Power receiver device for indcutive charging of electric vehicle

Abstract

A power receiver device mounted on a vehicle includes a power receiver antenna and wirelessly supplied with power from a power transmitting antenna of the power transmitting device to the power receiver antenna. The power receiver device includes a power-receiver communication antenna, a case (101a) accommodating the power receiver antenna and the power-receiver communication antenna and to be fixed to a vehicle body (11a) of the vehicle, a sensor (91, 95) configured to detect a correlation amount, which is correlated with an external force acting on the case, and a power-receiver control unit configured to determine that abnormality occurs in the power-receiver communication antenna based on the correlation amount detected by the sensor.

Description

POWER RECEIVER DEVICE FOR INDCUTIVE CHARGING OF ELECTRIC VEHICLECross Reference

[0001] This application is based on Japanese Application No. 2024-208020 filed on November 29, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a power receiver device.

[0003] For example, Patent Literature 1 discloses a system for executing wireless power supply from a ground-based power transmitter to a power receiver installed in an electric vehicle. The power transmitter device includes a power transmitter coil and a power transmitter communication antenna. The power receiver device includes a power receiver coil, which is supplied with electric power wirelessly from the power transmitter coil, and a power-receiver communication antenna. The power receiver device supplies a power supply request signal to the power-receiver communication antenna. The power transmitter device determines whether there is the power supply request based on an output signal of the power transmitter communication antenna. When the power transmitter device determines that there is the power supply request, the power transmitter device energizes the power transmitter coil.

[0004] JP2024-8088A

[0005] The power receiver coil (power receiver antenna) and the power-receiver communication antenna are accommodated in a case. The case is then fixed to a position in the vehicle body suitable for power reception by the power receiver coil and communication by the power-receiver communication antenna, for example, to the bottom of a vehicle body. Therefore, if an excessive external force acts on the vehicle body and ultimately on the case, while the vehicle travels, there is a risk that an abnormality would occur in the power-receiver communication antenna. When an abnormality occurs in the power-receiver communication antenna, for example, there is a risk that the power-receiver communication antenna may not be able to properly transmit the power supply request signal. Therefore, a technique is desired that enables to determine that an abnormality occurs in the power-receiver communication antenna.

[0006] It is a main object of the present disclosure to enable determination that an abnormality occurs in a power-receiver communication antenna in a power receiver device.

[0007] According to a first aspect to address the above-mentioned issue, a power receiver device is to be mounted on a vehicle. The power receiver device includes a power receiver antenna and configured to be wirelessly supplied with power by the power receiver antenna from a power transmitter antenna of a power transmitter device. The power receiver device comprises: a power-receiver communication antenna; a case accommodating the power receiver antenna and the power-receiver communication antenna and to be fixed to a vehicle body of the vehicle; a sensor configured to detect a correlation amount correlated with an external force acting on the case; and a power-receiver control unit configured to determine that abnormality occurs in the power-receiver communication antenna based on the correlation amount detected by the sensor.

[0008] According to the above configuration, the power receiver device mounted on the vehicle includes the power receiver antenna and is wirelessly supplied with power from the power transmitting antenna of the power transmitting device to the power receiver antenna. The power receiver device includes the power-receiver communication antenna and the case that accommodates the power receiver antenna and the power-receiver communication antenna and is fixed to the vehicle body of the vehicle. Therefore, for example, if an excessive external force acts on the vehicle body and ultimately on the case while the vehicle travels, the external force may be transmitted to the power-receiver communication antenna to cause an abnormality in the power-receiver communication antenna.

[0009] In view of this, the sensor detects the correlation amount correlated with an external force acting on the case. Therefore, this configuration enables to estimate the magnitude of the external force acting on the case based on the correlation amount detected by the sensor. Thus, the power-receiving-side control unit can determine that an abnormality occurs in the power-receiver communication antenna based on the correlation amount detected by the sensor.

[0010] According to a second aspect, a power receiver device is to be mounted on a vehicle. The power receiver device includes a power receiver antenna and configured to be wirelessly supplied with power by the power receiver antenna from a power transmitter antenna of a power transmitter device. The power receiver device comprises: a power-receiver communication antenna; a case accommodating the power receiver antenna and the power-receiver communication antenna and to be fixed to a vehicle body of the vehicle; a sensor configured to detect a correlation amount correlated with an external force acting on the case; and a power-receiver control unit configured to perform energization control of the power-receiver communication antenna to supply a power supply request signal, which indicates power supply request to the power transmitter antenna, to the power-receiver communication antenna, and prevent supply of the power supply request signal to the power-receiver communication antenna, when the correlation amount detected by the sensor exceeds a predetermined threshold, which is for determination that external force exceeding a predetermined external force acts.

[0011] This configuration enables to prevent transmission of the power supply request signal, when there is a high possibility that an external force, which exceeds the predetermined external force, acts on the case and that an abnormality occurs in the power-receiver communication antenna.

[0012] According to a third aspect, a power receiver device is to be mounted on a vehicle. The power receiver device includes a power receiver antenna and configured to be wirelessly supplied with power by the power receiver antenna from a power transmitter antenna of a power transmitter device. The power receiver device comprises: a power-receiver communication antenna; a case accommodating the power receiver antenna and the power-receiver communication antenna and to be fixed to a vehicle body of the vehicle; a sensor configured to detect a correlation amount correlated with an external force acting on the case; and a power-receiver control unit configured to perform energization control of the power-receiver communication antenna to supply a power supply request signal, which indicates power supply request to the power transmitter antenna, to the power-receiver communication antenna, calculate an integral value of the correlation amount detected by the sensor, and prevent supply of the power supply request signal to the power-receiver communication antenna, when the integral value exceeds a cumulative threshold, which is for determination that external force accumulates beyond a predetermined amount.

[0013] These configurations enable to prevent transmission of the power supply request signal, when there is a high possibility that acting of an external force on the case repeatedly accumulates and that an abnormality occurs in the power-receiver communication antenna.

[0014] 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.

[0015] FIG. 1 is an overall configuration diagram of a wireless power supply system.FIG. 2 is a diagram showing the wireless power supply system and a vehicle.FIG. 3 is a diagram showing a power transmitter and a power receiver.FIG. 4 is a diagram showing a power-receiver control unit and its peripheral configuration.FIG. 5 is a diagram showing the power-transmitter control unit and its peripheral configuration.FIG. 6 is a diagram showing an arrangement of an acceleration sensor and a strain sensor.FIG. 7 is a flowchart showing an abnormality determination process for the power-receiver communication antenna.FIG. 8 is a schematic diagram showing a state in which the vehicle runs up onto a step.

[0016] Embodiments and modifications will be described with reference to the drawings. In the embodiments and modifications, functionally and / or structurally corresponding and / or associated parts may be provided with the same reference numerals. For corresponding and / or associated parts, reference may be made to the descriptions of other embodiments and other modifications.

[0017] A first embodiment of a wireless power supply system of the present disclosure will be described below with reference to the drawings.

[0018] First, an overall configuration of the wireless power supply system will be described. As shown in FIGS. 1, 2, and 3, the wireless power supply system 10 includes a power transmitter 20 and a power receiver 100. The power receiver 100 is mounted on a vehicle 11 as a moving object that travels on a road RS, and is a vehicle-side device. The vehicle 11 is, for example, an electric automobile or a hybrid vehicle. While the vehicle 11 is traveling or stopped (including parked), electric power is supplied from the power transmitter 20 to the power receiver 100. The wireless power supply system 10 executes wireless power transfer from the power transmitter 20 to the power receiver 100 through magnetic field resonance coupling (magnetic field resonance). The wireless power supply system 10 is also referred to as a dynamic wireless power transfer (D-WPT) system.

[0019] The power transmitter 20 is a ground-side device and has 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 (also indicated as "GA") is installed (for example, buried) on a road RS, a parking lot, or the like. A power-transmitter power supply unit 51 (also indicated as "MU") is installed, for example, at the side of 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 source 15 and supplies AC (alternating-current) power from the AC power source 15 to the power-transmitter coil unit 21. The AC power source 15 is, for example, a commercial power source. Multiple power-transmitter coil units 21 are arranged along the lanes of the road RS. FIG. 2 shows an example of four power-transmitter coil units 21 aligned along the road RS and connected to one power-transmitter power supply unit 51. In other words, one power-transmitter power supply unit 51 is provided for the four power-transmitter coil units 21. The configuration is not limited to one power-transmitter power supply unit 51 for the multiple power-transmitter coil units 21, but one power-transmitter power supply unit 51 may be provided for each power-transmitter coil unit 21.

[0020] 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 source 15. The PFC circuit 61 includes switching elements (e.g., IGBTs or MOSFETs) that are switched and controlled to convert the input AC power to DC (direct current) power and improve a power factor of the AC power input from the AC power source 15.

[0021] The inverter 60 is connected to the PFC circuit 61. The inverter 60 includes switching elements (e.g., IGBTs or MOSFETs) that are switched and controlled to convert the DC power input from the PFC circuit 61 to AC power.

[0022] The filter circuit 52 removes noise contained in the AC current input from the inverter 60 and supplies the AC current from which noise has been removed to the power-transmitter coil unit 21. The filter circuit 52 is, for example, an LC filter that includes a coil and a capacitor. Circuits having various configurations can be used as the filter circuit 52, and, for example, a T-type filter circuit is used as the filter circuit 52.

[0023] The power-transmitter coil unit 21 includes a power transmitter coil 22 (corresponding to power transmitter antenna), a power-transmitter resonant circuit 30, and a power-transmitter communication antenna 40. The power-transmitter resonant circuit 30 supplies the AC power supplied by 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.

[0024] 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 receiver antenna"). The power receiver coil 102 has a flat shape in which the height dimension is the smallest among the width dimension, the depth dimension, and the height dimension. For example, the exterior shape of the power receiver coil 102 is a flattened rectangular column shape or a flattened circular column shape. The power-receiver coil unit 101 is provided at the bottom of the vehicle body 11a of the vehicle 11. 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 the vertical direction.

[0025] 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. The power receiver coil 102 is supplied with power from the power transmitter coil 22. The power receiver coil 102 supplies the received power to the power-receiver resonant circuit 140. The power-receiver resonant circuit 140 may employ various well-known resonant circuits such as a circuit including a resonant capacitor.

[0026] 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 current input from the power-receiver resonant circuit 140 and supplies the AC current from which 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 reactor and a capacitor.

[0027] The rectifier circuit 200 converts the input AC current into a DC current and outputs the DC current. The rectifier circuit 200 is, for example, a full-bridge circuit including semiconductor switching elements, or a diode rectifier circuit. A first end of the smoothing capacitor 210 is connected to a high potential side output terminal of the rectifier circuit 200. A second end of the smoothing capacitor 210 is connected to a low potential side output terminal of the rectifier circuit 200. The rectifier circuit 200 is also referred to as an ERB (Electronic Rectification Box).

[0028] The vehicle 11 includes a high potential main switch 301H, a low potential main switch 301L, and a high-voltage storage battery 300 as a power storage unit. The high potential main switch 301H and the low potential main switch 301L are, for example, relays (specifically, mechanical relays). The high potential side output terminal of the rectifier circuit 200 is connected to a positive terminal of the high-voltage storage battery 300 via the high potential main switch 301H. The low potential side output terminal of the rectifier circuit 200 is connected to a negative terminal of the high-voltage storage battery 300 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 several hundred volts, for example. The high-voltage storage battery 300 is, for example, a lithium-ion storage battery or a nickel-metal hydride storage battery.

[0029] The vehicle 11 includes a travelling inverter 310 and a rotary electric machine 320. The travelling inverter 310 is a 3-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 windings of the rotary electric machine 320 are connected to the upper and lower arm switches that constitute the travelling inverter 310. By switching control of the upper and lower arm switches of the travelling inverter 310 while the high potential main switch 301H and the low potential main switch 301L are turned on, the travelling inverter 310 converts the DC power supplied from the high-voltage storage battery 300 into AC power and supplies the AC power to the armature winding. This configuration causes the rotor of the rotary electric machine 320 to rotate, and the rotational power of the rotor rotates drive wheels of the vehicle 11. As a result, the vehicle 11 travels.

[0030] As shown in FIG. 3, the power-transmitter power supply unit 51, which constitutes 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 executes various controls of the power transmitters 20 and includes, as hardware, a processor, a storage unit, and a communication bus connecting the processor with the storage unit.

[0031] The storage unit includes a memory and a storage as hardware. The memory is a storage device for storing data used in the processing of the power-transmitter controller 71. The memory, for example, provides the processor with a work area for temporary use when the processor performs processing. The memory 212 includes, for example, RAM and ROM. 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, HDD or flash memory. The storage contains program information and other information for the processes described below.

[0032] The power receiver 100 includes a power-receiver power supply unit 181 (also referred to as “WPU”) having a power-receiver controller 231. The power-receiver controller 231 is an ECU that executes various controls of the power receiver 100, and includes a processor as hardware, a storage unit, and a communication bus that connects the processor and storage unit.

[0033] The storage unit includes a memory and a storage as hardware. The memory is a storage device for storing data used in the processing of the power-receiver controller 231. The memory, for example, provides the processor with a work area for temporary use when the processor performs processing. The memory 212 includes, for example, RAM and ROM. 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, HDD or flash memory. The storage contains program information and other information for the processes described below.

[0034] For example, the program information stored on the 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, CD-ROM or DVD. In addition, the program information transmitted over a communication network, such as OTA (Over The Air), for example, is installed in the storage unit.

[0035] The power-transmitter controller 71 executes a switching control of the PFC circuit 61 and a switching control of the inverter 60. Through the switching control of the inverter 60, a high-frequency AC voltage is applied to the power transmitter coil 22. This causes a high-frequency current to flow in the power transmitter coils 22 and a magnetic field for power transmission is generated in the power transmitter coils 22.

[0036] In this embodiment, the power-transmitter controller 71 switches and controls the inverter 60 so that the frequency of the high-frequency voltage applied to the power transmitter coil 22 is becomes a first specified frequency between 10 kHz and 100 GHz, specifically, 85 kHz. The resonant frequencies of the power-transmitter resonant circuit 30 and the power-receiver resonant circuit 140 are set at the same frequency or close to the first specified frequency.

[0037] When the magnetic field generated in the power transmitter coil 22 links with the power receiver coil 102 of the vehicle 11, a high-frequency current flows in the power receiver coil 102, varying with the frequency of the high-frequency current flowing in the power transmitter coil 22. The high-frequency current flowing in the power receiver coil 102 is supplied to the rectifier circuit 200 through the power-receiver resonant circuit 140 and the filter circuit 182. The rectifier circuit 200 converts the supplied AC current into a DC current and outputs the DC current. While 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 travelling inverter 310.

[0038] 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. The power supplied from the low-voltage storage battery 302 to the power-receiver controller 231 enables the power-receiver controller 231 to operate.

[0039] The power receiver 100 and the power transmitter 20 each has a configuration for communication between the power receiver 100 and the power transmitter 20. In detail, the power-receiver coil unit 101, which constitutes the power receiver 100, includes a power-receiver communication antenna 170. The power-receiver control unit 230 includes a transmitter 240 (also indicated as "TX").

[0040] The power-receiver communication antenna 170 includes a communication coil, and has a flat shape in which, among a width dimension, a depth dimension, and a height dimension, the height dimension is the smallest. For example, the exterior shape of the power receiver coil 102 is a flattened rectangular column shape or a flattened circular column shape.

[0041] The power-receiver coil unit 101 includes a case 101a that accommodates the power receiver coil 102, the power-receiver resonant circuit 140, and the power-receiver communication antenna 170. The case 101a has a flat shape in which, among a width dimension, a depth dimension, and a height dimension, the height dimension is the smallest. For example, the exterior shape of the case 101a is a flattened rectangular column shape or a flattened circular column shape. The case 101a is fixed to the bottom of the vehicle body 11a of the vehicle 11.

[0042] The power-transmitter coil unit 21, which constitutes the power transmitter 20, includes the power-transmitter communication antenna 40. The power-transmitter control unit 70 includes a receiver 80 (also indicated as "RX"). The power-receiver communication antenna 170 and the power transmitter communication antenna 40 are communication antennas for performing short range wireless communication. The narrow area wireless communication is those with a communication distance of less than 10 meters (e.g., a maximum of about 3 meters). The narrow area wireless communication is a communication with a shorter communication distance than wide area wireless communication.

[0043] Various short-range wireless communications can be used as the narrow area wireless communication. For example, communications compliant with any communication standards established by IEEE, ISO, and IEC can be used. Specifically, for example, Wi-Fi (registered trademark), Bluetooth (registered trademark), ZigBee (registered trademark), RFID (Radio Frequency Identification), or DSRC (Dedicated Short Range Communication) can used as the narrow area wireless communication.

[0044] The transmitter 240 is connected to the power-receiver controller 231. The power-receiver communication antenna 170 is connected to the transmitter 240. The power-receiver controller 231 controls the transmitter 240 to supply a power supply request signal COMM to the power-receiver communication antenna 170. The power supply request signal COMM is a signal requesting the power transmitter coil 22 close to the vehicle 11 to transmit power to the power receiver coil 102. For example, when the state of charge (SOC) of the high-voltage storage battery 300 is 70% or less, the power-receiver controller 231 controls the transmitter 240 to supply the power supply request signal COMM to the power-receiver communication antenna 170.

[0045] The power-receiver control unit 230 controls the transmitter 240 to supply a vehicle-side signal including, in one frame, the power supply request signal COMM and a traveling speed signal, which indicates a traveling speed Vsp of the vehicle 11, to the power-receiver communication antenna 170. The traveling speed signal may be acquired based on an output of a vehicle speed sensor mounted on the vehicle 11, for example. The power supply request signal COMM includes ID information of the vehicle 11 and requested power Weq, which is a requested value of power to be supplied to the vehicle 11. This control causes a high-frequency voltage to be applied from the transmitter 240 to the power-receiver communication antenna 170. As a result, a high-frequency current flows through the power-receiver communication antenna 170, and a magnetic field for information communication is generated in the power-receiver communication antenna 170. The power-receiver control unit 230 acquires the ID information and the traveling speed Vsp of the vehicle 11 from, for example, a vehicle ECU that controls the vehicle 11.

[0046] When the power-receiver coil unit 101 of the vehicle 11 approaches the power-transmitter coil unit 21 on the ground side, the generated magnetic field links to the power-transmitter communication antenna 40, and a high-frequency current flows through the power-transmitter communication antenna 40. This high-frequency current is input to the receiver 80. The receiver 80 recognizes the presence or absence of a power supply request and ID information based on the input signal from the power-transmitter communication antenna 40. In addition, the receiver 80 acquires the required power Weq and the traveling speed Vsp of the vehicle 11 having the recognized ID information based on the signal from the power transmitter communication antenna 40. The information recognized by the receiver 80, the required power Weq, and the traveling speed Vsp are input to the power-transmitter controller 71.

[0047] In this 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 antenna 170 becomes a second specified frequency between 10 kHz and 100 GHz. In this embodiment, the second specified frequency is a frequency that deviates from the first specified frequency above, specifically a frequency higher than the first specified frequency (e.g., 13.56 MHz).

[0048] 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, when the power-transmitter controller 71 determines that there is the power supply request based on the input signal from the receiver 80, the power-transmitter controller 71 applies high-frequency voltage to the power transmitter coil 22 by performing switching control of the inverter 60 and the PFC circuit 61. This results in a wireless power transmission from the power transmitter coil 22 to the power receiver coil 102.

[0049] The transmitter 240 and its peripheral configuration will be described with reference to FIG. 4.

[0050] The transmitter 240 includes a generating circuit 241, and a power-receiver amplifier 242. The generating circuit 241 is connected to the power-receiver controller 231 and the power-receiver amplifier 242. The generating circuit 241 generates a vehicle-side signal, which is a high-frequency signal including the power supply request signal COMM and the traveling speed signal, based on a command from the power-receiver controller 231. The frequency of the vehicle-side signal is the second specified frequency. The power-receiver amplifier 242 amplifies the high-frequency signal generated by the generating circuit 241 and supplies the amplified signal to the power-receiver communication antenna 170.

[0051] The power-receiver controller 231 instructs the generating circuit 241 to generate a vehicle-side signal. The high-frequency signal output from the generating circuit 241 is amplified by the power-receiver amplifier 242. The amplified signal is supplied to the power-receiver communication antenna 170.

[0052] Next, the receiver 80 and its peripheral configuration will be described with reference to FIG. 5.

[0053] The receiver 80 includes a power-transmitter amplifier 81, a detection circuit 82 and a determination circuit 83. The power-transmitter amplifier 81 amplifies the high-frequency signal (high frequency current or voltage signal) output from the power-transmitter communication antenna 40 and supplies the amplified signal to the detection circuit 82. The high-frequency signal output from the power-transmitter communication antenna 40 contains a frequency component that fluctuates at the second specified frequency.

[0054] The detection circuit 82 detects the high-frequency signal input from the power-transmitter amplifier 81, and calculates an intensity Intd which is an amplitude or effective value of the input power supply request signal COMM. The calculated intensity Intd is input to the determination circuit 83.

[0055] The determination circuit 83 determines whether there is a power supply request to the power transmitter coil 22 based on the input intensity Intd. Specifically, when determining that the intensity Intd exceeds a determination threshold Ijde, the determination circuit 83 determines that there is a power supply request. On the other hand, when determining that the intensity Intd is lower than (does not exceed) the determination threshold Ijde, the determination circuit 83 determines that there is no power supply request. The determination result information of the determination circuit 83 is input to the power-transmitter controller 71.

[0056] When determining that there is no power supply request based on the input determination result information, the power-transmitter controller 71 stops the switching control of the PFC circuit 61 and the inverter 60. As a result, the switches of the PFC circuit 61 and the inverter 60 are kept off, and the power transmitter coil 22 is not energized.

[0057] On the other hand, when determining that there is the power supply request based on the determination result information, the power-transmitter controller 71 applies a high frequency voltage to the power transmitter coil 22 by performing switching control of the PFC circuit 61 and the inverter 60 (corresponding to actual energization). This causes a high-frequency current to flow through the power transmitter coil 22. In this case, wireless power supply 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.

[0058] It is noted that, when the vehicle 11 is traveling, if an excessive external force acts on the vehicle body 11a and thus on the case 101a, this external force would be transmitted to the power-receiver communication antenna 170 via the case 101a to possibly cause a malfunction in the power-receiver communication antenna 170. When an abnormality occurs in the power-receiver communication antenna 170, for example, there is a risk that the power-receiver communication antenna 170 may not be able to properly transmit the power supply request signal COMM. Specifically, if the power-receiver communication antenna 170 is bent (i.e., deformed), the direction of the magnetic field generated by the power-receiver communication antenna 170 for information communication may deviate from its appropriate direction. In particular, the communication coil that constitutes the power-receiver communication antenna 170 is smaller in size than the power receiver coil 102, and its coil wiring is also thin so likely to be bent.

[0059] Therefore, the power receiver 100 is provided with an acceleration sensor and a strain gauge that detect a correlation amount that correlates with the external force acting on the case 101a. FIG. 6 is a diagram showing the arrangement of the acceleration sensor 91 and the strain gauge 95.

[0060] The acceleration sensor 91 (corresponding to sensor) is attached to the vehicle body 11a and detects acceleration (corresponding to correlation amount). The acceleration sensor 91 detects, for example, acceleration in the vertical direction (z-axis direction). The acceleration sensor 91 is attached, for example, to the vehicle body 11a close to a front wheel 12 (corresponding to wheel).

[0061] The strain gauge 95 (corresponding to sensor) is attached to an upper part of the case 101a of the power-receiver coil unit 101 and detects the strain (corresponding to correlation amount) of the upper part of the case 101a. The strain gauge 95 is attached, for example, to a center of an upper part of the case 101a. The strain gauge 95 may be attached to a lower part of the case 101a to detect the strain (corresponding to correlation amount) of a lower part of the case 101a. In this case, the strain gauge 95 is attached, for example, to a center of the lower part of the case 101a.

[0062] FIG. 7 is a flowchart showing an abnormality determination process for the power-receiver communication antenna 170. This series of processes is repeatedly executed by the power-receiver control unit 230 at a predetermined cycle.

[0063] First, the acceleration sensor 91 detects the acceleration (S10). The strain gauge 95 detects the strain in the upper part of the case 101a (S11). The order of the process of S10 and the process of S11 may be reversed.

[0064] Next, it is determined whether an abnormality occurs in the power-receiver communication antenna 170 (S12). Specifically, it is determined that an abnormality occurs in the power-receiver communication antenna 170, when the acceleration detected by the acceleration sensor 91 exceeds an acceleration threshold (corresponding to predetermined threshold) that enables to determine that an external force exceeding a predetermined external force (excessive external force) acts on the case 101a, or or when the strain detected by the strain gauge 95 exceeds a strain threshold (corresponding to predetermined threshold) that enables to determine that an external force exceeding a predetermined external force (excessive external force) acts on the case 101a. The acceleration threshold and the strain threshold are values corresponding to an external force that causes an abnormality in the power-receiver communication antenna 170 when acting on the case 101a only once, and may be set in advance based on a test or a simulation. As an abnormality occurring in the power-receiver communication antenna 170, for example, it is determined that the power-receiver communication antenna 170 is deformed. In addition, as an abnormality occurring in the power-receiver communication antenna 170, it may be determined that the power-receiver communication antenna 170 is damaged, that the power-receiver communication antenna 170 fails, or that the power-receiver communication antenna 170 is broken.

[0065] When it is determined that an abnormality occurs in the power-receiver communication antenna 170 (S12: YES), supply of the power supply request signal COMM is prevented (discontinued) (S13). Specifically, the power-receiver controller 231 prevents the transmitter 240 from supplying the power supply request signal COMM to the power-receiver communication antenna 170. For example, a flag for preventing the supply of the power supply request signal COMM is turned ON, and the state in which the supply of the power supply request signal COMM is prevented is maintained while the flag is ON. Then, the series of process is terminated (END). For example, when the power-receiver communication antenna 170 is repaired at an automobile repair shop or the like, the flag is turned OFF. Furthermore, when preventing supply of the power supply request signal COMM, the power-receiver controller 231 may transmit a notification signal to the vehicle ECU (vehicle 11). The notification signal includes a signal that instructs to notify a driver of the vehicle 11 that supply of the power supply request signal COMM to the power-receiver communication antenna 170 is prevented. In this way, the vehicle ECU is enabled to display (audio guidance) on an image display unit of an instrument panel or a navigation device of the vehicle 11 to notify the driver of the vehicle 11 that supply of the power supply request signal COMM to the power-receiver communication antenna 170 is prevented (power reception by the power receiver coil 102 is prevented).

[0066] On the other hand, when it is determined that no abnormality occurs in the power-receiver communication antenna 170 (S12: NO), this series of process is temporarily terminated (END).

[0067] FIG. 8 is a diagram showing a state in which the vehicle 11 runs up onto a step B. In the drawing, the vehicle body 11a and the lower portion of the vehicle 11 are mainly shown, and other parts are omitted. The step B is, for example, a curb or a large stone on the road RS on which the vehicle 11 travels.

[0068] When the front wheel 12 of the vehicle 11 runs up onto the step B, a large acceleration occurs around the front wheel 12. At this time, the acceleration sensor 91 provided close to the front wheel 12 can accurately detect the external force acting instantaneously on the vehicle body 11a.

[0069] Furthermore, when the front wheel 12 is pushed up by the reaction force from the step B and the vehicle body 11a is bent, the case 101a fixed to the vehicle body 11a is also bent. In particular, the power receiver coil 102, the power-receiver communication antenna 170, and the case 101a each has a flat shape in which the height dimension is the smallest. Therefore, the power receiver coil 102, the power-receiver communication antenna 170, and the case 101a are likely to bend due to bending of the vehicle body 11a. At this time, the strain gauge 95 can accurately detect the strain caused in the upper part of the case 101a.

[0070] According to the embodiment described above, the following effects can be exhibited.

[0071] The sensor (acceleration sensor 91 and strain gauge 95) detects the correlation amount (acceleration and strain) that correlates with the external force acting on the case 101a. Therefore, the magnitude of the external force acting on the case 101a can be estimated based on the correlation amount detected by the sensor. Therefore, the power-receiver control unit 230 can determine that an abnormality occurs in the power-receiver communication antenna 170 based on the correlation amount detected by the sensor.

[0072] The power-receiver control unit 230 prevents supply of the power supply request signal COMM to the power-receiver communication antenna 170 when determining that an abnormality occurs, thereby to enable to prevent supply of the power supply request signal COMM when an abnormality occurs in the power-receiver communication antenna 170.

[0073] the power-receiver control unit 230 determines that an abnormality occurs when the acceleration detected by the acceleration sensor 91 exceeds the acceleration threshold that enables determination that an external force exceeding the predetermined external force (excessive) acts. This configuration enables, when there is a high possibility that an excessive external force acts on the case 101a, and that an abnormality occurs in the power-receiver communication antenna 170, to immediately determine that an abnormality occurs.

[0074] The power-receiver control unit is configured to determine that an abnormality occurs, when the strain detected by the strain gauge 95 exceeds the strain threshold that enables to determine that an external force exceeding the predetermined external force (excessive) acts. This configuration enables, when there is a high possibility that an excessive external force acts on the case 101a, and that an abnormality occurs in the power-receiver communication antenna 170, to immediately determine that an abnormality occurs.

[0075] The acceleration sensor 91 can accurately detect an external force that momentarily acts on the vehicle body 11a. Therefore, the configuration enables to accurately determine that an abnormality occurs in the power-receiver communication antenna 170.

[0076] The acceleration sensor 91 is mounted on the vehicle body 11a close to the front wheels 12 of the vehicle 11. This configuration enables to accurately determine that there is a high possibility that the front wheel 12 of the vehicle 11 runs up onto the step B and that an abnormality occurs in the power-receiver communication antenna 170.

[0077] The power receiver coil 102, the power-receiver communication antenna 170, and the case 101a each has a flat shape in which the height dimension is the smallest. Therefore, when the front wheels 12 of the vehicle 11 runs up the step B and a large bending moment acts on the case 101a, the case 101a and furthermore the power-receiver communication antenna 170 are likely to bend significantly. At this time, the strain gauge 95 can accurately detect the strain caused in the upper part of the case 101a. Therefore, this configuration enables to accurately determine that there is a high possibility that the front wheel 12 of the vehicle 11 runs up onto the step B and that an abnormality occurs in the power-receiver communication antenna 170.

[0078] The power-receiver control unit 230 determines that the deformation of the power-receiver communication antenna 170 is an abnormality. This configuration enables to determine whether the signal cannot be transmitted from the power-receiver communication antenna 170 in the appropriate direction.

[0079] The above-described embodiment can be modified as follows in practical application. The same parts as those in each embodiment are denoted by the same reference numerals, and the description thereof will be incorporated herein.

[0080] The acceleration sensor 91 may be configured to detect, in addition to the acceleration in the vertical direction (z-axis direction), or instead of the acceleration in the vertical acceleration, acceleration in a direction perpendicular to the vertical direction (x direction and / or y direction).

[0081] Even when an excessive external force does not act on the case 101a, an abnormality may occur in the power-receiver communication antenna 170 due to accumulation of an external force repeatedly acting on the case 101a. In view of this, the power-receiver control unit may calculate an integral value of the acceleration detected by the acceleration sensor 91 and determine that an abnormality occurs when the integral value exceeds a cumulative acceleration threshold (corresponding to cumulative threshold) that enables to determine that an external force has accumulated beyond a predetermined amount (excessively). In addition, the power-receiver control unit 230 may calculate an integral value of the strain detected by the strain gauge 95 and determine that an abnormality occurs when the integral value exceeds a cumulative strain threshold (equivalent to cumulative threshold) that enables to determine that an external force has accumulated beyond a predetermined amount (excessively). These configurations enable, when an external force repeatedly acting on the case 101a accumulates and there is a high possibility that an abnormality occurs in the power-receiver communication antenna 170, to determine that an abnormality occurs. When calculating the integral values of the acceleration and the strain, the power-receiver control unit 230 may integrate continuous values of the acceleration and the strain, or may integrate intermittent values of the acceleration and the strain. In addition, the power-receiver control unit 230 may calculate an integral value of only the acceleration detected by the acceleration sensor 91 that exceeds a predetermined value, and determine that an abnormality occurs when the integral value exceeds a cumulative acceleration threshold. In addition, the power-receiver control unit 230 may calculate an integral value of only the strain detected by the strain gauge 95 that exceed a predetermined value, and determine that an abnormality occurs when the integral value exceeds a cumulative strain threshold. These configurations enables to reduce a calculation load and a memory load of the power-receiver control unit 230.

[0082] The power-receiver control unit 230 may also sum up the acceleration intermittently detected by the acceleration sensor 91 and determine that an abnormality occurs when the sum exceeds a threshold. The power-receiver control unit 230 may also sum up the strain intermittently detected by the strain gauges 95 and determine that an abnormality occurs when the sum exceeds a threshold. Also these configurations can produce effects similar to those in the above-described embodiment.

[0083] The power-receiver control unit may determine that an abnormality occurs, when the acceleration detected by the acceleration sensor 91 exceeds an acceleration threshold, which enables to determine that an external force exceeding a predetermined external force (excessive external force), acts for multiple times. The power-receiver control unit may determine that an abnormality occurs, when the strain detected by the strain gauge 95 exceeds the strain threshold, which enables to determine that an external force exceeding the predetermined external force (excessive), acts for multiple times. Also these configurations can produce effects similar to those in the above-described embodiment.

[0084] As shown by the dashed line in FIG. 6, an acceleration sensor 91 may also be mounted on the vehicle body 11a close to the rear wheel 13 of the vehicle 11. Furthermore, the power-receiver control unit 230 may determine that an abnormality occurs when the acceleration detected by any one of the multiple acceleration sensors 91 exceeds an acceleration threshold that enables to determine that an external force exceeding a specified external force acts. This configuration enables to accurately determine that there is a high possibility that the rear wheel 13 of the vehicle 11 runs up onto the step B and that an abnormality occurs in the power-receiver communication antenna 170. The acceleration sensor 91 may be mounted on the vehicle body 11a only close to the rear wheel 13 of the vehicle 11. The acceleration sensor 91 may also be provided close to the case 101a. This configuration enables to accurately detect an external force that momentarily acts on the case 101a.

[0085] As shown by the dashed lines in FIG. 6, multiple strain gauges 95 may be attached to the case 101a. For example, the strain gauges 95 are attached to the front and rear of the case 101a. Furthermore, the power-receiver control unit 230 may determine that an abnormality occurs when the strain detected by any one of the multiple strain gauges 95 exceeds a strain threshold that enables to determine that an external force exceeding a specified external force acts. The strain gauges 95 may be attached to the front, rear, left and right parts of the case 101a. This configuration enables to detect a twist of the case 101a (corresponding to correlation amount) based on the strain detected by the multiple strain gauges 95. The power-receiver control unit 230 may determine that an abnormality occurs when the detected twist exceeds a twist threshold that enables to determine that an external force exceeding a predetermined external force acts.

[0086] The process of S12 in FIG. 7 may be omitted, and the power-receiver control unit 230 may prevent supply of the power supply request signal COMM to the power-receiver communication antenna 170, when the acceleration detected by the acceleration sensor 91 exceeds an acceleration threshold that enables to determine that an external force exceeding a predetermined external force acts. The process of S12 in FIG. 7 may be omitted, and the power-receiver control unit 230 may prevent supply of the power supply request signal COMM to the power-receiver communication antenna 170, when the strain detected by the strain gauge 95 exceeds a strain threshold that enables to determine that an external force exceeding a predetermined external force acts. These configurations enable to prevent transmission of the power supply request signal COMM, when there is a high possibility that an excessive external force acts on the case 101a and that an abnormality occurs in the power-receiver communication antenna 170.

[0087] The process of S12 in FIG. 7 may be omitted, and the power-receiver control unit 230 may calculate an integral value of the acceleration detected by the acceleration sensor 91 and may prevent supply of the power supply request signal COMM to the power-receiver communication antenna 170, when the integral value exceeds an acceleration cumulative threshold, which enables to determine that external force is accumulated beyond a predetermined amount (excessive). The process of S12 in FIG. 7 may be omitted, and the power-receiver control unit 230 may calculate an integral value of the strain detected by the strain gauge 95 and may prevent supply of the power supply request signal COMM to the power-receiver communication antenna 170, when the integral value exceeds a strain cumulative threshold, which enables to determine that external force is accumulated beyond a predetermined amount (excessive). These configurations enable to prevent transmission of the power supply request signal COMM, when there is a high possibility that acting of an external force on the case 101a repeatedly accumulates and that an abnormality occurs in the power-receiver communication antenna 170.

[0088] The case 101a may accommodate part of or entirety of the components of the power-receiver power supply unit 181 in addition to the power receiver coil 102, the power-receiver resonant circuit 140, and the power-receiver communication antenna 170.The traveling speed signal may be acquired from a change in the position information of the vehicle 11 calculated based on a GPS signal, or may be acquired based on a reflected wave of an electromagnetic wave emitted by a Doppler radar. The driving speed signal is not limited to one that represents the vehicle speed numerically, and may represent the vehicle speed by an intensity of the signal, or by a position of a bit that is 1 in data consisting of multiple bits. The power-receiver communication antenna and the power-transmitter communication antenna are not limited to communication coils, and may employ various antennas. For example, the communication antenna is a dipole antenna or a monopole antenna.

[0089] In the wireless power supply system 10, the power transmitter 20 may perform wide-area wireless communication with the power receiver 100. Wide area wireless communication is a communication with a longer communication distance than the narrow area wireless communication. Examples of the wide area wireless communication include 3GPP (registered trademark), 4G, LTE, 5G, and WiMAX (registered trademark) developed by IEEE. The power-transmitter control unit 70 and the power-receiver control unit 230 may transmit and receive information using the wide area wireless communication.

[0090] The method of wireless power transmission by the power transmitter antenna and the power receiver antenna is not limited to the magnetic field resonance method, and may be an electric field coupling method. In this case, a power transmitter antenna and a power receiver antenna that are different in form from coils and use an electric field coupling method may be used.

[0091] The above-described embodiments and the modified examples may be combined to a possible extent.

[0092] Although the present disclosure has been described according to the embodiments, it is understood that the present disclosure is not limited to the above-described embodiments or structures. The present disclosure also encompasses various modifications and variations within the scope of equivalents. 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.

[0093] Characteristic configurations extracted from the above-described embodiments and modifications will be described below.(Configuration 1)A power receiver device (100) is to be mounted on a vehicle (11). The power receiver device includes a power receiver antenna (102) and configured to be wirelessly supplied with power by the power receiver antenna from a power transmitter antenna (22) of a power transmitter device (20). The power receiver device includes: a power-receiver communication antenna (170); a case (101a) accommodating the power receiver antenna and the power-receiver communication antenna and to be fixed to a vehicle body (11a) of the vehicle; a sensor (91, 95) configured to detect a correlation amount correlated with an external force acting on the case; and a power-receiver control unit (230) configured to determine that abnormality occurs in the power-receiver communication antenna based on the correlation amount detected by the sensor.(Configuration 2)The power receiver device according to configuration 1, in which the power-receiver control unit is configured to perform energization control of the power-receiver communication antenna to supply a power supply request signal, which indicates power supply request to the power transmitter antenna, to the power-receiver communication antenna, and prevent supply of the power supply request signal to the power-receiver communication antenna when determining that abnormality occurs.(Configuration 3)The power receiver device according to configuration 1 or 2, in which the power-receiver control unit is configured to determine that abnormality occurs when the correlation amount detected by the sensor exceeds a predetermined threshold, which is for determination that external force exceeding a predetermined external force acts.(Configuration 4)The power receiver device according to configuration 1 or 2, in which the power-receiver control unit is configured to calculate an integral value of the correlation amount detected by the sensor, and determine that abnormality occurs when the integral value exceeds a cumulative threshold, which is for determination that external force accumulates beyond a predetermined amount.(Configuration 5)The power receiver device according to configuration 4, in which the power-receiver control unit is configured to calculate an integral value of only the correlation amount, which is detected by the sensor and exceeds a predetermined value, and determine that abnormality occurs when the integral value exceeds the cumulative threshold.(Configuration 6)The power receiver device according to any one of configurations 1 to 5, in which the sensor is an acceleration sensor (91) mounted on the case or the vehicle body and configured to detect acceleration.(Configuration 7)The power receiver device according to configuration 6, in which the acceleration sensor is mounted on the vehicle body and located close to a wheel (12, 13) of the vehicle.(Configuration 8)The power receiver device according to any one of configurations 1 to 5, in which the power receiver antenna has a flat shape in which a dimension in a height direction is smallest, the power-receiver communication antenna includes a power-receiver communication coil having a flat shape in which a dimension in the height direction is smallest, the case has a flat shape in which a dimension in the height direction is smallest, and the sensor is a strain gauge (95) configured to detect strain caused in an upper part or a lower part of the case.(Configuration 9)The power receiver device according to any one of configurations 1 to 8, in which the abnormality is deformation caused in the power-receiver communication antenna.

Claims

1.A power receiver device (100) to be mounted on a vehicle (11), the power receiver device including a power receiver antenna (102) and configured to be wirelessly supplied with power by the power receiver antenna from a power transmitter antenna (22) of a power transmitter device (20), the power receiver device comprising:a power-receiver communication antenna (170);a case (101a) accommodating the power receiver antenna and the power-receiver communication antenna and to be fixed to a vehicle body (11a) of the vehicle;a sensor (91, 95) configured to detect a correlation amount correlated with an external force acting on the case; anda power-receiver control unit (230) configured to determine that abnormality occurs in the power-receiver communication antenna based on the correlation amount detected by the sensor.2.The power receiver device according to claim 1, whereinthe power-receiver control unit is configured toperform energization control of the power-receiver communication antenna to supply a power supply request signal, which indicates power supply request to the power transmitter antenna, to the power-receiver communication antenna, andprevent supply of the power supply request signal to the power-receiver communication antenna when determining that abnormality occurs.3.The power receiver device according to claim 1 or 2, whereinthe power-receiver control unit is configured to determine that abnormality occurs when the correlation amount detected by the sensor exceeds a predetermined threshold, which is for determination that external force exceeding a predetermined external force acts.4.The power receiver device according to claim 1 or 2, whereinthe power-receiver control unit is configured tocalculate an integral value of the correlation amount detected by the sensor, anddetermine that abnormality occurs when the integral value exceeds a cumulative threshold, which is for determination that external force accumulates beyond a predetermined amount.5.The power receiver device according to claim 4, whereinthe power-receiver control unit is configured tocalculate an integral value of only the correlation amount, which is detected by the sensor and exceeds a predetermined value, anddetermine that abnormality occurs when the integral value exceeds the cumulative threshold.6.The power receiver device according to claim 1 or 2, whereinthe sensor is an acceleration sensor (91) mounted on the case or the vehicle body and configured to detect acceleration.7.The power receiver device according to claim 6, whereinthe acceleration sensor is mounted on the vehicle body and located close to a wheel (12, 13) of the vehicle.8.The power receiver device according to claim 1 or 2, whereinthe power receiver antenna has a flat shape in which a dimension in a height direction is smallest,the power-receiver communication antenna includes a power-receiver communication coil having a flat shape in which a dimension in the height direction is smallest,the case has a flat shape in which a dimension in the height direction is smallest, andthe sensor is a strain gauge (95) configured to detect strain caused in an upper part or a lower part of the case.9.The power receiver device according to claim 1 or 2, whereinthe abnormality is deformation caused in the power-receiver communication antenna.10.A power receiver device (100) to be mounted on a vehicle (11), the power receiver device including a power receiver antenna (102) and configured to be wirelessly supplied with power by the power receiver antenna from a power transmitter antenna (22) of a power transmitter device (20), the power receiver device comprising:a power-receiver communication antenna (170);a case (101a) accommodating the power receiver antenna and the power-receiver communication antenna and to be fixed to a vehicle body (11a) of the vehicle;a sensor (91, 95) configured to detect a correlation amount correlated with an external force acting on the case; anda power-receiver control unit (230) configured toperform energization control of the power-receiver communication antenna to supply a power supply request signal, which indicates power supply request to the power transmitter antenna, to the power-receiver communication antenna, andprevent supply of the power supply request signal to the power-receiver communication antenna, when the correlation amount detected by the sensor exceeds a predetermined threshold, which is for determination that external force exceeding a predetermined external force acts.11.A power receiver device (100) to be mounted on a vehicle (11), the power receiver device including a power receiver antenna (102) and configured to be wirelessly supplied with power by the power receiver antenna from a power transmitter antenna (22) of a power transmitter device (20), the power receiver device comprising:a power-receiver communication antenna (170);a case (101a) accommodating the power receiver antenna and the power-receiver communication antenna and to be fixed to a vehicle body (11a) of the vehicle;a sensor (91, 95) configured to detect a correlation amount correlated with an external force acting on the case; anda power-receiver control unit (230) configured toperform energization control of the power-receiver communication antenna to supply a power supply request signal, which indicates power supply request to the power transmitter antenna, to the power-receiver communication antenna,calculate an integral value of the correlation amount detected by the sensor, andprevent supply of the power supply request signal to the power-receiver communication antenna, when the integral value exceeds a cumulative threshold, which is for determination that external force accumulates beyond a predetermined amount.12.The power receiver device according to any one of claims 2, 10, and 11, whereinthe power-receiver control unit is capable of communicating with a vehicle equipped with the power receiver device, andthe power-receiver control unit is configured to transmit a notification signal to the vehicle, when preventing supply of the power supply request signal to the power-receiver communication antenna.13.The power receiver device according to claim 12, whereinthe notification signal includes a signal that instructs to notify a driver of the vehicle that supply of the power supply request signal to the power-receiver communication antenna is prevented.

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