Power transmitter device, wireless power transfer system, power supply program, and control method for power transmitter device

Abstract

A power-transmitter control unit (70) of a power transmitter device (20) energizes a power transmitter coil when determining that there is power supply request based on a power supply request signal received by a power-transmitter communication antenna (40) and stops energization of the specific transmitter antenna when determining based on vehicle identification information received by a power-transmitter communication antenna that a period, during which power is continuously supplied from a specific power transmitter antenna (22) to a vehicle identified by the vehicle identification information, exceeds a determination period.

Description

POWER TRANSMITTER DEVICE, WIRELESS POWER TRANSFER SYSTEM, POWER SUPPLY PROGRAM, AND CONTROL METHOD FOR POWER TRANSMITTER DEVICECross Reference

[0001] This application is based on Japanese Application No. 2024-208022 filed on November 29, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a power transmitter device, a wireless power transfer system, a power supply program, and a control method for the power transmitter device.

[0003] Patent Literature 1 discloses a system for performing wireless power transfer from a power transmitter device on the ground to a power receiver device mounted on a parked electric vehicle. In this system, electric power is supplied wirelessly from a power transmitter antenna of the power transmitter device to a power receiver antenna of the power receiver device.

[0004] JP2021-154837A

[0005] The power transmitter antenna is not only the power transmitter antenna that supplies power wirelessly to the power receiver antenna of the parked vehicle, but also a power transmitter antenna that is buried in a roadway and supplies power wirelessly to a power receiver antenna of a moving vehicle. When wirelessly supplying power from any of the power transmitter antennas to the power receiver antenna, it is desirable to deal with a situation in which control for stopping the power supply does not function for some reason.

[0006] It is an object of the present disclosure to enable to deal with a situation in which control for stopping power supply does not function for some reason.

[0007] According to a first aspect to address the above-mentioned issue, a power transmitter device is to be applied to a wireless power transfer system. The wireless power transfer system includes the power transmitter device and a power receiver device. The power receiver device includes a power-receiver communication antenna, which is configured to perform wireless communication with a power-transmitter communication antenna, and configured to supply a power supply request signal, which includes vehicle identification information for identifying a vehicle and indicates power supply request to a power transmitter antenna, to a power power-receiver communication antenna. The power transmitter device comprises: at least one power transmitter antenna; a power-transmitter control unit configured to perform wireless power transfer from the power transmitter antenna to a power receiver antenna of the power receiver device mounted on the vehicle and control energization of the power transmitter antenna to perform wireless power transfer to the power receiver antenna; and the power-transmitter communication antenna. The power-transmitter control unit is configured to energize the power transmitter antenna when determining that there is the power supply request based on the power supply request signal received by the power-transmitter communication antenna, and stop energization of specific power transmitter antenna when determining that a period, during which power is continuously supplied from the specific power transmitter antenna to the vehicle identified by the vehicle identification information, exceeds a determination period based on the vehicle identification information received by the power-transmitter communication antenna.

[0008] According to the above configuration, the power transmitter device includes at least one power transmitter antenna, and wirelessly supplies power from the power transmitter antenna to the power receiver antenna of the power receiver device mounted on the vehicle. Herein, the power receiver device supplies, to the power power-receiver communication antenna, the power supply request signal, which includes vehicle identification information of the vehicle and indicates the power supply request to the power transmitter antenna. The power-transmitter control unit energizes the power transmitter antenna on condition that the power-transmitter control unit determines that there is the power supply request based on the power supply request signal. At this time, after the start of the wireless power transfer to the power receiver antenna by the power transmitter antenna, the control for stopping the power supply may cause malfunction due to some cause.

[0009] Therefore, the power-transmitter control unit stops the power supply to the specific power transmitter antenna, when determining that the period, during which power is continuously supplied from the specific power transmitter antenna to the vehicle identified by the vehicle identification information, exceeds the determination period. Therefore, even if the control to stop power supply fails to function for some reason, when the continuous power supply period from the specific power transmitter antenna exceeds the determination period, the configuration enables to stop the power supply from the specific power transmitter antenna.

[0010] Herein, when power is supplied to the parked vehicle, the vehicle is parked above the specific power transmitter antenna for a long period of time. On the other hand, when power is supplied to the traveling vehicle, the vehicle passes above multiple power transmitter antennas in a short period of time. In view of this, the power-transmitter control unit may be configured to acquire at least one of a first period, which is a determination period of the power transmitter antenna supplying power to the parked vehicle, and a second period, which is a determination period of the power transmitter antenna supplying power to the traveling vehicle, and set the second period to be shorter than the first period. This configuration enables to appropriately set the determination period for a duration of power supply to the traveling vehicle to be shorter than the determination period for a duration of power supply to the parked vehicle. Therefore, the configuration enables to appropriately set the upper limit of the period, during which the power supply is continued, depending on the usage mode of the power transmitter antenna.

[0011] According to a second aspect, a power supply program is to be applied to a wireless power transfer system. The wireless power transfer system includes: a power transmitter device including at least one transmitter antenna, a power-transmitter control unit configured to perform wireless power transfer from the power transmitter antenna to a power receiver antenna of a power receiver device mounted on a vehicle and control energization of the power transmitter antenna to perform wireless power transfer to the power receiver antenna, and a power-transmitter communication antenna; and a power receiver device including a power-receiver communication antenna, which is configured to perform wireless communication with the power-transmitter communication antenna, and configured to supply a power supply request signal, which includes vehicle identification information of a vehicle and indicates power supply request to the power transmitter antenna, to the power power-receiver communication antenna. The power supply program configured to carry out: executing a process to cause the power-transmitter control unit to energize the power transmitter antenna when determining that there is the power supply request based on the power supply request signal received by the power-transmitter communication antenna, and stop energization of a specific power transmitter antenna when determining that a period, during which power is continuously supplied from the specific power transmitter antenna to the vehicle identified by the vehicle identification information, exceeds a determination period based on the vehicle identification information received by the power-transmitter communication antenna.

[0012] The above configuration enables, in the power supply program for controlling the power transmitter device, to achieve the same effect as the first aspect.

[0013] According to a third aspect, a control method is for a power transmitter device to be applied to a wireless power transfer system. The wireless power transfer system includes: a power transmitter device including at least one transmitter antenna, a power-transmitter control unit configured to perform wireless power transfer from the power transmitter antenna to a power receiver antenna of a power receiver device mounted on a vehicle and control energization of the power transmitter antenna to perform wireless power transfer to the power receiver antenna, and a power-transmitter communication antenna; and a power receiver device including a power-receiver communication antenna, which is configured to perform wireless communication with the power-transmitter communication antenna, and configured to supply a power supply request signal, which includes vehicle identification information of a vehicle and indicates power supply request to the power transmitter antenna, to the power power-receiver communication antenna. The control method comprises: executing a process to cause the power-transmitter control unit to energize the power transmitter antenna when determining that there is the power supply request based on the power supply request signal received by the power-transmitter communication antenna, and stop energization of a specific power transmitter antenna when determining that a period, during which power is continuously supplied from the specific power transmitter antenna to the vehicle identified by the vehicle identification information, exceeds a determination period based on the vehicle identification information received by the power-transmitter communication antenna.

[0014] The above configuration enables, in the control method for the power transmitter device, to achieve the same effects as those of the first aspect.

[0015] 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.

[0016] FIG. 1 is an overall configuration diagram of a wireless power transfer system.FIG. 2 is a diagram showing the wireless power transfer 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 a condition in which power is supplied to the vehicle in a parking lot.FIG. 7 is a flowchart showing current control of a power transmitter coil.FIG. 8 is a flowchart showing a vehicle abnormality determination control.FIG. 9 is a flowchart showing a modified example of the current control of the power transmitter coil.FIG. 10 is a diagram showing a relationship between a vehicle traveling speed and a determination period.FIG. 11 is a diagram showing a modified example of the relationship between the vehicle traveling speed and the determination period.

[0017] 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.

[0018] A first embodiment of a wireless power transfer system of the present disclosure will be described below with reference to the drawings.

[0019] First, an overall configuration of the wireless power transfer system will be described. As shown in FIGS. 1, 2, and 3, the wireless power transfer system 10 includes a power transmitter 20 and a power receiver 100. The power receiver 100 is mounted on a vehicle 11 as a 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 transfer 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 transfer system 10 is also referred to as a dynamic wireless power transfer (D-WPT) system.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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. A rated power of the power transmitter coil 22 installed on the road RS is greater than a rated power of the power transmitter coil 22 installed in the parking lot.

[0025] 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 unit 101 is located at the bottom of the vehicle body 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.

[0026] 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.

[0027] 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.

[0028] 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).

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] The power receiver 100 includes a power-receiver power supply unit 181 (also referred to as “WPU”) having a power receiver control device 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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 a specified same frequency f0 or close to the first specified frequency. That is, the specified resonant frequency f0 of the wireless power transfer system including the power transmitter coil 22, the power transmitter resonant circuit 30, the power receiver coil 102, and the power receiver resonant circuit 140 is set to a frequency equal to or close to the first specified frequency. Notably, the specified resonant frequency f0 is a resonant frequency when the relative positional relationship between the power transmitter coil 22 and the power receiver coil 102 is appropriate.

[0038] 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.

[0039] 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.

[0040] 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").

[0041] 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.

[0042] 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.

[0043] 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 near 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.

[0044] The power-receiver control unit 230 controls the transmitter 240 to supply a vehicle-side signal COMM including, in one frame, the power supply request signal and a traveling speed signal (corresponding to a traveling state signal) indicating a traveling speed Vsp (corresponding to a traveling state) 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 (corresponding to vehicle identification information) 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.

[0045] 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.

[0046] 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).

[0047] 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 contactless power transmission from the power transmitter coil 22 to the power receiver coil 102.

[0048] The transmitter 240 and its peripheral configuration will be described with reference to FIG. 4.

[0049] 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.

[0050] 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.

[0051] Next, the receiver 80 and its peripheral configuration will be described with reference to FIG. 5.

[0052] The signal 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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 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.

[0057] When determining that there is the power supply request, the power-transmitter controller 71 (i.e., the power-transmitter control unit 70) performs the following tracking process prior to the actual energization. The power-transmitter controller 71 calculates the phase difference of the current with respect to the voltage applied to the power transmitter coil 22, while the frequency of the voltage applied to the power transmitter coil 22 is set to a plurality of different frequencies within a predetermined frequency range including the predetermined resonance frequency f0, and executes provisional energization of the power transmitter coil 22. At this time, the transmission power in the tracking process is set to be smaller than the transmission power in the actual energization. The phase difference value is expressed as an absolute value regardless of whether the phase difference value is positive or negative. The power-transmitter controller 71 sets, among multiple frequencies of the applied voltage that are set, a matching frequency, which is a frequency at which the calculated phase difference is below a phase difference threshold (energization state of power transmitter coil 22 satisfies a predetermined condition) as a frequency of high frequency current flowing through the power transmitter coil 22. That is, the power-transmitter controller 71 searches, in a predetermined frequency range including a predetermined resonant frequency f0 of the wireless power transfer system, the matching frequency, which is a frequency of the voltage applied to the power transmitter coil 22 that satisfies the predetermined condition when the power transmitter coil 22 is energized. The phase difference threshold may be set to, for example, a value at which a power supply efficiency from the power transmitter coil 22 to the power receiver coil 102 becomes greater than a predetermined efficiency, in advance based on a test or a simulation. Thereafter, the power-transmitter controller 71 executes the actual energization at the set matching frequency. The power-transmitter controller 71 may set, among the multiple frequencies of the applied voltage that are set, the matching frequency to a frequency at which a power factor of the power transmitter 20 exceeds a power factor threshold (energization state of power transmitter coil 22 satisfies a predetermined condition).

[0058] FIG. 6 is a diagram showing a mode in which power is supplied to the vehicle 11 in a parking lot (or charging station). As shown in (a) in FIG. 6, for example, a situation is assumed in which the power receiver coil 102 of the vehicle 11 receives wireless power transfer from the power transmitter coil 22 provided in the parking lot. As shown in (b) in FIG. 6, when the relative positional relationship between the power transmitter coil 22 and the power receiver coil 102 is appropriate, a leakage magnetic field is reduced, and a power supply efficiency is increased. The power receiver 100 supplies the power supply request signal COMM, which includes ID information of the vehicle 11 and indicates a power supply request to the power transmitter coil 22, to the power power-receiver communication antenna 170. The power-transmitter control unit 70 then energizes the power transmitter coil 22 on condition that the power-transmitter control unit 70 determines that there is the power supply request based on the power supply request signal COMM. For example, when the state of charge (SOC) of the high-voltage storage battery 300 reaches 100% (i.e., predetermined charge rate or higher), the power-receiver controller 231 controls the transmitter 240 to stop supplying the power supply request signal COMM to the power-receiver communication antenna 170. The power-transmitter control unit 70 stops the energization of the power transmitter coil 22 when determining that the power supply request signal COMM has stopped.

[0059] At this time, after the start of wireless power transfer to the power receiver antenna by the power transmitter coil 22, the control for stopping the power supply may cause malfunction due to some cause. For example, an abnormality in the power-receiver control unit 230 may cause the power supply request signal COMM to continue, or an abnormality in the power-transmitter control unit 70 may become unable to determine that the power supply request signal COMM has stopped.

[0060] Therefore, the power-transmitter control unit 70 stops energization of the specific power transmitter coil 22 when determining that a period during which power has been continuously supplied from the specific power transmitter coil 22 to the vehicle 11 identified by the ID information has exceeded a determination period. In other words, when determining that the period during which power has been continuously supplied from the power transmitter coil 22, which is recognized, to the vehicle 11, which is identified by the ID information contained in the power supply request signal COMM, has exceeded the determination period, the power-transmitter control unit 70 stops energization of the power transmitter coil 22 that is supplying power to the identified vehicle 11.

[0061] Herein, when power is supplied to the parked vehicle 11, the vehicle 11 is parked above the specific power transmitter coil 22 for a long period of time. On the other hand, as shown in FIG. 2, when power is supplied to the traveling vehicle 11, the vehicle 11 passes over multiple power transmitter coils 22 (power-transmitter coil units 21) in a short period of time. In this embodiment, the power transmitter 20 installed in the parking lot and the power transmitter 20 installed on the road RS are connected to each other so as to be able to communicate with each other wirelessly or by wire. In view of this, the power-transmitter control unit 70 acquires at least one of a first period, which is a determination period for the power transmitter coil 22 (power transmitter 20 installed in the parking lot) that supplies power to the parked vehicle 11, and a second period, which is a determination period for the power transmitter coil 22 (power transmitter 20 installed on the road RS) that supplies power to the traveling vehicle 11, and sets the second period to be shorter than the first period. The acquisition of the at least one of the first period and the second period by power-transmitter control unit 70 includes reading of the at least one of the first period and the second period from a storage unit, which is included in the power-transmitter controller 71, by the power-transmitter controller 71, in addition to receiving the at least one of the first period and the second period by the power-transmitter control unit 70 through communication between the power transmitter 20 corresponding to itself and another power transmitter 20.

[0062] FIG. 7 is a flowchart of energization control of the power transmitter coil 22 executed by the power- transmitter control unit 70. This series of process is executed by the power-transmitter control unit 70 of the power transmitter power supply unit 51 installed at the side of the road RS.

[0063] The power-transmitter amplifier 81 of the receiver 80 amplifies the high frequency signal received by the power-transmitter communication antenna 40 and inputs the amplified signal to the detection circuit 82 (S10).

[0064] The detection circuit 82 calculates an intensity Intd of the power supply request signal COMM based on the input signal from the power-transmitter amplifier 81 (S11). Further, the detection circuit 82 acquires the ID information of the vehicle 11 based on the input signal from the power-transmitter amplifier 81.

[0065] The determination circuit 83 determines whether the intensity Intd calculated in step S11 exceeds a determination threshold Ijde (S12). In this determination, when determining that the intensity Intd does not exceed a determination threshold Ijde (S12: NO), determination result information indicating that there is no power supply request is input to the power-transmitter controller 71, and this series of the process is temporarily terminated (END). That is, the power-transmitter controller 71 stops switching control of the PFC circuit 61 and the inverter 60, maintains the switches of the PFC circuit 61 and the inverter 60 off, and does not execute the energization of the power transmitter coil 22.

[0066] On the other hand, when determining in step S12 that the intensity Intd exceeds the determination threshold Ijde (S12: YES), the power-transmitter controller 71 is input with the determination result information that there is the power supply request.

[0067] Next, the first period is received through communication with the power transmitter 20 installed in the parking lot (S13). The first period is, for example, several hours, and is stored in a storage unit of the power-transmitter controller 71 of the power transmitter 20 installed in the parking lot.

[0068] Next, the second period is set (S14). Specifically, the second period is, for example, a few seconds and set to a period shorter than the received first period. When the power transmitter coil 22 is installed at a position where the vehicle 11 stops at a red signal light installed on the road RS, the second period may be set to several minutes, for example.

[0069] Next, the power-transmitter controller 71 executes the tracking process (S15). Specifically, the power-transmitter controller 71 sets the frequency of the voltage, which is applied to the power transmitter coil 22, to a frequency in order from high to low or from low to high, among multiple different frequencies, and meanwhile, calculates the phase difference of the current with respect to the voltage applied to the power transmitter coil 22. The power-transmitter controller 71 sets, among the multiple frequencies of the applied voltage that are set, the frequency of the high frequency current flowing through the power transmitter coil 22 to a frequency (matching frequency), at which the calculated phase difference is below the phase difference threshold. On the other hand, even when the matching frequency is searched in the predetermined frequency range, there may be no matching frequency in some cases.

[0070] Next, it is determined whether there is the matching frequency (S16). When it is determined that there is no matching frequency (S16: NO), the energization of the power transmitter coil 22 is stopped (S20). Specifically, the power-transmitter controller 71 stops switching control of the PFC circuit 61 and the inverter 60, turns the switches of the PFC circuit 61 and the inverter 60 off, and stops the energization of the power transmitter coil 22.

[0071] On the other hand, when it is determined in step S16 that the matching frequency is present (S16: YES), the power transmitter coil 22 is energized (S17). Specifically, the power-transmitter controller 71 executes the actual energization at the matching frequency set in the tracking process in S15 with a larger transmission power than that in the energization during the tracking process (corresponding to provisional energization). The power-transmitter controller 71 executes switching control of the PFC circuit 61 and the inverter 60 to energize the power transmitter coil 22.

[0072] Next, it is determined whether a power supply stop condition is satisfied (S18). Specifically, when it is determined through a process similar to the process in S10 to S12 that the intensity Intd does not exceed the determination threshold Ijde, it is determined that the power supply stop condition is satisfied. In this determination, when it is determined that the power supply stop condition is satisfied (S18: YES), the process proceeds to S20.

[0073] On the other hand, when it is determined in the process of S18 that the power supply stop condition is not satisfied (S18: NO), it is determined whether an energization period has exceeded a second period (S19). Specifically, with respect to the vehicle 11, which is identified by the ID information included in the signal received in the process of S10, it is determined whether the period during which power has been continuously supplied from the power transmitter coil 22 from the beginning of the energization in the processing of S17 has exceeded the second period.

[0074] When it is determined in S19 that the energization period exceeds the second period (S19: YES), the energization of the power transmitter coil 22 is stopped (S20). Then, the series of process is terminated (END).

[0075] The program that causes the power-transmitter control unit 70 to execute the process shown in the flowchart of FIG. 7 corresponds to a power supply program. The method that causes the power-transmitter control unit 70 to execute the process shown in the flowchart of FIG. 7 corresponds to a control method for power transmitter 20.

[0076] According to the embodiment described above, the following effects can be exhibited.

[0077] The power-transmitter control unit 70 stops the energization of the specific power transmitter coil 22 when determining that the period during which power has been continuously supplied from the specific power transmitter coil 22 to the vehicle 11 identified by the ID information has exceeded the determination period. Therefore, even when the control to stop power supply fails for some reason, when the continuous power supply period from the specific power transmitter coil 22 exceeds the determination period, the energization of the specific power transmitter coil 22 can be stopped. As a result, the configuration enables to prevent the high-voltage storage battery 300 from being overcharged and to prevent a metal component constituting the vehicle 11 from being excessively inductively heated due to a leakage magnetic field.

[0078] The power-transmitter control unit 70 acquires the first period, which is the determination period for the power transmitter coil 22 that supplies power to the parked vehicle 11, and the second period, which is the determination period for the power transmitter coil 22 that supplies power to the traveling vehicle 11, and sets the second period to be shorter than the first period. Therefore, the configuration enables to reduce the determination period for the duration of power supply to the traveling vehicle 11 to be shorter than the determination period for the duration of power supply to the parked vehicle 11. Therefore, the configuration enables to appropriately set the upper limit of the period, during which the power supply is continued, depending on the usage mode of the power transmitter coil 22.

[0079] The power transmitter 20 including the power transmitter coil 22 installed on the road RS is capable of acquiring the first period by communication with the power transmitter 20 including the power transmitter coil 22 installed in the parking lot. By setting the second period to be shorter than the first period, the upper limit of the period, during which the power supply is continued, can be set appropriately.

[0080] 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.

[0081] When power is supplied to the traveling vehicle 11, the vehicle 11 passes over multiple power transmitter coils 22 in a short period. Therefore, if the vehicle 11 is parked for a long period above the power transmitter coil 22 that supplies power to the traveling vehicle 11, there is a risk that an abnormality occurs in the vehicle 11.

[0082] In view of this, when determining that the period, during which the vehicle 11 identified by the ID information is continuously stopped above the power transmitter coil 22 that supplies power to the traveling vehicle 11, exceeds a third period, which is longer than the second period, based on the ID information and a traveling speed signal (corresponding to traveling state signal) received by the power-transmitter communication antenna 40, the power-transmitter control unit 70 determines that an abnormality occurs in the vehicle 11.

[0083] More specifically, the power-transmitter control unit 70 executes control shown in the flowchart of FIG. 8. The ID information and the traveling speed signal are received (S30). It is determined whether the vehicle 11 identified by the ID information is parked on the power transmitter coil 22 of the road RS (S31). For example, when the traveling speed Vsp acquired based on the traveling speed signal is lower than a vehicle stop determination speed, it is determined that the vehicle 11 is stopped. When it is determined that the vehicle 11 is not stopped on the power transmitter coil 22 on the road RS (S31: NO), this series of process is temporarily terminated (END). On the other hand, when it is determined that the vehicle 11 is stopped (S31: YES), the counter value Tcnt is counted (S32). An initial value of the counter Cnt is zero. It is determined whether the counter value Tcnt is greater than a counter threshold Tth (corresponding to third period) (S33). When it is determined that the counter value Tcnt is not greater than the counter threshold Tth (S33: NO), the process is executed again from S31. On the other hand, when it is determined that the counter value Tcnt is greater than the counter threshold Tth (S33: YES), it is determined that an abnormality occurs in the vehicle 11, and a notification is sent to an outside (S34). The outside may be, for example, a customer service center. Then, the series of process is terminated (END).

[0084] The above configuration enables, when the duration of the power supply from the specific power transmitter coil 22 exceeds the determination period, to determine that an abnormality has occurred in the vehicle 11, in addition to stopping the energization of the specific power transmitter coil 22. Note that the vehicle-side signal may include a vehicle position signal (corresponding to traveling state signal) indicating the position of the vehicle 11 (corresponding to traveling state) instead of the driving speed signal. In this case, the traveling speed Vsp of the vehicle 11 may be calculated from the position of the vehicle 11 acquired based on the vehicle position signal.

[0085] The power transmitter 20 installed in the parking lot may be equipped with the power transmitter coil 22 that supplies power to the parked vehicle 11, and the power-transmitter control unit 70 may acquire the second period by communicating with the power transmitter 20 equipped with the power transmitter coil 22 installed on the road RS, and may set the first period to be longer than the second period.

[0086] In detail, the power-transmitter control unit 70 of the power transmitter power supply unit 51 installed in the parking lot executes the energization control of the power transmitter coil 22 shown in the flowchart of FIG. 9. In this control, the process of S13, S14, and S19 in FIG. 7 are changed to process of S13A, S14A, and S19A, respectively, and the other process is the same as that in FIG. 7. The same process as that in the flowchart of FIG. 7 is denoted by the same step numbers and the description thereof is incorporated herein. When it is determined in S12 that the intensity Intd exceeds the determination threshold Ijde (S12: YES), the second period is received by communication with the power transmitter 20 installed on the road RS (S13A). The second period is, for example, several seconds, and is stored in a storage unit of the power-transmitter controller 71 of the power transmitter 20 installed in the road RS. Next, the first period is set (S14A). Specifically, the first period is, for example, a few hours and set to a period shorter than the received second period.

[0087] According to the above configuration, the power transmitter 20 equipped with the power transmitter coil 22 that supplies power to the parked vehicle 11 is enabled to acquire the second period by communication with the power transmitter 20 equipped with the power transmitter coil 22 that supplies power to the traveling vehicle 11. By setting the first period to be longer than the second period, the upper limit of the period, during which the power supply is continued, can be set appropriately.

[0088] The power transmitter 20 may include the power transmitter coil 22 that supplies power to the traveling vehicle 11 and the power transmitter coil 22 that supplies power to the parked vehicle 11. That is, the power transmitter 20 may have a function as the power transmitter coil 22 that supplies power to the traveling vehicle 11 and a function as the power transmitter coil 22 that supplies power to the parked vehicle 11. For example, the power transmitter 20 may be configured to comprehensively execute energization control of a large number (plurality) of power transmitter coils 22 installed in parking lots and roads RS included in an entire city. In this case, at least one of the first period and the second period is obtained, and at least one of the first period and the second period is set so that the second period is shorter than the first period. This configuration enables to appropriately set the upper limit on the period during which power supply is continued. The power transmitter 20 may control the energization of the power transmitter coil 22 installed in a parking lot of a store and the power transmitter coil 22 installed in a portion of the road RS in front of the store. The power transmitter coil 22 included in the power transmitter 20 may be capable of switching between supplying power to the traveling vehicle 11 and supplying power to the parked vehicle 11. That is, the power transmitter 20 may have a function as the power transmitter coil 22 that supplies power to the traveling vehicle 11 and a function as the power transmitter coil 22 that supplies power to the parked vehicle 11. Also in this case, the power-transmitter control unit 70 acquires at least one of the first period and the second period, and sets at least one of the first period and the second period so that the second period is shorter than the first period.

[0089] 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-transmitter control unit 70 may vary the determination period depending on the vehicle traveling speed Vsp. In this case, the power-transmitter control unit 70 sets the determination period according to the traveling speed Vsp, without distinguishing between the power transmitter coil 22 that supplies power to the parked vehicle 11 and the power transmitter coil 22 that supplies power to the traveling vehicle 11. For example, as shown in FIGS. 10 and 11, the determination period when the traveling speed Vsp is low can be made longer than the determination period when the traveling speed Vsp is high. At that time, the length of the determination period may be changed gradually (continuously) as shown in FIG. 10, or may be changed stepwisely (discontinuously) as shown in FIG. 11. In the examples of FIGS. 10 and 11, the power-transmitter control unit 70 sets the determination period when the traveling speed Vsp is lower than the predetermined speed to be longer than the determination period when the traveling speed Vsp is not lower than the predetermined speed. Furthermore, the power-transmitter control unit 70 may set the determination period to be longer as the traveling speed Vsp becomes lower. 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. 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.

[0090] The vehicle identification information for identifying the vehicle 11 is not limited to the ID information of the vehicle 11 (identifier for uniquely identifying vehicle 11), but may be a token that is a temporary certificate used in an authentication process or an authorization process. Various information capable of identifying the vehicle 11 may be be used as the vehicle identification information. In the wireless power transfer 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.

[0091] the power-transmitter controller 71 (power transmitter control unit 70) and the method described in the present disclosure may be implemented by a special purpose computer which is configured with a memory and a processor programmed to execute one or more particular functions (instructions) embodied in computer programs of the memory. Alternatively, the power-transmitter controller 71 and the technique according to the present disclosure may be achieved by a dedicated computer provided by constituting a processor with one or more dedicated hardware logic circuits. Alternatively, the power-transmitter controller 71 and the technique according to the present disclosure may be achieved using one or more dedicated computers constituted by a combination of the processor and the memory programmed to execute one or more functions and the processor with one or more hardware logic circuits. The computer programs may be stored, as instructions to be executed by a computer, in a tangible non-transitory computer-readable medium.

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

[0094] Characteristic configurations extracted from the above-described embodiments and modifications will be described below. (Configuration 1) A power transmitter device is to be applied to a wireless power transfer system (10). The wireless power transfer system includes the power transmitter device (20) and a power receiver device. The power receiver device includes a power-receiver communication antenna (170), which is configured to perform wireless communication with a power-transmitter communication antenna, and configured to supply a power supply request signal, which includes vehicle identification information for identifying a vehicle and indicates power supply request to a power transmitter antenna, to a power power-receiver communication antenna. The power transmitter device includes: at least one power transmitter antenna (22); a power-transmitter control unit (70) configured to perform wireless power transfer from the power transmitter antenna to a power receiver antenna (102) of the power receiver device (100) mounted on the vehicle (11) and control energization of the power transmitter antenna to perform wireless power transfer to the power receiver antenna; and the power-transmitter communication antenna (40). The power-transmitter control unit is configured to energize the power transmitter antenna when determining that there is the power supply request based on the power supply request signal received by the power-transmitter communication antenna, and stop energization of specific power transmitter antenna when determining that a period, during which power is continuously supplied from the specific power transmitter antenna to the vehicle identified by the vehicle identification information, exceeds a determination period based on the vehicle identification information received by the power-transmitter communication antenna. (Configuration 2) The power transmitter device according to configuration 1, in which the power-transmitter control unit is configured to acquire at least one of a first period, which is the determination period of the power transmitter antenna configured to supply power to the vehicle that is parked, and a second period, which is the determination period of the power transmitter antenna configured to supply power to the vehicle that travels, and set the second period to be shorter than the first period. (Configuration 3) The power transmitter device according to configuration 2, in which in the wireless power transfer system, the power receiver device is configured to supply a traveling state signal, which indicates a traveling state of the vehicle, to the power power-receiver communication antenna, and the power-transmitter control unit is configured to determine that an abnormality occurs in the vehicle when determining that a period, during which the vehicle identified by the vehicle identification information is continuously stopped on the power transmitter antenna configured to supply power to the vehicle that travels, exceeds a third period, which is longer than the second period, based on the vehicle identification information and the traveling state signal received by the power-transmitter communication antenna. (Configuration 4) The power transmitter device according to configuration 2 or 3, in which the power transmitter device includes the power transmitter antenna configured to supply power to the vehicle that travels, and the power-transmitter control unit is configured to acquire the first period by communication with the power transmitter device, which includes the power transmitter antenna configured to supply power to the vehicle that is parked, and set the second period to be shorter than the first period. (Configuration 5) The power transmitter device according to configuration 2 or 3, in which the power transmitter device includes the power transmitter antenna configured to supply power to the vehicle that is parked, and the power-transmitter control unit is configured to acquire the second period by communication with the power transmitter device, which includes the power transmitter antenna configured to supply power to the vehicle that travels, and set the first period to be longer than the second period. (Configuration 6) The power transmitter device according to configuration 1 or 2, in which the power transmitter device has a function as the power transmitter antenna configured to supply power to the vehicle that travels and a function as the power transmitter antenna configured to supply power to the vehicle that is parked. (Configuration 7) The power transmitter device according to configuration 1, in which the power-transmitter control unit is configured to vary the determination period depending on a traveling speed of the vehicle. (Configuration 8) A wireless power transfer system (10) including: the power transmitter device according to any one of configurations 1 to 7; and the power receiver device.

Claims

1. A power transmitter device to be applied to a wireless power transfer system (10), the wireless power transfer system including the power transmitter device (20) and a power receiver device, the power receiver device including a power-receiver communication antenna (170), which is configured to perform wireless communication with a power-transmitter communication antenna, and configured to supply a power supply request signal, which includes vehicle identification information for identifying a vehicle and indicates power supply request to a power transmitter antenna, to a power power-receiver communication antenna, the power transmitter device comprising: at least one power transmitter antenna (22); a power-transmitter control unit (70) configured to perform wireless power transfer from the power transmitter antenna to a power receiver antenna (102) of the power receiver device (100) mounted on the vehicle (11) and control energization of the power transmitter antenna to perform wireless power transfer to the power receiver antenna; and the power-transmitter communication antenna (40), wherein the power-transmitter control unit is configured to energize the power transmitter antenna when determining that there is the power supply request based on the power supply request signal received by the power-transmitter communication antenna, and stop energization of specific power transmitter antenna when determining that a period, during which power is continuously supplied from the specific power transmitter antenna to the vehicle identified by the vehicle identification information, exceeds a determination period based on the vehicle identification information received by the power-transmitter communication antenna.

2. The power transmitter device according to claim 1, wherein the power-transmitter control unit is configured to acquire at least one of a first period, which is the determination period of the power transmitter antenna configured to supply power to the vehicle that is parked, and a second period, which is the determination period of the power transmitter antenna configured to supply power to the vehicle that travels, and set the second period to be shorter than the first period.

3. The power transmitter device according to claim 2, wherein in the wireless power transfer system, the power receiver device is configured to supply a traveling state signal, which indicates a traveling state of the vehicle, to the power power-receiver communication antenna, and the power-transmitter control unit is configured to determine that an abnormality occurs in the vehicle when determining that a period, during which the vehicle identified by the vehicle identification information is continuously stopped on the power transmitter antenna configured to supply power to the vehicle that travels, exceeds a third period, which is longer than the second period, based on the vehicle identification information and the traveling state signal received by the power-transmitter communication antenna.

4. The power transmitter device according to claim 2 or 3, wherein the power transmitter device includes the power transmitter antenna configured to supply power to the vehicle that travels, and the power-transmitter control unit is configured to acquire the first period by communication with the power transmitter device, which includes the power transmitter antenna configured to supply power to the vehicle that is parked, and set the second period to be shorter than the first period.

5. The power transmitter device according to claim 2 or 3, wherein the power transmitter device includes the power transmitter antenna configured to supply power to the vehicle that is parked, and the power-transmitter control unit is configured to acquire the second period by communication with the power transmitter device, which includes the power transmitter antenna configured to supply power to the vehicle that travels, and set the first period to be longer than the second period.

6. The power transmitter device according to claim 1 or 2, wherein the power transmitter device has a function as the power transmitter antenna configured to supply power to the vehicle that travels and a function as the power transmitter antenna configured to supply power to the vehicle that is parked.

7. The power transmitter device according to claim 1, wherein the power-transmitter control unit is configured to vary the determination period depending on a traveling speed of the vehicle.

8. A wireless power transfer system (10) comprising: the power transmitter device according to claim 1 or 2; and the power receiver device.

9. A power supply program to be applied to a wireless power transfer system (10), the wireless power transfer system including: a power transmitter device (20) including at least one transmitter antenna (22), a power-transmitter control unit (70) configured to perform wireless power transfer from a power transmitter antenna to a power receiver antenna (102) of a power receiver device (100) mounted on a vehicle (11) and control energization of the power transmitter antenna to perform wireless power transfer to the power receiver antenna, and a power-transmitter communication antenna (40); and a power receiver device including a power-receiver communication antenna (170), which is configured to perform wireless communication with the power-transmitter communication antenna, and configured to supply a power supply request signal, which includes vehicle identification information of a vehicle and indicates power supply request to the power transmitter antenna, to the power power-receiver communication antenna, the power supply program configured to carry out: executing a process to cause the power-transmitter control unit to energize the power transmitter antenna when determining that there is the power supply request based on the power supply request signal received by the power-transmitter communication antenna, and stop energization of a specific power transmitter antenna when determining that a period, during which power is continuously supplied from the specific power transmitter antenna to the vehicle identified by the vehicle identification information, exceeds a determination period based on the vehicle identification information received by the power-transmitter communication antenna.

10. A control method for a power transmitter device to be applied to a wireless power transfer system (10), the wireless power transfer system including: a power transmitter device (20) including at least one transmitter antenna (22), a power-transmitter control unit (70) configured to perform wireless power transfer from a power transmitter antenna to a power receiver antenna (102) of a power receiver device (100) mounted on a vehicle (11) and control energization of the power transmitter antenna to perform wireless power transfer to the power receiver antenna, and a power-transmitter communication antenna (40); and a power receiver device including a power-receiver communication antenna (170), which is configured to perform wireless communication with the power-transmitter communication antenna, and configured to supply a power supply request signal, which includes vehicle identification information of a vehicle and indicates power supply request to the power transmitter antenna, to the power power-receiver communication antenna, the control method comprising: executing a process to cause the power-transmitter control unit to energize the power transmitter antenna when determining that there is the power supply request based on the power supply request signal received by the power-transmitter communication antenna, and stop energization of a specific power transmitter antenna when determining that a period, during which power is continuously supplied from the specific power transmitter antenna to the vehicle identified by the vehicle identification information, exceeds a determination period based on the vehicle identification information received by the power-transmitter communication antenna.

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