receivers 100 mounted on the vehicle 400, the ECU 430 preferentially determines a power receiver having a high rated power receiving capability within a range of a required power amount required at the time as a power receiver to be used for wireless power transfer. Specifically, the ECU 430 executes the process illustrated in FIG. 23. The process of FIG. 23 may be incorporated into the process of FIG. 14.

[0187] In FIG. 23, in step S701, it is determined whether some of the plurality of power receivers 100 mounted on the vehicle 400 are to be put on standby. In addition, in step S702, it is determined whether the plurality of power receivers 100 includes power receivers having different rated power receiving capabilities. When both steps S701 and S702 are YES, the process proceeds to step S703. In step S703, the power receiver 100 having the highest rated power receiving capability within the range of the required power receiving amount is preferentially determined as the power receiver 100 used for the wireless power transfer. The required power receiving amount is preferably determined by, for example, a traveling state of the vehicle 400, a state of charge (SOC) of the battery 411, and the like.

[0188] For example, it is assumed that the rated power receiving capabilities of the two power receivers 100 of the tractor 401 are each "5", and the rated power receiving capabilities of the two power receivers 100 of the trailer 402 are each "10". In such a case, when the required power receiving amount is "22.5", the two power receivers 100 of the trailer 402 and one power receiver 100 of the tractor 401 are set as the power receivers 100 used for the wireless power transfer. In this case, the wireless power transfer corresponding to the required power receiving amount is performed by the power receiving amount of "10+10+2.5 (half of 5)". When the required power receiving amount is "13", one power receiver 100 of the trailer 402 and one power receiver 100 of the tractor 401 are set as the power receivers 100 used for the wireless power transfer. In this case, the wireless power transfer corresponding to the required power receiving amount is performed by the power receiving amount of "10 +3 (3 / 5 of 5)".

[0189] According to this configuration, it is possible to perform power reception with high efficiency in a state close to 100% of the rated capacity while reducing the number of power receivers 100 to be used.

[0190] The form of the vehicle 400 may be any of the following forms.

[0191] As illustrated in FIG. 24, in the vehicle 400, two or more trailers 402 may be towed by the tractor 401. The power receiver 100 is mounted on each trailer 402.

[0192] As illustrated in FIG. 25, the vehicle 400 may have a configuration in which the towing unit and the towed unit are not separable. In this case, the vehicle 400 is a rigid type (cargo bed integrated type) truck or bus.

[0193] As illustrated in FIG. 26, in the vehicle 400, only the motor 412 out of the battery 411 and the motor 412 may be mounted on the tractor 401. That is, the battery 411 is not mounted. In this case, the power received by each power receiver 100 is supplied to the motor 412, and the vehicle 400 travels by motor driving by the power supply.

[0194] In addition, the vehicle 400 may be a vehicle other than a truck or a bus. For example, a trailer, a motorhome, or the like that is a towed unit and includes the power receiver 100 may be towed behind the passenger vehicle including the power receiver 100.

[0195] The method of wireless power transmission by the power transmitting antenna and the power receiving antenna is not limited to the magnetic field resonance method, and may be an electric field coupling method. In this case, a power transmitting antenna and a power receiving antenna that are different from the coil and are of an electric field coupling system may be used.

[0196] The power-transmitter communication coil 40 and the power-receiver communication coil 170 are only required to be a power-transmitter communication antenna and a reception communication antenna in a broad sense, and are not limited to the communication coil, and various antennas can be used. For example, the communication antenna is a dipole antenna or a monopole antenna.

[0197] The controller and the method thereof described in the present disclosure may be realized by a dedicated computer provided by configuring a processor and a memory programmed to execute one or a plurality of functions embodied by a computer program. Alternatively, the controller and the method thereof described in the present disclosure may be realized by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the controller and the method thereof described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transition tangible storage medium as an instruction executed by a computer.

[0198] While the present disclosure has been described with reference to various exemplary embodiments thereof, it is to be understood that the disclosure is not limited to the disclosed embodiments and constructions. To the contrary, the disclosure is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the disclosure are shown in various combinations and configurations, which are exemplary, other various combinations and configurations, including more, less or only a single element, are also within the spirit of the disclosure.

Claims

1. An in-vehicle power receiving system for a wireless power transfer system (10), the wireless power transfer system including a power transmitting antenna (22) provided at a travel path and an in-vehicle power receiving antenna (102), and performing wireless power transfer between the power transmitting antenna at the travel path and the in-vehicle power receiving antenna when a vehicle (400) travels on the travel path, the power receiving antenna being one of two or more power receiving antennas mountable on the vehicle, the in-vehicle power receiving system comprising: a recognition unit configured to recognize power receiving capability information indicating a power receiving capability of the vehicle by the power receiving antennas mounted on the vehicle; and a power receiving control unit configured to perform power receiving control based on the power receiving capability information recognized by the recognition unit.

2. The in-vehicle power receiving system according to claim 1, wherein the recognition unit is configured to recognize the power receiving capability information as a number of the power receiving antennas mounted on the vehicle.

3. The in-vehicle power receiving system according to claim 1, wherein the vehicle includes a towing unit (401) and a towed unit (402) towed by the towing unit, the towing unit and the towed unit are separable from each other, and each of the towing unit and the towed unit includes a power receiving antenna, and the recognition unit is configured to recognize the power receiving capability information about the power receiving antennas including the power receiving antenna of the towing unit and the power receiving antenna of the towed unit in the vehicle.

4. The in-vehicle power receiving system according to claim 3, wherein the recognition unit is configured to recognize each of the power receiving capability information about the power receiving antenna of the towing unit and the power receiving capability information about the power receiving antenna of the towed unit in the vehicle.

5. The in-vehicle power receiving system according to claim 1, wherein the power receiving antennas constitutes power receivers (100) configured to acquire state information indicating a state of the power receiving antennas, and the in-vehicle power receiving system further comprising a power receiving determination unit configured to receive the state information from each of the power receivers and determine for each of the power receivers whether to perform wireless power transfer to the power receivers based on the state information.

6. The in-vehicle power receiving system according to any one of claims 1 to 5, wherein the power receiving antennas are connected to power converters (181), respectively, the power converters of the power receiving antennas are connectable in series via a communication line (405) in the vehicle, each of the power converters is configured to output, via the communication line, a signal corresponding to presence or absence of a power converter connected at a lower stage than itself or a signal corresponding to a rated power receiving amount of a power receiving antenna corresponding to a power converter connected at a lower stage than itself, in an arrangement order where a front side of the vehicle is a higher stage and a rear side of the vehicle is a lower stage, and the recognition unit is configured to recognize the power receiving capability information as a total number of the power receiving antennas or a total rated power receiving amount of the power receiving antennas, in the vehicle based on signals output from the power converters.

7. The in-vehicle power receiving system according to any one of claims 1 to 5, wherein the vehicle includes a towing unit (401) and a towed unit (402) towed by the towing unit, the towing unit and the towed unit are separable from each other, and each of the towing unit and the towed unit includes a power receiving antenna, the power receiving antennas mounted on the towing unit and the towed unit are connected to power converters (181), respectively, power converters of power receiving antennas in the towed unit are connectable in series via a communication line (405B), each of the power converters of the towed unit is configured to output, via the communication line, a signal corresponding to presence or absence of a power converter connected at a lower stage than itself or a signal corresponding to a rated power receiving amount of a power receiving antenna corresponding to a power converter connected at a lower stage than itself, in an arrangement order where a side closer to the towing unit is a higher stage and a side farther from the towing unit is a lower stage, the towing unit includes a controller (430) including the recognition unit and the power receiving control unit, and the recognition unit of the controller is configured to recognize the power receiving capability information as a total number of the power receiving antennas or a total rated power receiving amount of the power receiving antennas in the vehicle, based on a known number or a known rated power receiving amount of the power receiving antenna in the towing unit and a number or a rated power receiving amount of the power receiving antennas recognized from signals output from the power converters of the towed unit.

8. The in-vehicle power receiving system according to any one of claims 1 to 5, wherein the power receiving antennas are connected to power converters (181), respectively, the power converters of the respective power receiving antennas in the vehicle are individually connected via a bus line (405) to a controller (430) configured to execute a recognition process of the recognition unit, the power converters are connected in series via a connection line (407) which is connected to the controller and capable of transmitting one specific signal, each of the power converters is configured to output, via the connection line, a signal corresponding to presence or absence of connection of a power converter located at a lower stage by one than itself, in an arrangement order where a front side of the vehicle is a higher stage and a rear side of the vehicle is a lower stage, and the recognition unit is configured to recognize the power receiving capability information as a number of the power receiving antennas in the vehicle based on signals output from the power converters.

9. The in-vehicle power receiving system according to any one of claims 1 to 5, wherein the power receiving antennas are connected to power converters (181), respectively, the power converter of the respective power receiving antennas in the vehicle are individually connected via a bus line (405) to a controller (430) configured to execute a recognition process of the recognition unit, each of the power converters is configured to output a predetermined response signal in response to a request from the controller, and the recognition unit is configured to recognize the power receiving capability information as a number of the power receiving antennas in the vehicle based on a number of the power converters outputting the response signal.

10. The in-vehicle power receiving system according to any one of claims 1 to 5, wherein the power receiving antennas are connected to power converters (181), respectively, the power converters of the respective power receiving antennas in the vehicle are connectable in series and in a ring shape via a communication line (405), each of the power converters is configured to output a signal indicating a presence of itself in an arrangement order where a front side of the vehicle is a higher stage and a rear side of the vehicle is a lower stage, and the recognition unit is configured to recognize the power receiving capability information as a number of the power receiving antennas in the vehicle based on a signal output from a power converter at a highest or lowest stage.

11. A wireless power transfer system (10) comprising: a power transmitter (20) including a power transmitting antenna (22) provided at a travel path; a power receiver (100) mounted on a vehicle (400) and including a power receiving antenna (102) configured to perform wireless power transfer with the power transmitting antenna; and a controller (430) configured to perform signal transmission to the power receiver, wherein the power receiving antenna is one of two or more power receiving antennas mountable on the vehicle, and the controller is configured to perform a recognition process of recognizing power receiving capability information, which indicates a power receiving capability of the vehicle by the power receiving antennas mounted on the vehicle, based on a signal output from the power receiver, and a power receiving control process of performing power receiving control based on the power receiving capability information recognized in the recognition process.

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