Contactless power transmission system and contactless power transmission method

Abstract

To provide a non-contact power transmission system capable of performing more appropriate power transmission even to a mobile, and a non-contact power transmission method.SOLUTION: A non-contact power transmission system supplies power from a power feeding device, which is installed in a movement path of a mobile, to a power receiving device which is installed in the mobile, in a non-contact manner. In the non-contact power transmission system, the power receiving device comprises a detection section for detecting a position of the power feeding device, and a power-receiving side control section for performing pairing by magnetic field coupling with the power feeding device, which is detected by the position detection section, and performing power reception control based on power obtained from the power feeding device on which the pairing is performed. The power feeding device comprises a power-feeding side control section for supplying to the power receiving deice power corresponding to requested power from the paired power receiving device.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] In recent years, research and development has been conducted on charging and supplying vehicles equipped with secondary batteries that contribute to energy efficiency, in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy.In this regard, in contactless power transfer systems that supply power to a vehicle from outside the vehicle by contactless power transfer, systems are known that control whether or not power can be supplied depending on whether authentication has been established between the power transmitting side and the power receiving side of the contactless power transfer, or that control the switching frequency of a power conversion unit on the power transmitting side depending on the load on the power receiving side of the contactless power transfer (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-75302 [Patent Document 2] Japanese Patent Application Publication No. 2017-163824 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in technologies related to charging and powering mobile objects, such as vehicles equipped with secondary batteries, depending on the conditions of the travel route, mobile objects may overtake or cut in between other mobile objects in the charging lane, resulting in multiple different types of mobile objects passing one after another, making it difficult to properly detect individual mobile objects. To address this issue, there are systems, such as the Double-LCC system, which automatically disables power transmission by increasing the coil impedance except for the one directly above. However, power transmission is initiated when another vehicle equipped with a similar coil passes, preventing mixed traffic. Conventional methods include installing four UWB (Ultra Wide Band) detection coils on the ground surface and two onboard, but burying the detection coils in the road to enable wireless power transfer while the vehicle is moving degrades performance and makes it unusable. Thus, conventional methods have faced the problem of inadequate power transmission.

[0005] In order to solve the above-mentioned problems, the present application aims to provide a contactless power transfer system and a contactless power transfer method that can transfer power more appropriately to a mobile object, thereby contributing to energy efficiency. [Means for solving the problem]

[0006] The contactless power transfer system and the contactless power transfer method according to the present invention employ the following configuration. (1): A contactless power transmission system according to one aspect of the present invention is a contactless power transmission system that contactlessly supplies power from a power supply device installed on a moving path of a moving body to a power receiving device installed on the moving body, wherein the power receiving device includes a position detection unit that detects the position of the power supply device, and a power receiving-side control unit that performs pairing with the power supply device detected by the position detection unit by magnetic field coupling and performs power reception control based on power obtained from the paired power supply device, and the power supply device includes a power supply-side control unit that supplies power to the power receiving device corresponding to power requested by the paired power receiving device. Contactless power transmission system. is.

[0007] (2): In the above aspect (1), the power supply device is a contactless power transmission system including a power supply side control 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.

[0008] (3): In the above aspect (1), the power supply device includes a voltage divider unit for dividing the voltage generated by the received signal in each of the power receiving device and the power supply side control unit, and the voltage divider unit converts the waveform of the voltage into a rectangular wave to obtain bit string information.

[0009] (4) In the above aspect (1), the power receiving side control unit controls the amount of phase shift of the signal from the power receiving device so that it is less than a threshold value.

[0010] (5): In the above aspect (1), the moving body is equipped with a detection device for recognizing the surrounding situation and a driving control unit for controlling at least the steering of the moving body out of the speed and steering based on the output of the detection device, and the moving body is positioned at a position corresponding to the position of the power supply device detected by the detection unit based on the driving control by the driving control unit to control the moving body to run in the center of the moving path.

[0011] (6): In the above aspect (1), the power supply device communicates with the power receiving device when the efficiency of power transmission with the power receiving device is below a predetermined value, and controls power supply to the power receiving device when the efficiency becomes greater than the predetermined value.

[0012] (7) A contactless power transmission method according to one aspect of the present invention is a contactless power transmission method for contactlessly supplying power from a power supply device installed on a path of a moving body to a power receiving device installed on the moving body, wherein the power receiving device detects a position of the power supply device, performs pairing with the detected power supply device by weak magnetic field coupling, and performs power reception control based on power obtained from the paired power supply device; The wireless power transmission method is such that the power supply device supplies, to the power receiving device, power corresponding to power requested by the power receiving device paired by the pairing. [Effects of the Invention]

[0013] According to the above aspects (1) to (7), more appropriate power transmission to the moving body can be performed. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic configuration diagram of a contactless power transfer system according to an embodiment. [Figure 2] 1 is a diagram illustrating an example of a configuration of a power supply device 100 according to an embodiment. [Figure 3] 1 is a diagram illustrating an example of the configuration of a vehicle 200 according to an embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of a circuit configuration on a power transmitting side and a power receiving side according to an embodiment. [Figure 5] 2 is a diagram showing an example of the circuit configuration of a power transmitting unit 116 and a power receiving unit 211. FIG. [Figure 6] FIG. 10 is a diagram illustrating a transition of an operation mode. [Figure 7] 10A and 10B are diagrams for explaining details of pairing and power transmission processing. [Figure 8] 10A and 10B are diagrams for explaining transitions of current values ​​and voltage values ​​on the power receiving device side and the power supply device side. [Figure 9] 4 is a flowchart illustrating an example of power transmission control according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a contactless power transfer system and a contactless power transfer method according to an embodiment of the present invention will be described with reference to the drawings.

[0016] [System Configuration] FIG. 1 is a schematic configuration diagram 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, which is an example of a mobile object, and an information processing server 300. The power supply device 100 and the information processing server 300 communicate with each other via a network NW. The network NW includes, for example, the Internet, a wide area network (WAN), a local area network (LAN), a cellular network, a public line, a provider device, a wireless base station, and the like. In the contactless power transmission system 1, the vehicle 200 may also communicate with the information processing server 300 via the network NW using an on-board communication device. In the contactless power transmission system 1, the power supply device 100 and the vehicle 200 communicate with each other using other communication means, which will be described later. In the contactless power transmission system 1, the vehicle 200 is, for example, an electric vehicle, a hybrid vehicle, a fuel cell vehicle, or the like. In addition to the vehicle 200, the mobile object according to the embodiment may be an object capable of moving along a path, such as an electric robot. Furthermore, the moving body may or may not have a person on board. Furthermore, the moving body may be configured to be capable of automatic driving as well as manual driving by a passenger (driver). In the following description, the moving body is assumed to be a vehicle.

[0017] The contactless power transfer system 1 supplies power from the power transfer device 100 to the vehicle 200 by contactless power transfer between the power transfer device 100 and the vehicle 200. In the contactless power transfer system 1, the power transfer device 100 supplies power to a plurality of vehicles 200, and the vehicles 200 receive power from a plurality of power transfer devices 100. However, for convenience of explanation, the following description will mainly focus on one-to-one contactless power transfer.

[0018] The power supply devices 100 are installed (buried) at predetermined intervals on the road surface of a predetermined power supply lane (e.g., lane L1) among lanes L1 and L2 (examples of travel paths) on which the vehicle 200 can travel (e.g., power supply devices 100-1, 100-2, 100-3, etc. shown in FIG. 1 ). The predetermined intervals are intervals at which the magnetic field coupling regions of the power supply devices 100 do not overlap. The predetermined intervals may be set according to the type of road (e.g., an ordinary road or an expressway) or according to traffic regulations such as the speed limit of the road. The power supply device 100 communicates with the vehicle 200 approaching within a predetermined distance, and supplies power in response to a power supply request from the vehicle 200. The power supply device 100 also performs processing related to power control and power protection functions (e.g., FSA (Fail Safe Action)) in response to the request.

[0019] Vehicle 200 is equipped with a power receiving device 210. Power receiving device 210 is installed at the bottom of vehicle 200 so as to easily receive power from a power supply device installed on the road surface, but the installation location is not limited to this. Power receiving device 210 performs processes related to, for example, vehicle energy management and power protection functions (e.g., FSA). Vehicle 200 also uses power stored in a power storage unit such as a battery to travel and supplies power to other in-vehicle devices. Vehicle 200 also communicates with power supply devices 100-1 to 100-3 while traveling in a power supply lane (lane L1) and charges the power storage unit installed in vehicle 200 using power supplied in response to requests. In wireless power transfer system 1, a communication system required between power supply device 100 and vehicle 200 is a system that can at least individually identify vehicle 200 and can communicate when vehicle 200 is traveling 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.

[0020] The information processing server 300 may be, for example, a server device or a PC (Personal Computer), or may be a cloud server configured by cloud computing including one or more information processing devices. The information processing server 300 communicates with the power supply device 100, the vehicle 200, and the like, and performs various processes related to power. The information processing server 300 may be, for example, a billing system for contactless power supply, a power input system, or a system linked to these systems. The billing system is, for example, a system that individually recognizes the vehicle 200 and collects fees according to the power charged. The power bidding system is, for example, a system that performs various controls and management to conduct low-cost power bidding based on demand forecasts. The information processing server 300 also manages the status of the power supply device 100, calculates the power supplied to the vehicle 200 from each of the power supply devices 100-1 to 100-3, and calculates and manages the actual power transmitted to each vehicle 200.

[0021] [Power supply device] 2 is a diagram illustrating an example of the configuration of a power supply device 100 according to an embodiment. The power supply device 100 includes, for example, a power transmitting device 110 and a power supply-side communication unit 130. The power transmitting device 110 includes, for example, a power supply unit 112, a power transmission power conversion unit 114, a power transmitting unit 116, a power transmitting-side control unit (an example of a power supply-side control unit) 118, and a communication control unit 120. The power transmitting-side control unit 118 includes a voltage detection unit 118A. Some or all of the power transmitting-side control unit 118 and the communication control unit 120 are realized by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as a large-scale integration (LSI), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a graphics processing unit (GPU), or a system on chip (SOC), or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device (a storage device having a non-transitory storage medium) such as a hard disk drive (HDD) or flash memory of the power supply device 100, or may be stored in a removable storage medium such as a DVD or CD-ROM, and installed in the HDD or flash memory of the power supply device 100 by inserting the storage medium (non-transitory storage medium) into a drive device.

[0022] The power supply unit 112 of the power transmitting device 110 is connected to the transmission power conversion unit 114. The power supply unit 112 includes, for example, an AC power supply such as a commercial power supply, an AC-DC converter that converts the AC power into DC power, and a capacitor for smoothing power. The power supply unit 112 converts, for example, AC power supplied from the AC power supply into DC power using the AC-DC converter. Furthermore, the power supply unit 112 performs a power smoothing process using a capacitor during power conversion.

[0023] The transmission power conversion unit 114 is connected to the power transmission unit 116. The 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 that are bridge-connected in two phases, a resonance capacitor for adjusting resonance of the coil, and a voltage divider circuit for voltage division (an example of a voltage divider). The circuit configuration of the transmission power conversion unit 114 will be described in detail later.

[0024] The power transmitting unit 116 transmits power to the outside (for example, the power receiving device 210 of the vehicle 200) by changing a high-frequency magnetic field, for example, by magnetic field coupling due to magnetic field resonance. In magnetic field resonance, for example, when a current flows through a power transmitting coil, a magnetic field oscillation occurs, and this is transmitted to a resonant circuit on the power receiving side that resonates at the same frequency, causing a current to flow. In addition to magnetic field resonance, known coupling methods such as electromagnetic induction may also be used for magnetic field coupling. In electromagnetic induction, for example, power is transmitted by utilizing an induced magnetic flux generated between the power transmitting side and the power receiving side.

[0025] The power transmitting-side control unit 118 comprehensively controls each function of the power transmitting device 110 or the entire power supply device 100. For example, the power transmitting-side control unit 118 controls pairing, power transmission, and the like based on information (e.g., a pairing signal or a power receiving-side operation mode) obtained by the power supply-side communication unit 130 communicating with the vehicle-side communication unit 230 of the vehicle 200. The pairing signal includes, for example, a power receiving device ID, which is identification information for identifying the power receiving device 210, or a vehicle ID, which is identification information for identifying the vehicle 200, parameter information such as required power, battery voltage, and the like. For example, the power transmitting-side control unit 118 identifies the power receiving device 210 or the vehicle 200 based on the power receiving device ID or the vehicle ID and establishes (completes) pairing. Furthermore, the power transmitting-side control unit 118 may refer to user information, etc., registered in advance based on the power receiving device ID or the vehicle ID, and establish pairing if the vehicle (or user) is capable of receiving power (capable of using the power supply service). The power transmission side control unit 118 controls the power transmission so that power is supplied to the vehicle 200 with which pairing has been established.

[0026] The power receiving side operation mode is an operation mode of the power receiving device 210 (described later) mounted on the vehicle 200, and includes, for example, a short mode, a parameter transmission mode, a standby mode, and a power receiving mode. The short mode is a mode that prevents unexpected power reception and is used, for example, in FSA and the like. The parameter transmission mode is a mode that transmits parameter information. The standby mode is, for example, a mode that waits for communication with the power supply side. The power receiving mode is a mode in which pairing is established and the power receiving unit 211 and the power receiving power conversion unit 212 are operating and waits for power reception, or is in a state where power can be received or is currently being received based on a predetermined frequency (a required frequency for resonance).

[0027] Furthermore, the power transmitting side control unit 118 controls the operation mode (power transmitting side operation mode) of the power transmitting device 110 depending on the situation. Examples include an off mode, a search mode, a standby mode, and a power transmission mode. The off mode among the power transmitting side operation modes is a mode in which there is no vehicle providing service within the power transmission service section (electric road) and the power transmitting device is not operating. The search mode is a mode in which pairing with the vehicle 200 is established, the coupling coefficient increases, and a situation is detected in which power transmission efficiency can be ensured, and power transmission is suspended. The standby mode is, for example, a mode in which communication with the power receiving side is on standby. The power transmission mode is, for example, a state in which power can be transmitted based on a requested frequency or a state in which power is being transmitted (power transmission state).

[0028] For example, when pairing with the vehicle 200 is established, the power transmitting-side control unit 118 transitions the operation mode of the power transmitting device 110 from the off mode to the reception (standby) mode. Furthermore, upon receiving information from the power receiving device 210, such as a requested frequency for power transmission from the vehicle 200, via the communication control unit 120, the power transmitting-side control unit 118 transitions the operation mode from the reception mode to the search mode. In the power transmission state, the power transmitting-side control unit 118 may transmit power at a preset drive frequency instead of the requested frequency. The power transmitting-side control unit 118 transmits power to the power receiving device 210 of the vehicle 200 by controlling the on (conduction) and off (cutoff) switching of each switching element of the transmission power conversion unit 114 according to the requested frequency. Furthermore, for example, when power transmission to the vehicle 200 or communication becomes impossible, the power transmitting-side control unit 118 terminates pairing and transitions the power transmitting device 110 to the off mode.

[0029] Furthermore, the power transmitting-side control unit 118 may control billing and settlement according to the amount of power used [kWh] after system use on the vehicle 200 side. Furthermore, a voltage detection unit 118A of the power transmitting-side control unit 118 detects the voltage at the power transmitting power conversion unit 114. The power transmitting-side control unit 118 acquires information (e.g., bit string information) from the vehicle side based on the waveform of the detected voltage (e.g., a rectangular wave). This process will be described in detail later. The power transmitting-side control unit 118 performs the various controls described above based on various information obtained through communication between the power supply-side communication unit 130 and the vehicle-side communication unit 230 or information obtained based on the voltage waveform.

[0030] The communication control unit 120 controls the operation of the power supply-side communication unit 130. For example, if the power supply device 100 has a plurality of power supply-side communication units 130, the communication control unit 120 controls the operation of all of the power supply-side communication units 130. For example, the communication control unit 120 attempts to acquire predetermined information (e.g., a pairing signal or information related to power transmission (e.g., a required frequency, information required for billing and settlement after system use, 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 timing such as a predetermined cycle. The communication control unit 120 outputs the acquired information to the power transmission-side control unit 118, and transmits information acquired from the power transmission-side control unit 118 (pairing establishment information, information required for starting power transmission), etc. to the vehicle-side communication unit 230 via the power supply-side communication unit 130.

[0031] The power supply-side communication unit 130 includes an antenna for wireless communication and communicates wirelessly with external devices (for example, the information processing server 300 and the vehicle 200). The power supply-side communication unit 130 also transmits and receives information relating to, for example, power transmission from the power transmitting device 110 to the vehicle 200. Specifically, the power supply-side communication unit 130 transmits and receives information for pairing with the vehicle 200 so that power is supplied to a specific vehicle 200 under the control of the power transmitting-side control unit 118 and the communication control unit 120, and transmits and receives information for adjusting the amount of power to be transmitted. The power supply-side communication unit 130 may also acquire information from other external devices via the network NW.

[0032] [vehicle] 3 is a diagram illustrating an example of the configuration 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. Although not shown in FIG. 1 , the vehicle 200 includes, in addition to the above-described on-board devices, various on-board devices (examples of loads and auxiliary devices) such as various devices (such as a driving control device) for traveling on roads by manual driving by a driver or automatic driving, a car navigation device, and an audio device. The power receiving device 210 includes, for example, a power receiving unit 211, a received 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 realized, for example, by a hardware processor such as a CPU executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as an LSI, ASIC, FPGA, or GPU, or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device (storage device having a non-transitory storage medium) such as a HDD or flash memory of the vehicle 200 or the power receiving device 210, or may 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 attaching the storage medium (non-transitory storage medium) to a drive device.

[0033] The power receiving unit 211 of the power receiving device 210 is connected to the received power conversion unit 212. The power receiving unit 211 receives power by changes in the high-frequency magnetic field transmitted from the power transmitting unit 116 due to magnetic field coupling such as magnetic resonance or electromagnetic induction.

[0034] The received power conversion unit 212 is connected to the power conversion unit 213. The received power conversion unit 212 includes, for example, an inverter that converts AC power into DC power and smooths and divides the voltage. The inverter includes, for example, a bridge circuit formed by a plurality of switching elements and rectifier elements that are bridge-connected in two phases, a capacitor for smoothing the voltage, and a voltage divider circuit (an example of a voltage divider). The circuit configuration of the received power conversion unit 212 will be described in detail later.

[0035] For example, a power receiving device 210 having a power receiving unit 211 and a power receiving power conversion unit 212 receives power transmitted from the power transmitting device 110 by controlling the power receiving side control unit 215 to switch on (conducting) and off (cutting) each switching element of the power receiving power conversion unit 212 in accordance with information on the frequency of power transmission by the power transmitting device 110.

[0036] The power conversion unit 213 is connected to the rotating electric machine 220. The power conversion unit 213 includes, for example, a power converter that converts between DC power and AC power. The power converter includes, for example, an element module and a capacitor for voltage smoothing. Details of the circuit configuration of the power conversion unit 213 will be described later.

[0037] The rotating electric machine 220 is, for example, a three-phase AC brushless DC motor provided for driving a vehicle. The rotating electric machine 220 includes a rotor having a permanent magnet for a field and a stator having a three-phase stator winding that generates a rotating magnetic field that rotates the rotor. The three-phase stator winding is connected to three-phase AC terminals of the power conversion unit 213. The rotating electric machine 220 generates a rotational driving force by performing a power running operation using electric power supplied from the power conversion unit 213. For example, if the rotating electric machine 220 can be connected to the wheels of the vehicle 200, the rotating electric machine 220 generates a driving force for driving the vehicle by performing a power running operation using electric power supplied from the power conversion unit 213. The rotating electric machine 220 may generate electric power by performing a regenerative operation using rotational power input from the wheels of the vehicle 200. If the rotating electric machine 220 can be connected to an internal combustion engine of the vehicle 200, the rotating electric machine 220 may generate electric power using the power of the internal combustion engine.

[0038] 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 that detects the current of the battery, a voltage sensor that detects the voltage of the battery, and a temperature sensor that measures the temperature of the battery. In the vehicle 200, the power storage unit 214 is connected to the power conversion unit 213 and the received power conversion unit 212, which will be described later. Under the control of the power receiving side control unit 215, for example, the power storage unit 214 stores power from the power feeding device 100 or the rotating electric machine 220 and supplies the stored power to the rotating electric machine 220 and various other on-board devices (loads, auxiliaries).

[0039] The power receiving-side control unit 215, for example, comprehensively controls each function 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 to drive each switching element on (conducting) and off (cutting), and generates gate signals for actually driving each switching element on and off based on the control signals. For example, the power receiving-side control unit 215 controls the switching of each switching element of the power receiving device 210, thereby rectifying the AC power received from the power transmitting device 110 into DC power and improving the power factor of the input voltage and input current.

[0040] Furthermore, the power receiving-side control unit 215 generates predetermined information (e.g., a pairing signal or information related to power transmission) for transmitting power from the power supply device 100 and transmits the generated signal from the vehicle-side communication unit 230 to the outside. The power receiving-side control unit 215 may transmit the pairing signal at a predetermined cycle or at another predetermined timing. When the power receiving-side control unit 215 acquires permission information (pairing completion information) indicating that power supply device 100 is able to supply power or information necessary to start power transmission from the vehicle-side communication unit 230, the power receiving-side control unit 215 acquires target power by performing a synchronous rectification operation that synchronously drives multiple switching elements of the power receiving device 210 to turn on and off, and a short-circuit operation that short-circuits the secondary-side coil, which will be described later. The power receiving-side control unit 215 also controls the current of the power transmission device 110 to perform independent power control, such as stopping power transmission, on the power receiving device 210 side.

[0041] The information related to power transmission includes, for example, the required power and required frequency of power transmission, a target output (power consumption) for fail-safe purposes, and information related to various abnormalities. The required power of power transmission is a target value of power that the power receiving device 210 receives from the power transmitting device 110, and is set, for example, in accordance with the target driving force of the vehicle 200 or the rotating electric machine 220, the power consumption of various auxiliaries connected to the power storage unit 214, and the power state (SOC: State of Charge) of the power storage unit 214. The power state includes, for example, the remaining capacity and charging rate of the power storage unit 214. The required frequency of power transmission is a frequency required for power transmission from the power transmitting device 110 and is set in accordance with the required power. The required frequency is set, for example, based on the minimum ground clearance of the vehicle 200 and the installation layout of the power receiving device 210 on the vehicle 200, so as to suppress a decrease in the efficiency of power transmission and the output (power). The required frequency may be set, for example, in accordance with the state of power transmission between the power transmitting device 110 and the power receiving device 210. Furthermore, the information regarding power transmission may include information necessary for billing and settlement after use of the system.

[0042] Furthermore, the power receiving-side control unit 215 controls the operation mode of the power receiving device 210 depending on the situation of the vehicle 200. The operation modes include the short mode, parameter transmission mode, standby mode, and power receiving mode, as described above. For example, the power receiving-side control unit 215 transmits a pairing signal at a predetermined cycle of approximately several tens of microseconds to several milliseconds, and upon receiving a response signal to the pairing signal from the power supply device 100, the power receiving-side control unit 215 transitions the operation mode of the power receiving device 210 from the off mode to the short mode and transmits information such as a requested frequency. Furthermore, the power receiving-side control unit 215 transitions from the short mode to the power receiving mode and starts power reception control for power transmission from the power supply device 100 in the power transmission section. Furthermore, when power reception is completed, the power receiving-side control unit 215 transitions the operation mode of the power receiving device 210 from the power receiving mode to the off mode.

[0043] Furthermore, the voltage detection unit 215A of the power receiving side control unit 215 detects the voltage of the received power conversion unit 212. Furthermore, predetermined information is acquired from the power feeding device 100 based on the waveform (for example, a rectangular wave) of the detected voltage.

[0044] The communication control unit 216 controls the operation of the vehicle-side communication unit 230. For example, the communication control unit 216 causes the vehicle-side communication unit 230 to transmit predetermined information (for example, parameter information such as a pairing signal) at a timing such as a predetermined cycle. Furthermore, the communication control unit 216 may cause the vehicle-side communication unit 230 to transmit the predetermined information when the position of the vehicle 200 is within a predetermined distance from the installation position (power supply section) of the power supply device 100 based on the position of the power supply device 100 detected by the position detection unit 217. Then, when pairing is established, the communication control unit 216 causes the vehicle-side communication unit 230 to transmit information related to power transmission (for example, a required frequency and information necessary for billing and settlement after using the system).

[0045] 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.

[0046] The vehicle-side communication unit 230 includes an antenna for wireless communication and communicates wirelessly with external devices (for example, the information processing server 300 and the power supply device 100). The vehicle-side communication unit 230 also 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 side so that power is supplied from a specific power supply device 100 under the control of the power receiving-side control unit 215, and transmits and receives information for adjusting the amount of power to be transmitted. The vehicle-side communication unit 230 may also acquire information from other external devices via the network NW.

[0047] The detection device 240 is a device that detects the surrounding conditions of the vehicle 200 (within a predetermined distance from the vehicle 200). The detection device 240 includes, for example, a camera, a radar device, a LIDAR (Light Detection and Ranging), a sensor fusion device, and the like. The detection device 240 recognizes the type, shape, position (relative position), speed (relative speed), and the like of objects present in the vicinity based on the detection results. The objects include traffic participants such as other vehicles and pedestrians, as well as the lane in which the vehicle 200 is traveling, road dividing lines that divide the lane, and other road structures (road signs, medians, curbs, traffic lights), and the like. The detection device 240 may refer to map information and the like stored in a memory unit in the vehicle 200 based on the position information of the vehicle 200 detected by the vehicle sensor 250, and recognize the shape of the surrounding roads (for example, the positions of road dividing lines), the power supply lane, the position of the power supply device 100, and the like from the position of the vehicle 200.

[0048] Vehicle sensor 250 includes, for example, a speed sensor that detects speed V1 of 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 vehicle 200 in the forward direction, and an operation amount detection sensor attached to a driving operator. Driving operators include, for example, an operator (e.g., an accelerator pedal or a brake pedal) for instructing acceleration or deceleration, and an operator (e.g., a steering wheel) for instructing steering. In this case, vehicle sensor 250 may include an accelerator opening sensor, a brake depression amount sensor, a steering torque sensor, etc. Vehicle sensor 250 may also be provided with a position sensor that detects the position of vehicle 200. The position sensor is, for example, a sensor that acquires position information (longitude and latitude information) from a GPS (Global Positioning System) device. The position sensor may also be a sensor that acquires position information using a GNSS (Global Navigation Satellite System) receiver.

[0049] The above-described position detection unit 217 detects the positions of the power supply lane and the power supply device based on the detection results of the detection device 240. For example, the position detection unit 217 analyzes an image of the surroundings of the vehicle 200 captured by a camera using a known image analysis process, and detects the positions of the power supply lane and the power supply device 100 from road signs and characters and marks drawn on the road. Furthermore, when the position detection unit 217 acquires the position information of the vehicle 200 using a position sensor or the like mounted on the vehicle 200, the position detection unit 217 acquires the installation position of the power supply device 100 (or power supply section information) by referring to map information stored in advance in a storage unit or the like.

[0050] The driving control unit 260 controls at least one of the steering and speed of the vehicle 200 based on the surrounding conditions detected by the detection device 240, information detected by the vehicle sensor 250, etc., to perform driving control. The driving control includes, for example, LKAS (Lane Keeping Assistance System) control (lane maintenance control) that performs steering control so that the vehicle 200 travels in the center of the driving lane (travel path) (in other words, so that the vehicle does not deviate from the road dividing lines that divide the driving lane). The driving control also includes ACC (Adaptive Cruise Control) that causes the vehicle 200 to travel at a constant speed set in advance and, when approaching a preceding vehicle, measures the distance and speed difference with the preceding vehicle and automatically accelerates or decelerates the vehicle, and ALC (Auto Lane Changing) control that, when an instruction to change lanes by the driver's operation of a turn signal switch is received, performs lane change (steering control) in the instructed direction.

[0051] [Circuit configuration on the power transmission and receiving sides] Next, an example of the circuit configuration of the power transmitting side of the power transmitting device 110 and the power receiving side of the power receiving device 210 in the embodiment will be described. Fig. 4 is a diagram showing an example of the circuit configuration of the power transmitting side and the power receiving side in the embodiment. Note that the example in Fig. 4 mainly specifically shows the circuit configuration of the transmission power conversion unit 114 in the power transmitting device 110 and the circuit configurations of the reception power conversion unit 212 and the power conversion unit 213 in the power receiving device 210.

[0052] The transmission power conversion unit 114 includes an inverter that converts DC power into AC power. The inverter of the transmission power conversion unit 114 includes, for example, a bridge circuit 114a formed by a plurality of switching elements and rectifying elements bridge-connected in two phases, a voltage-smoothing capacitor 114b, and a voltage-dividing circuit 114c. Each switching element is, for example, a silicon carbide (SiC) transistor. The plurality of switching elements are high-side arm and low-side arm transistors 114a-1 and 114a-2 that form a pair in each phase. The rectifying element is, for example, a free-wheeling diode connected in parallel to each of the transistors 114a-1 and 114a-2. The voltage-smoothing capacitor 114b is connected in parallel to the bridge circuit. The voltage-dividing circuit 114c includes, for example, one or more resistor elements connected in series or parallel on each of the positive and negative terminal sides, and divides and drops the voltage in the transmission power conversion unit 114 using these resistor elements.

[0053] For example, the power transmitting side control unit 118 controls the on (conduction) and off (cutoff) switching of each switching element of the power transmitting power conversion unit 114 in accordance with the frequency requested by the power receiving device 210, thereby transmitting power from the power transmitting device 110 via the power transmitting unit 116. The power transmitting side control unit 118 also controls the resistive elements of the voltage dividing circuit 114c, which are switched to conduct electricity, thereby generating a desired voltage waveform (e.g., a rectangular waveform) on the power transmitting side. The power transmitting 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 and 1s based on the detection result, thereby acquiring information from, for example, the voltage generated by the received signal.

[0054] The receiving power conversion unit 212 includes, for example, a bridge circuit 212a formed by a plurality of switching elements and rectifying elements bridge-connected in two phases, a voltage-smoothing capacitor 212b, and a voltage-dividing circuit 212c. Each switching element is, for example, a SiC transistor. The plurality of switching elements are high-side arm and low-side arm transistors 212a-1 and 212a-2 that form a pair in each phase. The rectifying elements are, for example, freewheeling diodes connected in parallel to each of the transistors 212a-1 and 212a-2. The voltage-smoothing capacitor 212b is connected in parallel to the bridge circuit. The voltage-dividing circuit 212c includes, for example, one or more resistor elements connected in series or parallel on each of the positive and negative terminal sides, and the resistor elements divide and drop the voltage in the receiving power conversion unit 212.

[0055] The power conversion unit 213 also 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 rectifying elements bridge-connected in three phases. Each switching element is, for example, a SiC transistor. The plurality of switching elements are high-side arm and low-side arm transistors 213a-1 and 213a-2 that form a pair in each phase. The rectifying element is, for example, a freewheeling diode connected in parallel to each of the transistors 213a-1 and 213a-2. The voltage smoothing capacitor 213b is connected in parallel to the second bridge circuit.

[0056] The second element module 213a controls the operation of the rotating electric machine 220 by receiving and sending electric power. For example, when the rotating electric machine 220 is powered, the second element module 213a converts DC power input from positive and negative DC terminals 213p, 213n into three-phase AC power and supplies the three-phase AC power to the rotating electric machine 220 from three-phase AC terminals 213c. The second element module 213a generates a rotational driving force by sequentially commutating the current to the three-phase stator windings of the rotating electric machine 220. For example, when the rotating electric machine 220 is regenerating, the second element module 213a converts the three-phase AC power input from the three-phase stator windings into DC power by driving the switching elements of each phase to turn on (conductive) and off (interrupted) in synchronization with the rotation of the rotating electric machine 220. The second element module 213a is capable of supplying the power storage unit 214 with DC power converted from three-phase AC power.

[0057] For example, the power receiving-side control unit 215 receives power transmitted from the power transmitting device 110 via the power receiving unit 211 by controlling the on (conduction) and off (cutoff) switching of each switching element of the power receiving power conversion unit 212 according to the requested frequency. The power receiving-side control unit 215 also controls the resistive elements of the voltage dividing circuit 212c that are made conductive by switches, thereby generating a desired voltage waveform (e.g., a rectangular waveform) on the power receiving side. The power 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, thereby obtaining information from, for example, the voltage generated by the received signal.

[0058] 5 is a diagram showing an example of the circuit configuration of the power transmitting unit 116 and the power receiving unit 211. The power transmitting unit 116 includes a resonant circuit formed by, for example, a primary coil (Lt) 116a, a primary resistor (Rt) 116b, and a primary capacitor (resonant capacitor, Ct) 116c connected in series. The voltage detecting unit 118A may detect a voltage Vt flowing in the resonant circuit. Furthermore, the power transmitting device 110 may include a current detecting unit that detects a current (power transmitting side current) It flowing in the resonant circuit. Various sensors such as a voltage sensor may also be provided.

[0059] The power receiving unit 211 includes, for example, a resonant circuit formed by a secondary coil (Lr) 211a, a secondary resistor (Rr) 211b, and a secondary capacitor (resonant capacitor, Cr) 211c connected in series. The primary capacitor 116c and the secondary capacitor 211c are, for example, capacitors for magnetic resonance. The voltage detection unit 215A may detect a voltage Vr flowing in the resonant circuit. The power receiving device 210 may also include a current detection unit that detects a current (power receiving side current) Ir flowing in the resonant circuit.

[0060] [Transmission and Reception of Information by Power Transmitting Device 110 and Power Receiving Device 210] Here, in the embodiment, as described above, voltage divider circuits 114c and 212c are provided in each of transmitting power conversion unit 114, which is the inverter on the power transmitting side, and receiving power conversion unit 212, which is the inverter on the power receiving side, as well as voltage detection units 118A and 215A, and the voltage value of the divided voltage waveform is converted into bit string information of 0 and 1, thereby enabling communication using power transmitting device 110 and power receiving device 210 and reducing power consumption due to communication between power supply-side communication unit 130 and vehicle-side communication unit 230. Note that the following mainly describes the case where information is transmitted from power receiving device 210 to power supply device 100 (power transmitting device 110), but in the present embodiment, information can also be transmitted from power supply device 100 to power receiving device 210 by applying control described later.

[0061] In the embodiment, in the power supply device 100, the power transmitting unit 116 divides the voltage excited by magnetic field coupling based on the voltage waveform signal of the power receiving side using the voltage divider circuit 114c, and acquires a voltage waveform from the divided voltage. Note that the power transmitting side control unit 118 converts the voltage waveform into a square wave using the voltage divided by the voltage divider circuit 114c, and acquires bit string information. Note that in the embodiment, voltage excitation occurs with a duty ratio of the voltage waveform (square wave) (for example, the rate at which the voltage is on (above a predetermined value) in a predetermined cycle) of 50[%], but the waveform can be adjusted by voltage control by the power receiving side control unit 215.

[0062] The power transmitting side control unit 118 acquires bit string information of 0 and 1, with a low voltage (minimum value) of the voltage waveform being "0" and a high voltage (maximum value) being "1." By performing voltage control in the embodiment, voltage excitation can be generated more reliably through smooth magnetic field coupling, and information can be acquired from a rectangular voltage waveform.

[0063] Furthermore, the power receiving-side control unit 215 controls the voltage so that the amount of phase shift of the signal from the power receiving device 210 is less than a threshold value. The threshold value is, for example, a duty ratio (on state) of 50%. The power receiving-side control unit 215 controls the voltage so that the on state of the voltage is greater than 0% and less than 50% in a predetermined cycle. In this way, by reducing the time during which the voltage is in a high state (on state), it is possible to reduce the power consumption on the vehicle 200 side.

[0064] [Transition of operation modes in contactless power transfer] Next, transitions of the operation modes of the power transmitting device 110 and the power receiving device 210 in contactless power feeding will be described with reference to the drawings. FIG. 6 is a diagram for explaining transitions of the operation modes. In the example of FIG. 6, the horizontal axis represents time, and the vertical axis represents the operation of the vehicle 200, the operation mode of the power receiving device 210 (VA operation), and the operation mode of the power feeding device 100 (GA operation). Note that the operation transitions in FIG. 6 illustrate, as an example, a case where contactless power transmission is performed between the power feeding device 100 and the power receiving device 210 while the vehicle 200 is traveling at a predetermined speed (for example, approximately 80 km / h). The operation transitions over time will be described below. Note that in the example of FIG. 6, in contactless power feeding, FSA (Fail Safe Action) is always executed on the power receiving device 210 side and the power feeding device 100 side, and FSA is executed to control to the safe side when an abnormality is detected (VA-side FSA, GA-side FSA).

[0065] At time T1, the power receiving-side control unit 215 of the vehicle 200 communicates with the information processing server 300 or the like via the vehicle-side communication unit 230, for example, and performs billing processing for contactless power feeding or preliminary processing for billing corresponding to the amount of power to be fed (in-vehicle device billing). Note that, prior to time T1, the operation mode of the power receiving device 210 is in standby mode. Also, during the billing processing, the operation mode of the power feeding device is in off mode.

[0066] At time T2, after the billing process is completed, the power receiving device 210 aligns the vehicle 200 so that it passes over the power supply device 100 installed on the road surface (e.g., a power supply lane). In this case, the alignment may be performed by the driving control unit 260 based on information detected by the position detection unit 217. Alternatively, an image showing the position of the power supply device 100 (or the position of the power supply lane) and the current position of the vehicle 200 may be displayed on a display unit (not shown) or the like mounted on the vehicle 200, and the driver may manually align the vehicle 200 while viewing the image displayed on the display unit. For example, when the driving control unit 260 is executing the LKAS control, the vehicle 200 is controlled to travel in the center of the lane. Therefore, by performing the LKAS control and traveling on the power supply lane, the vehicle 200 can be aligned. Note that from time T2 to time T3, the power receiving device 210 remains short-circuited, and the power supply device 100 transitions from the off mode to the standby (standby) mode.

[0067] At time T3, when the distance between the power receiving device 210 and the power supply device 100 becomes within a predetermined distance (a distance at which communication is possible) due to the travel of the vehicle 200, the power receiving-side control unit 215 of the vehicle 200 starts pairing through communication (VA-GA communication) between the power receiving device 210 and the power supply device 100. Between times T3 and T4, the power receiving-side control unit 215 alternates between a transmission mode in which parameter information (ID, requested power, battery voltage, etc.) is transmitted and a standby mode until the efficiency of power transmission becomes greater than a predetermined value (for example, greater than 0[%]). Meanwhile, the power transmitting-side control unit 118 of the power supply device 100 alternates between a reception mode and a search mode. In the search mode, for example, the power transmission efficiency is obtained from the correspondence information of the power (transmission power) and efficiency of the power transmission corresponding to the horizontal distance (the relative movement amount between the primary coil and the secondary coil in the direction parallel to the road surface) in the contactless power transmission system 1 of the embodiment, which is preset. The power transmission side control unit 118 also determines the efficiency based on the ratio of the voltage to the current. If the efficiency is below a predetermined value, the power transmission side control unit 118 outputs information to that effect to the power receiving device 210, causing the power receiving device 210 to execute a retry operation. That is, in this embodiment, if the transmission efficiency is not suitable for power supply, the above-described pairing-related communication can be performed. For example, when the vehicle 200 is traveling at a speed of 80 km / h, the expected period from time T3 to T4 (expected communication completion time) is approximately 22.5 msec.

[0068] At time T4, the efficiency of power transmission exceeds a predetermined value, and therefore power transmission control is executed. For example, the power supply device 100 performs power control (GA power control) to transmit power corresponding to the required power specified by the parameters to the outside. The power receiving device 210 performs power control (VA charging (power reception) control) 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, the power supply device 100 performs communication (pairing communication) with the power receiving device 210 when the efficiency of power transmission with the power receiving device 210 is equal to or lower than a predetermined value, and performs power supply control to the power receiving device 210 when the efficiency exceeds the predetermined value. This allows the pairing communication to be completed when the power transmission efficiency is low, and allows power to be supplied more efficiently when the power transmission efficiency is high.

[0069] At time T5, the power transmission efficiency falls below a predetermined value, and therefore the power supply operation is terminated at this time. This allows power supply control using efficient power transmission. For example, when vehicle 200 is traveling at 80 km / h, the expected period from time T4 to T5 (expected power transmission time) is approximately 18 msec. Note that, since a plurality of power supply devices 100 are installed at predetermined intervals on the power supply lane, vehicle 200 can be charged up to the requested power by each power supply device 100 performing the control shown in FIG. 6. Furthermore, when power supply is completed, the amount of power supplied up to that point is accumulated, and billing processing (billing processing) for that amount is executed.

[0070] Next, details of the pairing and power transmission process from time T3 to T5 explained in Fig. 6 will be explained. Fig. 7 is a diagram for explaining the details of the pairing and power transmission process. Between time T1 and T3, the vehicle 200 controls the timing at which the power receiving device 210 of the vehicle 200 communicates with the power supply device 100 by cooperative control using a camera or other on-board devices, etc., as a pairing start timing process ((1) in the figure).

[0071] 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 using a 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, communication from the power receiving device 210 is detected by a voltage induced in the primary coil of the power transmitting device 110. The power transmitting side control unit 118 acquires information superimposed on the PING signal by demodulating the voltage detected during PING transmission. Furthermore, as described above, if the efficiency of power transmission does not exceed a predetermined value (80%), a predetermined number of retries are performed. Furthermore, the transmitted signal includes, for example, identification information (vehicle ID) for identifying the vehicle 200, required power, battery voltage, and other information. By limiting the information required for pairing to a minimum, such as 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 moving and when it is stopped. Furthermore, until time T4 when charging starts (until the current value exceeds the threshold), PING communication and standby mode (reception standby) are repeated at predetermined timings (timeout retry). Note that even in standby mode, it is determined whether the diode-rectified current value is greater than the threshold.

[0072] On the power supply device 100 side, the power supply side communication unit 130 receives a signal transmitted from the power receiving device 210 side by PING communication, and the power transmission side control unit 118 acquires a voltage value, a current value, etc. from the received signal and acquires the efficiency of power transmission from the ratio of the acquired peak-to-peak (PP) voltage and current, etc. ((3) in the figure). Next, the power transmission side control unit 118 determines whether the power efficiency is greater than 80% in a state where only the duty and phase shift are limited as search pulse processing (search mode) ((4) in the figure). Note that the power supply device 100 repeatedly performs the reception processing and search pulse processing at a predetermined timing (timeout retry) until the power efficiency becomes greater than 80%.

[0073] At time T4, when the current value becomes larger than the threshold, the power receiving device 210 performs power receiving control ((5) in the figure). In this case, the power receiving device 210 efficiently receives power through synchronous rectification. For example, the power receiving-side control unit 215 controls the output according to the target output through synchronous rectification, which synchronously drives multiple switching elements of the power receiving device 210 on and off, and through short-circuiting, which short-circuits the secondary coil. For example, the power receiving-side control unit 215 controls the synchronous rectification operation according to the magnitude and phase of a current Ir that is generated in the power receiving device 210 by power transmitted from the power transmitting device 110, i.e., the current Ir that flows through the secondary coil. The power receiving-side control unit 215 controls the multiple switching elements of the power receiving power conversion unit 212 through soft switching, so-called zero voltage switching (ZVS). In zero voltage switching (ZVS), each switching element is turned on (switched from an off state to an on state) after the voltage across both ends is reduced to zero by discharging the output capacitance (parasitic capacitance) in the off state during the dead time period of each phase. For example, the power receiving side control unit 215 controls the short-circuit operation by turning on only the low-side arm of each phase while continuing the synchronous rectification operation of zero voltage switching (ZVS) in the high-side arm of each phase of the power receiving power conversion unit 212. The power receiving side control unit 215 short-circuits the secondary coil, thereby increasing the secondary-side impedance when the secondary-side power receiving device 210 is viewed from the primary-side power transmitting device 110, and thereby restricting the primary-side current (power transmitting side current: current flowing through the primary-side coil). The power receiving side control device 17 controls the current of the primary-side power transmitting device 110 using the secondary-side power receiving device 210, thereby performing independent power control, such as stopping power transmission, on the power receiving device 210 side. Furthermore, the power receiving device 210 may execute a safety-side control (FSA) when an abnormality or the like occurs.

[0074] At time T4, when the efficiency is greater than 80%, the power supply device 100 performs ramp-up control to gradually increase the power, power FB (Feedback) control, and ramp-down control to gradually decrease the power ((6) in the figure). The ramp-up control and ramp-down control are processed quickly and with little noise so as to be able to handle even when the vehicle 200 passes by at 100 km / h, for example.

[0075] Next, transitions in current and voltage values ​​corresponding to the situations on the power receiving device 210 side and the power supply device 100 side will be described using diagrams. FIG. 8 is a diagram for explaining transitions in current and voltage values ​​on the power receiving device side and the power supply device side. In the example of FIG. 8, the horizontal axis represents time, and the vertical axis represents signals resulting from operations on the power supply device (GA) side and the power receiving device (VA) side, and measured current and voltage values ​​corresponding to each operation. Note that in the example of FIG. 8, the operations on the power supply device 100 side are shown as search pulse processing (search mode) shown in FIG. 7 (4) and ramp-up processing and power feedback control shown in FIG. 7 (6), and the controls on the power receiving device 210 side are shown as PING communication shown in FIG. 7 (2) and synchronous rectification shown in FIG. 7 (5).

[0076] At the timing when the PING signal is transmitted on the power receiving device 210 side (VA side), the measured current value is small (≈0) and power consumption is minimum (min). Also, when the search mode is executed on the power supply device 100 side, the measured voltage (GA measured voltage) on the power supply device 100 side increases. In the example of FIG. 8, the measured voltage (VA measured voltage) on the power receiving device 210 side decreases at the timing when the GA measured voltage increases. Here, when the power efficiency exceeds a predetermined value, the measured current (GA measured current) on the power supply device 100 side increases due to a ramp-up operation, and the VA measured current increases based on synchronous rectification while power feedback control and the like are executed. This allows power receiving (charging) control on the power receiving device 210 side to be executed.

[0077] In the above process, the vehicle 200 is shown traveling at a high speed (for example, 80 km / h), but similar control may be applied when traveling at a low speed or when the vehicle is stopped. That is, the process of this embodiment is widely applicable, for example, when the speed V1 of the vehicle 200 is 0 to 100 km / h. When the vehicle is stopped, power supply is controlled in consideration of a time rating, such as 1, 3, or 10 seconds, that is set in advance.

[0078] [Processing flow] Next, a flow of power transmission processing in the embodiment will be described. Note that the following processing will mainly describe contactless power transmission processing of the entire system by the vehicle 200 (power receiving device 210) and the power transmitting device 110, among the processing in the contactless power transmission system 1. FIG. 9 is a flowchart showing an example of power transmission control in the embodiment. In the example of FIG. 9, the vehicle 200 searches for the position of a charging lane based on the detection result of the detection device 240, such as a camera (step S100). In the processing of step S100, for example, a camera image captured by the camera is analyzed using a known image analysis process or the like, and the position of the power supply lane is acquired from the position of a road sign or text information indicating the position of the power supply lane (or the power supply device 100) included in the camera image. Furthermore, in the processing of step S100, the vehicle 200 may refer to map information based on position information of the vehicle 200 obtained from the vehicle sensor 250, and acquire the position of the power supply lane present around the vehicle 200 from the information on the power supply lane included in the map information. Furthermore, if the driver of the vehicle 200 visually finds the position of the power supply lane from road signs or text information and manually drives the vehicle 200M into the power supply lane, the process of step S100 may be omitted.

[0079] Next, vehicle 200 performs a positioning process (step S110). In the process of step S110, for example, driving control unit 260 can perform LKAS control to position vehicle 200 so that vehicle 200 travels in the center of the lane. For example, power feeding device 100 is installed in the center of the lane, and power receiving device 210 is installed in the center (near the middle) of vehicle 200 in the width direction. Therefore, by performing LKAS control, vehicle 200 can be positioned at a more appropriate position for contactless power feeding.

[0080] Next, vehicle 200 detects a charging spot in the charging lane (step S120). A charging spot is a location where a power supply device 100 is installed. The location of the power supply device 100 may be detected from a camera image or from map information. Alternatively, the next location of a power supply device 100 installed at a predetermined interval may be detected based on the location and speed of vehicle 200. Next, vehicle 200 performs a pairing process between power supply device 100 and vehicle 200 (or power receiving device 210) by PING communication using weak electrolytic coupling (step S130). After pairing is completed, power supply device 100 performs a search determination in a search mode and determines whether the efficiency of power transmission is greater than a predetermined value (step S140). If the efficiency is greater than the predetermined value, non-contact power supply control is executed (step S150). Note that if an abnormality or the like occurs in the power supply control, FSA control or the like may be executed.

[0081] Next, vehicle 200 determines whether or not to complete power feeding (step S160). For example, if power feeding according to the requested amount has been completed, it is determined that power feeding has been completed. Alternatively, it may be determined that power feeding has been completed if the efficiency of power transmission is equal to or less than a predetermined value. If it is determined that power feeding has not been completed, the process returns to step S150 to continue power feeding control, and if it is determined that power feeding has been completed, the process of this flowchart ends. Note that in the process of FIG. 9, billing processing, etc. may be executed after power feeding has been completed.

[0082] According to the embodiment described above, there is provided a contactless power transfer system 1 that contactlessly supplies power from a power transfer device 100 installed on a road (an example of a travel route) of a vehicle 200 (an example of a moving body) to a power receiving device 210 installed on the vehicle 200, wherein the power receiving device 210 includes a position detection unit 217 that detects the position of the power transfer device 100, and a power receiving side control unit 215 that performs pairing with the power transfer device detected by the position detection unit 217 by magnetic field coupling and performs power reception control based on the power obtained from the paired power transfer device, and the power transfer device 100 includes a power transmission side control unit 118 (an example of a power transfer side control unit) that supplies power to the power receiving device corresponding to the power requested by the paired power receiving device, thereby enabling more appropriate power transfer to the moving body.

[0083] For example, in the embodiment, a voltage divider circuit and a voltage detection unit are set on each of the power supply device 100 side and the power receiving device 210 side. The in-vehicle side prevents unintended power transmission due to short mode. 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 voltage excitation according to the supply voltage, and the communication transmission side performs switching at 79-90 kHz, and adjusts the phase shift amount within a duty ratio range of 0 to 50% to minimize output. In this way, power consumption can be reduced by transmitting power with a phase shift amount. Furthermore, according to the embodiment, for example, since there is no need to search for a charging spot by communication using Wi-Fi or the like, this can be applied not only when the vehicle is stopped but also when driving at high speeds.

[0084] Furthermore, according to the embodiment, for example, power can be transmitted only when the efficiency of power transmission is greater than a specified value (for example, the total efficiency of the inverter coil = 80%). Furthermore, according to the embodiment, the VA side can determine the communication peak value according to the vehicle voltage, so that the detection circuit unit can be set according to the vehicle 200, and the GA side can also detect the peak value according to the supply voltage regardless of the vehicle voltage.

[0085] Furthermore, according to the embodiment, since the pairing process is performed by a weak magnetic field coupling method using the power transmission frequency, communication is possible even when the speed V1 of the vehicle 200 is high (approximately 100 km / h), and by completing pairing using communication in a state where the efficiency of power transmission is low before the efficiency exceeds a predetermined value, more efficient power transmission can be performed when the efficiency exceeds the predetermined value. Furthermore, according to the embodiment, the information required for pairing is limited to the minimum information of required power, battery voltage, and vehicle ID, and thus the vehicle can be identified and appropriate power control can be performed.

[0086] In addition, in the embodiment, the information required for pairing is limited to the minimum information such as the vehicle ID, required power, and battery voltage, thereby enabling appropriate vehicle identification and appropriate power control. Furthermore, in the embodiment, the coupling state is estimated based on a search pulse that results in low power, allowing appropriate searching for the start timing of power transmission.

[0087] The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0088] 1...contactless power transmission system, 100...power supply device, 110...power transmission device, 112...power supply unit, 114...transmission power conversion unit, 116...power transmission unit, 118...power transmission side control unit, 118A, 215A...voltage detection unit, 120, 216...communication control unit, 130...power supply side communication unit, 200...vehicle, 210...power receiving device, 211...power receiving unit, 212...receiving power conversion unit, 213...power conversion unit, 214...power storage unit, 215...power receiving side control unit, 216...communication control unit, 217...position detection unit, 220...rotating electric machine, 230...vehicle side communication unit, 240...detection device, 250...vehicle sensor, 260...driving control unit

Claims

1. A contactless power transmission system that supplies power contactlessly from a power supply device installed on a path of a moving object to a power receiving device installed on the moving object, The power receiving device is a position detection unit that detects the position of the power supply device; a power receiving-side control unit that performs pairing by communicating with the power supply device detected by the position detection unit through magnetic field coupling and performs power reception control based on power obtained from the paired power supply device, The power supply device is a power supply side control unit that performs the communication with the power receiving device using a voltage waveform generated by magnetic field coupling based on a signal from the power receiving device, and supplies the power receiving device with power corresponding to a power requested by the power receiving device. Contactless power transmission system.

2. a voltage dividing unit that divides a voltage generated by a received signal, in each of the power supply device and the power receiving device; The voltage dividing unit converts the waveform of the voltage into a rectangular wave to obtain information of a bit string. The contactless power transfer system according to claim 1 .

3. The power receiving side control unit controlling the amount of phase shift of the signal from the power receiving device to be less than a threshold value; The contactless power transfer system according to claim 1 .

4. The moving body includes a detection device for recognizing a surrounding situation, and a driving control unit for controlling at least steering of the speed and steering of the moving body based on an output of the detection device, positioning the moving body at a position corresponding to the position of the power supply device detected by the position detection unit, based on operation control by the operation control unit to control the moving body to travel in the center of the movement path; The contactless power transfer system according to claim 1 .

5. The power supply device is When the efficiency of power transmission with the power receiving device is equal to or lower than a predetermined value, communication with the power receiving device is performed; When the efficiency becomes greater than the predetermined value, power supply control is performed for the power receiving device. The contactless power transfer system according to claim 1 .

6. A contactless power transmission method for contactlessly supplying power from a power supply device installed on a path of a moving body to a power receiving device installed on the moving body, comprising: The power receiving device, Detecting the position of the power supply device; and performing pairing with the detected power supply device by communicating with the power supply device through weak magnetic field coupling; performing power reception control based on the power obtained from the paired power supply device; The power supply device is performing the pairing by communicating with the power receiving device using a voltage waveform generated by magnetic field coupling based on a signal from the power receiving device; supplying power corresponding to a power request from the power receiving device paired by the pairing to the power receiving device; Contactless power transmission method.

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