Power receiver, power transmitter and wireless power transfer system

Abstract

A power transmitter (20) includes a power-transmitter control unit (70) and power-transmitter communication coils (40a to 40d). A power receiver (100) includes a power-receiver communication coil (170) and a power-receiver control unit (230). The power-transmitter communication coils (40a to 40d) are arranged such that at least a part of each receivable range is different. The power-receiver control unit divides vehicle-side information into multiple pieces, includes each piece in separate communication frames, and transmits the communication frames via the power-receiver communication coil at different timings. The power-transmitter control unit receives the communication frames via the power-transmitter communication coils, respectively, receives the vehicle-side information from the received communication frames, and controls energization of a power transmitter coil (22) based on the vehicle-side information. Accordingly, necessary information can be transmitted.

Description

POWER RECEIVER, POWER TRANSMITTER AND WIRELESS POWER TRANSFER SYSTEMCross Reference

[0001] This application is based on Japanese Patent Application No. 2024-208000 filed on November 29, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a power receiver, a power transmitter and a wireless power transfer system.

[0003] Patent Literature 1 discloses a system for executing wireless power transfer from a ground-based power transmitter to a power receiver installed in an electric vehicle. The power transmitter includes a power transmitter coil and a controller that energizes the power transmitter coil. The power receiver includes a power receiver coil that is supplied with power wirelessly from the power transmitter coil.

[0004] The power transmitter and the power receiver include communication coils for narrow area wireless communication. The power receiver supplies a vehicle-side signal related to the wireless power transfer to the communication coil of the power receiver. The vehicle-side signal is a signal including a power supply request signal that indicates a request for power supply to the power transmitter coil. The power transmitter determines whether there is a power supply request based on an output signal from the communication coil of the power transmitter. When the power transmitter determines that there is a power supply request, the power transmitter energizes the power transmitter coil.

[0005] JP2024-008088A

[0006] However, when a vehicle is moving at high speed, it may pass through the receivable range of the communication coil quickly, making it difficult to ensure sufficient communication time for wireless communication. For this reason, depending on the circumstances, vehicle-side information may not be transmitted or received properly. If vehicle-side information cannot be transmitted and received properly, the inability to supply power or, conversely, overcharging may occur.

[0007] The present disclosure has been made in view of the circumstances described above, and it is a main object to provide a power receiver, power transmitter and a wireless power transfer system that are capable of transmitting necessary information.

[0008] According to an aspect of the present disclosure, a first power receiver is applied to a wireless power transfer system including a ground-side device and a vehicle-side device. The ground-side device is a power transmitter having a power transmitting antenna, and the vehicle-side device is the power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power receiver includes a power-receiver communication antenna configured to perform wireless communication, and a power-receiver control unit configured to control energization of the power-receiver communication antenna to wirelessly transmit power-receiver information via the power-receiver communication antenna. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas configured to perform wireless communication. Each of the power-transmitter communication antennas has a receivable range. The power-transmitter communication antennas are arranged such that at least a part of each receivable range is different. The power-receiver control unit is configured to divide the power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-receiver communication antenna, thereby causing the power-transmitter control unit to receive each of the communication frames via the power-transmitter communication antennas, receive the multiple pieces of the power-receiver information from each of the communication frames, and control energization of the power transmitting antenna.

[0009] According to an aspect of the present disclosure, a first power transmitter is applied to a wireless power transfer system including a ground-side device and a vehicle-side device. The ground-side device is the power transmitter having a power transmitting antenna, and the vehicle-side device is a power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas configured to perform wireless communication. The power receiver includes a power-receiver communication antenna configured to perform wireless communication, and a power-receiver control unit configured to control energization of the power-receiver communication antenna to wirelessly transmit power-receiver information via the power-receiver communication antenna. Each of the power-transmitter communication antennas has a receivable range. The power-transmitter communication antennas are arranged such that at least a part of each receivable range is different. The power-receiver control unit is configured to divide the power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-receiver communication antenna. The power-transmitter control unit is configured to receive each of the communication frames via the power-transmitter communication antennas, receive the multiple pieces of the power-receiver information from each of the communication frames, and control energization of the power transmitting antenna.

[0010] According to an aspect of the present disclosure, a first wireless power transfer system includes a ground-side device and a vehicle-side device. The ground-side device is a power transmitter having a power transmitting antenna. The vehicle-side device is a power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas configured to perform wireless communication. The power receiver includes a power-receiver communication antenna configured to perform wireless communication, and a power-receiver control unit configured to control energization of the power-receiver communication antenna to wirelessly transmit power-receiver information via the power-receiver communication antenna. Each of the power-transmitter communication antennas has a receivable range. The power-transmitter communication antennas are arranged such that at least a part of each receivable range is different. The power-receiver control unit is configured to divide the power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-receiver communication antenna. The power-transmitter control unit is configured to receive each of the communication frames via the power-transmitter communication antennas, receive each of the multiple pieces of the power-receiver information from of the communication frames, and control energization of the power transmitting antenna.

[0011] According to an aspect of the present disclosure, a second power receiver is applied to a wireless power transfer system including a ground-side device and a vehicle-side device. The ground-side device is a power transmitter having a power transmitting antenna, and the vehicle-side device is the power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power receiver includes a power-receiver communication antenna configured to perform wireless communication, and a power-receiver control unit configured to control receiving via the power-receiver communication antenna. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas configured to perform wireless communication. Each of the power-transmitter communication antennas has a transmittable range. The power-transmitter communication antennas are arranged such that at least a part of each transmittable range is different. The power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-transmitter communication antennas. The power-receiver control unit is configured to receive the communication frames via the power-receiver communication antenna, and receive the power-transmitter information from the received communication frames.

[0012] According to an aspect of the present disclosure, a second power transmitter is applied to a wireless power transfer system including a ground-side device and a vehicle-side device. The ground-side device is the power transmitter having a power transmitting antenna, and the vehicle-side device is a power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas configured to perform wireless communication. The power receiver includes a power-receiver communication antenna configured to perform wireless communication, and a power-receiver control unit configured to control receiving via the power-receiver communication antenna. Each of the power-transmitter communication antennas has a transmittable range, The power-transmitter communication antennas are arranged such that at least a part of each transmittable range is different. The power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-transmitter communication antennas. The power-receiver control unit is configured to receive the communication frames via the power-receiver communication antenna, and receive the multiple pieces of the power-transmitter information from the received communication frames.

[0013] According to an aspect of the present disclosure, a second wireless power transfer system includes a ground-side device and a vehicle-side device. The ground-side device is a power transmitter having a power transmitting antenna, and the vehicle-side device is a power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas configured to perform wireless communication. The power receiver includes a power-receiver communication antenna configured to perform wireless communication, and a power-receiver control unit configured to control receiving via the power-receiver communication antenna. Each of the power-transmitter communication antennas has a transmittable range. The power-transmitter communication antennas are arranged such that at least a part of each transmittable range is different. The power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-transmitter communication antennas. The power-receiver control unit is configured to receive the communication frames via the power-receiver communication antenna, and receive the power-transmitter information from the received communication frames.

[0014] According to an aspect of the present disclosure, a third power receiver is applied to a wireless power transfer system including a vehicle-side device and a ground-side device. The vehicle-side device is a power transmitter having a power transmitting antenna, and the ground-side device is the power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power receiver includes power-receiver communication antennas configured to perform wireless communication, and a power-receiver control unit configured to control receiving via the power-receiver communication antenna. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna configured to perform wireless communication. Each of the power-receiver communication antennas has a receivable range. The power-receiver communication antennas are arranged such that at least a part of each receivable range is different. The power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-transmitter communication antenna. The power-receiver control unit is configured to receive the communication frames via the power-receiver communication antennas, and receive the power-transmitter information from the received communication frames.

[0015] According to an aspect of the present disclosure, a third power transmitter is applied to a wireless power transfer system including a vehicle-side device and a ground-side device. The vehicle-side device is the power transmitter having a power transmitting antenna, and the ground-side device is a power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna configured to perform wireless communication. The power receiver includes power-receiver communication antennas configured to perform wireless communication, and a power-receiver control unit configured to control receiving via the power-receiver communication antenna. Each of the power-receiver communication antennas has a receivable range. The power-receiver communication antennas are arranged such that at least a part of each receivable range is different. The power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-transmitter communication antenna. The power-receiver control unit is configured to receive the communication frames via the power-receiver communication antennas, and receive the power-transmitter information from the received communication frames.

[0016] According to an aspect of the present disclosure, a third wireless power transfer system includes a vehicle-side device and a ground-side device. The vehicle-side device is a power transmitter having a power transmitting antenna, and the ground-side device is a power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna configured to perform wireless communication. The power receiver includes power-receiver communication antennas configured to perform wireless communication, and a power-receiver control unit configured to control receiving via the power-receiver communication antenna. Each of the power-receiver communication antennas has a receivable range. The power-receiver communication antennas are arranged such that at least a part of each receivable range is different. The power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-transmitter communication antenna. The power-receiver control unit is configured to receive the communication frames via the power-receiver communication antennas, and receive the power-transmitter information from the received communication frames.

[0017] According to an aspect of the present disclosure, a fourth power receiver is applied to a wireless power transfer system including a vehicle-side device and a ground-side device. The vehicle-side device is a power transmitter having a power transmitting antenna, and the ground-side device is the power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power receiver includes power-receiver communication antennas configured to perform wireless communication, and a power-receiver control unit configured to control energization of the power-receiver communication antennas. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna configured to perform wireless communication. Each of the power-receiver communication antennas has a transmittable range. The power-receiver communication antennas are arranged such that at least a part of each transmittable range is different. The power-receiver control unit is configured to divide power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-receiver communication antennas. The power-transmitter control unit is configured to receive each of the communication frames via the power-transmitter communication antenna, receive the power-receiver information from of the received communication frames, and control energization of the power transmitting antenna.

[0018] According to an aspect of the present disclosure, a fourth power transmitter is applied to a wireless power transfer system including a vehicle-side device and a ground-side device. The vehicle-side device is the power transmitter having a power transmitting antenna, and the ground-side device is a power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna configured to perform wireless communication. The power receiver includes power-receiver communication antennas configured to perform wireless communication, and a power-receiver control unit configured to control energization of the power-receiver communication antennas. Each of the power-receiver communication antennas has a transmittable range. The power-receiver communication antennas are arranged such that at least a part of each transmittable range is different. The power-receiver control unit is configured to divide power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-receiver communication antennas. The power-transmitter control unit is configured to receive the communication frames via the power-transmitter communication antenna, receive the power-receiver information from the received communication frames, and control energization of the power transmitting antenna.

[0019] According to an aspect of the present disclosure, a fourth wireless power transfer system includes a vehicle-side device and a ground-side device. The vehicle-side device is a power transmitter having a power transmitting antenna, and the ground-side device is a power receiver including having a power receiving antenna. The power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter. The power transmitter includes a power-transmitter control unit configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna configured to perform wireless communication. The power receiver includes power-receiver communication antennas configured to perform wireless communication, and a power-receiver control unit configured to control energization of the power-receiver communication antennas. Each of the power-receiver communication antennas has a transmittable range. The power-receiver communication antennas are arranged such that at least a part of each transmittable range is different. The power-receiver control unit is configured to divide power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-receiver communication antennas. The power-transmitter control unit is configured to receive the communication frames via the power-transmitter communication antenna, receive the power-receiver information from the received communication frames, and control energization of the power transmitting antenna.

[0020] According to the above configuration, information can be separated to be transmitted and received. This allows the communication frame to be shortened, ensuring reliable transmission and reception.

[0021] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.FIG. 1 is an overall configuration diagram of a wireless power transfer system according to a first embodiment.FIG. 2 is an overall configuration diagram of the wireless power transfer system.FIG. 3 is a diagram illustrating a power transmitter and a power receiver.FIG. 4 is a diagram showing a signal transmitter and its peripheral configuration.FIG. 5 is a diagram showing a signal receiver and its peripheral configuration.FIG. 6 is a diagram for explaining vehicle-side information.FIG. 7 is a flowchart illustrating a flow a transmission process.FIG. 8 is a diagram showing an outline of a communication frame.FIG. 9 is a flowchart illustrating a flow a receiving process.FIG. 10 is a flowchart illustrating a flow of a transmission process according to a second embodiment.FIG. 11 is a diagram illustrating a method of transmitting a communication frame.

[0022] Embodiments of a power receiver, a power transmitter and a wireless power transfer system of the present disclosure will be described below with reference to the drawings.

[0023] First Embodiment 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 as an in-vehicle power receiver. 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. The power is supplied from the power transmitter 20 to the power receiver 100 while the vehicle 11 is travelling or stopped. 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.

[0024] 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 is installed (for example, buried) in the road RS, a parking lot, or the like. The power-transmitter power supply unit 51 is installed, for example, on 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 each of the four power-transmitter coil units 21. The number of power-transmitter coil units 21 is not limited to four and may be changed to any number.

[0025] 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. IGBT is an abbreviation of Insulated Gate Bipolar Transistor. MOSFET is an abbreviation of Metal-Oxide-Semiconductor Field-Effect Transistor.

[0026] 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.

[0027] 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.

[0028] The power-transmitter coil unit 21 includes a power transmitter coil 22 (corresponding to power transmitting antenna), a power-transmitter resonant circuit 30, and a power-transmitter communication coil 40. The power-transmitter resonant circuit 30 supplies the AC power supplied 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.

[0029] The power receiver 100 includes a power-receiver coil unit 101 and a power-receiver power supply unit 181. The power-receiver coil unit 101 includes a power receiver coil 102 (corresponding to a "power receiving antenna"). The power-receiver coil unit 101 is located at the bottom of the vehicle body of the vehicle 11. The power-receiver coil unit 101 is located at the bottom of the vehicle body to face the ground surface. When the vehicle 11 travels on the road RS where the power transmitter coil 22 is buried, the power transmitter coil 22 on the ground side and the power receiver coil 102 of the vehicle 11 face each other in the vertical direction.

[0030] 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 can employ various well-known resonant circuits such as a circuit including a resonant capacitor.

[0031] 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.

[0032] 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).

[0033] The vehicle 11 includes a high potential main switch 301H, a low potential main switch 301L, and a high-voltage storage battery 300 (corresponding to "supply target device") 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.

[0034] 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 it to the armature winding. This 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.

[0035] 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 a processor as hardware, a storage unit, and a communication bus connecting the processor and storage unit.

[0036] 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 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.

[0037] The power-receiver power supply unit 181, which constitutes the power receiver 100, includes 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.

[0038] 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 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.

[0039] 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 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.

[0040] 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.

[0041] 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.

[0042] 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 transmitter coil 22 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.

[0043] 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.

[0044] The power receiver 100 and the power transmitter 20 each have a configuration for communication between the power receiver 100 and the power transmitter 20. In detail, the power-receiver coil unit 101, which constitutes the power receiver 100, includes a power-receiver communication coil 170 (corresponding to a power-receiver communication antenna). In the power-receiver coil unit 101, the power-receiver communication coil 170 and the power receiver coil 102 are integrated and housed in a housing (case). A power-receiver control unit 230 includes a signal transmitter 240.

[0045] The power-transmitter coil unit 21, which constitutes the power transmitter 20, includes a power-transmitter communication coil 40 (corresponding to a power-transmitter communication antenna). The power-transmitter control unit 70 includes a signal receiver 80. The power-receiver communication coil 170 and the power-transmitter communication coil 40 are communication antennas for wireless communication. In particular, in the present embodiment, the power-receiver communication coil 170 and the power-transmitter communication coil 40 are communication coils for narrow area wireless communication. Narrow area wireless communications are those with a communication distance of less than 10 meters (e.g., a maximum of about 3 meters). Narrow area wireless communication is a communication with a shorter communication distance than wide area wireless communication.

[0046] 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.

[0047] Communication networks used in wide area wireless communication include, for example, a WAN (Wide Area Network), which is a public communication network such as the Internet, a telephone communication network for a mobile phone, an information and communication network for ETC, and an information and communication network for a Vehicle Information and Communication System (VICS (registered trademark)). Wide area wireless communication is a communication with a longer communication distance than the narrow area wireless communication. Wide area wireless communication is communication with a communication distance of, for example, 10 meters to 10 kilometers. Examples of the wide area wireless communication include 3GPP (registered trademark), 4G, LTE, 5G, and WiMAX (registered trademark) developed by IEEE.

[0048] The signal transmitter 240 is connected to the power-receiver controller 231. The signal transmitter 240 is connected to the power-receiver communication coil 170. The power-receiver controller 231 controls the signal transmitter 240 to wirelessly send vehicle-side information, such as a request for power supply, via the power-receiver communication coil 170. The request for power supply is information for requesting the power transmitter coil 22 near the vehicle 11 to transmit power to the power receiver coil 102. This control causes a high-frequency voltage to be applied from the signal transmitter 240 to the power-receiver communication coil 170. Consequently, a high-frequency current flows in the power-receiver communication coil 170, and a magnetic field for information communication is generated in the power-receiver communication coil 170. The vehicle-side information and the communication method will be described in detail later.

[0049] 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 coil 40, and a high-frequency current flows through the power-transmitter communication coil 40. This high-frequency current is input to the signal receiver 80. The signal receiver 80 recognizes the vehicle-side information, such as a request for power supply, based on the input signal from the power-transmitter communication coil 40. The vehicle-side information recognized by the signal receiver 80 is input to the power-transmitter controller 71.

[0050] In this embodiment, the power-receiver controller 231 controls the signal transmitter 240 so that the frequency of the high-frequency voltage applied to the power-receiver communication coil 170 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).

[0051] The power-transmitter controller 71 determines whether to energize the power transmitter coil 22 based on the input signal from the signal receiver 80. In detail, when the power-transmitter controller 71 determines that there is a power supply request based on the input signal from the signal receiver 80, the power-transmitter controller 71 applies high-frequency voltage to the power transmitter coil 22 by controlling the inverter 60 and the PFC circuit 61. This results in a wireless power transfer from the power transmitter coil 22 to the power receiver coil 102.

[0052] The signal transmitter 240 and its peripheral configuration will be described in detail with reference to FIG. 4. The signal transmitter 240 includes a generating circuit 241 which is a modulation circuit, 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 high-frequency signal based on a command from the power-receiver controller 231. More specifically, the generating circuit 241 modulates the vehicle-side information (transmission data) input from the power-receiver controller 231 and then generates the high-frequency signal. The frequency of this high-frequency signal is the second specified frequency.

[0053] As a modulation method in the generating circuit 241, various methods can be used (see FIG. 4). For example, digital modulation may be used, specifically, phase shift keying (PSK), frequency shift keying (FSK), or amplitude shift keying (ASK). Also, for example, analog modulation may be used, specifically, amplitude modulation (AM), frequency modulation (FM), or phase modulation (PM) is used. Also, for example, Manchester coding may be used. When FSK or FM is used, the frequency of the high-frequency signal supplied to the power-receiver communication coil 170 has a certain frequency range relative to 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 coil 170.

[0054] The power-receiver controller 231 instructs the generating circuit 241 to generate a high-frequency signal in order to wirelessly transmit a communication frame including the vehicle-side information in its payload. 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 coil 170 as a high-frequency signal.

[0055] The signal receiver 80 and its peripheral configuration will be described in detail with reference to FIG. 5. The signal receiver 80 includes a power-transmitter amplifier 81 and a detection circuit 82. The power-transmitter amplifier 81 amplifies the high-frequency signal (high frequency current or voltage signal) input from the power-transmitter communication coil 40 and supplies the amplified signal to the detection circuit 82. The high-frequency signal output from the power-transmitter communication coil 40 contains a frequency component that fluctuates at the second specified frequency.

[0056] The detection circuit 82 demodulates the high-frequency signal input from the power-transmitter amplifier 81 and extracts the communication frame. The extracted communication frame is input to the power-transmitter controller 71.

[0057] The power-transmitter controller 71 receives the vehicle-side information from the input communication frame and performs various controls. For example, when the input vehicle-side information includes a request for power supply, the power-transmitter controller 71 performs control related to power transmission. That is, the power-transmitter controller 71 applies a high frequency voltage to the power transmitter coil 22 by controlling the switching of the PFC circuit 61 and the inverter 60. 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.

[0058] However, the receivable range of the power-transmitter communication coil 40 is determined for each power-transmitter communication coil 40. The receivable range may not be set very large depending on various conditions such as the installation location, the size and shape of the power-transmitter communication coil 40, the communication frequency, and the power used for communication. Furthermore, when the vehicle 11 is moving at high speed, the vehicle 11 may pass through the receivable range quickly, and it may not be possible to ensure sufficient communication time for wireless communication. On the other hand, the vehicle-side information includes not only power-related information related to power transmission, but also abnormality-related information related to abnormalities in the vehicle 11 and authentication-related information such as a payer ID for electricity charges, for example. The amount of this information may increase due to changes in the situation or environment. Due to these circumstances, if an attempt is made to send and receive data in a single communication frame, the frame length of the communication frame becomes long compared to the communication time, and there is a risk that it will exceed the length that one power-transmitter communication coil 40 can optimally receive. That is, the receivable time at each power-transmitter communication coil 40 may be short compared to the amount of data to be transmitted and received, and there is a risk that the vehicle-side information may not be received appropriately.

[0059] Therefore, in this embodiment, the vehicle-side information is divided and transmitted in multiple communication frames, thereby ensuring reliable transmission. The configuration relating to the communication method in this embodiment will be described in detail below.

[0060] First, the receivable range of the power-transmitter communication coil 40 will be described. As shown in FIG. 2, one power transmitter 20, i.e., one power-transmitter power supply unit 51, is provided with four power-transmitter coil units 21, and each power-transmitter coil unit 21 is provided with a power-transmitter communication coil 40a to 40d. The receivable ranges R11 to R14 of the power-transmitter communication coils 40a to 40d are determined for each of the power-transmitter communication coils 40a to 40d. In FIG. 2, the receivable ranges R11 to R14 are all the same in size, but they may be different. As shown in FIG. 2, the power-transmitter communication coils 40a to 40d are buried in the road RS so that the receivable ranges R11 to R14 do not overlap. Note that a part of the receivable ranges R11 to R14 may overlap with the receivable ranges R11 to R14 of the other power-transmitter communication coils 40a to 40d. In this embodiment, the power-transmitter communication coils 40a to 40d are arranged along the traveling direction of the road RS.

[0061] Next, the vehicle-side information will be described. The vehicle-side information is information acquired or generated in the vehicle 11, that is, in the power receiver 100, and corresponds to "power-receiver information." In this embodiment, the vehicle-side information to be transmitted includes abnormality-related information, power-related information, authentication-related information, and other information, as shown in FIG. 6. It is not necessary for the vehicle-side information to include all of these pieces of information, and only one of them may be included in the vehicle-side information. Further, other information may be included in the vehicle-side information.

[0062] The abnormality-related information is information regarding an abnormality in the vehicle 11, and includes information regarding whether an abnormality has occurred in the vehicle 11. If an abnormality has occurred, the abnormality-related information includes information regarding the location where the abnormality occurred, the time when the abnormality occurred, and the type of abnormality that occurred (such as a broken wire abnormality, an overvoltage abnormality, or a temperature abnormality). The abnormality-related information is mainly notified to the power-receiver controller 231 from a device external to the power receiver 100 (such as a vehicle ECU). If an abnormality relates to the power receiver 100 or the like, the power-receiver controller 231 may detect it.

[0063] The power-related information is information regarding power transmission, and includes, for example, a signal (information) for requesting power supply, a requested power Weq which is the requested value (command value) of the power supply to the vehicle 11, a power class (the rated wattage of the power receiver 100), charging priority, urgency, vehicle speed, and other information. The predetermined information such as the power class is stored, for example, in the storage unit of the power-receiver controller 231, and the power-receiver controller 231 obtains the information by reading it out. The power supply request, the requested power Weq, and the like may be obtained from a battery ECU that manages the high-voltage storage battery 300, or the like. The power-receiver controller 231 may acquire the battery information and generate a power supply request, requested power Weq, and the like. The vehicle speed is notified to the power-receiver controller 231 from an external device (such as a vehicle ECU or a vehicle speed sensor) of the power receiver 100.

[0064] The authentication-related information is information related to authentication of the vehicle 11 or the owner of the vehicle 11, and includes, for example, a payer ID. Specifically, the authentication-related information is information used to identify the billing address and payment method for electricity charges related to the electricity transmission. The authentication-related information is set in advance and stored in the storage unit or the like of the power-receiver controller 231, and the power-receiver controller 231 obtains the authentication-related information by reading it out from the storage unit.

[0065] Next, a flow of a transmission process when transmitting the vehicle-side information will be described with reference to FIG. 7. As described above, the power-receiver controller 231 acquires the abnormality-related information, the power-related information, the authentication-related information, and the like, and determines the vehicle-side information to be transmitted (step S101).

[0066] The power-receiver controller 231 also identifies the receivable ranges R11 to R14 of the power-transmitter communication coils 40a to 40d of one power transmitter 20 embedded in the road RS on which the vehicle 11 is traveling (step S102). In step S102, the positions, sizes, number, etc. of the receivable ranges R11 to R14 are identified.

[0067] For example, the power-receiver controller 231 acquires position information of the vehicle 11 from an external GPS device or the like, and identifies the road on which the vehicle 11 is traveling from the position information using a navigation system. Then, the power-receiver controller 231 acquires facility information on the identified road. The facility information includes information such as the positions, sizes, and number of the receivable ranges R11 to R14 in advance, and the power-receiver controller 231 can determine the positions, sizes, number, etc. of the receivable ranges R11 to R14 from the facility information. The facility information may be acquired from an external device or may be stored in advance in the storage unit of the power-receiver controller 231. Additionally, the facility information may be acquired via an external communication network.

[0068] Then, the power-receiver controller 231 determines a payload length of a communication frame that can be transmitted to one power-transmitter communication coil 40 based on the sizes of the identified receivable ranges R11 to R14 (step S103).

[0069] After determining the payload length, the power-receiver controller 231 specifies the number of times a communication frame can be transmitted based on the number of the specified receivable ranges R11 to R14 (step S104). In this embodiment, the number of possible transmissions is specified as "4".

[0070] Thereafter, the power-receiver controller 231 determines a method for transmitting the vehicle-side information based on the payload length and the data amount of the vehicle-side information (step S105). In step S105, the payload length is compared with the data amount of the vehicle-side information to be transmitted to determine whether the vehicle-side information can be transmitted in one communication frame. If the vehicle-side information cannot be sent in one communication frame, it is determined how to divide the vehicle-side information. For example, the vehicle-side information transmitted between the power receiver 100 and the power transmitter 20 may be data transmitted between the vehicle-side device and the ground-side device.

[0071] To explain in more detail, when the payload length determined in step S103 is sufficiently long compared to the data amount of the vehicle-side information and can be included in one communication frame, the power-receiver controller 231 decides to include all of the vehicle-side information in one communication frame.

[0072] On the other hand, when the payload length determined in step S103 is not sufficiently long compared to the data amount of the vehicle-side information, the power-receiver controller 231 decides to divide the vehicle-side information into meaningful categories and include each of them in the payload of the communication frame. In this embodiment, the power-receiver controller 231 divides the information into four categories, namely, abnormality-related information, power-related information, authentication-related information, and other information, and determines to include each category in the payload of a separate communication frame.

[0073] Next, the power-receiver controller 231 determines whether to divide and transmit the vehicle-side information (step S106). When the determination result in step S106 is affirmative, the power-receiver controller 231 determines the priority of the divided information in the processes of steps S107 to S111, and generates communication frames so that the information is transmitted according to the priority.

[0074] More specifically, first, the power-receiver controller 231 determines whether any abnormality has occurred in the vehicle 11 (step S107). For example, when the abnormality-related information transmitted by the power-receiver controller 231 includes information indicating that an abnormality has occurred, the power-receiver controller 231 determines that some abnormality has occurred in the vehicle 11. When the abnormality-related information does not include information indicating that an abnormality has occurred, the power-receiver controller 231 determines that no abnormality has occurred.

[0075] When the determination result of step S107 is affirmative, the power-receiver controller 231 divides the vehicle-side information using the division method determined in step S105, and generates a communication frame containing the divided information so as to prioritize transmission of the abnormality-related information (step S108). In this embodiment, a communication frame containing abnormality-related information in its payload, a communication frame containing power-related information in its payload, a communication frame containing authentication-related information in its payload, and a communication frame containing other information in its payload are generated. As shown in FIG. 8, when generating a communication frame, the power-receiver control unit 230 generates (or reads) a receiver ID, a frame identification ID, a sequence ID, and a CRC, and assigns them to each communication frame.

[0076] The receiver ID is an identification number (identification information) for identifying the power receiver 100 (vehicle 11), is predetermined for each power receiver 100 (or vehicle 11), and is set in the storage unit of the power-receiver controller 231. The frame identification ID is an identification number (identification information) used to identify that divided communication frames constitute a single communication frame, that is, the communication frames have been divided in order to transmit a single piece of vehicle-side information. The frame identification ID is generated by the power-receiver control unit 230. The CRC (Cyclic Redundancy Check) is a code for detecting an error in a transmitted communication frame (transmission signal), and is generated by the power-receiver control unit 230.

[0077] The sequence ID is an identification number (identification information) that indicates a transmission order of the divided communication frames, and is generated by the power-receiver control unit 230 in accordance with the transmission order. In step S108, the transmission order is determined so that the communication frame including the abnormality-related information is transmitted with priority, that is, so that the communication frame is transmitted earliest. A transmission order of other communication frames is determined arbitrarily.

[0078] On the other hand, when the determination result in step S107 is negative, the power-receiver controller 231 determines whether the battery voltage of the high-voltage storage battery 300 is outside the appropriate range (step S109). That is, it is determined whether the state of the high-voltage storage battery 300 is normal. The battery voltage of the high-voltage storage battery 300 may be obtained by detection using a voltage sensor (not shown) or the like. When the battery voltage of the high-voltage storage battery 300 exceeds the upper limit of the appropriate range, there is a risk of overvoltage, so it is preferable to limit the power transmission. On the other hand, when the battery voltage of the high-voltage storage battery 300 is below the lower limit of the appropriate range, it is desirable to supply power as soon as possible. For the above reasons, when the battery voltage of the high-voltage storage battery 300 is outside the appropriate range, the power-related information is transmitted with priority, so that it is possible to quickly determine whether to limit the power transmission.

[0079] That is, when the determination result of step S109 is affirmative, the power-receiver controller 231 divides the vehicle-side information using the division method determined in step S105, and generates a communication frame containing the divided information so as to prioritize transmission of the power-related information (step S110). The division method and the communication frame generation method are almost the same as those in step S108. However, in step S110, the transmission order is determined so that the communication frame including the power-related information is transmitted with priority, that is, so that the communication frame is transmitted earliest. Other transmission order is determined arbitrarily.

[0080] On the other hand, when the determination result of step S109 is negative, the power-receiver controller 231 divides the vehicle-side information using the division method determined in step S105, and generates a communication frame containing the divided information so as to prioritize transmission of a communication frame including the authentication-related information (step S111). The division method and the communication frame generation method are almost the same as those in step S108. However, in step S111, the transmission order is determined so that the communication frame including the authentication-related information is transmitted with priority, that is, so that the communication frame is transmitted earliest. Other transmission order is determined arbitrarily.

[0081] After the processes of steps S108, S110, and S111, the power-receiver controller 231 sequentially transmits the generated communication frames in accordance with the determined transmission order while passing through the receivable ranges R11 to R14 (step S112). It is preferable that the communication frame to be transmitted first among the multiple communication frames contains information (information related to division) such as information that the vehicle-side information has been divided and transmitted, information that it is the first communication frame, and information of the number of divided communication frames to be transmitted. Moreover, it is preferable that the communication frame to be transmitted last among the multiple communication frames contains information notifying that it is the last.

[0082] On the other hand, when the determination result in step S106 is negative, the power-receiver controller 231 generates a communication frame including all of the vehicle-side information in the payload (step S113). Then, the power-receiver controller 231 controls the signal transmitter 240 to transmit the communication frame when the identified receivable ranges R11 to R14 are reached (step S114). Since the number of possible transmissions is "4", the same communication frame (the communication frame including the vehicle-side information) may be repeatedly transmitted each time the receivable ranges R11 to R14 are passed.

[0083] Next, a process performed by the power transmitter 20 when receiving a communication frame will be described. When the power-transmitter controller 71 receives an input of communication frames from the signal receiver 80 in which vehicle-side information is divided and contained therein, the power-transmitter controller 71 integrates the information contained in the communication frames (abnormality-related information, power-related information, authentication-related information, and other information) to reconstruct the vehicle-side information and acquire the vehicle-side information. More specifically, the power-transmitter controller 71 identifies the communication frames transmitted from one power receiver 100 based on the receiver IDs assigned to the multiple received communication frames. Then, the power-transmitter controller 71 identifies divided communication frames based on the frame identification IDs assigned to the multiple received communication frames. Then, the power-transmitter controller 71 sequentially integrates the multiple pieces of divided vehicle-side information contained in the multiple communication frames according to the sequence IDs assigned to the multiple communication frames, to reconstruct the vehicle-side information. When all the vehicle-side information is included in one communication frame, the power-transmitter controller 71 acquires the vehicle-side information included in the communication frame.

[0084] In addition, when the vehicle-side information is divided into multiple communication frames, and the power-transmitter controller 71 receives a communication frame containing abnormality-related information and determines that an abnormality has occurred based on the abnormality-related information, the power-transmitter controller 71 may stop or limit power transmission without waiting for reception of all communication frames. In other words, the power-transmitter controller 71 may stop or limit the power transmission without waiting for reception of a communication frame or the like that includes the power-related information to be transmitted thereafter. The limiting of power transmission means reducing an amount of power to be transmitted below the requested amount of power.

[0085] In addition, when the vehicle-side information is divided into multiple communication frames, and the power-transmitter controller 71 receives a communication frame including power-related information and determines based on the power-related information that the battery voltage exceeds the upper limit and power supply has been stopped or restricted, the power-transmitter controller 71 may stop power transmission without waiting for reception of all communication frames. In other words, the power-transmitter controller 71 may stop or limit the power transmission without waiting for reception of a communication frame or the like that includes abnormality-related information to be transmitted thereafter.

[0086] In addition, when the vehicle-side information is divided into multiple communication frames, and the power-transmitter controller 71 receives a communication frame including power-related information and determines based on the power-related information that the battery voltage has fallen below a lower limit value and that an emergency power supply is requested, the power-transmitter controller 71 may start transmitting power or preparing for power transmission without waiting for the reception of all communication frames. In other words, the power-transmitter controller 71 may start transmitting power or preparing for transmitting power without waiting for reception of a communication frame or the like that includes abnormality-related information to be transmitted thereafter.

[0087] In addition, when the vehicle-side information is divided into multiple communication frames and the power-transmitter controller 71 receives a communication frame including authentication-related information, the power-transmitter controller 71 may start authentication without waiting for reception of all of the divided communication frames.

[0088] A flow of a receiving process when receiving a communication frame will be described below with reference to FIG. 9. The receiving process is performed by the power-transmitter controller 71 when a communication frame is received.

[0089] The power-transmitter controller 71 determines whether the received communication frames include divided vehicle-side information (step S201). When the result of this determination is negative, that is, when the vehicle-side information has not been divided, the power-transmitter controller 71 performs various controls based on the vehicle-side information contained in the received communication frame (step S202). For example, the power-transmitter controller 71 controls the energization of the power transmitter coil 22 based on the power-related information of the vehicle-side information. Furthermore, when the power-transmitter controller 71 determines that an abnormality has occurred in the power receiver 100 based on the abnormality-related information in the vehicle-side information, the power-transmitter controller 71 stops control related to power transmission or limits the power transmission. Moreover, when authentication has not been performed, the power-transmitter controller 71 performs authentication based on the authentication-related information of the vehicle-side information. Then, the power-transmitter controller 71 ends the process.

[0090] When the determination result in step S201 is affirmative, the power-transmitter controller 71 determines whether all of the multiple communication frames including the divided vehicle-side information have been received (step S203). When this determination result is affirmative, the power-transmitter controller 71 integrates the divided vehicle-side information as described above to reconstruct the vehicle-side information (step S204). Then, similarly to step S202, the power-transmitter controller 71 performs various controls based on the reconstructed vehicle-side information (step S205). Then, the power-transmitter controller 71 ends the process.

[0091] On the other hand, when the determination result in step S203 is negative, the power-transmitter controller 71 determines whether a communication frame including abnormality-related information has been received (step S206). When the determination result is affirmative, the power-transmitter controller 71 determines whether an abnormality has occurred in the power receiver 100 based on the abnormality-related information (step S207). When this determination result is affirmative, the power-transmitter controller 71 stops control related to power transmission or limits power transmission without waiting for reception of all communication frames (step S208). Then, the receiving process ends.

[0092] On the other hand, when the determination result in step S206 or step S207 is negative, the power-transmitter controller 71 determines whether a communication frame including power-related information has been received (step S209). When this determination result is affirmative, the power-transmitter controller 71 performs energization control for the power transmitter coil 22 based on the power-related information without waiting for reception of all communication frames (step S210). For example, when power supply is requested in a state where authentication has already been completed, the power-transmitter controller 71 controls energization of the power transmitter coil 22 to transmit power. On the other hand, when the power supply is stopped or limited, energization control of the power transmitter coil 22 is performed so as to stop or limit the power transmission. When power supply is requested in a state in which authentication has not been performed, the power-transmitter controller 71 may start preparations for power transmission (such as various settings). Then, the power-transmitter controller 71 ends the process.

[0093] When the determination result in step S209 is negative, the power-transmitter controller 71 determines whether a communication frame including authentication-related information has been received (step S211). If the result of this determination is positive, the power-transmitter controller 71 performs authentication based on the authentication-related information (step S212). On the other hand, when the determination result in step S211 is negative, the power-transmitter controller 71 ends the process.

[0094] According to the first embodiment, the power-receiver controller 231 divides the vehicle-side information into multiple pieces, includes each piece in a separate communication frame, and transmits multiple communication frames via the power-receiver communication coil 170 at different timings. Then, the power-transmitter controller 71 receives each communication frame via the multiple power-transmitter communication coils 40a to 40d, and integrates multiple pieces of information (abnormality-related information, power-related information, authentication-related information, etc.) contained in the multiple received communication frames to reconstruct vehicle-side information. Then, the power supply control for the power transmitter coil 22 is performed based on the vehicle-side information. This makes it possible to transmit vehicle-side information divided into multiple communication frames even in a situation where the receivable ranges are narrow and the payload length must be shortened. Therefore, even if the amount of vehicle-side information is large, necessary information can be transmitted and received reliably.

[0095] When the power-receiver controller 231 divides the vehicle-side information into multiple pieces and includes each piece in a separate communication frame, the power-receiver controller 231 assigns a receiver ID and a frame identification ID as common identification information to each communication frame. Therefore, it is possible to determine which vehicle 11 the communication frame is from, and also to easily determine that the communication frames belong to a group of communication frames.

[0096] When the power-receiver controller 231 divides the vehicle-side information into multiple pieces and includes each piece in a separate communication frame, the power-receiver controller 231 assigns a sequence ID to each communication frame as a sequence number indicating the transmission order. This makes it possible to recognize an unreceived communication frame when there is an unreceived communication frame, and to easily determine whether all of the divided communication frames have been received.

[0097] As shown in the receiving process of FIG. 9, the power-transmitter controller 71 can start control based on a portion of the divided vehicle-side information that has been received earlier, before receiving all of the divided vehicle-side information.

[0098] For example, when the battery voltage of the high-voltage storage battery 300 is outside the appropriate range, the power-receiver controller 231 prioritizes the transmission of a communication frame whose payload includes power-related information over other communication frames. When the power-transmitter controller 71 receives a communication frame including power-related information, the power-transmitter controller 71 controls the energization of the power transmitter coil 22 based on the power-related information. For example, when the battery voltage exceeds the upper limit and power transmission is limited, the power-transmitter controller 71 stops or limits power transmission without waiting for reception of all communication frames. Accordingly, overcharging and overvoltage can be prevented.

[0099] Furthermore, when the battery voltage falls below the lower limit and an emergency power supply is requested, the power-transmitter controller 71 starts transmitting power or preparing for power transmission without waiting for the reception of all communication frames. Accordingly, charging can be started quickly when urgent charging is required.

[0100] When an abnormality occurs in the vehicle 11, the power-receiver controller 231 prioritizes transmission of a communication frame including abnormality-related information over other communication frames. Then, when the power-transmitter controller 71 receives a communication frame including the abnormality-related information and determines that an anomaly has occurred, the power-transmitter controller 71 stops or limits power transmission. As a result, when an abnormality occurs, the power-transmitter controller 71 can stop or limit power transmission without waiting for reception of all communication frames. Therefore, when an abnormality occurs and charging is not possible, power supply from the power transmitter 20 can be prevented.

[0101] When no abnormality has occurred and the battery voltage is within the appropriate range, the power-receiver controller 231 prioritizes transmission of a communication frame including authentication-related information over other communication frames. When the power-transmitter controller 71 receives a communication frame including the authentication-related information, the power-transmitter controller 71 performs control related to authentication based on the authentication-related information. This allows authentication to be performed quickly.

[0102] The power-receiver controller 231 identifies the sizes of the receivable ranges R11 to R14, determines a payload length of a communication frame according to the identified sizes of the receivable ranges R11 to R14, and determines an amount of data when dividing the vehicle-side information according to the determined payload length. This makes it possible to appropriately determine the payload length of a communication frame that can be transmitted and received, thereby ensuring reliable transmission and reception.

[0103] When dividing vehicle-side information, the information is divided into meaningful categories. This allows the power transmitter 20 to transmit and receive abnormality-related information and power-related information on a priority basis, and quickly perform various processes based on the information that is transmitted and received on the priority basis, without having to wait for all communication frames.

[0104] Second Embodiment In the first embodiment of the wireless power transfer system 10, the power transmitter 20 may be provided with a function of power-transmitter information (ground side information), and the power receiver 100 may be provided with a function of receiving the power-transmitter information transmitted from the power transmitter 20. This will be described below in detail.

[0105] A power-transmitter control unit 70 of the power transmitter 20 is configured to be able to control energization of the power-transmitter communication coil 40 in order to transmit a communication frame including power-transmitter information via the power-transmitter communication coil 40. That is, like the power receiver 100, the power-transmitter control unit 70 includes a signal transmitter having an amplifier and a generating circuit, and the power-transmitter controller 71 controls the signal transmitter to wirelessly transmit a communication frame via the power-transmitter communication coil 40. The signal transmitter is similar to the signal transmitter 240 described in the first embodiment and in FIG. 4. In the power transmitter 20, the signal receiver 80 and the signal transmitter may be integrated into one body.

[0106] On the other hand, the power-receiver control unit 230 of the power receiver 100, like the power transmitter 20, is equipped with a signal receiver having an amplifier and a detection circuit, and the signal receiver receives a communication frame including power-transmitter information via the power-receiver communication coil 170. The signal receiver is similar to the signal receiver 80 described in the first embodiment and in FIG. 5. In this case, the power-transmitter communication coil 40 and the power-receiver communication coil 170 can be used as they are. The power-transmitter information includes, for example, reception confirmation information of a communication frame during communication, information regarding an abnormality in the power transmitter 20, and the like. Furthermore, in the power receiver 100, the signal receiver and the signal transmitter 240 may be integrated into one body.

[0107] In addition, while the power transmitter 20 has the transmitting function and the power receiver 100 has the receiving function, the power-transmitter information may be divided and included in multiple communication frames to be transmitted, as in the first embodiment described above.

[0108] More specifically, as shown in FIG. 10, the power-transmitter controller 71 determines power-transmitter information to be transmitted (step S301). Then, the power-transmitter controller 71 identifies transmittable ranges R11 to R14 of its own power-transmitter communication coils 40a to 40d (step S302). The transmittable ranges R11 to R14 of the power-transmitter communication coils 40a to 40d are the same as the receivable ranges R11 to R14. In step S302, the positions, sizes, number, etc. of the transmittable ranges R11 to R14 are identified. The positions, sizes, numbers, and the like of the transmittable ranges R11 to R14 are stored in advance in the storage unit or the like of the power-transmitter controller 71, and the power-transmitter controller 71 identifies them by reading them.

[0109] Then, the power-transmitter controller 71 determines the payload length of a transmittable communication frame based on the sizes of the identified transmittable ranges R11 to R14 (step S303). Furthermore, the power-transmitter controller 71 identifies the number of times that the communication frame can be transmitted based on the number of the identified transmittable ranges R11 to R14 (step S304).

[0110] Thereafter, the power-transmitter controller 71 determines whether to divide the power-transmitter information based on the payload length and the data amount of the power-transmitter information in the same manner as in steps S105 and S106 (step S305).

[0111] When the determination result in step S305 is affirmative, the power-receiver controller 231 divides the power-transmitter information, determines the priority of the divided information, and generates communication frames so that the information is transmitted according to the priority (step S306). When dividing the power-transmitter information, the information may be divided according to the payload length, or may be divided according to meaningful categories.

[0112] When generating a communication frame, the power-transmitter control unit 70 generates (or reads) a transmitter ID, a frame identification ID, a sequence ID, and a CRC, and assigns them to each communication frame. The transmitter ID is an identification number (identification information) for identifying each power transmitter 20 and is determined in advance for each power transmitter 20. The frame identification ID, CRC, and sequence ID are the same as those in the first embodiment.

[0113] Thereafter, when the vehicle 11, that is, the power receiver 100, passes through the transmittable ranges R11 to R14, the power-transmitter controller 71 sequentially transmits the generated communication frames in accordance with the determined transmission order (step S307). Specifically, when the vehicle 11 passes through a first transmittable range R11 in the traveling direction of the vehicle 11, a first communication frame is transmitted via the power-transmitter communication coil 40a. Next, when the vehicle 11 passes through a second transmittable range R12 in the traveling direction of the vehicle 11, a second communication frame is transmitted via the power-transmitter communication coil 40b. Thereafter, in a similar manner, the power-transmitter controller 71 transmits multiple communication frames using the different power-transmitter communication coils 40a to 40d. In addition, when the vehicle 11 passes through the transmittable ranges R11 to R14, it means that the transmittable ranges R11 to R14 of the respective power-transmitter communication coils 40a to 40d and the receivable ranges of the power-receiver communication coil 170 overlap (including partial overlap) in their positional relationship. Further, the position of the vehicle 11 can be identified by receiving the vehicle-side information. When the information is not divided (when the determination result of step S305 is negative), the power-transmitter controller 71 generates one communication frame including the power-transmitter information (step S308), and transmits the communication frame when the vehicle 11 passes through any of the transmittable ranges R11 to R14 (step S309).

[0114] On the other hand, when the power-transmitter information is divided, the power-receiver controller 231 receives, via the power-receiver communication coil 170, each of the multiple communication frames transmitted at different timings from the multiple power-transmitter communication coils 40a to 40d. Then, the power-receiver controller 231 integrates the power-transmitter information contained in the multiple received communication frames to reconstruct the power-transmitter information, and executes various controls based on the reconstructed power-transmitter information. Since the integration method is the same as that of the first embodiment, the description thereof will be omitted. When the power-transmitter information is not divided, the power-receiver controller 231 receives the power-transmitter information from one communication frame and executes various controls based on the power-transmitter information.

[0115] As a result, the second embodiment can achieve the same effects as the first embodiment. For example, when the transmittable range is narrow, the power-transmitter information can be transmitted in multiple communication frames. Therefore, even if the amount of data of the power-transmitter information is large, necessary information can be transmitted and received reliably.

[0116] Modifications of Embodiments The first and second embodiments may be combined to be implemented. For example, the power-receiver control unit 230 may start control based on a portion of the power-transmitter information that has been received among the multiple pieces of divided power-transmitter information prior to receiving all of the multiple pieces of the divided power-transmitter information. Furthermore, the power-transmitter information may include power-related information, abnormality-related information, and the like.

[0117] In the above embodiments, the power transmitter 20 installed on the same road RS or parking lot may share information that does not change depending on the situation of the vehicle 11, such as authentication-related information of the vehicle 11. In this case, the priority of transmission of the communication frame including the authentication-related information may be increased when the communication frame is transmitted to a first one power transmitter 20 of the multiple power transmitters 20 installed on the road RS or in the parking lot.

[0118] In the above embodiments, the power transmitters 20 may transfer the divided vehicle-side information (or a communication frame including the divided vehicle-side information) via a communication network to other power transmitters 20 that are located within a specified range, such as other adjacent power transmitters 20. Then, the other adjacent power transmitters 20 may integrate the transferred divided vehicle-side information with divided vehicle-side information contained in communication frames received via their own power-transmitter communication coils 40, reconstruct the vehicle-side information, and perform various controls. This will be described below in detail.

[0119] As shown in FIG. 2, the power-transmitter control unit 70 of the power-transmitter power supply unit 51A is configured to transfer information to a power-transmitter control unit 70 of an adjacent power-transmitter power supply unit 51B. The information may be transferred by the above-mentioned narrow area wireless communication or wide area wireless communication, or may be transferred by wire.

[0120] Then, when the determination result of step S203 in the receiving process is negative, and all communication frames have not been received even after a predetermined time has elapsed, the power-transmitter control unit 70 of the power-transmitter power supply unit 51A transfers one or more communication frames (or the divided vehicle-side information contained therein) that have been received so far to the power-transmitter control unit 70 of the adjacent power-transmitter power supply unit 51B. At that time, information required for integrating the divided vehicle-side information, such as the receiver ID, frame identification ID, and sequence ID, is also transferred.

[0121] Thereafter, when the power-transmitter control unit 70 of the adjacent power-transmitter power supply unit 51B receives a communication frame (the rest of communication frames) containing the divided vehicle-side information, the power-transmitter control unit 70 integrates the divided vehicle-side information contained in the communication frames with the divided vehicle-side information contained in the transferred communication frames, and reconstructs the vehicle-side information.

[0122] When integrating, the receiver ID, frame identification ID, sequence ID, etc. are used, similarly to step S204. For example, the source of the communication frame is identified based on the receiver ID. In addition, the communication frames including the divided vehicle-side information are identified based on the frame identification ID. In addition, the transmission order of multiple communication frames is identified based on the sequence ID, and it is confirmed whether any communication frames have been omitted. Then, the power-transmitter control unit 70 of the adjacent power-transmitter power supply unit 51B executes various controls based on the reconstructed vehicle-side information in the same manner as in step S205.

[0123] In the above embodiments, the control based on the authentication-related information may wait until all communication frames are received. In other words, the processes in steps S211 and S212 do not need to be performed. Similarly, the control based on the power-related information may wait until all communication frames are received. In other words, the processes in steps S209 and S210 do not need to be performed. Similarly, the control based on the abnormality-related information may wait until all communication frames are received. In other words, the processes in steps S206 to S208 do not need to be performed.

[0124] In step S109 of the above embodiments, the power-receiver controller 231 determines whether the battery voltage is outside the appropriate range. However, instead of the battery voltage, it may determine whether the state of charge (SOC, etc.) of the high-voltage storage battery 300 is outside the appropriate range. It may also be determined whether the battery voltage or state of charge is outside an appropriate range.

[0125] In step S109 of the above embodiments, the power-receiver controller 231 determines whether the state of the high-voltage storage battery 300 is normal or not, but it may also determine whether a state of a supply target device other than the high-voltage storage battery 300 (e.g., the travelling inverter 310 or the rotary electric machine 320) is normal. When the supply target device is not normal, the power transmission may be stopped or limited.

[0126] In the above embodiments, even if the sizes (widths) of the receivable ranges R11 to R14 (or the transmittable ranges R11 to R14, the same below) are the same, when the speed (vehicle speed) of the vehicle 11 is fast, the period during which transmission and reception is possible will be shorter and the amount of data that can be transmitted and received will be smaller. Therefore, the power-receiver controller 231 (or the power-transmitter controller 71) may determine the payload length of the communication frame depending on the speed of the vehicle 11, even if the sizes (widths) of the receivable ranges R11 to R14 are the same. For example, when the speed of the vehicle 11 is high, the payload length of the communication frame may be made shorter than when the speed is low. That is, in step S103, the power-receiver controller 231 may determine the payload length of the communication frame according to the sizes (widths) of the receivable ranges R11 to R14 and the vehicle speed.

[0127] In the above embodiments, when the vehicle 11 is an electric vehicle, and the vehicle speed is high, it is expected that the power consumption of the high-voltage storage battery 300 will increase accordingly and charging will be required promptly. Therefore, when the vehicle speed is higher than a speed threshold, the power-receiver controller 231 may be configured to prioritize transmission of a communication frame including power-related information over other communication frames. For example, instead of step S109 or in addition to step S109, the power-receiver controller 231 determines whether the vehicle speed is greater than or equal to a speed threshold. When this determination result is affirmative, the power-receiver controller 231 proceeds to step S110 and generates a communication frame to prioritize transmission of power-related information. In this way, in a situation where it is expected that urgent charging will be required, power-related information can be transmitted and received quickly, and power transmission or preparation for power transmission can be performed quickly.

[0128] In the above embodiments, the power-receiver controller 231 may set a priority for each of multiple communication frames, and may transmit a communication frame having a high priority multiple times. More specifically, when the number of possible transmissions is "4", and the vehicle-side information is divided into three communication frames to be transmitted, the power-receiver controller 231 may transmit a communication frame having the highest priority twice and transmit the other communication frames once each. For example, when a communication frame including the abnormality-related information has the highest priority, the power-receiver controller 231 may transmit the communication frame including the abnormality-related information twice and transmit other communication frames (such as communication frames including power-related information) once each.

[0129] When transmitting the same communication frame multiple times, the same communication frame may be transmitted consecutively. For example, as shown in FIG. 11, when the priority of the communication frame including the abnormality-related information is the highest, the power-receiver controller 231 may transmit the communication frame including the abnormality-related information for the first and second times, and transmit other communication frames from the third time onwards.

[0130] In the above embodiments, the vehicle-side information is divided into categories such as abnormality-related information. However, the vehicle-side information may be divided into any units. For example, the abnormality-related information and power-related information may be further divided into meaningful categories. Specifically, the power supply request and the requested power Weq may be transmitted separately in separate communication frames. In addition, two different categories, abnormality-related information and power-related information, may be included together in one communication frame. Also, the vehicle-side information may be simply divided according to the payload length, ignoring the category and the like.

[0131] In the above embodiments, the method of dividing the vehicle-side information may be changed depending on the number of receivable ranges, that is, the number of possible transmissions. For example, in the above embodiments, when the number of possible transmissions is "3", a communication frame including abnormality-related information, a communication frame including power-related information, and a communication frame including authentication-related information and other information may be generated. Similarly, in the above embodiments, when the number of possible transmissions is "2", a communication frame including power-related information and a communication frame including abnormality-related information, authentication-related information, and other information may be generated.

[0132] In the above embodiments, the wireless power transfer system may have a second function of wirelessly supplying power from the vehicle-side device to the ground-side device, in addition to the first function of wirelessly supplying power from the ground-side device to the vehicle-side device. In this case, the in-vehicle power receiver 100 has a power transmitting function in addition to the power receiving function. Moreover, the power transmitter 20 on the ground side has a power receiving function in addition to the power transmitting function. The second function will be described below with reference to FIG. 3.

[0133] The power-receiver controller 231 applies a high frequency AC voltage to the power receiver coil 102 by controlling the switching of the rectifier circuit 200. This causes a high-frequency current to flow in the power receiver coil 102 and a magnetic field for power transmission is generated in the power receiver coil 102.

[0134] When the magnetic field generated in the power receiver coil 102 links with the power transmitter coil 22, a high-frequency current flows in the power transmitter coil 22, varying with the frequency of the high-frequency current flowing in the power receiver coil 102. The high-frequency current flowing through the power transmitter coil 22 is supplied to the AC power source 15 via the power-transmitter resonant circuit 30, the filter circuit 52, the inverter 60 and the PFC circuit 61. In this case, the power-transmitter controller 71 controls the switching of the inverter 60 and the PFC circuit 61.

[0135] In addition, in the wireless power transfer system having the second function, as described in the second embodiment, the power transmitter 20 may have a function of transmitting power-transmitter information (ground side information), and the power receiver 100 may have a function of receiving the power-transmitter information transmitted from the power transmitter 20. For example, the power transmitter 20 may include a signal transmitter that supplies power-transmitter information, such as a power supply request, to the power-transmitter communication coil 40. Furthermore, the power receiver 100 may include a signal receiver that receives the power-transmitter information received by the power-receiver communication coil 170 and inputs the information to the power-receiver controller 231.

[0136] The wireless power transfer system of the above embodiments may have the function of wirelessly supplying power from the vehicle-side device to the ground-side device, instead of the function of wirelessly supplying power from the ground-side device to the vehicle-side device.

[0137] In each of the above embodiments, the ground-side device may include the signal transmitter 240 or a function for transmitting information, and the vehicle-side device may include the signal receiver 80 or a function for receiving information.

[0138] In the above embodiments, the power-receiver communication coil 170 and the power-transmitter communication coil 40 are used as wireless antennas. However, the shape of the wireless antennas may be changed as desired. For example, they may be dipole antennas or monopole antennas.

[0139] The method of wireless power transmission by the power transmitting antenna and the power receiving antenna in the above embodiments is not limited to the magnetic field resonance method, and may be an electric field coupling method. In this case, a power transmitting antenna and a power receiving antenna that are different in form from coils and use an electric field coupling method may be used.

[0140] In the above embodiments, the vehicle on which the power receiver 100 is mounted is not limited to a vehicle traveling on the road RS, but may be, for example, an AGV (Automated Guided Vehicle) or a traveling robot. In this case, the power-transmitter coil unit 21 is not buried in the road RS, but may be installed on a sidewalk adjacent to the road RS, in a parking lot, or in the path along which the AGV travels.

[0141] The control units and methods thereof described in the present disclosure may be implemented using a dedicated computer with a processor and a memory, programmed to execute one or more functions defined by a computer program. Alternatively, the control units and methods thereof described in the present disclosure may be implemented using a dedicated computer with a processor consisting of one or more dedicated hardware logic circuits. Alternatively, the controller and method described in the present disclosure may be implemented using one or more dedicated computers, which include a combination of a processor consisting of one or more hardware logic circuits, and a processor and memory programmed to perform one or more functions. The computer programs may be stored, as instructions to be executed by a computer, in a tangible non-transitory computer-readable medium.

[0142] While the present disclosure has been described with reference to various exemplary embodiments thereof, it is to be understood that the disclosure is not limited to the disclosed embodiments and constructions. To the contrary, the disclosure is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the disclosure are shown in various combinations and configurations, which are exemplary, other various combinations and configurations, including more, less or only a single element, are also within the spirit of the disclosure.

Claims

1. A power receiver (100) applied to a wireless power transfer system (10) including a ground-side device and a vehicle-side device, the ground-side device being a power transmitter (20) having a power transmitting antenna (22), the vehicle-side device being the power receiver including having a power receiving antenna (102), the power transmitting antenna being configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power receiver comprising: a power-receiver communication antenna (170) configured to perform wireless communication; and a power-receiver control unit (230) configured to control energization of the power-receiver communication antenna to wirelessly transmit power-receiver information via the power-receiver communication antenna, wherein the power transmitter includes a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas (40) configured to perform wireless communication, each of the power-transmitter communication antennas has a receivable range, the power-transmitter communication antennas are arranged such that at least a part of each receivable range is different, the power-receiver control unit is configured to divide the power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-receiver communication antenna, thereby causing the power-transmitter control unit to receive each of the communication frames via the power-transmitter communication antennas, receive the multiple pieces of the power-receiver information from each of the communication frames, and control energization of the power transmitting antenna.

2. The power receiver according to claim 1, wherein the power-receiver control unit is configured to assign common identification information to each of the communication frames when the power-receiver control unit divides the power-receiver information into multiple pieces and includes each piece in the separate communication frames.

3. The power receiver according to claim 1 or 2, wherein the power-receiver control unit is configured to assign a sequence number to each of the communication frames to indicate an order of transmission when the power-receiver control unit divides the power-receiver information into multiple pieces and includes each piece in the separate communication frames.

4. The power receiver according to any one of claims 1 to 3, wherein the power-receiver information includes power-related information regarding power transmission, and the power-receiver control unit is configured to prioritize transmission of a communication frame including power-related information over other communication frames when a target device to be supplied with power is not normal.

5. The power receiver according to any one of claims 1 to 4, wherein the power receiver is installed in a vehicle, the power-receiver information includes power-related information regarding power transmission, and the power-receiver control unit is configured to prioritize transmission of a communication frame including power-related information over other communication frames when a speed of the vehicle is higher than a speed threshold.

6. The power receiver according to any one of claims 1 to 5, wherein the power-receiver information includes abnormality-related information for notifying an abnormality on a power receiver side, and the power-receiver control unit is configured to prioritize transmission of a communication frame including abnormality-related information over other communication frames when an abnormality has been occurred on the power receiver side.

7. The power receiver according to any one of claims 1 to 6, wherein the power-receiver information includes authentication-related information regarding authentication performed when transmitting power, and the power-receiver control unit is configured to prioritize transmission of a communication frame including the authentication-related information over other communication frames when a target device to be supplied with power is normal, no abnormality has occurred on a power receiver side, and the authentication has not been performed on a power transmitter side.

8. The power receiver according to any one of claims 1 to 7, wherein the power-receiver control unit is configured to set a priority for each of multiple communication frames, and transmit a communication frame having a high priority multiple times.

9. The power receiver according to any one of claims 1 to 8, wherein the power receiver is installed in a vehicle, the power-receiver control unit is configured to determine a payload length of a communication frame in accordance with a speed of the vehicle, and determine an amount of data when dividing the power-receiver information based on the payload length.

10. The power receiver according to any one of claims 1 to 9, wherein the power receiver is installed in a vehicle, the power-receiver control unit is configured to acquire position information of the vehicle and facility information, and identify receivable ranges of the power-transmitter communication antennas installed in a location where the vehicle is traveling based on the position information of the vehicle and the facility information, determine a payload length of a communication frame in accordance with identified receivable ranges, and determine an amount of data when dividing the power-receiver information based on the payload length.

11. The power receiver according to any one of claims 1 to 10, wherein the power receiving antenna and the power-receiver communication antenna are integrated and housed in a housing.

12. A power transmitter (20) applied to a wireless power transfer system (10) including a ground-side device and a vehicle-side device, the ground-side device being the power transmitter having a power transmitting antenna (22), the vehicle-side device being a power receiver (100) including having a power receiving antenna (102), the power transmitting antenna being configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power transmitter comprising: a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna; and power-transmitter communication antennas (40) configured to perform wireless communication, wherein the power receiver includes a power-receiver communication antenna (170) configured to perform wireless communication, and a power-receiver control unit (230) configured to control energization of the power-receiver communication antenna to wirelessly transmit power-receiver information via the power-receiver communication antenna, each of the power-transmitter communication antennas has a receivable range, the power-transmitter communication antennas are arranged such that at least a part of each receivable range is different, the power-receiver control unit is configured to divide the power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-receiver communication antenna, and the power-transmitter control unit is configured to receive each of the communication frames via the power-transmitter communication antennas, receive the multiple pieces of the power-receiver information from each of the communication frames, and control energization of the power transmitting antenna.

13. The power transmitter according to claim 12, wherein the power-transmitter control unit is configured to integrate the multiple pieces to reconstruct the power-receiver information after receiving the multiple pieces of the power-receiver information, and control energization of the power transmitting antenna based on the reconstructed power-receiver information.

14. The power transmitter according to claim 13, wherein the power-receiver control unit is configured to assign common identification information to each of the communication frames when the power-receiver information is divided into multiple pieces and transmitted in separate communication frames, and the power-transmitter control unit is configured to integrate the multiple pieces of the power-receiver information based on the identification information to reconstruct the power-receiver information.

15. The power transmitter according to any one of claims 12 to 14, wherein the power-transmitter control unit is configured to start control based on a piece of the power-receiver information that has been received earlier among the multiple pieces of the power-receiver information, before receiving all of the multiple pieces of the power-receiver information.

16. The power transmitter according to claim 15, wherein the power-receiver information includes power-related information regarding power transmission, and the power-transmitter control unit is configured to start controlling energization of the power transmitting antenna based on the power-related information when the power-transmitter control unit receives a communication frame including the power-related information.

17. The power transmitter according to claim 15 or 16, wherein the power-receiver information includes abnormality-related information for notifying an abnormality on a power receiver side, and the power-transmitter control unit is configured to stop or limit power transmission when the power-transmitter control unit receives a communication frame including the abnormality-related information and determines that an abnormality has occurred on a power receiver side based on the abnormality-related information.

18. The power transmitter according to any one of claims 15 to 17, wherein the power-receiver information includes authentication-related information regarding authentication performed when transmitting power, and the power-transmitter control unit is configured to start control related to authentication based on the authentication-related information when the power-transmitter control unit receives a communication frame including the authentication-related information.

19. The power transmitter according to any one of claims 12 to 18, wherein the power transmitter is configured to communicate with another power transmitter via a communication network, and when the power-transmitter control unit receives communication frames including the multiple pieces of the power-receiver information, the power-transmitter control unit is configured to transfer the received communication frames or the multiple pieces of the power-receiver information to the other power transmitter via the communication network.

20. The power transmitter according to claim 19, wherein the power-receiver control unit is configured to assign common identification information to each of the communication frames when the power-receiver information is divided into multiple pieces and transmitted in separate communication frames, and the power-transmitter control unit is configured to integrate the multiple pieces of the power-receiver information contained in the communication frames to reconstruct the power-receiver information when the communication frames transferred via the communication network and a communication frame received via the power-transmitter communication antennas are assigned the common identification information.

21. A wireless power transfer system (10) comprising a ground-side device and a vehicle-side device, wherein the ground-side device is a power transmitter (20) having a power transmitting antenna (22), the vehicle-side device is a power receiver (100) including having a power receiving antenna (102), the power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power transmitter includes a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas (40) configured to perform wireless communication, the power receiver includes a power-receiver communication antenna (170) configured to perform wireless communication, and a power-receiver control unit (230) configured to control energization of the power-receiver communication antenna to wirelessly transmit power-receiver information via the power-receiver communication antenna, each of the power-transmitter communication antennas has a receivable range, the power-transmitter communication antennas are arranged such that at least a part of each receivable range is different, the power-receiver control unit is configured to divide the power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-receiver communication antenna, and the power-transmitter control unit is configured to receive each of the communication frames via the power-transmitter communication antennas, receive each of the multiple pieces of the power-receiver information from of the communication frames, and control energization of the power transmitting antenna.

22. A power receiver (100) applied to a wireless power transfer system (10) including a ground-side device and a vehicle-side device, the ground-side device being a power transmitter (20) having a power transmitting antenna (22), the vehicle-side device being the power receiver including having a power receiving antenna (102), the power transmitting antenna being configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power receiver comprising: a power-receiver communication antenna (170) configured to perform wireless communication; and a power-receiver control unit (230) configured to control receiving via the power-receiver communication antenna, wherein the power transmitter includes a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas (40) configured to perform wireless communication, each of the power-transmitter communication antennas has a transmittable range, the power-transmitter communication antennas are arranged such that at least a part of each transmittable range is different, the power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-transmitter communication antennas, and the power-receiver control unit is configured to receive the communication frames via the power-receiver communication antenna, and receive the power-transmitter information from the received communication frames.

23. A power transmitter (20) applied to a wireless power transfer system (10) including a ground-side device and a vehicle-side device, the ground-side device being the power transmitter having a power transmitting antenna (22), the vehicle-side device being a power receiver (100) including having a power receiving antenna (102), the power transmitting antenna being configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power transmitter comprising: a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna; and power-transmitter communication antennas (40) configured to perform wireless communication, wherein the power receiver includes a power-receiver communication antenna (170) configured to perform wireless communication, and a power-receiver control unit (230) configured to control receiving via the power-receiver communication antenna, each of the power-transmitter communication antennas has a transmittable range, the power-transmitter communication antennas are arranged such that at least a part of each transmittable range is different, the power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-transmitter communication antennas, and the power-receiver control unit is configured to receive the communication frames via the power-receiver communication antenna, and receive the multiple pieces of the power-transmitter information from the received communication frames.

24. A wireless power transfer system (10) comprising a ground-side device and a vehicle-side device, wherein the ground-side device is a power transmitter (20) having a power transmitting antenna (22), the vehicle-side device is a power receiver (100) including having a power receiving antenna (102), the power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power transmitter includes a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and power-transmitter communication antennas (40) configured to perform wireless communication, the power receiver includes a power-receiver communication antenna (170) configured to perform wireless communication, and a power-receiver control unit (230) configured to control receiving via the power-receiver communication antenna, each of the power-transmitter communication antennas has a transmittable range, the power-transmitter communication antennas are arranged such that at least a part of each transmittable range is different, the power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-transmitter communication antennas, and the power-receiver control unit is configured to receive the communication frames via the power-receiver communication antenna, and receive the power-transmitter information from the received communication frames.

25. A power receiver (100) applied to a wireless power transfer system (10) including a vehicle-side device and a ground-side device, the vehicle-side device being a power transmitter (20) having a power transmitting antenna (22), the ground-side device being the power receiver including having a power receiving antenna (102), the power transmitting antenna being configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power receiver comprising: power-receiver communication antennas (170) configured to perform wireless communication; and a power-receiver control unit (230) configured to control receiving via the power-receiver communication antenna, wherein the power transmitter includes a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna (40) configured to perform wireless communication, each of the power-receiver communication antennas has a receivable range, the power-receiver communication antennas are arranged such that at least a part of each receivable range is different, the power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-transmitter communication antenna, and the power-receiver control unit is configured to receive the communication frames via the power-receiver communication antennas, and receive the power-transmitter information from the received communication frames.

26. A power transmitter (20) applied to a wireless power transfer system (10) including a vehicle-side device and a ground-side device, the vehicle-side device being the power transmitter having a power transmitting antenna (22), the ground-side device being a power receiver (100) including having a power receiving antenna (102), the power transmitting antenna being configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power transmitter comprising: a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna; and a power-transmitter communication antenna (40) configured to perform wireless communication, wherein the power receiver includes power-receiver communication antennas (170) configured to perform wireless communication, and a power-receiver control unit (230) configured to control receiving via the power-receiver communication antenna, each of the power-receiver communication antennas has a receivable range, the power-receiver communication antennas are arranged such that at least a part of each receivable range is different, the power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-transmitter communication antenna, and the power-receiver control unit is configured to receive the communication frames via the power-receiver communication antennas, and receive the power-transmitter information from the received communication frames.

27. A wireless power transfer system (10) comprising a vehicle-side device and a ground-side device, wherein the vehicle-side device is a power transmitter (20) having a power transmitting antenna (22), the ground-side device is a power receiver (100) including having a power receiving antenna (102), the power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power transmitter includes a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna (40) configured to perform wireless communication, the power receiver includes power-receiver communication antennas (170) configured to perform wireless communication, and a power-receiver control unit (230) configured to control receiving via the power-receiver communication antenna, each of the power-receiver communication antennas has a receivable range, the power-receiver communication antennas are arranged such that at least a part of each receivable range is different, the power-transmitter control unit is configured to divide power-transmitter information into multiple pieces, include each piece in separate communication frames, and transmit the communication frames at different times via the power-transmitter communication antenna, and the power-receiver control unit is configured to receive the communication frames via the power-receiver communication antennas, and receive the power-transmitter information from the received communication frames.

28. A power receiver (100) applied to a wireless power transfer system (10) including a vehicle-side device and a ground-side device, the vehicle-side device being a power transmitter (20) having a power transmitting antenna (22), the ground-side device being the power receiver including having a power receiving antenna (102), the power transmitting antenna being configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power receiver comprising: power-receiver communication antennas (170) configured to perform wireless communication; and a power-receiver control unit (230) configured to control energization of the power-receiver communication antennas, wherein the power transmitter includes a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna (40) configured to perform wireless communication, each of the power-receiver communication antennas has a transmittable range, the power-receiver communication antennas are arranged such that at least a part of each transmittable range is different, the power-receiver control unit is configured to divide power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-receiver communication antennas, and the power-transmitter control unit is configured to receive each of the communication frames via the power-transmitter communication antenna, receive the power-receiver information from of the received communication frames, and control energization of the power transmitting antenna.

29. A power transmitter (20) applied to a wireless power transfer system (10) including a vehicle-side device and a ground-side device, the vehicle-side device being the power transmitter having a power transmitting antenna (22), the ground-side device being a power receiver (100) including having a power receiving antenna (102), the power transmitting antenna being configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power transmitter comprising: a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna; and a power-transmitter communication antenna (40) configured to perform wireless communication, wherein the power receiver includes power-receiver communication antennas (170) configured to perform wireless communication, and a power-receiver control unit (230) configured to control energization of the power-receiver communication antennas, each of the power-receiver communication antennas has a transmittable range, the power-receiver communication antennas are arranged such that at least a part of each transmittable range is different, the power-receiver control unit is configured to divide power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-receiver communication antennas, and the power-transmitter control unit is configured to receive the communication frames via the power-transmitter communication antenna, receive the power-receiver information from the received communication frames, and control energization of the power transmitting antenna.

30. A wireless power transfer system (10) comprising a vehicle-side device and a ground-side device, wherein the vehicle-side device is a power transmitter (20) having a power transmitting antenna (22), the ground-side device is a power receiver (100) including having a power receiving antenna (102), the power transmitting antenna is configured to be energized to perform wireless power transfer to the power receiving antenna on condition that a power supply request is made from the power receiver to the power transmitter, the power transmitter includes a power-transmitter control unit (70) configured to control energization of the power transmitting antenna to perform the wireless power transfer to the power receiving antenna, and a power-transmitter communication antenna (40) configured to perform wireless communication, the power receiver includes power-receiver communication antennas (170) configured to perform wireless communication; a power-receiver control unit (230) configured to control energization of the power-receiver communication antennas, each of the power-receiver communication antennas has a transmittable range, the power-receiver communication antennas are arranged such that at least a part of each transmittable range is different, the power-receiver control unit is configured to divide power-receiver information into multiple pieces, include each piece in separate communication frames, and transmit each of the communication frames via different ones of the power-receiver communication antennas, and the power-transmitter control unit is configured to receive the communication frames via the power-transmitter communication antenna, receive the power-receiver information from the received communication frames, and control energization of the power transmitting antenna.

Images