Power receiver, program, and method for controlling power receiver

Abstract

A power receiver controller (231) provided in the subject vehicle determines whether an abnormality occurs in the subject vehicle, determines whether another vehicle is present on a same power transmitter coil (22) as the subject vehicle when determining that an abnormality occurs in the subject vehicle, and executes a resolution process to resolve an abnormality of the subject vehicle without requesting a power transmitter (20) to stop power transfer from the power transmitter coil (22) to the power receiver coil (102) when determining that the other vehicle is present.

Description

POWER RECEIVER, PROGRAM, AND METHOD FOR CONTROLLING POWER RECEIVERCross Reference

[0001] This application is based on Japanese Application No. 2025-019561 filed on February 07, 2025, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a power receiver, a program, and a method for controlling the power receiver.

[0003] Conventionally, as described in Patent Literature 1, for example, a wireless power transfer system has been known which includes a power transmitter circuit including a power transmitter coil arranged in a vehicle's travel path, and a power receiving circuit including a power receiver coil and provided in the vehicle. The wireless power transfer system performs wireless power transfer from the power transmitter coil to the power receiver coil.

[0004] JP2024-122073A

[0005] An abnormality may occur in a subject vehicle. In such case, it is desirable to resolve the abnormality of the subject vehicle while causing as little inconvenience as possible to other vehicles in the vicinity of the subject vehicle.

[0006] It is a main object of the present disclosure to provide a power receiver, a program, and a control method for a power receiver that can resolve an abnormality in a subject vehicle while causing minimal inconvenience in other vehicles in the vicinity of the subject vehicle.

[0007] The present disclosure relates to a power receiver applicable to a wireless power transfer system. The wireless power transfer system includes a power transmitter, which is a ground-side device including a power transmitter antenna, and a power receiver, which is provided to a vehicle and including a power receiving antenna, the power receiver configured to transmit a power transfer request signal to the power transmitter for requesting power transfer, and the power transmitter configured to perform wireless power transfer to the power receiving antenna by energizing the power transmitter antenna when receiving the power transfer request signal. The power receiver comprises: a controller provided to a subject vehicle. The controller is configured to determine whether an abnormality occurs in the subject vehicle, when determining that an abnormality occurs in the subject vehicle, determine whether an other vehicle is present on a same power transmitter antenna as the subject vehicle, and when determining that an other vehicle is present, execute a resolution process to resolve the abnormality of the subject vehicle without requesting the power transmitter to stop power transfer from the power transmitter antenna to the power receiving antenna.

[0008] In a situation in which an abnormality occurs in the subject vehicle, there may be cases where another vehicle is present on the same power transmitter antenna as the subject vehicle. In such case, when a request is made to the power transmitter to stop power transfer from the power transmitter antenna to the power receiving antenna in order to resolve the abnormality in the subject vehicle, wireless power transfer to the other vehicle or vehicles will also be stopped.

[0009] Therefore, in the present disclosure, the control device of the subject vehicle performs a resolution process to resolve the abnormality in the subject vehicle without requesting the power transmitter to stop power transfer. In such manner, the abnormality in the subject vehicle is resolvable while minimizing inconvenience to the other vehicle or vehicles in the vicinity of the subject vehicle.

[0010] The drawings described herein are intended to illustrate selected embodiments, do not depict all possible embodiments, and are not intended to limit the scope of the present disclosure.FIG. 1 is an overall configuration diagram of a wireless power transfer system according to a first embodiment.FIG. 2 is an overall configuration diagram of the wireless power transfer system.FIG. 3 is a diagram of a power transmitter and a power receiver.FIG. 4 is a configuration diagram of wide-area wireless communication between the power transmitter and a vehicle.FIG. 5 is a flowchart of a process performed by the power receiver.FIG. 6 is a diagram of a lateral shift of the vehicle.FIG. 7 is a diagram of an outline of a lane receding process.FIG. 8 is another diagram of an outline of a lane receding process.FIG. 9 is yet another diagram of an outline of a lane receding process.FIG. 10 is a flowchart of a process performed by a power receiver according to a second embodiment.FIG. 11 is a diagram of an outline of a short-circuit process.FIG. 12 is a diagram of a power receiver according to a modified example of the second embodiment.FIG. 13 is a diagram of an outline of a process performed by a power receiver according to other embodiments.

[0011] Multiple embodiments will be described with reference to the drawings. In multiple embodiments, functionally and / or structurally corresponding and / or related parts may be labeled with the same reference numerals or with reference numerals that differ in the hundredth or higher digits. Thus, the explanation in the other embodiments may be referrable with respect to the corresponding and / or related parts.

[0012] <First Embodiment> The first embodiment of a wireless power transfer system in the present disclosure will be described below with reference to the drawings.

[0013] First, an overall configuration of the wireless power transfer system will be described. As shown in FIGs. 1, 2 and 3, a wireless power transfer system 10 includes a power transmitter 20 and a power receiver 100. The power receiver 100 is a vehicle-side device, which is mounted on a vehicle 11, which is a moving object traveling on a road RS. The vehicle 11 is, for example, an electric vehicle or a hybrid vehicle. While the vehicle 11 is traveling or stopped, electric power is supplied from the power transmitter 20 to the power receiver 100. The wireless power transfer system 10 performs wireless power transfer from the power transmitter 20 to the power receiver 100 by magnetic field resonant coupling (magnetic field resonance). The wireless power transfer system 10 is also called a dynamic wireless power transfer (D-WPT) system.

[0014] The power transmitter 20 is a ground-side device, and has a power-transmitter coil unit 21 and a power-transmitter power transfer unit 51 that supplies electric 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, buried) in the road RS, a parking lot, or the like. The power-transmitter power transfer unit 51 is installed, for example, at a side of the road RS. The power-transmitter coil unit 21 is connected to the power-transmitter power transfer unit 51. The power-transmitter power transfer unit 51 is connected to an AC electric power source 15, and supplies AC electric power from the AC electric power source 15 to the power-transmitter coil unit 21. The AC electric power source 15 is, for example, a commercial power source. A plurality of power-transmitter coil units 21 are disposed along the lanes of the road RS. FIG. 2 shows an example in which four power-transmitter coil units 21 arranged in a row along the road RS are connected to one power-transmitter power transfer unit 51. In other words, one power-transmitter power transfer unit 51 is provided for every four power-transmitter coil units 21. Multiple power-transmitter coil units 21 are arranged at predetermined intervals in the vehicle travel direction. The power-transmitter coil units 21 are installed at intervals of, for example, about 1.5 to 2 m between the center positions of the power-transmitter coil units 21 in the vehicle travel direction, and the distance between the power-transmitter coil units 21 is, for example, about 0.5 to 0.8 m. In FIG. 2, the installation interval between the power-transmitter coil units 21 is designated as D1.

[0015] Note that the configuration is not limited to the one in which one power-transmitter power transfer unit 51 for each of the multiple power-transmitter coil units 21, and may also include the one in which one power-transmitter power transfer unit 51 is provided for each of the multiple power-transmitter coil units 21.

[0016] The power-transmitter power transfer unit 51 includes a PFC circuit 61, an inverter 60, and a filter circuit 52. The PFC circuit 61 includes an AC / DC converter, and is connected to the AC electric power source 15. The PFC circuit 61 includes switching elements (e.g., IGBTs or MOSFETs) that are switched and controlled to convert the input AC electric power to DC (direct current) electric power and to improve a power factor of the AC electric power input from the AC electric power source 15.

[0017] The inverter 60 is connected to the PFC circuit 61. The DC electric power input from the PFC circuit 61 is converted into the AC electric power by controlling the switching of switching elements (for example, IGBTs or MOSFETs) S1H, S1L, S2H, and S2L included in the inverter 60.

[0018] The filter circuit 52 removes noise contained in an AC electric current input from the inverter 60, and supplies the noise-removed AC electric current to the power-transmitter coil unit 21. The filter circuit 52 is, for example, an LC filter including a coil and a capacitor. Circuits having various configurations are usable as the filter circuit 52, and, for example, a T-type filter circuit is used as the filter circuit 52.

[0019] The power-transmitter coil unit 21 includes a power transmitter coil 22 (corresponding to a “power transmitter antenna”), a power-transmitter resonant circuit 30, and a power-transmitter communication coil 40. The power-transmitter resonant circuit 30 supplies the AC electric power supplied from the filter circuit 52 to the power transmitter coil 22. The power-transmitter resonant circuit 30 can employ various well-known resonant circuits such as a circuit including a resonant capacitor.

[0020] Note that, in the present embodiment, the inverter 60, the filter circuit 52 and the power-transmitter resonant circuit 30 constitute a power transmitter circuit 400.

[0021] The power receiver 100 includes a power-receiver coil unit 101 and a power-receiver power transfer 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 a bottom of a vehicle body of the vehicle 11. The power-receiver coil unit 101 is provided at the bottom of the vehicle body to face a ground surface. When the vehicle 11 travels on the road RS where the power transmitter coil 22 is buried, the power transmitter coil 22 on the ground side and the power receiver coil 102 of the vehicle 11 face each other in a vertical direction.

[0022] 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. Electric power is transmitted to the power receiver coil 102 from the power transmitter coil 22. The power receiver coil 102 supplies the received electric power to the power-receiver resonant circuit 140. The power-receiver resonant circuit 140 can employ various well-known resonant circuits such as a circuit including a resonant capacitor.

[0023] The power receiver 100 includes a filter circuit 182, a rectifier circuit 200 that functions as a DC-AC conversion circuit, and a smoothing capacitor 210. The filter circuit 182 removes noise contained in the AC electric current input from the power-receiver resonant circuit 140, and supplies the noise-removed AC electric 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 that includes a reactor and a capacitor.

[0024] The rectifier circuit 200 converts the input AC electric current into a DC electric current, and outputs the DC electric current. The rectifier circuit 200 is, for example, a full-bridge circuit including semiconductor switching elements, or a diode rectifier circuit. The rectifier circuit 200 of the present embodiment is a full-bridge circuit including switching elements (for example, IGBTs or MOSFETs) Q1H, Q1L, Q2H, and Q2L (see FIGs. 5 and 6). A first end of the smoothing capacitor 210 is connected to a high-potential side output terminal of the rectifier circuit 200. A second end of the smoothing capacitor 210 is connected to a low potential side output terminal of the rectifier circuit 200. The rectifier circuit 200 may also be referred to as an ERB (Electronic Rectification Box).

[0025] In the present embodiment, the power-receiver resonant circuit 140, the filter circuit 182 and the rectifier circuit 200 constitute a power receiving circuit 500.

[0026] The vehicle 11 includes a high-potential side main switch 301H, a low potential side main switch 301L, and a high-voltage power storage battery 300 as a power storage unit. The high-potential side main switch 301H and the low potential side main switch 301L are, for example, relays (specifically, mechanical relays). A high-potential side output terminal of the rectifier circuit 200 is connected to a positive electrode terminal of the high-voltage power storage battery 300 via the high-potential side main switch 301H. A low potential side output terminal of the rectifier circuit 200 is connected to a negative electrode terminal of the high-voltage power storage battery 300 via the low potential side main switch 301L. The high-voltage power storage battery 300 is a secondary battery that can be charged and discharged, and has a rated voltage of, for example, several hundred volts. The high-voltage power storage battery 300 is, for example, a lithium-ion storage battery or a nickel-metal hydride storage battery.

[0027] The vehicle 11 includes a traveling inverter 310 and a rotary electric machine 320. The traveling inverter 310 is a three-phase inverter, and is connected to the high-voltage power storage battery 300 via the high-potential side main switch 301H and the low potential side main switch 301L. An armature winding of the rotary electric machine 320 is connected to upper and lower arm switches constituting the traveling inverter 310. With the high-potential side main switch 301H and the low potential side main switch 301L turned on, the switching of the upper and lower arm switches of the traveling inverter 310 is controlled such that the traveling inverter 310 converts the DC electric power supplied from the high-voltage power storage battery 300 into the AC electric power, and supplies the AC electric power to the armature winding. In such manner, a rotor of the rotary electric machine 320 rotates, and wheels 12 (drive wheels) of the vehicle 11 rotate by a rotational power of the rotor. As a result, the vehicle 11 travels. In the present embodiment, the high-voltage power storage battery 300 and the traveling inverter 310 correspond to a “target device receiving supply of electric power.”

[0028] The power-transmitter power transfer 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 controls of the power transmitter 20, and includes, as hardware, a processor, a storage unit, and a communication bus connecting the processor and the storage unit.

[0029] The storage unit includes a memory and a storage as hardware. The memory is a storage device for storing data used in the process of the power transmitter controller 71. The memory provides the processor with, for example, a working area for temporary use when the processor executes a process. The memory includes, for example, a ROM or a RAM. The storage is a storage device that stores various programs and data to be read and executed by the processor, and is a non-transitory, tangible storage medium. The storage includes, for example, an HDD or a flash memory. The storage stores program information and other information for the processes described below.

[0030] The power-receiver power transfer unit 181, which constitutes the power receiver 100, includes a power receiver controller 231. The power receiver controller 231 is an ECU that performs various controls of the power receiver 100, and includes, as hardware, a processor, a storage unit, and a communication bus that connects the processor and storage unit.

[0031] The storage unit includes memory and storage as hardware. The memory is a storage device for storing data used in the process of the power receiver controller 231. The memory provides the processor with, for example, a working area for temporary use when the processor executes a process. The memory includes, for example, a ROM or a RAM. The storage is a storage device that stores various programs and data to be read and executed by the processor, and is a non-transitory, tangible storage medium. The storage includes, for example, an HDD or a flash memory. The storage stores program information and other information for the processes described below.

[0032] The power receiver 100 includes a magnetic field sensor 311 and a temperature sensor 312. The magnetic field sensor 311 detects the magnetic field strength in the vicinity of the vehicle 11. The temperature sensor 312 detects the temperatures of various components of the vehicle 11 (specifically, for example, the wheels, the body of the vehicle, or components of the power receiver 100). The detected values of the sensors 311 and 312 are input to the power receiver controller 231.

[0033] The power transmitter controller 71 controls the switching of the PFC circuit 61 and the inverter 60. A high-frequency AC voltage is applied to the power transmitter coil 22 by controlling the switching of the inverter 60. Therefore, a high-frequency electric current flows through the power transmitter coil 22, and a magnetic field for power transmission is generated in the power transmitter coil 22.

[0034] In the present embodiment, the power transmitter controller 71 controls the switching of the inverter 60 so that the frequency of the high-frequency voltage applied to the power transmitter coil 22 becomes a first specified frequency that is equal to or higher than 10 kHz and equal to or lower than 100 GHz (specifically, 85 kHz). The resonance frequencies of the power-transmitter resonant circuit 30 and the power-receiver resonant circuit 140 are set to the same frequency as the first specified frequency or to a frequency close to the first specified frequency.

[0035] When the magnetic field generated in the power transmitter coil 22 interlinks with the power receiver coil 102 of the vehicle 11, a high-frequency electric current that fluctuates with the frequency of the high-frequency electric current flowing through the power transmitter coil 22 flows through the power receiver coil 102. The high-frequency electric 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 AC electric current into a DC electric current and outputs the DC electric current. When the high-potential side main switch 301H and the low potential side main switch 301L are turned on, an output current of the rectifier circuit 200 is supplied to the high-voltage power storage battery 300 and the traveling inverter 310.

[0036] The vehicle 11 includes a low-voltage power storage battery 302. The rated voltage of the low-voltage power storage battery 302 is lower than the rated voltage of the high-voltage power storage battery 300. The low-voltage power storage battery 302 is, for example, a lead power storage battery. When electric power is supplied from the low-voltage power storage battery 302 to the power receiver controller 231, the power receiver controller 231 becomes operable.

[0037] The power receiver 100 and the power transmitter 20 each have a configuration for communication between the power receiver 100 and the power transmitter 20. In detail, the power-receiver coil unit 101 constituting the power receiver 100 includes a power-receiver communication coil 170 (corresponding to a “power-receiver communication antenna”). A power-receiver control unit 230 includes a transmitter 240.

[0038] The power-transmitter coil unit 21, which constitutes the power transmitter 20, includes the power-transmitter communication coil 40 (corresponding to a “power-transmitter communication antenna”). The power-transmitter control unit 70 includes a receiver 80. The power-receiver communication coil 170 and the power-transmitter communication coil 40 are communication coils for performing short range wireless communication. The short range wireless communication is a communication with a communication distance of less than 10 meters (for example, a maximum of 3 meters). The short range wireless communication is a communication with a shorter communication distance than wide-area wireless communication.

[0039] As the short range wireless communication, various near field communication methods can be used, and for example, communication conforming to any communication standard established by IEEE, ISO, IEC, or the like is used. Specifically, for example, Wi-Fi (registered trademark), Bluetooth (registered trademark), ZigBee (registered trademark), RFID (Radio Frequency Identification), or DSRC (Dedicated Short Range Communication) is used as short range wireless communication.

[0040] The transmitter 240 is connected to the power receiver controller 231. The power-receiver communication coil 170 is connected to the transmitter 240. The power receiver controller 231 controls the transmitter 240 to supply a power transfer request signal COMM to the power-receiver communication coil 170. The power transfer request signal COMM is a signal requesting the power transmitter coil 22 near the vehicle 11 to transmit electric power to the power receiver coil 102.

[0041] The power-receiver control unit 230 includes a vehicle-side signal, which contains the power transfer request signal COMM, into one frame and supplies the frame to the power-receiver communication coil 170. In such manner, a high-frequency voltage is applied from the transmitter 240 to the power-receiver communication coil 170. As a result, a high-frequency electric 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. In the present embodiment, the power transfer request signal includes ID information that identifies the vehicle 11 and a requested electric power Weq, which is a requested value of electric power to be supplied to the vehicle 11.

[0042] When the magnetic field generated by the power-receiver communication coil 170 interlinks with the power-transmitter communication coil 40 in a state in which the power-receiver coil unit 101 of the vehicle 11 comes close to the power-transmitter coil unit 21 on the ground side, a high-frequency electric current flows through the power-transmitter communication coil 40. This high-frequency electric current is input to the receiver 80. The receiver 80 recognizes the presence or absence of a power transfer request and the ID information based on the input signal from the power-transmitter communication coil 40. Also, the receiver 80 acquires the requested electric power Weq of the vehicle 11 having the recognized ID information based on the signal from the power-transmitter communication coil 40. The information recognized by the receiver 80 and the requested electric power Weq are input to the power transmitter controller 71.

[0043] In the present embodiment, the power receiver controller 231 controls the transmitter 240 so that the frequency of the high-frequency voltage applied to the power-receiver communication coil 170 becomes a second specified frequency equal to or higher than 10 kHz and equal to or lower than 100 GHz. In the present embodiment, the second specified frequency is a frequency that deviates from the first specified frequency described above, specifically a frequency higher than the first specified frequency (specifically, 13.56 MHz).

[0044] The power transmitter controller 71 determines whether to energize the power transmitter coil 22 based on the input signal from the receiver 80. In detail, on condition that it is determined that there is a power transfer request based on an input signal from the receiver 80, the power transmitter controller 71 applies a high-frequency voltage to the power transmitter coil 22 by controlling the switching of the inverter 60 and the PFC circuit 61.

[0045] More specifically, when it is determined that there is no power transfer request, the power transmitter controller 71 stops a switching control of the PFC circuit 61 and the inverter 60. As a result, the switching elements of the PFC circuit 61 and the inverter 60 are kept off, and the power transmitter coil 22 is not energized.

[0046] On the other hand, when it is determined that there is a power transfer request, the power transmitter controller 71 applies a high-frequency voltage to the power transmitter coil 22 by performing the switching control of the PFC circuit 61 and the inverter 60 for a predetermined period of time. In such manner, a high-frequency electric current flows through the power transmitter coil 22 for a predetermined period of time. In such case, wireless power transfer from the power transmitter coil 22 to the power receiver coil 102 that faces the power transmitter coil 22 in the vertical direction is performed. After energizing the power transmitter coil 22 for a predetermined period of time, the power transmitter controller 71 does not energize the power transmitter coil 22 until it determines next time that there is a power transfer request.

[0047] FIG. 4 is a schematic diagram for illustrating wide-area wireless communication in the wireless power transfer system 10. In the wireless power transfer system 10, each vehicle 11 is communicable via the power transmitter 20 and a communication network 16. The communication network 16 includes, for example, a wide area network (WAN), which is a public communication network such as the Internet, a telephone communication network for mobile phones, an information and communication network for ETC, and an information and communication network for road and communication, which is designated as Vehicle Information and Communication System or VICS (registered trademark). The wide-area wireless communication has a longer communication distance than short range wireless communication. The wide-area wireless communication is communication with a communication distance of, for example, 10 meters to 10 kilometers. Examples of the wide-area wireless communication include 3GPP (registered trademark), 4G, LTE, 5G defined by IEEE, and WiMAX (registered trademark).

[0048] The vehicle 11 includes a position sensor 330, a navigation device 331, and a communication unit 332. The position sensor 330 is a sensor that detects the current position of the vehicle, and is, for example, a GPS sensor. The storage unit (for example, storage) of the navigation device 331 stores map information including road information. The navigation device 331 receives information on the current position of the vehicle detected by the position sensor 330 and weather information. The power-transmitter control unit 70 of the power transmitter 20 includes a communication unit 90. The communication unit 332 of the vehicle 11 and the communication unit 90 of the power-transmitter control unit 70 perform wide-area wireless communication via the communication network 16.

[0049] The wireless power transfer system 10 includes a server 410. The server 410 is, for example, a cloud server, and includes a server control device 411 and a communication unit 412. The server control device 411 is an electronic control unit (ECU) that performs various controls of the server 410, and includes a processor as hardware, a storage unit, and a communication bus that connects the processor and the storage unit. The storage unit includes memory and storage as hardware. The memory is a storage device for storing data used in the process of the server control device 411. The memory provides the processor with, for example, a working area for temporary use when the processor executes a process. The memory includes, for example, a ROM or a RAM. The storage is a storage device that stores various programs and data to be read and executed by the processor, and is a non-transitory, tangible storage medium. The storage includes, for example, an HDD or a flash memory. The storage stores program information and other information for the processes described below.

[0050] The server control device 411 is connected to the communication unit 412. The server control device 411 performs wide-area wireless communication with the communication unit 332 of the vehicle 11 and the communication unit 90 of the power-transmitter control unit 70 via the communication unit 412 and the communication network 16.

[0051] Note that, for example, program information stored in a non-transitory, tangible storage medium is installed in the storage units of the power receiver controller 231, the power transmitter controller 71, and the server control device 411. The storage medium is, for example, a USB memory, a CD-ROM, or a DVD. Further, for example, program information transmitted via the communication network 16, such as over the air (OTA), is installed in the storage unit.

[0052] An abnormality may occur in the vehicle while it is traveling. In such case, it is desirable to resolve the abnormality in the subject vehicle while causing as little inconvenience as possible to other vehicles in the vicinity of the subject vehicle. For example, as shown in FIG. 7, the ground-side power transmitter coil 22 may have an elongated shape extending in the vehicle travel direction. In such case, a situation may arise in which a subject vehicle 1010 and an other vehicle 600 are present on one power transmitter coil 22. In such situation, when the subject vehicle 1010 transmits a signal requesting the stop of wireless power transfer, the power transfer from the power transmitter coil 22 to the subject vehicle 1010 will be stopped, and the power transfer to the other vehicle 600 will also be stopped. Such a situation should be avoided as much as possible.

[0053] Therefore, the processor of the power receiver controller 231 provided in the subject vehicle 1010 of the present embodiment performs the process shown in FIG. 5.

[0054] In step S10, the power receiver controller 231 determines whether a lateral shift abnormality has occurred in the subject vehicle 1010. The abnormality described above will be explained in the following. D2 shown in FIG. 6 is a degree of deviation, and is a distance in the vehicle width direction between (a) a center position in a vehicle width direction of the power-receiver coil unit 101 (the power-receiver communication coil 170) and (b) a center position in the vehicle width direction of the power-transmitter coil unit 21 (the power-transmitter communication coil 40) when the vehicle 11 is traveling on a lane LL. A lateral shift abnormality is an abnormality in which the degree of deviation D2 exceeds a predetermined value. Note that, in FIG. 6, 501 indicates a communication range of the power-receiver communication coil 170. The communication range is an elliptical communication range. That is, in such case, the communication range in the vehicle width direction becomes narrower as one approaches the front or rear end of the vehicle in a vehicle length direction. In other words, the communication range in the vehicle length direction becomes narrower as one approaches the ends in the vehicle width direction.

[0055] In during-travel power transfer while the vehicle is traveling, wireless power transfer may be performed in a state where the degree of deviation D2 is large compared to power transfer while the vehicle is stopped. When a lateral shift abnormality occurs in the subject vehicle 1010, the magnetic flux may affect unexpected vehicle components (for example, wheels or sensors near the wheels), which may cause the components to overheat or break down.

[0056] The power receiver controller 231 may determine that a lateral shift abnormality has occurred, for example, when it determines that the magnetic field strength near the above-mentioned component detected by the magnetic field sensor 311 exceeds a strength threshold value, or when it determines that the temperature of the above-mentioned component detected by the temperature sensor 312 exceeds a temperature threshold value.

[0057] Further, the power receiver controller 231 may determine that a lateral shift abnormality has occurred when, for example, (a) calculating a degree of deviation D2 based on information received by the wide-area wireless communication, such as the current position information of the subject vehicle 1010 detected by the position sensor 330 and road information, and (b) determining that the calculated degree of deviation D2 exceeds a predetermined value.

[0058] When the power receiver controller 231 determines that a lateral shift abnormality has occurred, the process proceeds to step S11, and performs a resolution process to resolve the lateral shift abnormality of the subject vehicle 1010. The resolution process is, for example, a process of notification to a driver of the subject vehicle 1010, for example, by a display on or a voice from the navigation device 331, for steering in a manner that will bring the degree of deviation D2 closer to 0 and resolve the lateral shift abnormality. The resolution process may also be a process of instructing a steering device of the subject vehicle 1010 to perform an automatic operation to bring the degree of deviation D2 closer to 0 and resolve the lateral shift abnormality, for example.

[0059] In the resolution process, the power-receiver communication coil 170 does not transmit a stop request signal. In such manner, the lateral shift abnormality of the subject vehicle 1010 is resolvable while minimizing inconvenience to other vehicles as much as possible.

[0060] In step S12, the power receiver controller 231 determines whether the lateral shift abnormality of the subject vehicle 1010 has been resolved by the resolution process in step S11.

[0061] For example, the power receiver controller 231 may determine that the lateral shift abnormality has been resolved (a) when it determines that the magnetic field strength near the above-mentioned component detected by the magnetic field sensor 311 is equal to or lower than the strength threshold value, or (b) when it determines that the temperature of the above-mentioned component detected by the temperature sensor 312 is equal to or lower than the temperature threshold value.

[0062] Also, for example, when it is determined that the degree of deviation D2 calculated by the above-described method is equal to or lower than a predetermined value, the power receiver controller 231 may determine that the lateral shift abnormality has been resolved.

[0063] When the power receiver controller 231 makes a negative determination in step S10 or makes an affirmative determination in step S12, the power receiver controller 231 once ends the series of processes shown in FIG. 5. On the other hand, when the power receiver controller 231 determines in step S12 that the lateral shift abnormality has not been resolved, the process proceeds to step S13. That is, when it is determined again that a lateral shift abnormality has occurred, the process proceeds to step S13. In step S13, the power receiver controller 231 determines whether the subject vehicle 1010 can recede to an adjacent lane L2 adjacent to the lane L1 on which the subject vehicle 1010 is traveling, as shown in FIGs. 7 and 8. For example, the power receiver controller 231 determines that the subject vehicle 1010 cannot recede to the adjacent lane L2, when, for example, it determines that an other vehicle 601 is present in the adjacent lane L2 near the subject vehicle 1010 based on (a) image information from a camera device that captures images of the area around the subject vehicle 1010 or (b) detection information from a sonar device that detects objects near the subject vehicle 1010, which are on-board devices of the subject vehicle 1010. On the other hand, when the power receiver controller 231 determines that there is no other vehicle 601 in the adjacent lane L2 near the subject vehicle 1010, it determines that the subject vehicle 1010 can recede to the adjacent lane L2.

[0064] Note that a receding area into which the subject vehicle 1010 is to recede is not limited to the adjacent lane L2, but may be, for example, a shoulder strip L3 adjacent to the lane L1 as shown in FIG. 9. However, when both of the adjacent lane L2 and the shoulder strip L3 are available as receding areas into which the subject vehicle 1010 can recede, it is desirable for the power receiver controller 231 to select the adjacent lane L2 as a receding destination. The receding area may also be, for example, a parking lot adjacent to the lane.

[0065] When the power receiver controller 231 determines that the subject vehicle 1010 can recede, the process proceeds to step S14, and the power receiver controller 231 performs a lane receding process. The lane receding process is either (a) an automatic steering process that controls the steering device to guide the subject vehicle 1010 into the adjacent lane L2, or (b) a notification process that notifies the driver of the subject vehicle 1010, for example, by a display on or a voice from the navigation device 331, to steer the subject vehicle 1010 to guide the subject vehicle 1010 into the adjacent lane L2.

[0066] By performing the lane receding process without transmitting a stop request signal, the lateral shift abnormality of the subject vehicle 1010 can be resolved while minimizing inconvenience to other vehicles as much as possible.

[0067] On the other hand, when it is determined in step S13 that receding is not possible, the power receiver controller 231 proceeds to step S15, and performs a stop request process. The stop request process is a process in which the power-receiver communication coil 170 transmits a stop request signal requesting a stop of the power transfer from the power transmitter coil 22 to the power receiver coil 102. When determining that the power-transmitter communication coil 40 has received the stop request signal, the power transmitter controller 71 prohibits energization to the target power transmitter coil. The target power transmitter coil is the power transmitter coil 22 in the power-transmitter coil unit 21 that includes the power-transmitter communication coil 40 that has received the stop request signal. In such manner, even when the power transmitter controller 71 determines that the power-transmitter communication coil 40 in the power-transmitter coil unit 21 that includes the target power transmitter coil has received a power transfer request signal, the power transmitter controller 71 does not energize the target power transmitter coil.

[0068] By performing the stop request process, wireless power transfer to the subject vehicle 1010 can be stopped. As a result, the power receiver 100 provided in the subject vehicle 1010 can be protected.

[0069] In the next step S16, the power receiver controller 231 performs a notification process to notify other vehicles around the subject vehicle 1010 that wireless power transfer will be stopped, for example, by short range wireless communication or wide-area wireless communication. In such manner, it is possible to prevent a situation which makes the user of other vehicle uncomfortable due to a stop of the wireless power transfer.

[0070] After completing the process of step S16, the power receiver controller 231 proceeds to step S13, and determines again whether receding is possible. When the power receiver controller 231 determines in the second determination that receding is possible, the process proceeds to step S18 via steps S14 and S17. In step S18, the power receiver controller 231 stops the transmission of the stop request signal from the power-receiver communication coil 170. Then, in step S19, the power receiver controller 231 performs a notification process to notify other vehicles around the subject vehicle 1010, for example, via short range wireless communication or wide-area wireless communication, that the receding of the subject vehicle 1010 is complete and the stop of wireless power transfer has been released.

[0071] <Modified Example of First Embodiment> In step S15 of FIG. 5, the power receiver controller 231 may transmit a stop request signal to each of the power transmitter controllers 71 via, for example, wide-area wireless communication instead of short range wireless communication.

[0072] <Second Embodiment> The second embodiment will be described below with reference to the drawings mainly in terms of differences from the first embodiment. In the present embodiment, an overvoltage abnormality is resolved instead of resolving a lateral shift abnormality.

[0073] FIG. 10 is a flowchart of a process performed by a processor of the power receiver controller 231 provided in the subject vehicle 1010.

[0074] In step S20, the power receiver controller 231 determines whether an overvoltage abnormality has occurred in the subject vehicle 1010. An overvoltage abnormality is an abnormality in which the output voltage of the rectifier circuit 200 rises excessively. The overvoltage abnormality is, for example, an interruption abnormality in which the electrical connection between the smoothing capacitor 210 and the high-voltage power storage battery 300 is interrupted. The interruption abnormality may occur due to, for example, an open circuit failure of the high-potential side main switch 301H, an open circuit failure of the low potential side main switch 301L, or a break in the electrical path connecting the smoothing capacitor 210 and the high-voltage power storage battery 300. Moreover, an overvoltage abnormality may occur due to an open circuit failure of the smoothing capacitor 210, for example.

[0075] The power receiver controller 231 may determine whether an interruption abnormality has occurred based on, for example, the detection value of (a) a current sensor that detects the electric current flowing through the high-voltage power storage battery 300, or (b) a voltage sensor that detects the voltage across the high-potential side main switch 301H. Further, the power receiver controller 231 may determine that an overvoltage abnormality has occurred, for example, when determining that the detection value of a voltage sensor that detects (a) the output voltage of the rectifier circuit 200 or (b) the voltage between the terminals of the smoothing capacitor 210 exceeds an overvoltage threshold value.

[0076] When it is determined that an overvoltage abnormality has occurred, the power receiver controller 231 proceeds to step S21, and performs a short-circuit process to resolve the overvoltage abnormality in the subject vehicle 1010. As shown in FIG. 11, the short-circuit process is a process of turning on only the upper arm switches Q1H and Q2H of the upper and lower arm switches Q1H, Q2H, Q1L, and Q2L of each phase that constitute the rectifier circuit 200, and is a process of stopping the output of electric current from the rectifier circuit 200 to the smoothing capacitor 210. Note that, in FIG. 11, an example of the power-transmitter resonant capacitor 141 that constitutes the power-receiver resonant circuit 140.

[0077] Incidentally, the short-circuit process may also be a process of turning on only the lower arm switches Q1L and Q2L among the second upper and lower arm switches Q1H, Q2H, Q1L, and Q2L of each phase that constitute the rectifier circuit 200.

[0078] In step S22, the power receiver controller 231 determines whether the overvoltage abnormality has been resolved by the short-circuit process. For example, when determining that the detection value of a voltage sensor that detects (a) the output voltage of the rectifier circuit 200 or (b) the voltage between the terminals of the smoothing capacitor 210 has fallen to be equal to or lower than the overvoltage threshold value, the power receiver controller 231 may determine that the overvoltage abnormality has been resolved.

[0079] When the power receiver controller 231 determines that the overvoltage abnormality has not been resolved, the process proceeds to step S13.

[0080] According to the present embodiment described above, it is possible to resolve the overvoltage abnormality while minimizing inconvenience to other vehicles as much as possible.

[0081] <Modified Example of Second Embodiment> As shown in FIG. 12, the power receiver 250 may include a short-circuit switch 700 that connects one end of each of the power-transmitter resonant capacitors 141. In such case, the power receiver controller 231 may perform a process of switching the short-circuit switch 700 from OFF to ON as the short-circuit process in step S21 of FIG. 10. Note that the short-circuit switch 700 may be provided at a position between the filter circuit 182 and the rectifier circuit 200, rather than a position between the power-receiver resonant circuit 140 and the filter circuit 182.

[0082] <Other Embodiments> The above-described embodiments may be changed and carried out as follows.

[0083] The configurations of the above-described embodiments can be applied not only to a situation when the subject vehicle 1010 is traveling, but also to a situation when the subject vehicle 1010 is stopped or traveling at an extremely low speed. An extremely low speed travel is, for example, traveling at a speed of 5 km / h or less. FIG. 13 shows an example in which the subject vehicle 1010 cuts in from a first lane LA into an area sandwiched between two other vehicles 602 and 603 in a second lane LB adjacent to the first lane LA just before a traffic light. In FIG. 13, 610 indicates a center line, and 611 indicates a crosswalk.

[0084] When the subject vehicle 1010 cuts into an area between the other stopped vehicles 602 and 603, the magnetic flux may affect unexpected components of the subject vehicle 1010, causing the components to overheat or break down. Even in such a case, the configurations of each of the above-described embodiments can be applied. Note that, when resolving an abnormality in the subject vehicle 1010 through automatic steering process in a situation that an inter-vehicle distance between the subject vehicle 1010 and the other vehicles 602, 603 is short, for ensuring the safety of the other vehicles 602, 603, an instruction may be transmitted from the subject vehicle 1010 to the other vehicles 602, 603, for example, via short range wireless communication or wide-area wireless communication, to increase the inter-vehicle distance therebetween. In the other vehicles 602 and 603 that have received the instruction, automatic driving control is performed to keep the inter-vehicle distance therebetween.

[0085] The power-receiver communication antenna and the power-transmitter communication antenna are not limited to communication coils, and various antennas may also be used. For example, the communication antenna is a dipole antenna or a monopole antenna.

[0086] The method of wireless power transfer by the power transmitter antenna and the power receiving antenna is not limited to the magnetic field resonance method, and may also be an electric field coupling method. In such case, a power transmitter antenna and a power receiving antenna that are different in form from coils and that use an electric field coupling method may be used.

[0087] The vehicle identification information used in the process of the above-described embodiments is not limited to vehicle ID information, and may also be, for example, a token or credit card information of a vehicle user.

[0088] The vehicle on which the power receiver 100 is mounted is not limited to a vehicle that travels on the road RS, and may also be, for example, an automated guided vehicle (AGV) or a traveling robot. In such case, the power-transmitter coil unit 21 does not need to be buried in the road RS, but may be installed on a sidewalk adjacent to the road RS, in a parking lot, or on a route along which the AGV travels.

[0089] The control units and methods thereof described in the present disclosure may be implemented by a dedicated computer including a processor programmed to perform one or more functions embodied by a computer program and a memory. Alternatively, the control units and the methods thereof described in the present disclosure may be implemented by a dedicated computer including a processor with one or more dedicated hardware logic circuits. Alternatively, the control units and the methods thereof described in the present disclosure may be implemented by using one or more dedicated computers constituted by a combination of the processor and the memory programmed to perform one or more functions and the processor with one or more hardware logic circuits. Further, the computer programs may be stored, as instructions to be executed by a computer, in a non-transitory, tangible computer-readable storage medium.

[0090] While the present disclosure has been described with reference to embodiments thereof, it is to be understood that the disclosure is not limited to the embodiments and constructions. To the contrary, the present disclosure is intended to cover various modification and equivalent arrangements. Furthermore, although various combinations and modes are described in the present disclosure, the scope and idea of the present disclosure further include other combinations and modes including only one element, more elements, or less elements in these.

Claims

1. A power receiver applicable to a wireless power transfer system, the wireless power transfer system including a power transmitter (20), which is a ground-side device including a power transmitter antenna (22), and a power receiver (100), which is provided to a vehicle (11) and including a power receiving antenna (102), the power receiver configured to transmit a power transfer request signal to the power transmitter for requesting power transfer, and the power transmitter configured to perform wireless power transfer to the power receiving antenna by energizing the power transmitter antenna when receiving the power transfer request signal, the power receiver comprising: a controller (231) provided to a subject vehicle (1010), wherein the controller is configured to determine whether an abnormality occurs in the subject vehicle, when determining that an abnormality occurs in the subject vehicle, determine whether an other vehicle (600, 602, 603) is present on a same power transmitter antenna as the subject vehicle, and when determining that an other vehicle is present, execute a resolution process to resolve the abnormality of the subject vehicle without requesting the power transmitter to stop power transfer from the power transmitter antenna to the power receiving antenna.

2. The power receiver according to claim 1, wherein the controller provided to the subject vehicle is configured to determine, as an abnormality in the subject vehicle, whether a lateral shift abnormality of the subject vehicle occurs while the subject vehicle travels, and execute, as the resolution process, a process for resolving the lateral shift abnormality.

3. The power receiver according to claim 1, wherein the vehicle includes: a rectifier circuit (200) configured to convert an AC current from the power receiving antenna into a DC current; a power storage unit (300) to which the rectifier circuit is configured to supply an output current; and a smoothing capacitor (210) provided between the rectifier circuit and the power storage unit and connected in parallel to the power storage unit, and the controller provided to the subject vehicle is configured to determine, as an abnormality in the subject vehicle, whether an overvoltage abnormality, in which an output voltage of the rectifier circuit becomes an overvoltage, occurs in the subject vehicle, and execute, as the resolution process, a process for resolving the overvoltage.

4. The power receiver according to claim 2 or 3, wherein the controller provided to the subject vehicle is configured to determine whether the abnormality of the subject vehicle is resolved by executing the resolution process, when determining that the abnormality of the subject vehicle is not resolved even after executing the resolution process, determine whether the subject vehicle is capable of receding to a receding area adjacent to a lane in which the subject vehicle travels, and when determining that the subject vehicle is capable of receding, execute a lane receding process to execute an automatic steering process to guide the subject vehicle to the receding area, or a notification process to notify a driver of the subject vehicle to steer the subject vehicle to guide the subject vehicle to the receding area.

5. The power receiver according to claim 4, wherein the controller provided to the subject vehicle is configured to when determining that the subject vehicle is incapable of receding, request the power transmitter to stop power transfer from the power transmitter antenna to the power receiving antenna.

6. The power receiver according to claim 5, wherein the controller provided to the subject vehicle is configured to when requesting the power transmitter to stop power transfer, execute a notification process to notify the other vehicle that wireless power transfer is to be stopped.

7. The power receiver according to any one of claims 1 to 3, wherein the controller provided to the subject vehicle is configured to after executing the resolution process, re-determine whether the abnormality occurs in the subject vehicle, and when re-determining that the abnormality occurs in the subject vehicle, request the power transmitter to stop power transfer from the power transmitter antenna to the power receiving antenna.

8. A program applicable to a wireless power transfer system, the wireless power transfer system including a power transmitter (20), which is a ground-side device including a power transmitter antenna (22), and a power receiver (100), which is provided to a vehicle (11) and including a power receiving antenna (102), the power receiver configured to transmit a power transfer request signal to the power transmitter for requesting power transfer, and the power transmitter configured to perform wireless power transfer to the power receiving antenna by energizing the power transmitter antenna when receiving the power transfer request signal, the program configured to cause a processor of a subject vehicle (1010) to execute a process to determine whether an abnormality occurs in the subject vehicle, a process, when determining that an abnormality occurs in the subject vehicle, to determine whether an other vehicle (600, 602, 603) is present on a same power transmitter antenna as the subject vehicle, and a process to execute a resolution process, when determining that an other vehicle is present, to resolve the abnormality of the subject vehicle without requesting the power transmitter to stop power transfer from the power transmitter antenna to the power receiving antenna.

9. A control method applicable to a wireless power transfer system, the wireless power transfer system including a power transmitter (20), which is a ground-side device including a power transmitter antenna (22), and a power receiver (100), which is provided to a vehicle (11) and including a power receiving antenna (102), the power receiver configured to transmit a power transfer request signal to the power transmitter for requesting power transfer, and the power transmitter configured to perform wireless power transfer to the power receiving antenna by energizing the power transmitter antenna when receiving the power transfer request signal, the control method comprising: determining, by a processor in a process, whether an abnormality occurs in a subject vehicle, when determining that an abnormality occurs in the subject vehicle, determining, by the processor in a process, whether an other vehicle (600, 602, 603) is present on a same power transmitter antenna as the subject vehicle, and when determining that an other vehicle is present, execute, by the processor in a resolution process, to resolve the abnormality of the subject vehicle without requesting the power transmitter to stop power transfer from the power transmitter antenna to the power receiving antenna.

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