Non-contact power transmission system and non-contact power transmission method

Abstract

The invention provides a non-contact power transmission system and a non-contact power transmission method. A non-contact power transmission system according to an embodiment of the present invention supplies power in a non-contact manner from a power supply device provided on a movement path of a moving body to a power receiving device provided on the moving body, the power receiving device comprising: a position detection unit that detects the position of the power supply device; and a power reception side control unit that performs pairing between the power supply device and the power reception device by magnetic field coupling detected by the position detection unit, and performs power reception control on the basis of power obtained from the paired power supply devices, the power supply device being provided with a power supply side control unit that controls the power reception of the power supply device by the power reception side control unit. And a power supply-side control unit that supplies, to the power receiving device, power corresponding to the required power from the paired power receiving device.

Description

Technical Field

[0001] The present invention relates to a contactless power transmission system and a contactless power transmission method. Background Art

[0002] In recent years, research and development related to charging and power supply in vehicles equipped with secondary batteries has been increasingly underway, aiming to ensure convenient, reliable, sustainable, and advanced energy use, thereby contributing to energy efficiency. In this regard, in contactless power transmission systems that supply power to a vehicle from outside the vehicle via contactless power transmission, there are known systems that control the availability of power supply based on the presence or absence of authentication between the power transmitting and receiving sides of the contactless power transmission, or that control the switching frequency of a power conversion unit on the power transmitting side based on the load on the power receiving side of the contactless power transmission (see, for example, Japanese Patent Application Publication Nos. 2012-75302 and 2017-163824). Summary of the Invention

[0003] In technologies related to charging and powering mobile objects such as vehicles equipped with secondary batteries, depending on the conditions of the road, mobile objects may overtake other mobile objects in the charging lane or cut in line between mobile objects. This results in different types of mobile objects constantly passing through, making it sometimes impossible to properly detect individual mobile objects. To address this, there are methods such as the Double-LCC method that automatically stop power transmission by increasing the impedance of coils other than those directly above. However, power transmission will begin when other vehicles equipped with the same coils pass, making it impossible to handle mixed traffic. In addition, there are conventional methods that use four UWB (Ultra Wide Band) detection coils on the ground surface and two detection coils on the vehicle side for detection. However, when the detection coils are buried in the road for contactless power supply during driving, performance degrades and cannot be used. In this way, there has been a problem in the past where proper power transmission was sometimes impossible.

[0004] The present application aims to provide a non-contact power transmission system and a non-contact power transmission method that can more appropriately transmit power to a moving object, and further contribute to improving energy efficiency.

[0005] A contactless power transmission system according to a first embodiment of the present invention supplies power in a contactless manner from a power supply device provided on a moving path of a mobile body to a power receiving device provided on the mobile body, wherein the power receiving device comprises: a position detection unit that detects the position of the power supply device; and a power receiving-side control unit that pairs the power supply device and the power receiving device detected by the position detection unit based on magnetic field coupling, and performs power receiving control based on the power obtained from the paired power supply device, wherein the power supply device comprises a power supply-side control unit that supplies power corresponding to the required power from the paired power receiving device to the power receiving device.

[0006] According to a second aspect, in the contactless power transmission system of the first aspect, the power supply device may include a power supply-side communication unit for communicating with the power receiving device using a voltage waveform generated by magnetic field coupling based on a signal from the power receiving device.

[0007] A third solution, based on the contactless power transmission system of the first solution, may be such that the power supply device and the power receiving device each include a voltage divider for dividing a voltage generated by a received signal, and the power supply side control unit obtains information on the bit string by making the waveform of the voltage a rectangular wave through the voltage divider.

[0008] A fourth aspect is the contactless power transmission system according to the first aspect, wherein the power receiving-side control unit may control the signal from the power receiving device so that a phase shift amount is smaller than a threshold value.

[0009] The fifth scheme may be based on the contactless power transmission system of the above-mentioned first scheme, and the movable body may include: a detection device for identifying surrounding conditions; and a driving control unit, which controls the speed and at least the steering of the movable body based on the output of the detection device, wherein the movable body is positioned at a position corresponding to the position of the power supply device detected by the position detection unit based on the driving control that controls the movable body to travel in the center of the moving path through the driving control unit.

[0010] A sixth embodiment, based on the contactless power transmission system of the first embodiment, may be such that the power supply device communicates with the power receiving device when the efficiency of power transmission between the power supply device and the power receiving device is below a specified value, and the power supply device controls power supply to the power receiving device when the efficiency becomes greater than the specified value.

[0011] The contactless power transmission method of the seventh embodiment of the present invention provides contactless power supply from a power supply device provided on a moving path of a mobile body to a power receiving device provided on the mobile body, wherein the power receiving device performs the following processing: detecting the position of the power supply device; pairing with the detected power supply device based on weak magnetic field coupling; and performing power reception control based on the power obtained from the paired power supply device, wherein the power supply device supplies power corresponding to the required power from the power receiving device paired by the pairing to the power receiving device.

[0012] According to the first to seventh aspects described above, more appropriate power transmission can be performed to a moving object. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 is a schematic diagram of the configuration of a contactless power transmission system according to an embodiment.

[0014] Figure 2 It is a diagram showing an example of the configuration of a power supply device according to an embodiment.

[0015] Figure 3 It is a diagram showing an example of the structure of a vehicle according to the embodiment.

[0016] Figure 4 This is a diagram showing an example of a circuit configuration on the power transmission side and the power reception side according to the embodiment.

[0017] Figure 5 This is a diagram showing an example of a circuit configuration of a power transmission unit and a power reception unit.

[0018] Figure 6 A diagram for explaining transitions of operation modes.

[0019] Figure 7 A diagram for explaining the details of pairing and power transmission processing.

[0020] Figure 8 This is a diagram for explaining the transition of current and voltage values ​​on the power receiving device side and the power supply device side.

[0021] Figure 9 This is a flowchart showing an example of power transmission control in the embodiment. DETAILED DESCRIPTION

[0022] Hereinafter, a contactless power transmission system and a contactless power transmission method according to embodiments of the present invention will be described with reference to the drawings.

[0023] [System Structure]

[0024] Figure 1This is a schematic diagram of the structure of a contactless power transmission system according to an embodiment. The contactless power transmission system 1 according to the embodiment includes, for example, a power supply device 100, a vehicle 200 as an example of a mobile object, and an information processing server 300. The power supply device 100 and the information processing server 300 communicate, for example, via a network NW. The network NW includes, for example, the Internet, a WAN (Wide Area Network), a LAN (Local Area Network), a cellular network, a public line, a supplier device, a wireless base station, and the like. It should be noted that in the contactless power transmission system 1, the vehicle 200 can also communicate with the information processing server 300 via the network NW using an onboard communication device. Furthermore, in the contactless power transmission system 1, the power supply device 100 and the vehicle 200 communicate using other communication methods described later. Furthermore, in the contactless power transmission system 1, the vehicle 200 is, for example, an electric vehicle such as an electric motor vehicle, a hybrid vehicle, or a fuel cell vehicle. It should be noted that, in addition to the vehicle 200, the mobile object according to the embodiment may also be an object capable of moving on a moving path, such as an electric robot. Furthermore, the mobile object may or may not carry a person. In addition, the mobile object may not only be manually driven by a passenger (driver) but may also have a structure capable of automatic driving.

[0025] The contactless power transmission system 1 supplies power from the power supply device 100 to the vehicle 200 through contactless power transmission between the power supply device 100 and the vehicle 200. It should be noted that in the contactless power transmission system 1, the power supply device 100 supplies power to multiple vehicles 200, and the vehicle 200 receives power from multiple power supply devices 100. However, for ease of explanation, the description focuses primarily on one-to-one contactless power supply.

[0026] The power supply device 100 is installed (buried) at predetermined intervals on a road surface (for example, lane L1) of a predetermined power supply lane (for example, lane L2) in lanes L1 and L2 (an example of a moving path) where the vehicle 200 can travel. Figure 1 The power supply devices 100-1, 100-2, 100-3, etc. shown in the figure).

[0027] The predetermined interval is, for example, an interval at which the magnetic field coupling regions between power supply devices 100 do not overlap. Furthermore, the predetermined interval may be set based on the type of road (e.g., general road, expressway), or may be set based on traffic regulations such as the road's speed limit. For example, power supply device 100 communicates with vehicle 200 approaching within a predetermined distance and supplies power in response to a power supply request from vehicle 200. Furthermore, power supply device 100 performs processing related to power control and power protection functions (e.g., FSA (Fail Safe Action)) in response to the request.

[0028] Vehicle 200 is equipped with a power receiving device 210. Power receiving device 210 is installed on the bottom of vehicle 200 to facilitate receiving power from a power supply device installed on the road, but the installation location is not limited to this. Power receiving device 210 performs processing related to vehicle energy management and power conservation functions (e.g., FSA). Vehicle 200 uses power stored in an onboard battery or other power storage unit to travel and supply power to other onboard equipment. While traveling on the powered lane (lane L1), vehicle 200 communicates with power supply devices 100-1 to 100-3, charging the power storage units installed in vehicle 200 using power supplied upon request. In the contactless power transmission system 1, the communication system required between power supply device 100 and vehicle 200 is a system that allows at least individual identification of vehicle 200 and enables communication while vehicle 200 is moving at a speed V1 of approximately 0 to 100 km / h. The functional configurations of the power supply device 100 and the vehicle 200 will be described in detail later.

[0029] The information processing server 300 may be, for example, a server device, a PC (Personal Computer), or a cloud server formed by cloud computing composed of one or more information processing devices. The information processing server 300 communicates with the power supply device 100, the vehicle 200, etc. to perform various processes related to electricity. The information processing server 300 may be, for example, a charging system related to contactless power supply, an electricity quotation system, or a system that cooperates with these systems. The charging system is, for example, a system for individually identifying the vehicle 200 and charging a fee based on the charged electricity. The electricity quotation system performs, for example, various controls and management for providing low-cost electricity quotation based on demand forecasts.

[0030] The information processing server 300 also manages the status of the power supply device 100 , accumulates the power supplied from each power supply device 100 - 1 to 100 - 3 to the vehicle 200 , and calculates and manages the power actually transmitted to each vehicle 200 .

[0031] [Power supply device]

[0032] Figure 2 This figure shows an example of the structure of a power supply device 100 according to an embodiment. The power supply device 100 includes, for example, a power transmission device 110 and a power supply-side communication unit 130. The power transmission device 110 includes, for example, a power supply unit 112, a power transmission power conversion unit 114, a power transmission unit 116, a power transmission-side control unit (an example of a power supply-side control unit) 118, and a communication control unit 120. The power transmission-side control unit 118 includes a voltage detection unit 118A. Part or all of the power transmission-side control unit 118 and the communication control unit 120 are implemented, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Part or all of these components may also be implemented by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), a GPU (Graphics Processing Unit), or an SOC (System on Chip), or may be implemented through the collaboration of software and hardware. The program can be pre-stored in a storage device (a storage device with a non-temporary storage medium) such as the HDD (Hard Disk Drive) or flash memory of the power supply device 100, or it can be stored in a detachable storage medium such as a DVD or CD-ROM, and installed in the HDD or flash memory of the power supply device 100 by assembling the storage medium (non-temporary storage medium) in a drive device.

[0033] The power supply unit 112 of the power transmission device 110 is connected to the power transmission power conversion unit 114. The power supply unit 112 includes, for example, an AC power source such as a commercial power source, an AC-DC converter that converts the AC power into DC power, and capacitors for power smoothing. For example, the power supply unit 112 converts the AC power supplied from the AC power source into DC power using the AC-DC converter. Furthermore, the power supply unit 112 uses capacitors to smooth the power during power conversion.

[0034] The power transmission power conversion unit 114 is connected to the power transmission unit 116. The power transmission power conversion unit 114 includes, for example, an inverter that converts DC power into AC power. The inverter includes, for example, a bridge circuit formed by a plurality of switching elements and rectifier elements connected in a two-phase bridge, a resonant capacitor for adjusting the resonance of the coil, and a voltage divider circuit (an example of a voltage divider) for voltage division. Details of the circuit configuration of the power transmission power conversion unit 114 will be described later.

[0035] Power transmission unit 116 transmits power to an external device (e.g., power receiving device 210 of vehicle 200) using magnetic field coupling based on magnetic field resonance, for example, by utilizing changes in a high-frequency magnetic field. In magnetic field resonance, for example, when current flows through a coil on the power transmission side, magnetic field vibrations are generated, which are then transmitted to a resonant circuit on the power reception side that resonates at the same frequency, thereby flowing current. In addition to magnetic field resonance, magnetic field coupling can also utilize known coupling methods such as electromagnetic induction. In electromagnetic induction, for example, power is transmitted using the induced magnetic flux generated between the power transmission and reception sides.

[0036] The power-transmitting-side control unit 118 comprehensively controls various functions of the power transmitting device 110 or the power supply device 100 as a whole. For example, the power-transmitting-side control unit 118 controls pairing, power transmission, and other functions based on information (e.g., pairing signals, power-receiving-side operation modes) obtained through communication between the power-supplying-side communication unit 130 and the vehicle-side communication unit 230 of the vehicle 200. The pairing signal includes, for example, the power receiving device ID, which identifies the power receiving device 210, the vehicle ID, which identifies the vehicle 200, and parameter information such as the requested power and battery voltage.

[0037] For example, the power-transmitting-side control unit 118 identifies the power receiving device 210 and vehicle 200 based on the power receiving device ID and vehicle ID, and establishes (completes) pairing. Alternatively, the power-transmitting-side control unit 118 may reference user information pre-registered based on the power receiving device ID and vehicle ID, and establish pairing if the vehicle (or user) is capable of power supply (capable of using the power supply service). The power-transmitting-side control unit 118 controls power transmission so that power is supplied to the paired vehicle 200.

[0038] The power receiving side operating mode refers to the operating mode of the power receiving device 210, described later, mounted on the vehicle 200. Examples include short-circuit mode, parameter transmission mode, standby mode, and power receiving mode. Short-circuit mode prevents unintended power reception and is used, for example, in FSA. Parameter transmission mode transmits parameter information. Standby mode, for example, waits for communication with the power supply side.

[0039] The power reception mode is a mode in which pairing is established, the power reception unit 211 and the received power conversion unit 212 are in operation and waiting for power reception, or in a state in which power reception is possible or in progress based on a predetermined frequency (required frequency for resonance).

[0040] In addition, the power transmission side control unit 118 controls the operation mode of the power transmission device 110 (power transmission side operation mode) according to the situation. For example, it includes a stop mode, a search (exploration) mode, a standby (standby) mode, and a power transmission mode. The stop mode in the power transmission side operation mode is a mode in which there is no vehicle providing service within the power transmission service area (electric road) and it is not operating. The search mode is a mode in which pairing with the vehicle 200 is established, the coupling coefficient is detected to increase, and the power transmission efficiency is ensured, and the power transmission is retained. The standby mode is, for example, a mode of waiting for communication with the power receiving side. The power transmission mode is, for example, a state in which power can be transmitted based on the required frequency or a state in which power is being transmitted (power transmission state).

[0041] For example, when pairing with vehicle 200 is established, the power transmitting-side control unit 118 changes the operating mode of the power transmitting device 110 from the stop mode to the receive (standby) mode. Furthermore, upon receiving information such as the requested frequency for power transmission from vehicle 200 from the power receiving device 210 via the communication control unit 120, the power transmitting-side control unit 118 changes the operating mode from the receive mode to the search mode. It should be noted that during power transmission, the power transmitting-side control unit 118 may also perform power transmission at a pre-set drive frequency instead of the requested frequency. The power transmitting-side control unit 118 controls the switching of each switching element of the power transmission power conversion unit 114 in accordance with the requested frequency, thereby transmitting power to the power receiving device 210 of vehicle 200. Furthermore, if power transmission to vehicle 200 becomes impossible or communication becomes impossible, for example, the power transmitting-side control unit 118 terminates pairing and changes the power transmitting device 110 to the stop mode.

[0042] Furthermore, the power transmission-side control unit 118 can control the charging and settlement of the amount of electricity used (kWh) after the system is used on the vehicle 200 side. Furthermore, the voltage detection unit 118A of the power transmission-side control unit 118 detects the voltage in the power transmission power conversion unit 114. Based on the waveform of the detected voltage (e.g., a rectangular wave), the power transmission-side control unit 118 obtains information (e.g., bit string information) from the vehicle side. Details of this processing will be described later. The power transmission-side control unit 118 performs the various controls described above based on various information obtained from communication between the power supply-side communication unit 130 and the vehicle-side communication unit 230, or based on information obtained based on the voltage waveform.

[0043] The communication control unit 120 controls the operation of the power supply-side communication unit 130. For example, when there are multiple power supply-side communication units 130 in the power supply device 100, the communication control unit 120 controls the operation of all power supply-side communication units 130. For example, the communication control unit 120 attempts to obtain specified information (e.g., pairing signals, information related to power transmission (e.g., requested frequency, charges after system use, information required for settlement, etc.)) through communication between the power supply-side communication unit 130 and the vehicle-side communication unit 230 of the surrounding vehicle 200 at a predetermined period or other timing. The communication control unit 120 outputs the obtained information to the power transmission-side control unit 118, or transmits information obtained from the power transmission-side control unit 118 (pairing establishment information, information required to start power transmission), etc. to the vehicle-side communication unit 230 via the power supply-side communication unit 130.

[0044] The power supply-side communication unit 130 is equipped with an antenna for wireless communication and other devices, and wirelessly communicates with external devices (e.g., information processing server 300, vehicle 200). Furthermore, the power supply-side communication unit 130 transmits and receives information related to power transmission from the power transmission device 110 to the vehicle 200. Specifically, the power supply-side communication unit 130 transmits and receives information for pairing with the vehicle 200, or for adjusting the amount of power to be transmitted, so that power is supplied to a specific vehicle 200 under the control of the power transmission-side control unit 118 and the communication control unit 120. Furthermore, the power supply-side communication unit 130 can also obtain information from other external devices via the network NW.

[0045] [vehicle]

[0046] Figure 3 2 is a diagram showing an example of the structure of a vehicle 200 according to an embodiment. The vehicle 200 includes, for example, a power receiving device 210, a rotating electric machine 220, a vehicle-side communication unit 230, a detection device 240, a vehicle sensor 250, and a driving control unit 260. Figure 1Although not shown, in addition to the aforementioned on-board devices, vehicle 200 also includes various on-board devices (e.g., various devices for driving on the road, either manually or automatically by the driver (driving control devices), navigation devices, audio devices, and other devices (examples of loads and auxiliary devices). The power receiving device 210 includes, for example, a power receiving unit 211, a power receiving power conversion unit 212, a power conversion unit 213, a power storage unit 214, a power receiving-side control unit 215, a communication control unit 216, and a position detection unit 217. The power receiving-side control unit 215 includes, for example, a voltage detection unit 215A. Some or all of the power receiving-side control unit 215, the communication control unit 216, and the position detection unit 217 are implemented, for example, by a hardware processor such as a CPU executing a program (software). Some or all of these components may also be implemented using hardware (including circuitry) such as an LSI, ASIC, FPGA, or GPU, or through the collaboration of software and hardware. The program can be pre-stored in a storage device such as an HDD or flash memory of the vehicle 200 or the power receiving device 210 (a storage device having a non-transitory storage medium), or can be stored in a removable storage medium such as a DVD or CD-ROM and installed in the HDD or flash memory of the vehicle 200 or the power receiving device 210 by assembling the storage medium (non-transitory storage medium) in a drive device.

[0047] Power receiving unit 211 of power receiving device 210 is connected to received power converter 212. Power receiving unit 211 receives power by utilizing changes in the high-frequency magnetic field transmitted from power transmitting unit 116 through magnetic field coupling such as magnetic resonance or electromagnetic induction.

[0048] The receiving power conversion unit 212 is connected to the power conversion unit 213. The receiving power conversion unit 212 includes, for example, an inverter that converts AC power into DC power and performs voltage smoothing and voltage division. The inverter includes, for example, a bridge circuit formed by multiple switching elements and rectifier elements connected in a two-phase bridge, capacitors for voltage smoothing, and a voltage divider circuit (an example of a voltage divider) for voltage division. Details of the circuit configuration of the receiving power conversion unit 212 will be described later.

[0049] For example, the power receiving device 210, which includes a power receiving unit 211 and a power receiving power conversion unit 212, controls the on / off switching of each switching element of the power receiving power conversion unit 212 based on information about the frequency of power transmission from the power transmitting device 110 under the control of the power receiving-side control unit 215, thereby receiving power transmitted from the power transmitting device 110.

[0050] The power converter 213 is connected to the rotating electrical machine 220. The power converter 213 includes, for example, a power converter that converts DC power into AC power. The power converter includes, for example, a component module and a capacitor for voltage smoothing. Details of the circuit configuration of the power converter 213 will be described later.

[0051] The rotating electric machine 220 is, for example, a three-phase AC brushless DC motor used to drive the vehicle. The rotating electric machine 220 includes a rotor with permanent magnets for excitation and a stator with three-phase stator windings that generate a rotating magnetic field to rotate the rotor. The three-phase stator windings are connected to the three-phase AC terminals of the power converter 213. The rotating electric machine 220 generates a rotational driving force by operating in a power-driven manner using the power supplied from the power converter 213. For example, when the rotating electric machine 220 is coupled to the wheels of the vehicle 200, it generates a driving force by operating in a power-driven manner using the power supplied from the power converter 213. The rotating electric machine 220 can also generate electric power by regenerating the rotational power input from the wheels of the vehicle 200. When the rotating electric machine 220 is coupled to the internal combustion engine of the vehicle 200, it can also generate electric power using the power of the internal combustion engine.

[0052] The power storage unit 214 includes, for example, a battery (an example of a secondary battery) such as a lithium-ion battery, a current sensor for detecting the battery's current, a voltage sensor for detecting the battery's voltage, and a temperature sensor for measuring the battery's temperature. In the vehicle 200, the power storage unit 214 is connected to the power conversion unit 213 and the power receiving power conversion unit 212 (described later). For example, the power storage unit 214, under the control of the power receiving-side control unit 215, receives power from the power supply device 100 or the rotating electric machine 220 and supplies the received power to the rotating electric machine 220 and various other onboard devices (loads, auxiliary equipment).

[0053] The power receiving-side control unit 215 comprehensively controls various functions of the power receiving device 210 or the entire vehicle 200. For example, the power receiving-side control unit 215 generates control signals indicating the timing for driving each switching element on (conducting) and off (disconnecting), and generates gate signals for actually driving each switching element on and off based on the control signals. For example, by controlling the switching of each switching element in the power receiving device 210, the power receiving-side control unit 215 rectifies the AC power received from the power transmitting device 110 into DC power, while also improving the power factor of the input voltage and input current.

[0054] The power receiving control unit 215 also generates specified information (e.g., pairing signals and information related to power transmission) for power transmission from the power supply device 100 and transmits the generated signal externally from the vehicle-side communication unit 230. It should be noted that the power receiving control unit 215 may transmit the pairing signal at a specified period or at other specified timings. Furthermore, upon receiving permission information (pairing completion information) indicating that power supply is possible from the power supply device 100, as well as information required to start power transmission, from the vehicle-side communication unit 230, the power receiving control unit 215 obtains the target power by synchronously driving the multiple switching elements of the power receiving device 210 on and off, performing a synchronous rectification operation, or short-circuiting the secondary coil (described later). Furthermore, the power receiving control unit 215 controls the current flowing through the power transmitting device 110, thereby performing independent power control on the power receiving device 210, such as stopping power transmission.

[0055] Information related to power transmission includes, for example, the required power and frequency for power transmission, target output (power consumption) for failsafe, and information related to various abnormalities. The required power for power transmission is the target value of power that power receiving device 210 receives from power transmitting device 110. It is set based on, for example, the target driving force of vehicle 200 or rotating electric machine 220, the power consumption of various auxiliary machines connected to power storage unit 214, and the power state (SOC) of power storage unit 214. The power state includes, for example, the remaining capacity and charge rate of power storage unit 214. The required frequency for power transmission is the frequency required for power transmission by power transmitting device 110 and is set based on the required power. The required frequency is set based on, for example, the minimum ground clearance of vehicle 200 and the layout of power receiving device 210 in vehicle 200 to minimize reductions in power transmission efficiency and output (power). The required frequency can also be set based on, for example, the power transmission status between power transmitting device 110 and power receiving device 210. Furthermore, information related to power transmission may include information required for billing and settlement after system utilization.

[0056] Furthermore, the receiving-side control unit 215 controls the operating mode of the power receiving device 210 based on the status of the vehicle 200. As described above, the operating modes include short-circuit mode, parameter transmission mode, standby mode, and power receiving mode. For example, the receiving-side control unit 215 transmits a pairing signal at a predetermined interval, ranging from several tens of μs to several milliseconds. Upon receiving a response signal to the pairing signal from the power supply device 100, the receiving-side control unit 215 changes the operating mode of the power receiving device 210 from stop mode to short-circuit mode and transmits information such as the requested frequency. Furthermore, the receiving-side control unit 215 transitions from short-circuit mode to power receiving mode and begins controlling power transmission from the power supply device 100 during the power transmission interval. Furthermore, upon completion of power reception, the receiving-side control unit 215 changes the operating mode of the power receiving device 210 from receiving mode to stop mode.

[0057] The voltage detection unit 215A of the power receiving-side control unit 215 detects the voltage of the power receiving power conversion unit 212. The voltage detection unit 215A acquires predetermined information from the power supply device 100 based on the waveform (for example, a rectangular wave) of the detected voltage.

[0058] The communication control unit 216 controls the operation of the vehicle-side communication unit 230. For example, the communication control unit 216 transmits predetermined information (e.g., parameter information such as a pairing signal) to the vehicle-side communication unit 230 at a predetermined period or other timing. Furthermore, the communication control unit 216 may transmit the predetermined information when the vehicle 200 is within a predetermined distance from the installation location (power supply interval) of the power supply device 100, based on the position of the power supply device 100 detected by the position detection unit 217.

[0059] Then, when pairing is established, information related to power transmission (for example, requested frequency, charges after system use, information required for settlement, etc.) is transmitted to the vehicle-side communication unit 230 .

[0060] The position detection unit 217 detects the position of the power supply device 100 based on the surrounding conditions of the vehicle 200 detected by the detection device 240 , information about the vehicle 200 detected by the vehicle sensor 250 , and the like.

[0061] The vehicle-side communication unit 230 is equipped with an antenna for wireless communication and other functions, and wirelessly communicates with external devices (e.g., the information processing server 300 and the power supply device 100). Furthermore, the vehicle-side communication unit 230 transmits and receives information related to power transmission from the power supply device 100, for example. Specifically, the vehicle-side communication unit 230 transmits and receives information for pairing with the power supply device 100, or for adjusting the amount of power to be transmitted, so that power can be supplied from a specific power supply device 100 under the control of the power receiving-side control unit 215. Furthermore, the vehicle-side communication unit 230 can also obtain information from other external devices via the network NW.

[0062] The detection device 240 is a variety of equipment that detects the surrounding conditions of the vehicle 200 (within a specified distance from the vehicle 200). The detection device 240 includes, for example, a camera, a radar device, LIDAR (Light Detection and Ranging), a sensor fusion device, etc. In addition, the detection device 240 identifies the type, shape, position (relative position), speed (relative speed), etc. of objects in the surrounding area based on the detection results. Objects include not only other vehicles, pedestrians, and other traffic participants, but also the lane in which the vehicle 200 is traveling, the road dividing lines that divide the lanes, and other road structures (road signs, medians, curbs, traffic lights). In addition, the detection device 240 can also identify the surrounding road shape (for example, the position of the road dividing lines), the powered lane, the position of the power supply device 100, etc. based on the position information of the vehicle 200 detected by the vehicle sensor 250, and with reference to the map information stored in the storage unit of the vehicle 200.

[0063] The vehicle sensor 250 includes, for example, a speed sensor that detects the speed V1 of the vehicle 200, an acceleration sensor that detects acceleration, a yaw rate sensor that detects yaw rate (angular velocity), an orientation sensor that detects the orientation of the front direction of the vehicle 200, and an operation amount detection sensor installed on a driving operating part. The driving operating part includes, for example, an operating part for indicating acceleration and deceleration (for example, an accelerator pedal, a brake pedal) and an operating part for indicating steering (for example, a steering wheel). In this case, the vehicle sensor 250 may include an accelerator opening sensor, a brake pedaling amount sensor, a steering torque sensor, etc. In addition, the vehicle sensor 250 may also be provided with a position sensor that detects the position of the vehicle 200. The position sensor is, for example, a sensor that obtains position information (longitude, latitude information) from a GPS (Global Positioning System) device. In addition, the position sensor may also be a sensor that obtains position information using a GNSS (Global Navigation Satellite System) receiver.

[0064] The position detection unit 217 detects the location of the powered lane and the power supply device based on the detection results from the detection device 240. For example, the position detection unit 217 analyzes the image of the surrounding area of ​​the vehicle 200 captured by the camera using known image analysis processing, and detects the location of the powered lane and the location of the power supply device 100 based on road signs, text, and markings drawn on the road. Furthermore, when the position detection unit 217 obtains vehicle position information using a position sensor mounted on the vehicle 200, it references map information pre-stored in a storage unit, etc., to obtain the installation location of the power supply device 100 (or power supply section information).

[0065] Driving control unit 260 performs driving control by controlling at least one of the steering and speed of vehicle 200 based on the surrounding conditions detected by detection device 240 and information detected by vehicle sensors 250. Driving control includes, for example, LKAS (Lane Keeping Assistance System) control (lane keeping control) to maintain the vehicle 200 in the center of its lane (travel path) (in other words, to avoid departing from the road dividing lines that demarcate the lanes). Furthermore, driving control includes ACC (Adaptive Cruise Control), which maintains the vehicle 200 at a predetermined speed and automatically accelerates and decelerates by measuring the distance and speed difference to a preceding vehicle when approaching it; and ALC (Auto Lane Changing) control, which, upon receiving a lane change instruction from the driver through operation of a turn signal switch, executes a lane change (steering control) in the indicated direction.

[0066] [Circuit Configurations on the Power Transmitting and Receiving Sides]

[0067] Next, an example of a circuit configuration on the power transmission side by the power transmission device 110 and on the power reception side by the power reception device 210 in the embodiment will be described. Figure 4 This is a diagram showing an example of the circuit configuration of the power transmission side and the power reception side of the embodiment. Figure 4 In the example shown in FIG. 1 , the circuit configuration of the transmission power converter 114 in the power transmission device 110 and the circuit configurations of the reception power converter 212 and the power converter 213 in the power reception device 210 are mainly specifically shown.

[0068] The power transmission power conversion unit 114 includes an inverter that converts DC power into AC power. The inverter of the power transmission power conversion unit 114 includes, for example, a bridge circuit 114a formed by multiple switching elements and rectifier elements connected in a two-phase bridge, a capacitor 114b for voltage smoothing, and a voltage divider circuit 114c. Each switching element is, for example, a SiC (Silicon Carbide) transistor. The multiple switching elements are transistors 114a-1 and 114a-2, each forming a pair of high-side and low-side arms for each phase. The rectifier element is, for example, a freewheeling diode connected in parallel with each transistor 114a-1 and 114a-2. The voltage smoothing capacitor 114b is connected in parallel with the bridge circuit. The voltage divider circuit 114c includes, for example, one or more resistor elements connected in series or in parallel on the + and - terminal sides, respectively. These resistor elements divide the voltage in the power transmission power conversion unit 114 to reduce the voltage.

[0069] For example, the power transmission-side control unit 118 controls the switching of each switching element of the power transmission power conversion unit 114, turning them on (conductive) and off (disconnected), based on the requested frequency from the power receiving device 210. This allows power to be transmitted from the power transmission device 110 via the power transmission unit 116. Furthermore, the power transmission-side control unit 118 controls the resistor element in the voltage divider circuit 114c, which is made conductive by the switches, to generate a desired voltage waveform (e.g., a rectangular waveform) on the power transmission side. The power transmission-side control unit 118 detects the voltage of this waveform using the voltage detection unit 118A and generates a bit string signal consisting of 0s (zeros) and 1s based on the detection result. This allows information to be obtained from, for example, the voltage generated by the received signal.

[0070] The receiving power conversion unit 212 includes, for example, a bridge circuit 212a formed by a plurality of switching elements and rectifier elements connected in a two-phase bridge, a voltage smoothing capacitor 212b, and a voltage divider circuit 212c. Each switching element is, for example, a SiC transistor. The plurality of switching elements are transistors 212a-1 and 212a-2, each forming a pair of high-side and low-side arms for each phase. The rectifier elements are, for example, freewheeling diodes connected in parallel with each of the transistors 212a-1 and 212a-2. The voltage smoothing capacitor 212b is connected in parallel with the bridge circuit. The voltage divider circuit 212c includes, for example, one or more resistor elements connected in series or in parallel on the + and - terminal sides, respectively. These resistor elements divide the voltage in the receiving power conversion unit 212 to reduce the voltage.

[0071] Furthermore, the power conversion unit 213 includes, for example, a second element module 213a and a voltage smoothing capacitor 213b. The second element module 213a includes, for example, a second bridge circuit formed by a plurality of switching elements and rectifier elements connected in a three-phase bridge. Each switching element is, for example, a SiC transistor. The plurality of switching elements are transistors 213a-1 and 213a-2, each forming a pair of high-side and low-side arms for each phase. The rectifier elements are, for example, freewheeling diodes connected in parallel with each transistor 213a-1 and 213a-2. The voltage smoothing capacitor 213b is connected in parallel with the second bridge circuit.

[0072] The second element module 213a controls the operation of the rotating electric machine 220 by transferring power. For example, during power operation of the rotating electric machine 220, the second element module 213a converts DC power input from the positive and negative DC terminals 213p and 213n into three-phase AC power and supplies the three-phase AC power to the rotating electric machine 220 from the three-phase AC terminal 213c. The second element module 213a generates a rotational driving force by sequentially rectifying the current flowing through the three-phase stator windings of the rotating electric machine 220. For example, during regeneration of the rotating electric machine 220, the second element module 213a converts the three-phase AC power input from the three-phase stator windings into DC power by turning on and off the switching elements of each phase in synchronization with the rotation of the rotating electric machine 220. The second element module 213a can supply the DC power converted from the three-phase AC power to the power storage unit 214.

[0073] For example, the receiving-side control unit 215 controls the on / off switching of each switching element of the receiving power conversion unit 212 according to the required frequency, thereby receiving power transmitted from the power transmitting device 110 via the receiving unit 211. Furthermore, the receiving-side control unit 215 controls the resistor element in the voltage divider circuit 212c, which is made conductive by the switches, to generate a desired voltage waveform (e.g., a rectangular waveform) on the receiving side. The receiving-side control unit 215 detects the voltage of this waveform using the voltage detection unit 215A and generates a bit string signal consisting of 0s and 1s based on the detection result. This allows the control unit 215 to obtain information, such as the voltage generated by the received signal.

[0074] Figure 5 This diagram shows an example of the circuit configuration of power transmission unit 116 and power reception unit 211. Power transmission unit 116 includes, for example, a resonant circuit formed by a primary-side coil (Lt) 116a, a primary-side resistor (Rt) 116b, and a primary-side capacitor (resonant capacitor, Ct) 116c connected in series. Voltage detection unit 118A can detect voltage Vt in the resonant circuit.

[0075] Furthermore, the power transmission device 110 may include a current detection unit that detects the current (power transmission side current) It flowing through the resonant circuit.

[0076] The power transmission device 110 may further include various sensors such as a voltage sensor.

[0077] The power receiving unit 211 includes, for example, a resonant circuit formed by a secondary-side coil (Lr) 211a, a secondary-side resistor (Rr) 211b, and a secondary-side capacitor (resonant capacitor, Cr) 211c connected in series. The primary-side capacitor 116c and the secondary-side capacitor 211c are, for example, magnetic field resonance capacitors. The voltage detection unit 215A can detect the voltage Vr in the resonant circuit. The power receiving device 210 may also include a current detection unit that detects the current (receiving-side current) Ir flowing through the resonant circuit.

[0078] [Transmission and Reception of Information by Power Transmitting Device 110 and Power Receiving Device 210]

[0079] In this embodiment, as described above, voltage divider circuits 114c and 212c are provided in the power-transmitting inverter 114 and the power-receiving inverter 212, respectively, along with voltage detectors 118A and 215A. These circuits convert the voltage values ​​of the divided voltage waveforms into bit strings of 0s and 1s, enabling communication between the power transmitting device 110 and the power receiving device 210, thereby reducing power consumption associated with communication between the power supply-side communication unit 130 and the vehicle-side communication unit 230. While the following description focuses on information transmission from the power receiving device 210 to the power supply device 100 (power transmitting device 110), in this embodiment, information can also be transmitted from the power supply device 100 to the power receiving device 210 by applying the control described below.

[0080] In the embodiment, in power supply device 100, power transmission unit 116 uses voltage divider circuit 114c to divide the voltage generated by magnetic field coupling based on the voltage waveform signal on the power receiving side, and obtains a voltage waveform from the divided voltage. It should be noted that power transmission-side control unit 118 obtains bit string information by converting the voltage waveform divided by voltage divider circuit 114c into a rectangular wave. It should be noted that in the embodiment, a voltage waveform (rectangular wave) with a duty ratio (e.g., the proportion of the voltage being on (above a specified value) in a specified period) of 50% is generated. However, the waveform can be adjusted through voltage control by power receiving-side control unit 215.

[0081] The power transmission-side control unit 118 sets the voltage waveform's low voltage (minimum value) to "0" and the high voltage (maximum value) to "1," thereby acquiring bit string information of 0 and 1. By performing voltage control in this embodiment, voltage excitation can be more reliably generated through smooth magnetic field coupling, enabling information to be acquired from the rectangular voltage waveform.

[0082] Furthermore, during the aforementioned voltage control, the power receiving-side control unit 215 controls the signal from the power receiving device 210 so that the phase shift is less than a threshold. For example, the threshold is a duty cycle (on state) of 50%. The power receiving-side control unit 215 controls the voltage so that the voltage remains in the on state within a range between 0% and 50% during a predetermined period. This reduces the time spent in the high voltage state (on state), thereby reducing power consumption in the vehicle 200.

[0083] [About the transition of the operating mode during contactless power supply]

[0084] Next, transitions in the respective operating modes of the power transmitting device 110 and the power receiving device 210 during contactless power feeding will be described using the drawings. Figure 6 is a diagram for explaining the transition of the action mode. Figure 6 In the example, the horizontal axis represents time, and the vertical axis represents the operation of the vehicle 200, the operation mode (VA operation) of the power receiving device 210 side, and the operation mode (GA operation) of the power supply device 100. Figure 6 As an example of the action transition, an example of a case where contactless power transmission is performed between the power supply device 100 and the power receiving device 210 when the vehicle 200 is traveling at a predetermined speed (for example, about 80 [km / h]) is shown. The following describes the action transition accompanying the passage of time. It should be noted that Figure 6 In the example, during contactless power supply, abnormality detection is always performed on the power receiving device 210 side and the power supply device 100 side. When an abnormality is detected, FSA (Fail Safe Action) (VA side FSA, GA side FSA) is executed to control to the safe side.

[0085] At time T1, the power receiving-side control unit 215 of the vehicle 200 communicates with the information processing server 300, for example, via the vehicle-side communication unit 230, to perform billing for contactless power supply or pre-processing (on-board device billing) for billing corresponding to the amount of power supplied. It should be noted that before time T1, the operating mode on the power receiving device 210 is in standby mode. Furthermore, during the billing process, the operating mode on the power supply device is in shutdown (OFF) mode.

[0086] At time T2, after the toll collection process is complete, power receiving device 210 positions vehicle 200 so that it can pass over power supply device 100 located on the road surface (e.g., a powered lane). In this case, positioning can be performed by driving control unit 260 based on information detected by position detection unit 217. Alternatively, an image showing the position of power supply device 100 (or the position of the powered lane) and the current position of vehicle 200 can be displayed on a display unit (not shown) mounted on vehicle 200, and the driver can manually perform positioning while observing the image displayed on the display unit. For example, if LKAS control is being executed by driving control unit 260, vehicle 200 is controlled to travel in the center of the lane. Therefore, LKAS control allows vehicle 200 to travel in the powered lane, resulting in positioning. It should be noted that during the period from time T2 to time T3, power receiving device 210 remains in the short-circuited state, and power supply device 100 transitions from stop mode to standby mode.

[0087] At time T3, when the distance between power receiving device 210 and power supply device 100 decreases to within a predetermined distance (a communicable distance) due to vehicle 200's travel, the power receiving-side control unit 215 of vehicle 200 initiates pairing based on communication (VA-GA communication) between power receiving device 210 and power supply device 100. From time T3 to T4, the power receiving-side control unit 215 repeatedly performs a transmission mode (transmitting parameter information (ID, required power, battery voltage, etc.)) and a standby mode until the power transmission efficiency exceeds a predetermined value (e.g., greater than 0%). Meanwhile, the power transmitting-side control unit 118 of power supply device 100 repeatedly performs a reception mode and a search mode. In the search mode, for example, the efficiency is determined based on the correspondence information between power (transmitted power) and efficiency for power transmission according to horizontal distance (relative movement between the primary and secondary coils in a direction parallel to the road surface) in the contactless power transmission system 1 according to a predetermined embodiment, based on the correspondence information. Furthermore, power transmission control unit 118 performs an efficiency assessment based on the voltage-to-current ratio. If the ratio is below a specified value, it outputs information to that effect to power receiving device 210, initiating a retry. In other words, in this embodiment, even when the transmission efficiency is unsuitable for power supply, communication related to the pairing described above can be performed. For example, if vehicle 200 is traveling at 80 km / h, the assumed period from time T3 to T4 (the assumed communication completion time) is approximately 22.5 msec.

[0088] At time T4, the efficiency of power transmission becomes greater than a specified value, so power transmission control is performed. For example, on the power supply device 100 side, power control (GA power control) is performed to transmit power corresponding to the required power specified by the parameter to the outside. In addition, on the power receiving device 210 side, power control (VA charging (power reception) control) is performed to receive the power transmitted from the power supply device 100 and store the power in the power storage unit 214 mounted on the vehicle 200. That is, when the power transmission efficiency between the power supply device 100 and the power receiving device 210 is below the specified value, the power supply device 100 communicates with the power receiving device 210 (pairing communication), and when the efficiency becomes greater than the specified value, the power supply control to the power receiving device 210 is performed. As a result, when the power transmission efficiency is poor, pairing communication can be completed in advance, and when the power transmission efficiency is good, power supply can be performed more efficiently.

[0089] At time T5, the power transmission efficiency becomes less than the specified value, so the power supply operation is terminated at this time point. Thus, power supply control using effective power transmission can be performed. For example, when the vehicle 200 is traveling at 80 [km / h], the assumed period from time T4 to T5 (the assumed power transmission time) is about 18 [msec]. It should be noted that since a plurality of power supply devices 100 are provided at specified intervals on the power supply lane, the power supply is performed by each power supply device 100. Figure 6 The control shown above allows the vehicle 200 to be charged to the required power. When the power supply is completed, the power amount accumulated so far is accumulated, and the corresponding request processing (billing processing) is executed.

[0090] Next, explain Figure 6 Details of the pairing and power transfer processing at times T3 to T5 are described in . Figure 7 This figure is used to explain the details of pairing and power transmission processing. During the period from time T1 to T3, as a pairing start timing process, vehicle 200 controls the timing of communication between power receiving device 210 of vehicle 200 and power supply device 100 by using coordinated control such as a camera or other onboard devices ((1) in the figure).

[0091] At time T3, the power receiving device 210 of the vehicle 200 performs PING communication with the power supply device 100 ((2) in the figure). The transmission method in this case uses a magnetic field coupling method. More specifically, a weak magnetic field coupling method that utilizes the power transmission frequency is used. For example, when a magnetic field is generated by the secondary coil of the power receiving device 210 during PING transmission, the communication from the power receiving device 210 is detected by the voltage induced in the primary coil of the power transmitting device 110. The power transmitting side control unit 118 obtains information superimposed on the PING signal by demodulating the voltage detected during PING transmission. In addition, when the power transmission efficiency is not greater than the specified value (80%) as described above, a specified number of retry processes are performed. In addition, the transmitted signal includes, for example, identification information (vehicle ID) for identifying the vehicle 200, required power, battery voltage, and other information. By minimizing the information required for pairing to the vehicle ID, required power, and battery voltage, it is possible to appropriately identify the vehicle and achieve appropriate power control. Here, the required power may be the maximum chargeable power, or may be a different value when the vehicle 200 is traveling and when it is parked. Furthermore, from time T4 until charging starts (until the current value exceeds the threshold), PING communication and standby mode (receive standby) (timeout retry) are repeated at predetermined timings. It should be noted that even in standby mode, a determination is made as to whether the current value after diode rectification is greater than the threshold.

[0092] On the power supply device 100 side, the power supply side communication unit 130 receives the signal sent from the power receiving device 210 side through PING communication, and the power transmission side control unit 118 obtains the voltage value, current value, etc. from the received signal, and obtains the power transmission efficiency based on the obtained PP (peak-to-peak) voltage and current ratio ((3) in the figure). Next, as a search pulse process (search mode), the power transmission side control unit 118 determines whether the power efficiency is greater than 80% in the state of reduced duty and phase shift ((4) in the figure). It should be noted that the power supply device 100 repeats the reception process and the search pulse process (timeout retry) at a specified timing until the power efficiency becomes greater than 80%.

[0093] At time T4, when the current value becomes larger than the threshold value, the power receiving device 210 performs power receiving control ((5) in the figure). In this case, the power receiving device 210 receives power efficiently through synchronous rectification. For example, the power receiving side control unit 215 controls the output corresponding to the target output by synchronously driving the multiple switching elements of the power receiving device 210 to turn on and off, and the short-circuiting operation to short-circuit the secondary side coil. For example, the power receiving side control unit 215 controls the synchronous rectification operation based on the magnitude and phase of the current Ir flowing through the secondary side coil generated in the power receiving device 210 by the power transmitted from the power transmitting device 110. The power receiving side control unit 215 controls the multiple switching elements of the power receiving power conversion unit 212 through soft switching called zero voltage switching (ZVS). In zero-voltage switching (ZVS), each switching element turns on (switches from the off state to the on state) after the voltage across both ends reaches zero by discharging the output capacity (parasitic capacity) in the off state during the dead time of each phase. For example, the receiving-side control unit 215 controls the short-circuit operation by continuing the zero-voltage switching (ZVS) synchronous rectification operation in the high-side arm of each phase of the receiving power converter 212 while simultaneously switching on only the low-side arm of each phase. By short-circuiting the secondary-side coil, the receiving-side control unit 215 increases the impedance of the secondary-side receiving device 210 as seen from the primary-side power transmitting device 110, thereby reducing the primary-side current (transmitting-side current: the current flowing through the primary-side coil). The receiving-side control device 17 controls the current of the primary-side power transmitting device 110 through the secondary-side receiving device 210, thereby performing independent power control on the receiving device 210, such as stopping power transmission. Furthermore, the power receiving device 210 can execute safety-side control (FSA) when an abnormality or the like occurs.

[0094] Furthermore, at time T4, when the efficiency of the power supply device 100 is greater than 80%, the power supply device 100 performs a light-on control to gradually increase the power, a power FB (Feedback) control, and a light-off control to gradually decrease the power ((6) in the figure). It should be noted that the light-on control and light-off control are processed with low noise and high speed in a manner that can also cope with, for example, a vehicle 200 passing at 100 km / h.

[0095] Next, transitions of current and voltage values ​​according to the situations on the power receiving device 210 side and the power supply device 100 side will be described using the drawings. Figure 8 This is a diagram for explaining the transition of current and voltage values ​​on the power receiving device side and the power supply device side. Figure 8In the example, the horizontal axis represents time, and the vertical axis represents the signals generated by the respective actions of the power supply device (GA) side and the power receiving device (VA) side, and the measured current value and measured voltage value corresponding to each action. Figure 8 In the example of FIG. 1 , as the operation of the power supply device 100 side, Figure 7 The search pulse processing (search mode) shown in (4), the lamp lighting processing and power FB control shown in (6) are shown in the control of the power receiving device 210 side. Figure 7 The PING communication of (2) and the synchronous rectification of (5) are shown.

[0096] On the power receiving device 210 side (VA side), when the PING signal is sent, the measured current value is small (≈0), and the power consumption is minimized (min). Also, on the power supply device 100 side, when the search mode is executed, the measured voltage (GA measured voltage) increases on the power supply device 100 side. Figure 8 In the example shown, when the GA measured voltage increases, the measured voltage (VA measured voltage) on the power receiving device 210 side decreases. Here, when the power efficiency exceeds a specified value, the measured current (GA measured current) on the power supply device 100 side increases due to the lamp lighting operation, and power FB control is performed, etc., and the VA measured current increases due to synchronous rectification. This controls power reception (charging) on ​​the power receiving device 210 side.

[0097] It should be noted that while the above processing illustrates a case where vehicle 200 is traveling at a high speed (e.g., 80 km / h), similar control can be applied at lower speeds or when the vehicle is parked. That is, the processing of this embodiment is broadly applicable, for example, in scenarios where vehicle 200 has a speed V1 between 0 and 100 km / h. Regarding power supply during a parked state, power control is performed based on a preset rated time, such as 1, 3, or 10 seconds.

[0098] [Processing Flow]

[0099] Next, the power transmission process flow in the embodiment will be described. It should be noted that the following process focuses on the overall system-wide contactless power transmission process between the vehicle 200 (power receiving device 210 ) and the power transmitting device 110 , within the process of the contactless power transmission system 1 . Figure 9 This is a flowchart showing an example of power transmission control in the embodiment. Figure 9In the example, the vehicle 200 searches for the location of the charging lane based on the detection results of the detection device 240 such as a camera (step S100). In the process of step S100, for example, the camera image captured by the camera is analyzed by a known image analysis process, and the location of the charging lane (or the power supply device 100) is obtained based on the location of the road signs and text information contained in the camera image. In addition, in the process of step S100, the vehicle 200 can also refer to the map information based on the location information of the vehicle 200 obtained from the vehicle sensor 250, and obtain the location of the charging lane existing around the vehicle 200 based on the information of the charging lane contained in the map information. Moreover, in the case where the driver of the vehicle 200 visually finds the location of the charging lane from the road signs and text information and manually drives the vehicle 200M into the charging lane, the process of step S100 can be omitted.

[0100] Next, vehicle 200 performs positioning processing (step S110). During step S110, for example, driving control unit 260 executes LKAS control to position vehicle 200 so that it travels in the center of the lane. For example, if power supply device 100 is located in the center of the lane and power receiving device 210 is located in the center (near the center) of the width of vehicle 200, executing LKAS control allows vehicle 200 to be positioned more appropriately while providing contactless power supply.

[0101] Next, the vehicle 200 detects the charging point in the charging lane (step S120). The charging point is the location where the power supply device 100 is installed. The location of the power supply device 100 can be detected from the camera image, or from the map information, and the next location of the power supply device 100 set at a specified interval can also be detected based on the location and speed of the vehicle 200. Next, the vehicle 200 performs a pairing process between the power supply device 100 and the vehicle 200 (or the power receiving device 210) by using PING communication that utilizes weak electric decoupling (step S130). After the pairing is completed, the power supply device 100 performs a search judgment based on the search pattern to determine the state where the efficiency of power transmission is greater than the specified value (step S140). When the efficiency becomes greater than the specified value, non-contact power supply control is performed (step S150). It should be noted that in the power supply control, FSA control, etc. can be performed when an abnormality occurs, etc.

[0102] Next, the vehicle 200 determines whether the power supply is completed (step S160). For example, when the power supply corresponding to the required amount is completed, it is determined that the power supply is completed. In addition, when the efficiency of power transmission becomes below the specified value, it can also be determined that the power supply is completed. If it is determined that the power supply is not completed, the process returns to step S150 and the power supply control is continued. If it is determined that the power supply is completed, the process of this flowchart is terminated. It should be noted that in Figure 9 During the processing, charging processing can also be performed after the power supply is completed.

[0103] According to the embodiment described above, in a contactless power transmission system 1 that supplies power in a contactless manner from a power supply device 100 installed on a road (an example of a moving path) near a vehicle 200 (an example of a moving object), the power receiving device 210 includes: a position detection unit 217 that detects the position of the power supply device 100; and a power receiving-side control unit 215 that performs pairing based on magnetic field coupling with the power supply device detected by the position detection unit 217 and controls power reception based on the power received from the paired power supply device. The power supply device 100 includes a power transmitting-side control unit 118 (an example of a power supplying-side control unit) that supplies power corresponding to the power requested by the paired power receiving device to the power receiving device, thereby enabling more appropriate power transmission to the moving object.

[0104] For example, in the embodiment, a voltage divider circuit is provided on the power supply device 100 side and the power receiving device 210 side, and a voltage detection unit is provided. In addition, the vehicle-mounted side uses a short-circuit mode to prevent the receipt of unintended power transmission. In addition, in the embodiment, for example, when approaching a location where a power supply device is present, a pairing signal is transmitted, the detection side generates a voltage excitation corresponding to the supply voltage, and the communication transmission side performs switching at 79-90 [kHz], performing a phase shift within the duty ratio range of 0 to 50 [%] to minimize the output. In this way, by transmitting power with a phase shift, power consumption can be reduced. In addition, according to the embodiment, for example, by using communication such as Wi-Fi, there is no need to search for a charging point, so it can be applied not only when parked but also when driving at high speeds.

[0105] Furthermore, according to embodiments, for example, power transmission can be performed only when the power transmission efficiency exceeds a specified value (e.g., total inverter / coil efficiency = 80%). Furthermore, according to embodiments, the VA side can determine the communication peak based on the vehicle voltage, enabling the detection circuit unit to be set to correspond to vehicle 200. The GA side can also detect the peak corresponding to the supply voltage regardless of the vehicle voltage.

[0106] Furthermore, according to the embodiment, pairing is performed using a weak magnetic field coupling method that utilizes the power transmission frequency. This allows communication even at a high speed (approximately 100 km / h) for vehicle 200. Pairing is completed by using communication in a state of low efficiency before the power transmission efficiency exceeds a specified value. This allows for more efficient power transmission once the efficiency exceeds the specified value. Furthermore, according to the embodiment, by limiting the information required for pairing to minimal information such as the required power, battery voltage, and vehicle ID, it is possible to identify the vehicle and implement appropriate power control.

[0107] Furthermore, in the embodiments, by limiting the information required for pairing to minimal information such as vehicle ID, required power, and battery voltage, appropriate vehicle identification and power control can be achieved. Furthermore, in the embodiments, by estimating the coupling state based on low-power search pulses, the timing for starting power transfer can be appropriately determined.

[0108] The embodiments of the present invention are provided as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways and can be omitted, replaced, or modified without departing from the scope of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and are also included in the invention described in the technical solutions and their equivalents.

Claims

1. A contactless power transmission system for supplying power in a contactless manner from a power supply device provided on a moving path of a moving object to a power receiving device provided on the moving object, wherein: The power receiving device comprises: a position detection unit that detects the position of the power supply device; and a power receiving-side control unit that pairs the power supply device and the power receiving device detected by the position detection unit based on magnetic field coupling, and performs power reception control based on the power obtained from the paired power supply device; The power supply device includes a power supply-side control unit configured to supply power corresponding to a power request from the paired power receiving device to the power receiving device.

2. The contactless power transmission system according to claim 1, wherein: The power supply device includes a power supply-side communication unit that communicates with the power receiving device using a voltage waveform generated by magnetic field coupling based on a signal from the power receiving device.

3. The contactless power transmission system according to claim 1, wherein: The power supply device and the power receiving device each include a voltage dividing unit for dividing a voltage generated by a received signal. The power supply side control unit obtains information on a bit string by making the waveform of the voltage a rectangular wave through the voltage divider.

4. The contactless power transmission system according to claim 1, wherein: The power receiving-side control unit performs control so that a phase shift amount of a signal from the power receiving device becomes smaller than a threshold value.

5. The contactless power transmission system according to claim 1, wherein: The mobile body includes: a detection device for recognizing a surrounding condition; and a driving control unit for controlling at least a speed and a steering of the mobile body based on an output of the detection device. Based on the driving control performed by the driving control unit so as to control the moving body to travel in the center of the moving path, the moving body is positioned at a position corresponding to the position of the power supply device detected by the position detection unit. The contactless power transmission system according to claim 1 , wherein: The power supply device communicates with the power receiving device when the efficiency of power transmission between the power supply device and the power receiving device is equal to or less than a predetermined value. The power supply device controls power supply to the power receiving device when the efficiency becomes greater than the predetermined value.

7. A contactless power transmission method for supplying power in a contactless manner from a power supply device provided on a moving path of a moving body to a power receiving device provided on the moving body, wherein: The power receiving device performs the following processing: detecting a position of the power supply device; performing pairing with the detected power supply device based on weak magnetic field coupling; and performing power reception control based on the power obtained from the paired power supply device, The power supply device supplies electric power corresponding to the electric power requested from the power receiving device paired by the pairing to the power receiving device.

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