JP2013240130A - Power transmission unit, power transmission device, power reception device, vehicle and contactless power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently pair each transmission unit with each vehicle in a contactless power supply system having a plurality of transmission units.SOLUTION: A contactless power supply system 10 transmits power from a power transmission device 20 to vehicles 100A, 100B in a contactless manner. The power transmission device 20 includes a plurality of power transmission units 200A-200C. Each vehicle can mutually radio communicate with the power transmission device 20. The power transmission device 20 allows the plurality of power transmission units 200A-200C to perform simultaneous test power transmission. On receipt of power by the test power transmission, the vehicles 100A, 100B transmits a power reception success report to the power transmission device 20. If the power reception success report is received from a plurality of vehicles, the power transmission device individually re-executes test power transmission to each power reception unit having successful test power transmission.

Description

  The present invention relates to a power transmission unit, a power transmission device, a power reception device, a vehicle, and a contactless power supply system, and more specifically, a power transmission device and a vehicle in a contactless power supply system that supplies power from an external power source to the vehicle in a contactless manner. Communication control between.

  In recent years, non-contact wireless power transmission without using a power cord or a power transmission cable has attracted attention, and an electric vehicle, a hybrid vehicle, or the like that can charge an in-vehicle power storage device with a power source outside the vehicle (hereinafter also referred to as “external power source”). Application to is proposed.

  WO 2011/125525 pamphlet (Patent Document 1) discloses a non-contact power feeding system for a vehicle having a plurality of power supply devices (hereinafter, also referred to as “power transmission units”) in a wireless communicable region of a control device. Discloses a technique for identifying pairing between a power supply device and a vehicle. In the international publication 2011/125525 pamphlet (patent document 1), the control device of the non-contact power supply system outputs a signal transmission command to sequentially supply weak power to each power supply device with a time difference. And a control apparatus specifies pairing with an electric power supply apparatus and a vehicle by acquiring the signal which shows having received the electric power supplied corresponding to signal transmission instruction | command from a vehicle using wireless communication.

International Publication No. 2011-125525 Pamphlet

  According to the technology disclosed in the pamphlet of International Publication No. 2011/125525 (Patent Document 1), in a non-contact power feeding system for a vehicle having a plurality of power supply devices, pairing between the power supply device and the vehicle is specified. be able to.

  However, in the international publication 2011/125525 pamphlet (patent document 1), it is necessary to output signal transmission commands at different timings for a plurality of power supply apparatuses. Therefore, when there are a large number of power supply devices in the communicable region of the control device, it may take a lot of time to recognize the vehicle in the control device.

  The present invention has been made to solve such a problem, and an object of the present invention is to efficiently perform pairing between a power transmission unit and a vehicle in a non-contact power feeding system having a plurality of power transmission units. is there.

  The power transmission unit according to the present invention supplies electric power to the power receiving device in a contactless manner. The power transmission unit includes a power transmission unit that supplies power to the power reception device in a contactless manner, a communication unit that performs wireless communication with the power reception device, and a control unit. In response to the power transmission request from the power receiving device, the control unit executes test power transmission for specifying the power receiving device to be transmitted from the power transmitting unit. When the control unit receives power supplied by the test power transmission and receives only one power reception success signal indicating that power reception was successful from the power receiving apparatus, the power receiving apparatus to which the power receiving apparatus should transmit power When the power reception success signal is received from a plurality of power receiving apparatuses, the test power transmission is executed again.

  Preferably, when the power receiving device to be transmitted is specified, the control unit outputs a signal for identifying the power transmission unit to the specified power receiving device.

  Preferably, when the power is transmitted to another power receiving device other than the power receiving device that has transmitted the power transmission request, the control unit does not perform the test power transmission even when the power transmission request is received.

  Preferably, the control unit receives the power transmission request when the power transmission to another power receiving device other than the power receiving device that transmitted the power transmission request is completed and the other power receiving device exists in the power transmission possible range of the power transmission unit. Do not perform test transmission even at times.

  Preferably, the power transmission unit further includes a detection unit that detects the presence or absence of a power receiving device in a power transmission possible range of the power transmission unit. When the detection unit indicates that the power receiving device does not exist within the power transmission possible range, the control unit does not execute the test power transmission even when the power transmission request is received.

  Preferably, the power reception device includes a power reception unit that receives power from the power transmission unit in a contactless manner. The difference between the natural frequency of the power transmission unit and the natural frequency of the power reception unit is ± 10% or less of the natural frequency of the power transmission unit or the natural frequency of the power reception unit.

  Preferably, the power reception device includes a power reception unit that receives power from the power transmission unit in a contactless manner. The coupling coefficient between the power transmission unit and the power reception unit is 0.1 or less.

  Preferably, the power reception device includes a power reception unit that receives power from the power transmission unit in a contactless manner. The power receiving unit, through at least one of a magnetic field that vibrates at a specific frequency formed between the power receiving unit and the power transmitting unit, and an electric field that vibrates at a specific frequency formed between the power receiving unit and the power transmitting unit, Receives power from the power transmission unit.

  A power transmission device according to the present invention includes a plurality of the power transmission units described above. The power transmission request from the power receiving device is transmitted from the power receiving device simultaneously to each power transmission unit.

  Preferably, each power transmission unit executes test power transmission in concert with other power transmission units in response to a power transmission request.

  Preferably, when executing the test power transmission again, the control unit executes the test power transmission at a timing different from that of the other power transmission units.

  The power transmission device according to the present invention supplies power to the power reception device in a contactless manner. The power transmission device includes a plurality of power transmission units and a control device that controls the plurality of power transmission units while performing wireless communication with the power reception device. In response to the power transmission request from the power receiving device, the control device causes the plurality of power transmitting units to simultaneously perform test power transmission for specifying the power receiving devices to be transmitted by each of the plurality of power transmitting units. The control device receives only one power reception success signal indicating that the power supplied by the test power transmission is received from a plurality of power transmission units, and that the power reception has been successful. In this case, the power receiving device is identified as a power receiving device that should transmit power from the power transmission unit. When receiving a power reception success signal from a plurality of power reception devices, the control device individually causes the power transmission unit that has received the power supplied by the test power transmission to individually execute the test power transmission again.

  Preferably, the power transmission device further includes a plurality of control units corresponding to the plurality of power transmission units. The control device is a management server that manages a plurality of control units.

  A power receiving device according to the present invention receives power from a power transmitting device including a plurality of power transmission units in a contactless manner. The power receiving device includes a power receiving unit that receives power in a non-contact manner from one of a plurality of power transmitting units, a communication unit that performs wireless communication with the power transmitting device, and a control device. The control device transmits to the power transmission device a first power transmission request for executing test power transmission for specifying a power transmission unit that performs power transmission to the power receiving unit, and the power supplied by the test power transmission transmitted from the power transmission device is A second power transmission for determining a power transmission unit candidate to transmit power to the power receiving unit based on a power transmission success signal indicating that the power has been received, and causing the power transmission unit included in the candidate to individually re-execute the test power transmission The request is transmitted, and the power transmission unit that transmits power to the power reception unit is specified according to the power reception state of the power supplied by the test power transmission for the second power transmission request.

  Preferably, the first power transmission request is a signal that causes a plurality of power transmission units to perform test power transmission all at once.

  Preferably, the difference between the natural frequency of the power transmission unit and the natural frequency of the power reception unit is ± 10% or less of the natural frequency of the power transmission unit or the natural frequency of the power reception unit.

Preferably, the coupling coefficient between the power transmission unit and the power reception unit is 0.1 or less.
Preferably, the power receiving unit includes at least a magnetic field that vibrates at a specific frequency formed between the power receiving unit and the power transmitting unit, and an electric field that vibrates at a specific frequency formed between the power receiving unit and the power transmitting unit. The power is received from the power transmission unit through one side.

  A vehicle according to the present invention includes the above-described power receiving device, a power storage device capable of charging the power received by the power receiving device, and a drive device for generating travel driving force using the power from the power storage device.

  The non-contact power feeding system according to the present invention transmits electric power in a non-contact manner between a power transmission device and a vehicle. The power transmission device includes a plurality of power transmission units. The power transmission device and the vehicle can perform wireless communication with each other. In response to a power transmission request from the vehicle, the power transmission device simultaneously performs test power transmission for specifying power transmission units that transmit power to the vehicle by a plurality of power transmission units. In response to receiving the power supplied by the test power transmission, the vehicle transmits a power reception success signal indicating that the power reception is successful to the power transmission device. A power transmission device has one power transmission unit that has received power supplied by test power transmission among a plurality of power transmission units, and when only one power reception success signal is received, the power transmission unit has received power successfully. If the power transmission unit is identified as a power transmission unit that transmits power to the vehicle that transmitted the signal, and a power reception success signal is received from multiple vehicles, the test power transmission is individually performed again for the power transmission unit that received the power supplied by the test power transmission. Run.

  ADVANTAGE OF THE INVENTION According to this invention, in the non-contact electric power feeding system which has several power transmission units, pairing with a power transmission unit and a vehicle can be performed efficiently.

1 is an overall configuration diagram of a vehicle power feeding system according to a first embodiment of the present invention. It is a functional block diagram explaining the structure of the vehicle and power transmission apparatus which are shown in FIG. 1 in detail. It is an equivalent circuit diagram at the time of power transmission from the power transmission unit to the vehicle. It is a figure which shows the simulation model of an electric power transmission system. It is a figure which shows the relationship between the shift | offset | difference of the natural frequency of a power transmission part and a power receiving part, and electric power transmission efficiency. It is a graph which shows the relationship between the electric power transmission efficiency when changing an air gap in the state which fixed the natural frequency, and the frequency of the electric current supplied to a power transmission part. It is the figure which showed the relationship between the distance from an electric current source (magnetic current source), and the intensity | strength of an electromagnetic field. 6 is a diagram for illustrating a schematic communication sequence in the first embodiment. FIG. 4 is a flowchart for illustrating details of a pairing control process between a vehicle and a power transmission unit in the first embodiment. In Embodiment 1, it is a figure for demonstrating the state transition of the power transmission unit in the case of having a vehicle detection sensor. FIG. 6 is an overall configuration diagram of a vehicle power supply system according to a second embodiment. FIG. 10 is a diagram for explaining a schematic communication sequence in the second embodiment. 12 is a flowchart for illustrating details of a pairing control process between a vehicle and a power transmission unit in the second embodiment. It is a flowchart which shows an example of the detailed process of step S320 in FIG. FIG. 10 is a diagram for illustrating a schematic communication sequence in a third embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
(Configuration of contactless power supply system)
FIG. 1 is an overall configuration diagram of a vehicle power supply system (non-contact power supply system) 10 according to the first embodiment of the present invention. Referring to FIG. 1, vehicle power feeding system 10 includes a power transmission device 20 including a plurality of power transmission units 200A, 200B, and 200C, and vehicles 100A and 100B.

  In addition, in FIG. 1, although the power transmission apparatus 20 is shown as a structure containing three power transmission unit 200A, 200B, 200C, if the number of power transmission units is two or more, it can be made into arbitrary numbers. Further, the number of vehicles is not limited to two vehicles as shown in FIG. 1, and may correspond to at least one of a plurality of power transmission units.

  Each of the plurality of power transmission units 200A, 200B, and 200C basically has the same configuration, and the vehicles 100A and 100B also have the same configuration. Therefore, in the following description, a plurality of power transmission units 200A, 200B, and 200C are representatively represented as “power transmission unit 200”, and vehicles 100A and 100B are typically represented as “vehicle 100”. The same applies to the elements constituting the power transmission unit and the vehicle.

  Vehicle 100 includes a power reception unit 110 and a communication unit 160. The power transmission unit 200 includes a power supply device 210, a power transmission unit 220, and a communication unit 230.

  The power receiving unit 110 is installed on the bottom surface of the vehicle body, for example, and receives high-frequency AC power output from the power transmission unit 220 of the power transmission unit 200 in a contactless manner via an electromagnetic field. The detailed configuration of power reception unit 110 will be described later together with the configuration of power transmission unit 220 and power transmission from power transmission unit 220 to power reception unit 110. Communication unit 160 is a communication interface for vehicle 100 to communicate with power transmission unit 200.

  The power supply device 210 in the power transmission unit 200 generates AC power having a predetermined frequency. As an example, the power supply device 210 receives power from a system power supply (not shown), generates high-frequency AC power, and supplies the generated AC power to the power transmission unit 220.

  The power transmission unit 220 is installed, for example, on the floor of a parking lot and receives supply of high-frequency AC power from the power supply device 210. Then, power transmission unit 220 outputs electric power in a non-contact manner to power reception unit 110 of vehicle 100 via an electromagnetic field generated around power transmission unit 220. The detailed configuration of the power transmission unit 220 will be described later together with the configuration of the power reception unit 110 and the power transmission from the power transmission unit 220 to the power reception unit 110. Communication unit 230 is a communication interface for power transmission unit 200 to communicate with vehicle 100.

  Thus, in the vehicle power supply system 10, power is transmitted in a non-contact manner from the power transmission unit 220 of the power transmission unit 200 to the power reception unit 110 of the vehicle 100.

  FIG. 2 is a detailed configuration diagram of the vehicle power supply system 10 shown in FIG. Referring to FIG. 2, power transmission unit 200 includes power supply device 210, power transmission unit 220, and vehicle detection unit 270 as described above. In addition to communication unit 230, power supply device 210 further includes a power transmission ECU 240 that is a control device, a power supply unit 250, and a matching unit 260. The power transmission unit 220 includes a resonance coil 221 (also referred to as a primary coil), a capacitor 222, and an electromagnetic induction coil 223.

  Power supply unit 250 is controlled by control signal MOD from power transmission ECU 240, and converts power received from an AC power supply such as commercial power supply 400 into high-frequency power. Then, the power supply unit 250 supplies the converted high frequency power to the electromagnetic induction coil 223 via the matching unit 260.

  In addition, power supply unit 250 outputs power transmission voltage Vtr and power transmission current Itr detected by a voltage sensor and a current sensor (not shown) to power transmission ECU 240, respectively.

  Matching device 260 is a circuit for matching the impedance between power transmission unit 200 and vehicle 100. Matching device 260 is provided between power supply unit 250 and power transmission unit 220, and can change the impedance of the circuit. Arbitrary configuration can be adopted as matching unit 260. As an example, matching unit 260 includes a variable capacitor and a coil (not shown), and the impedance can be changed by changing the capacitance of the variable capacitor. By changing the impedance in the matching unit 260, the impedance of the power transmission unit 200 can be matched with the impedance of the vehicle 100 (impedance matching). In FIG. 2, matching unit 260 is described as a configuration provided separately from power supply unit 250, but power supply unit 250 may include the function of matching unit 260.

  The vehicle detection unit 270 detects that the vehicle 100 exists within the power transmission possible range of the power transmission unit 200. The vehicle detection unit 270 can use, for example, an arbitrary sensor such as a non-contact type sensor such as a laser, infrared ray, or ultrasonic wave, a contact type sensor such as a limit switch, or a load sensor that detects the vehicle weight.

  The resonance coil 221 transfers electric power to the resonance coil 111 included in the power reception unit 110 of the vehicle 100 in a non-contact manner. Note that power transmission between the power reception unit 110 and the power transmission unit 220 will be described later with reference to FIG.

  As described above, communication unit 230 is a communication interface for performing wireless communication between power transmission unit 200 and vehicle 100, and exchanges information INFO with communication unit 160. Communication unit 230 receives vehicle information transmitted from communication unit 160 on vehicle 100 side, a signal for instructing start and stop of power transmission, and the like, and outputs the received information to power transmission ECU 240. Communication unit 230 transmits information including power transmission voltage Vtr and power transmission current Itr from power transmission ECU 240 to vehicle 100.

  Although not shown in FIG. 1, the power transmission ECU 240 includes a CPU (Central Processing Unit), a storage device, and an input / output buffer, and inputs signals from each sensor and outputs control signals to each device. Each device in the power supply device 210 is controlled. Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  In addition to power reception unit 110 and communication unit 160, vehicle 100 includes a charging relay CHR 170, a rectifier 180, a power storage device 190, a system main relay SMR 115, a drive device 155, and a vehicle ECU (Electronic Control Unit) that is a control device. ) 300, a voltage sensor 195, and a current sensor 196.

  Drive device 155 includes a power control unit PCU (Power Control Unit) 120, a motor generator 130, a power transmission gear 140, and drive wheels 150. Power reception unit 110 includes a resonance coil 111 (also referred to as a secondary coil), a capacitor 112, and an electromagnetic induction coil 113.

  In this embodiment, an electric vehicle is described as an example of vehicle 100, but the configuration of vehicle 100 is not limited to this as long as the vehicle can travel using electric power stored in the power storage device. Other examples of the vehicle 100 include a hybrid vehicle equipped with an engine and a fuel cell vehicle equipped with a fuel cell.

  The resonance coil 111 receives power from the resonance coil 221 included in the power transmission unit 200 in a contactless manner.

  Rectifier 180 rectifies the AC power received from electromagnetic induction coil 113 and outputs the rectified DC power to power storage device 190 via CHR 170. For example, the rectifier 180 may include a diode bridge and a smoothing capacitor (both not shown). As the rectifier 180, a so-called switching regulator that performs rectification using switching control may be used. When the rectifier 180 is included in the power receiving unit 110, it is more preferable to use a static rectifier such as a diode bridge in order to prevent a malfunction of the switching element due to the generated electromagnetic field.

  CHR 170 is electrically connected between rectifier 180 and power storage device 190. CHR 170 is controlled by a control signal SE2 from vehicle ECU 300, and switches between supply and interruption of power from rectifier 180 to power storage device 190.

  The power storage device 190 is a power storage element configured to be chargeable / dischargeable. The power storage device 190 includes, for example, a secondary battery such as a lithium ion battery, a nickel metal hydride battery, or a lead storage battery, and a power storage element such as an electric double layer capacitor.

  Power storage device 190 is connected to rectifier 180. Power storage device 190 stores the power received by power reception unit 110 and rectified by rectifier 180. The power storage device 190 is also connected to the PCU 120 via the SMR 115. Power storage device 190 supplies power for generating vehicle driving force to PCU 120. Further, power storage device 190 stores the electric power generated by motor generator 130. The output of power storage device 190 is, for example, about 200V.

  Although not shown in FIG. 2, when the power reception voltage and the charging voltage of the power storage device 190 are different, a power conversion device such as a DC-DC converter is provided between the rectifier 180 and the power storage device 190. You may make it provide. Further, similarly to the power transmission unit 200, a matching unit that performs impedance matching may be provided.

  Although not shown, power storage device 190 is provided with a voltage sensor and a current sensor for detecting voltage VB of power storage device 190 and input / output current IB. These detection values are output to vehicle ECU 300. Vehicle ECU 300 calculates the state of charge of power storage device 190 (also referred to as “SOC (State Of Charge)”) based on voltage VB and current IB.

  SMR 115 is electrically connected between power storage device 190 and PCU 120. SMR 115 is controlled by control signal SE <b> 1 from vehicle ECU 300, and switches between supply and interruption of power between power storage device 190 and PCU 120.

  Although not shown, the PCU 120 includes a converter and an inverter. The converter is controlled by a control signal PWC from vehicle ECU 300 to convert the voltage from power storage device 190. The inverter is controlled by a control signal PWI from vehicle ECU 300 and drives motor generator 130 using electric power converted by the converter.

  Motor generator 130 is an AC rotating electric machine, for example, a permanent magnet type synchronous motor including a rotor in which permanent magnets are embedded.

  The output torque of motor generator 130 is transmitted to drive wheel 150 via power transmission gear 140. The vehicle 100 travels using this torque. The motor generator 130 can generate electric power by the rotational force of the drive wheels 150 during the regenerative braking operation of the vehicle 100. Then, the generated power is converted by PCU 120 into charging power for power storage device 190.

  Further, in a hybrid vehicle equipped with an engine (not shown) in addition to motor generator 130, necessary vehicle driving force is generated by operating engine and motor generator 130 in a coordinated manner. In this case, the power storage device 190 can be charged using the power generated by the rotation of the engine.

  As described above, the communication unit 160 is a communication interface for performing wireless communication between the vehicle 100 and the power transmission unit 200, and exchanges information INFO with the communication unit 230 of the power transmission unit 200. Information INFO output from communication unit 160 to power transmission unit 200 includes vehicle information from vehicle ECU 300 and a signal for instructing start and stop of power transmission.

  Although not shown in FIG. 1, vehicle ECU 300 includes a CPU, a storage device, and an input / output buffer, and inputs a signal from each sensor and outputs a control signal to each device. Control. Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  The voltage sensor 195 is connected in parallel to the electromagnetic induction coil 113 and detects the received voltage Vre received by the power receiving unit 110. The current sensor 196 is provided on a power line connecting the electromagnetic induction coil 113 and the rectifier 180, and detects the received current Ire. The detected power reception voltage Vre and power reception current Ire are transmitted to the vehicle ECU 300 and used for calculation of transmission efficiency.

  2 shows a configuration in which the electromagnetic induction coils 113 and 223 are provided in the power reception unit 110 and the power transmission unit 220, respectively, but the electromagnetic induction coils 113 and 223 are not provided in the power reception unit 110 and the power transmission unit 220. A configuration is also possible. In this case, although not shown in FIG. 2, the resonance coil 221 is connected to the matching unit 260 in the power transmission unit 220, and the resonance coil 111 is connected to the rectifier 180 in the power reception unit 110.

(Principle of power transmission)
FIG. 3 is an equivalent circuit diagram at the time of power transmission from the power transmission unit 200 to the vehicle 100. Referring to FIG. 3, power transmission unit 220 of power transmission unit 200 includes a resonance coil 221, a capacitor 222, and an electromagnetic induction coil 223.

  The electromagnetic induction coil 223 is provided, for example, substantially coaxially with the resonance coil 221 at a predetermined interval from the resonance coil 221. The electromagnetic induction coil 223 is magnetically coupled to the resonance coil 221 by electromagnetic induction, and supplies high frequency power supplied from the power supply device 210 to the resonance coil 221 by electromagnetic induction.

  The resonance coil 221 forms an LC resonance circuit together with the capacitor 222. As will be described later, an LC resonance circuit is also formed in the power receiving unit 110 of the vehicle 100. The difference between the natural frequency of the LC resonant circuit formed by the resonant coil 221 and the capacitor 222 and the natural frequency of the LC resonant circuit of the power receiving unit 110 is ± 10% or less of the natural frequency of the former or the latter. The resonance coil 221 receives electric power from the electromagnetic induction coil 223 by electromagnetic induction, and transmits the electric power to the power receiving unit 110 of the vehicle 100 in a non-contact manner.

  The electromagnetic induction coil 223 is provided to facilitate power feeding from the power supply device 210 to the resonance coil 221. The power supply device 210 is directly connected to the resonance coil 221 without providing the electromagnetic induction coil 223. Also good. The capacitor 222 is provided to adjust the natural frequency of the resonance circuit. When a desired natural frequency is obtained using the stray capacitance of the resonance coil 221, the capacitor 222 is not provided. Also good.

  Power receiving unit 110 of vehicle 100 includes a resonance coil 111, a capacitor 112, and an electromagnetic induction coil 113. The resonance coil 111 and the capacitor 112 form an LC resonance circuit. As described above, the natural frequency of the LC resonance circuit formed by the resonance coil 111 and the capacitor 112 and the natural frequency of the LC resonance circuit formed by the resonance coil 221 and the capacitor 222 in the power transmission unit 220 of the power transmission unit 200. The difference is ± 10% of the former natural frequency or the latter natural frequency. The resonance coil 111 receives power from the power transmission unit 220 of the power transmission unit 200 in a non-contact manner.

  The electromagnetic induction coil 113 is provided, for example, substantially coaxially with the resonance coil 111 at a predetermined interval from the resonance coil 111. The electromagnetic induction coil 113 is magnetically coupled to the resonance coil 111 by electromagnetic induction, takes out the electric power received by the resonance coil 111 by electromagnetic induction, and outputs it to the electric load device 118. The electric load device 118 comprehensively represents electric devices after the rectifier 180 (FIG. 2).

  The electromagnetic induction coil 113 is provided to facilitate the extraction of electric power from the resonance coil 111, and the rectifier 180 may be directly connected to the resonance coil 111 without providing the electromagnetic induction coil 113. The capacitor 112 is provided to adjust the natural frequency of the resonance circuit. When a desired natural frequency is obtained using the stray capacitance of the resonance coil 111, the capacitor 112 is not provided. Also good.

  In the power transmission unit 200, high-frequency AC power is supplied from the power supply device 210 to the electromagnetic induction coil 223, and power is supplied to the resonance coil 221 using the electromagnetic induction coil 223. Then, energy (electric power) moves from the resonance coil 221 to the resonance coil 111 through a magnetic field formed between the resonance coil 221 and the resonance coil 111 of the vehicle 100. The energy (electric power) moved to the resonance coil 111 is taken out using the electromagnetic induction coil 113 and transmitted to the electric load device 118 of the vehicle 100.

  As described above, in this power transmission system, the difference between the natural frequency of the power transmission unit 220 of the power transmission unit 200 and the natural frequency of the power reception unit 110 of the vehicle 100 is the natural frequency of the power transmission unit 220 or the natural frequency of the power reception unit 110. It is ± 10% or less of the frequency. By setting the natural frequencies of the power transmission unit 220 and the power reception unit 110 in such a range, the power transmission efficiency can be increased. On the other hand, if the difference between the natural frequencies is larger than ± 10%, there is a possibility that the power transmission efficiency becomes smaller than 10% and the power transmission time becomes longer.

  In addition, the natural frequency of the power transmission unit 220 (power reception unit 110) means a vibration frequency when the electric circuit (resonance circuit) constituting the power transmission unit 220 (power reception unit 110) freely vibrates. In the electric circuit (resonance circuit) constituting the power transmission unit 220 (power reception unit 110), the natural frequency when the braking force or the electrical resistance is substantially zero is the resonance frequency of the power transmission unit 220 (power reception unit 110). Also called.

  A simulation result obtained by analyzing the relationship between the natural frequency difference and the power transmission efficiency will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram illustrating a simulation model of the power transmission system. FIG. 5 is a diagram illustrating the relationship between the deviation of the natural frequency of the power transmission unit and the power reception unit and the power transmission efficiency.

  Referring to FIG. 4, power transmission system 89 includes a power transmission unit 90 and a power reception unit 91. The power transmission unit 90 includes a first coil 92 and a second coil 93. The second coil 93 includes a resonance coil 94 and a capacitor 95 provided in the resonance coil 94. The power receiving unit 91 includes a third coil 96 and a fourth coil 97. The third coil 96 includes a resonance coil 99 and a capacitor 98 connected to the resonance coil 99.

  The inductance of the resonance coil 94 is defined as an inductance Lt, and the capacitance of the capacitor 95 is defined as a capacitance C1. Further, the inductance of the resonance coil 99 is an inductance Lr, and the capacitance of the capacitor 98 is a capacitance C2. When each parameter is set in this way, the natural frequency f1 of the second coil 93 is represented by the following equation (1), and the natural frequency f2 of the third coil 96 is represented by the following equation (2).

f1 = 1 / {2π (Lt × C1) ^1/2 } (1)
f2 = 1 / {2π (Lr × C2) ^1/2 } (2)
Here, when the inductance Lr and the capacitances C1 and C2 are fixed and only the inductance Lt is changed, the relationship between the deviation of the natural frequency of the second coil 93 and the third coil 96 and the power transmission efficiency is shown in FIG. Show. In this simulation, the relative positional relationship between the resonance coil 94 and the resonance coil 99 is fixed, and the frequency of the current supplied to the second coil 93 is constant.

  In the graph shown in FIG. 5, the horizontal axis indicates the deviation (%) of the natural frequency, and the vertical axis indicates the power transmission efficiency (%) at a constant frequency current. The deviation (%) in natural frequency is expressed by the following equation (3).

(Deviation of natural frequency) = {(f1−f2) / f2} × 100 (%) (3)
As is clear from FIG. 5, when the deviation (%) of the natural frequency is 0%, the power transmission efficiency is close to 100%. When the deviation (%) in natural frequency is ± 5%, the power transmission efficiency is about 40%. When the deviation (%) in natural frequency is ± 10%, the power transmission efficiency is about 10%. When the deviation (%) in natural frequency is ± 15%, the power transmission efficiency is about 5%. That is, the natural frequencies of the second coil 93 and the third coil 96 are set so that the absolute value (natural frequency difference) of the deviation (%) of the natural frequency falls within the range of 10% or less of the natural frequency of the third coil 96. It can be seen that the power transmission efficiency can be increased to a practical level by setting. Furthermore, when the natural frequency of the second coil 93 and the third coil 96 is set so that the absolute value of the deviation (%) of the natural frequency is 5% or less of the natural frequency of the third coil 96, the power transmission efficiency is further increased. This is more preferable. The simulation software employs electromagnetic field analysis software (JMAG (registered trademark): manufactured by JSOL Corporation).

  Referring to FIG. 2 again, power transmission unit 220 of power transmission unit 200 and power reception unit 110 of vehicle 100 are formed between power transmission unit 220 and power reception unit 110, and a magnetic field that vibrates at a specific frequency, and power transmission Power is exchanged in a non-contact manner through at least one of an electric field that is formed between the unit 220 and the power receiving unit 110 and vibrates at a specific frequency. The coupling coefficient κ between the power transmission unit 220 and the power reception unit 110 is preferably 0.1 or less, and power is transmitted from the power transmission unit 220 to the power reception unit 110 by causing the power transmission unit 220 and the power reception unit 110 to resonate with each other by an electromagnetic field. Is transmitted.

  Here, a magnetic field having a specific frequency formed around the power transmission unit 220 will be described. The “magnetic field of a specific frequency” typically has a relationship with the power transmission efficiency and the frequency of the current supplied to the power transmission unit 220. First, the relationship between the power transmission efficiency and the frequency of the current supplied to the power transmission unit 220 will be described. The power transmission efficiency when power is transmitted from the power transmission unit 220 to the power reception unit 110 varies depending on various factors such as the distance between the power transmission unit 220 and the power reception unit 110. For example, the natural frequency (resonance frequency) of the power transmission unit 220 and the power reception unit 110 is f0, the frequency of the current supplied to the power transmission unit 220 is f3, and the air gap between the power transmission unit 220 and the power reception unit 110 is the air gap AG. And

  FIG. 6 is a graph showing the relationship between the power transmission efficiency when the air gap AG is changed and the frequency f3 of the current supplied to the power transmission unit 220 while the natural frequency f0 is fixed. With reference to FIG. 6, the horizontal axis indicates the frequency f3 of the current supplied to the power transmission unit 220, and the vertical axis indicates the power transmission efficiency (%). The efficiency curve L1 schematically shows the relationship between the power transmission efficiency when the air gap AG is small and the frequency f3 of the current supplied to the power transmission unit 220. As shown in the efficiency curve L1, when the air gap AG is small, the peak of power transmission efficiency occurs at frequencies f4 and f5 (f4 <f5). When the air gap AG is increased, the two peaks when the power transmission efficiency is increased change so as to approach each other. As shown in the efficiency curve L2, when the air gap AG is larger than the predetermined distance, the power transmission efficiency has one peak, and the power transmission efficiency is obtained when the frequency of the current supplied to the power transmission unit 220 is the frequency f6. Becomes a peak. When the air gap AG is further increased from the state of the efficiency curve L2, the peak of power transmission efficiency is reduced as shown by the efficiency curve L3.

  For example, the following method can be considered as a method for improving the power transmission efficiency. As a first technique, the frequency of the current supplied to the power transmission unit 220 is made constant in accordance with the air gap AG, and the capacitance of the capacitor 222 or the capacitor 112 is changed, so that the power transmission unit 220 and the power reception unit 110 can be changed. It is conceivable to change the power transmission efficiency characteristics between the two. Specifically, the capacitances of the capacitor 222 and the capacitor 112 are adjusted so that the power transmission efficiency reaches a peak in a state where the frequency of the current supplied to the power transmission unit 220 is constant. In this method, the frequency of the current flowing through the power transmission unit 220 and the power reception unit 110 is constant regardless of the size of the air gap AG. Note that, as a technique for changing the characteristics of the power transmission efficiency, a technique using the matching unit 260 of the power transmission unit 200 or a converter (not shown) provided between the rectifier 180 and the power storage device 190 in the vehicle 100 is used. It is also possible to adopt a technique to do so.

  The second method is a method of adjusting the frequency of the current supplied to the power transmission unit 220 based on the size of the air gap AG. For example, when the power transmission characteristic is the efficiency curve L1, a current having a frequency f4 or f5 is supplied to the power transmission unit 220. When the frequency characteristic is the efficiency curves L2 and L3, the current having the frequency f6 is supplied to the power transmission unit 220. In this case, the frequency of the current flowing through power transmission unit 220 and power reception unit 110 is changed in accordance with the size of air gap AG.

  In the first method, the frequency of the current flowing through the power transmission unit 220 is a fixed constant frequency, and in the second method, the frequency flowing through the power transmission unit 220 is a frequency that changes as appropriate depending on the air gap AG. A current having a specific frequency set so as to increase the power transmission efficiency is supplied to the power transmission unit 220 by the first method, the second method, or the like. When a current having a specific frequency flows through the power transmission unit 220, a magnetic field (electromagnetic field) that vibrates at a specific frequency is formed around the power transmission unit 220. The power receiving unit 110 receives power from the power transmitting unit 220 through a magnetic field that is formed between the power receiving unit 110 and the power transmitting unit 220 and vibrates at a specific frequency. Therefore, the “magnetic field oscillating at a specific frequency” is not necessarily a magnetic field having a fixed frequency. In the above example, focusing on the air gap AG, the frequency of the current supplied to the power transmission unit 220 is set, but the power transmission efficiency is the horizontal direction of the power transmission unit 220 and the power reception unit 110. The frequency changes due to other factors such as a deviation, and the frequency of the current supplied to the power transmission unit 220 may be adjusted based on the other factors.

  In the above description, an example in which a helical coil is used as the resonance coil has been described. However, when an antenna such as a meander line is used as the resonance coil, a current having a specific frequency flows in the power transmission unit 220. Thus, an electric field having a specific frequency is formed around the power transmission unit 220. And electric power transmission is performed between the power transmission part 220 and the power receiving part 110 through this electric field.

  In this power transmission system, power transmission and power reception efficiency are improved by using a near field (evanescent field) in which the “electrostatic magnetic field” of the electromagnetic field is dominant.

  FIG. 7 is a diagram showing the relationship between the distance from the current source (magnetic current source) and the intensity of the electromagnetic field. Referring to FIG. 7, the electromagnetic field is composed of three components. The curve k1 is a component that is inversely proportional to the distance from the wave source, and is referred to as a “radiated electromagnetic field”. A curve k2 is a component inversely proportional to the square of the distance from the wave source, and is referred to as an “induction electromagnetic field”. The curve k3 is a component inversely proportional to the cube of the distance from the wave source, and is referred to as an “electrostatic magnetic field”. When the wavelength of the electromagnetic field is “λ”, the distance at which the strengths of “radiation electromagnetic field”, “induction electromagnetic field”, and “electrostatic magnetic field” are substantially equal can be expressed as λ / 2π.

  The “electrostatic magnetic field” is a region where the intensity of the electromagnetic wave suddenly decreases with the distance from the wave source. In the power transmission system according to this embodiment, the near field (evanescent field) in which the “electrostatic magnetic field” is dominant. ) Is used to transmit energy (electric power). That is, in the near field where the “electrostatic magnetic field” is dominant, by resonating the power transmitting unit 220 and the power receiving unit 110 (for example, a pair of LC resonance coils) having adjacent natural frequencies, the power receiving unit 220 and the other power receiving unit are resonated. Energy (electric power) is transmitted to 110. Since this “electrostatic magnetic field” does not propagate energy far away, the resonance method transmits power with less energy loss than electromagnetic waves that transmit energy (electric power) by “radiant electromagnetic field” that propagates energy far away. be able to.

  Thus, in this power transmission system, power is transmitted between the power transmission unit 220 and the power reception unit 110 in a non-contact manner by causing the power transmission unit 220 and the power reception unit 110 to resonate (resonate) with each other by an electromagnetic field. . Such an electromagnetic field formed between the power reception unit and the power transmission unit may be referred to as a near-field resonance (resonance) coupling field, for example. And the coupling coefficient ((kappa)) between the power transmission part 220 and the power receiving part 110 is about 0.3 or less, for example, Preferably, it is 0.1 or less. As a matter of course, a coupling coefficient (κ) in the range of about 0.1 to 0.3 can also be adopted. The coupling coefficient (κ) is not limited to such a value, and may take various values that improve power transmission.

  Note that the coupling between the power transmission unit 220 and the power reception unit 110 in the power transmission is, for example, “magnetic resonance coupling”, “magnetic field (magnetic field) resonance coupling”, “magnetic field resonance (resonance) coupling”, “proximity” The field resonance (resonance) coupling, the electromagnetic field (electromagnetic field) resonance coupling, the electric field (electric field) resonance coupling, and the like. The “electromagnetic field (electromagnetic field) resonance coupling” means a coupling including any of “magnetic resonance coupling”, “magnetic field (magnetic field) resonance coupling”, and “electric field (electric field) resonance coupling”.

  When the power transmission unit 220 and the power reception unit 110 are formed by coils as described above, the power transmission unit 220 and the power reception unit 110 are mainly coupled by a magnetic field (magnetic field), and are referred to as “magnetic resonance coupling” or “magnetic field”. (Magnetic field) resonance coupling "is formed. For example, an antenna such as a meander line may be employed for the power transmission unit 220 and the power reception unit 110. In this case, the power transmission unit 220 and the power reception unit 110 are mainly based on an electric field (electric field). The “electric field (electric field) resonance coupling” is formed.

(Description of pairing control between power transmission unit and vehicle)
In the vehicle power feeding system that transmits power in a non-contact manner as described above, wired connection for power transmission between the power transmission unit and the vehicle is not performed. For this reason, in many cases, information transmission between the power transmission unit and the vehicle is also performed using wireless communication, and the power transmission unit and the vehicle are mutually authenticated based on information obtained by wireless communication.

  In wireless communication, when there are a plurality of devices (vehicles, power transmission units) that can communicate within the communication range, it is possible to communicate with each device individually. Accordingly, in the case of FIG. 1 in which a non-contact power feeding system as described above is provided in a plurality of adjacent parking spaces such as a parking lot of a commercial facility, the power transmission unit communicates with the plurality of vehicles, and the vehicle May be in a state of communicating with a plurality of power transmission units.

  Then, in each device, there are a plurality of counterpart devices that should transmit or receive power. Therefore, in order to appropriately supply power from the power transmission unit to the vehicle, it is necessary to reliably identify the counterpart device to be transmitted or received.

  As a technique for solving such a problem, a small amount of power (hereinafter also referred to as “test power transmission”) is sequentially transmitted to a plurality of power transmission units with a time difference compared to a case where a charging operation is performed. A technique is known that recognizes pairing between a power transmission unit and a vehicle based on a response signal from the vehicle that has been executed and received the power. However, in a large-scale parking lot, authentication work between the power transmission unit and the vehicle may take time for power transmission to all the power transmission units. Then, when the user tries to start charging after the parking is completed, the user may have to wait in the vicinity of the vehicle until the pairing between the power transmission unit and the vehicle is completed.

  Therefore, in the first embodiment, the time required for pairing between the power transmission unit and the vehicle is shortened by devising the execution form of the test power transmission in the power transmission device having a plurality of power transmission units. Specifically, when a charge request from a vehicle is instructed, execution of the above-described test power transmission is instructed simultaneously to a plurality of power transmission units. Then, based on the execution state of the test power transmission, a power transmission unit that can be a candidate for power transmission is selected. And the vehicle which should be transmitted is specified by performing test power transmission further about the candidate of the selected power transmission unit.

  FIG. 8 is a diagram for explaining a schematic communication sequence in the first embodiment. 8, in the power transmission apparatus including three power transmission units (hereinafter also referred to as “charging stands” or “stands”) 200A, 200B, and 200C as in the example of FIG. 1, two vehicles 100A and 100B are used. A case where charging is performed will be described as an example. Power transmission unit 200A (stand 1) transmits power to vehicle 100A (vehicle A), and power transmission unit 200B (stand 2) transmits power to vehicle 100B (vehicle B). The power transmission unit 200C (stand 3) is in an empty state.

  Referring to FIG. 8, in the state where parking of vehicle A and vehicle B at predetermined stop positions of stand 1 and stand 2 is completed, the users of vehicle A and vehicle B charge almost simultaneously in each vehicle. Consider the case where a start operation is performed. At this time, a charge request signal is broadcast (broadcasted) from each vehicle to all charging stations. The charge request signal transmitted from each vehicle includes an ID for identifying the vehicle. Therefore, in each stand that has received the charge request signal, it is possible to identify from which vehicle the received signal is transmitted.

  In response to the charge request signal, each stand attempts to perform the test power transmission as described above individually or in cooperation with other stands. In addition, when a charge request signal is received, a stand that is performing power transmission to another vehicle, and a stand that has completed power transmission to another vehicle but the vehicle is still in the parking space No test transmission is performed. Here, “simultaneous” execution of test power transmission does not necessarily mean that it is executed completely at the same time, and there may be a time difference that is indistinguishable depending on the timing of receiving the charging request signal and the response time of each stand. included.

  At this time, since power is received by the parked vehicle at the stand 1 and the stand 2, minute electric power is transmitted. On the other hand, with respect to the stand 3, since the vehicle does not exist, that is, the power receiving unit 110 and the subsequent parts do not exist, the impedance after the power supply unit 250 is greatly different from that when the vehicle exists. Therefore, since the stand 3 can recognize that no power is received by monitoring the transmission voltage and the transmission current, the stand 3 recognizes that there is no vehicle to be transmitted at this stage.

  By simultaneous transmission of such charge request signals, the number of stands that can transmit power can be reduced.

  The vehicles A and B receive the power supplied from the stand, but at this stage, it is not possible to recognize which stand has received the power. Therefore, each vehicle simultaneously transmits a power reception success notification indicating that power has been received toward all the stands.

  At this time, the stand 1 and the stand 2 receive two power reception success notifications from the vehicle A and the vehicle B during a short time interval. Therefore, at this stage, the stand 1 and the stand 2 cannot specify the vehicle to be transmitted.

  Therefore, the stand 1 and the stand 2 individually re-execute test power transmission at predetermined time intervals different from each other. For example, for the stand 1, test power transmission is executed at a time interval T1 (for example, 3 seconds), and for the stand 2, test power transmission is performed at a time interval T2 (for example, 5 seconds). The time interval is not limited to a predetermined fixed value, and a random time may be set.

  For a single test power transmission from the stand 1 after the time interval T1, a power reception success notification is transmitted simultaneously from only the vehicle A. Thereby, the stand 1 can recognize that the vehicle to be transmitted is the vehicle A. The stand 1 that has recognized the vehicle to which power is transmitted notifies the vehicle A of the stand ID through wireless communication. The vehicle A can specify the other party's stand by the ID notification from the stand 1.

  Similarly, for a single test power transmission from the stand 2 after the time interval T2, a power reception success notification is transmitted simultaneously from only the vehicle B. Thereby, the stand 2 can recognize that the vehicle to be transmitted is the vehicle B. Then, the ID notification is transmitted from the stand 2 to the vehicle B, whereby the other party's stand can be specified in the vehicle B.

  In addition, when only one vehicle is required to be charged, when performing the first simultaneous power transmission from each stand, only one station can actually perform the test power transmission, and a power reception success notification is transmitted. Since only one vehicle is used, as a result, pairing between the vehicle and the stand can be specified at this stage.

  As described above, when charging is instructed by the user, the power transmission unit candidates that can be the power transmission target are limited by causing a plurality of power transmission units to try the test power transmission all at once, and then the limited power transmission unit candidates are limited. The correct pairing between the vehicle and the power transmission unit can be specified by re-execution of the test power transmission individually. By limiting the power transmission unit candidates that can be the target of power transmission, it is possible to specify pairing as compared to the case where test power transmission is performed sequentially for all power transmission units to identify the correct pairing between the vehicle and the power transmission unit. Can be shortened.

  FIG. 9 is a flowchart for explaining details of the pairing control process between the vehicle and the power transmission unit described in FIG. 8. Each step in the flowchart shown in FIG. 9 is executed by a program stored in advance in power transmission ECU 240 or vehicle ECU 300 being called from the main routine and executed in response to the establishment of a predetermined cycle or a predetermined condition. Realized. Alternatively, for some steps, it is also possible to construct dedicated hardware (electronic circuit) and realize processing.

  In the flowchart shown in FIG. 9, a case where communication is performed between the power transmission unit 200 and the vehicle 100 as shown in FIG. 2 will be described as an example.

  With reference to FIG. 9, the process in power transmission ECU240 of the power transmission unit 200 is demonstrated first. When power transmission ECU 240 starts communication at step (hereinafter, step is abbreviated as S) 200, next, at S210, power transmission ECU 240 determines whether or not a charge request signal has been received from the vehicle.

  If the charging request signal has not been received (NO in S210), the subsequent processing is unnecessary, and power transmission ECU 240 ends the processing.

  If the charging request signal has been received (YES in S210), the process proceeds to S220, and power transmission ECU 240 attempts a test power transmission. Then, the power transmission ECU 240 determines whether or not the test power transmission is successful in S230.

  If the test power transmission is not successful (NO in S230), since there is no vehicle in the parking space of the power transmission unit, power transmission ECU 240 ends the process.

  If the test power transmission is successful (YES in S230), the process proceeds to S240, and power transmission ECU 240 determines whether or not a power reception success notification from the vehicle has been received.

  If power reception success notification has not been received (NO in S240), there is no vehicle that can receive power, and power transmission ECU 240 ends the process.

  When power reception success notification is received (NO in S240), power transmission ECU 240 determines whether or not there is one vehicle that has notified power reception success notification in S250.

  If the received power reception success notification is one (YES in S250), the process proceeds to S280, and power transmission ECU 240 recognizes that the vehicle that has transmitted the power reception success notification is the vehicle that should transmit power. And power transmission ECU240 notifies stand ID with respect to the vehicle recognized as the vehicle which should transmit power in S290. Thereby, the power transmission unit in which power transmission is performed is specified also on the vehicle side.

  Next, processing in vehicle ECU 300 of vehicle 100 will be described. When the vehicle is parked in the parking space and the charging request operation is performed by the user, vehicle ECU 300 starts communication in S100 and simultaneously transmits a charging request signal to all transmission units in S110.

  In S120, vehicle ECU 300 determines whether or not the power supplied as the test power transmission from the power transmission unit is received in response to the charge request signal transmitted in S110.

  If power is not received (NO in S120), vehicle ECU 300 determines that power cannot be transmitted from the power transmission unit due to some condition such as a failure, and the process ends.

  If power is received (YES in S120), the process proceeds to S130, and vehicle ECU 300 transmits a power reception success notification to all power transmission units simultaneously. Then, vehicle ECU 300 determines whether or not the stand ID is notified from the power transmission unit in S140.

  As described in the processing of the power transmission unit described above, when the power reception success notification for the first test power transmission is transmitted from only one vehicle, it is possible to identify the counterpart vehicle to be transmitted by the power transmission unit. . Therefore, when the stand ID is notified in S140 (YES in S140), the process proceeds to S170, and vehicle ECU 300 transmits the power transmission unit notified of the ID to vehicle 100. To be identified.

  If the stand ID is not notified (NO in S140), it is determined whether or not the power from the test power transmission that each power transmission unit executes independently is received.

If no power is received (NO in S150), vehicle ECU 300 ends the process.
If power is received (YES in S150), the process proceeds to S160, and vehicle ECU 300 transmits a power reception success notification to all power transmission units. At this time, as described above, in the power transmission unit, since the test power transmission is performed independently, the vehicle to be transmitted can be specified. Therefore, the stand ID is notified from the power transmission unit that can identify the vehicle. In response to this, the vehicle ECU 300 identifies a power transmission unit in which power is transmitted to the vehicle 100 (S170).

  By performing control according to such processing, in the non-contact power feeding system having a plurality of power transmission units, pairing between the power transmission unit and the vehicle can be performed efficiently.

  In the above example, when the first test power transmission cannot be executed, it is determined that the vehicle is not parked in the power transmission unit, but the vehicle detection unit 270 (for detecting the presence or absence of the vehicle in the parking space) When FIG. 2) is provided in the power transmission unit, the presence or absence of the vehicle may be determined based on the detection signal of the vehicle detection unit 270. In the configuration having the vehicle detection unit 270 as described above, the vehicle detection unit 270 makes the presence of the vehicle a condition for performing the first test power transmission, so that unnecessary power transmission in the power transmission unit without the vehicle is performed. Can be prevented.

  FIG. 10 shows a state transition in power transmission ECU 240 when vehicle detection unit 270 is provided in power transmission unit 200.

  In this case, power transmission ECU 240 includes an empty vehicle state, a standby state, a charging state, and a charging end state as states.

  The empty state is a state in which the vehicle is not detected by the vehicle detection unit 270. When the vehicle is detected by the vehicle detection unit 270, the state transits from the empty state to the standby state. This standby state is a state in which a vehicle exists in the parking space of the power transmission unit 200 but power is not yet supplied from the power transmission unit 200.

  When power transmission from the power transmission unit 200 is started and charging of the power storage device 190 of the vehicle is further started, the state of the power transmission unit 200 changes from the standby state to the charging state.

  When the power storage device 190 is fully charged and the charging operation is completed, the state transitions from the charging state to the charging end state. In addition, also when charge is forcibly stopped before a full charge by the user, the state of the power transmission unit 200 changes to the charge end state.

  When the state of the power transmission unit 200 is the standby state, the charging state, and the charging end state, when the vehicle is moved by the user and the vehicle cannot be detected by the vehicle detection unit 270, the state of the power transmission unit 200 is Transition from each state to the empty state.

[Embodiment 2]
In the first embodiment, the configuration in which each of the plurality of power transmission units has a communication unit and communicates with each vehicle has been described.

  In the second embodiment, a configuration in which the power transmission apparatus has a management server for managing a plurality of power transmission units, and the management server and each vehicle communicate with each other will be described.

  FIG. 11 is an overall configuration diagram of a vehicle power feeding system 10A according to the second embodiment. The power transmission device 20A in the vehicle power supply system 10A includes a management server 30 that manages these power transmission units in addition to the power transmission units 200A, 200B, and 200C. The management server 30 is connected to each power transmission unit, and exchanges information by wired communication.

  The management server 30 includes a communication unit 31. The communication unit 31 is a communication interface for the management server 30 to communicate with the vehicles 100A and 100B. The information received by the communication unit 31 is transmitted to the power transmission ECU included in each power transmission unit. Information to be transmitted from each power transmission unit to the vehicle is transmitted from the communication unit 31 of the management server 30 to each vehicle. Each power transmission unit in the second embodiment is not provided with an individual communication unit.

  FIG. 12 is a diagram for explaining a schematic communication sequence in the second embodiment. FIG. 12 is obtained by adding the operation of the management server 30 to FIG. 8 of the first embodiment. In FIG. 12, test power transmission is performed except that each vehicle and each power transmission unit communicate with each other via the management server 30 and that a successful notification of test power transmission is transmitted from each power transmission unit to the management server 30. The pairing method between the vehicle and the power transmission device using the is substantially the same as that described in FIG. Therefore, detailed description will not be repeated in FIG.

  FIG. 13 is a flowchart for explaining details of the pairing control process between the vehicle and the power transmission unit in the second embodiment. In FIG. 13, control of vehicle 100 is the same as the process in the first embodiment, and therefore description thereof will not be repeated. Therefore, in FIG. 13, the process in the management server 30 and the power transmission unit 200 is demonstrated.

  With reference to FIG. 13, the process of the management server 30 is demonstrated first. When the communication starts in S300, the management server 30 determines whether or not a charge request signal from the vehicle is received in S310.

  If the charging request signal has not been received (NO in S310), the subsequent processing is unnecessary, and management server 30 ends the processing.

  When the charge request signal is received (YES in S310), the process proceeds to S320, and management server 30 receives information on the state of the power transmission unit as described with reference to FIG. A list of power transmission unit candidates used for power transmission is created based on the information.

  Here, an example of detailed processing of candidate list creation in S320 of FIG. 13 will be described using FIG. With reference to FIG. 14, the management server 30 acquires the information regarding the state of power transmission unit (i) based on the information from a power transmission unit in S321. Note that “i” is an index for repetitive processing. For example, the initial value is set to i = 1.

  In step S322, the management server 30 determines whether the acquired information regarding the state of the power transmission unit (i) indicates a “standby state”. If it is “standby state”, the management server 30 registers the power transmission unit (i) in the candidate list in S323 and advances the process to S324.

  On the other hand, if it is not in the “standby state”, it is not in a state where test power transmission can be executed, and therefore the management server 30 skips S323 and advances the process to S324.

  In S324, the management server 30 determines whether or not the search for all power transmission units has been completed. If the search for all power transmission units has been completed (YES in S324), the process proceeds to S330 in FIG. 13 and the subsequent process is executed.

  If all the power transmission units have not been searched (NO in S324), the index is incremented by 1 in S325 (i = i + 1), the process returns to S321, and the next power transmission unit starts from S321. The process of S324 is repeated.

In this way, a candidate list of power transmission units is generated.
Referring to FIG. 13 again, the management server 30 broadcasts a power transmission request signal to the power transmission units listed in the candidate list created in S320. The power transmission units listed in the candidate list attempt test power transmission all at once in response to the power transmission request signal.

  Next, in S340, the management server 30 determines whether or not a power reception success notification for the power supplied by the test power transmission from the vehicle has been received.

  If the power reception success notification has not been received (NO in S340), there is no vehicle that can receive power, and the management server 30 ends the process.

  When the power reception success notification is received (NO in S340), the management server 30 can identify the correspondence between the vehicle and the power transmission unit in S350 in consideration of the test power transmission success notification transmitted from the power transmission unit. It is determined whether or not. Specifically, in the case where there is one test transmission success notification and one power reception success notification, the management server 30 corresponds to the vehicle that has transmitted the power reception success notification to the power transmission unit that has transmitted the power transmission success notification. Judge.

  If the correspondence between the vehicle and the power transmission unit can be specified (YES in S350), the process proceeds to S380, and management server 30 notifies the corresponding vehicle and the power transmission unit of the stand ID and the vehicle ID, respectively. .

  If the correspondence between the vehicle and the power transmission unit cannot be specified (NO in S350), the process proceeds to S360, and the test power transmission is executed individually at different timings with respect to the power transmission unit that transmitted the power transmission success notification. As described above, the power transmission request signal is transmitted. The power transmission unit that has transmitted the power transmission success notification executes test power transmission again in response to the power transmission request signal. That is, the test power transmission at this stage is executed independently for each power transmission unit for which the first test power transmission has succeeded.

  Thereafter, in S370, the management server 30 determines whether or not a power reception success notification transmitted from the vehicle has been received in response to a successful test power transmission notification for each power transmission unit.

  If the power reception success notification has not been received (NO in S370), management server 30 ends the process.

  When the power reception success notification is received (YES in S370), the management server 30 determines that the vehicle that has transmitted the power reception success notification corresponds to the power transmission unit that has transmitted the power transmission success notification. The unit is notified of the stand ID and the vehicle ID (S380).

  Note that the processing from S360 to S380 is sequentially performed on the power transmission units for which the first test power transmission has succeeded.

  Next, processing in power transmission ECU 240 of power transmission unit 200 will be described. In S400, power transmission ECU 240 indicates whether the state of the power transmission unit is “empty state”, “standby state”, “charging state”, or “charging end state” as shown in FIG. Information is output to the management server 30.

  Thereafter, power transmission ECU 240 determines in S410 whether or not a power transmission request signal for test power transmission has been received from management server 30.

  If the power transmission request signal has not been received (NO in S410), that is, it means that the power transmission unit is in a state in which test power transmission other than “standby state” cannot be performed, and therefore power transmission ECU 240 performs processing. Exit.

  If a power transmission request signal has been received (YES in S410), the process proceeds to S420, and power transmission ECU 240 attempts a test power transmission.

  Then, the power transmission ECU 240 determines whether or not the test power transmission can be executed in S430. The power transmission ECU 240 outputs a power transmission success notification to the management server 30 when the test power transmission can be executed (YES at S430) (S440), and performs the process when the test power transmission cannot be executed (NO at S430). finish.

  Next, when power transmission ECU 240 receives an individual power transmission request signal from management server 30 (YES in S450), power transmission ECU 240 executes test power transmission again in S460. When the test power transmission is successful (YES in S470), power transmission ECU 240 transmits a power transmission success notification to management server 30. If test power transmission is not successful (NO in S470), power transmission ECU 240 ends the process.

  After that, when the correspondence between the vehicle and the power transmission unit is specified by the management server 30, the vehicle ID is notified from the management server 30, and the power transmission ECU 240 specifies the vehicle to be transmitted in S490.

  In the description of the second embodiment, as shown in FIG. 2, the management server executes overall management control of the power transmission ECU in each power transmission unit, and the operation of each power transmission unit is controlled by the power transmission ECU. Although an example of a configuration to be performed has been described, each power transmission unit may not have a power transmission ECU, and the management server may directly control each power transmission unit. In this case, the management server executes both the processing of the management server and the processing of the power transmission ECU in FIG.

[Embodiment 3]
In the first and second embodiments, the case has been described in which the power transmission apparatus determines that the test power transmission is to be re-executed and specifies the counterpart vehicle to which power is to be transmitted.

  In the third embodiment, an example in which re-execution of test power transmission is determined on the vehicle side and the power transmission unit on the other side is specified will be described.

  FIG. 15 is a diagram for explaining a schematic communication sequence in the third embodiment. In FIG. 15, similarly to the first embodiment, it is assumed that the vehicle A is parked in the parking space of the stand 1, the vehicle B is parked in the parking space of the stand 2, and the stand 3 is in an empty state. .

  Referring to FIG. 15, as in FIG. 8 of the first embodiment, when a charge request signal is transmitted from vehicle A and vehicle B at almost the same timing without specifying the opponent's stand, the charge request The stands 1, 2, and 3 that have received the signal attempt test transmission.

  In the stands 1 and 2, the power transmission is successfully received in the vehicles A and B, respectively, so that the test power transmission is successful, and the power transmission success notification is transmitted from the stands 1 and 2 to the vehicles A and B. On the other hand, since the stand 3 is in an empty state, the test power transmission is not successful, and the power transmission success notification is not transmitted from the stand 3.

  Vehicles A and B both receive power transmission success notifications from stands 1 and 2. Accordingly, at this stage, the corresponding stands cannot be specified for the vehicles A and B.

  Therefore, when a plurality of power transmission success notifications are received in this manner, each of the vehicles A and B determines the stand that transmitted the power transmission success notification as a candidate stand, and provides an individual time difference with respect to this candidate stand. A request signal for test power transmission is transmitted. Then, for example, in the vehicle A, the power supplied by the test power transmission is appropriately charged with respect to the power transmission request signal transmitted by specifying the stand 1, and the power transmission success notification from the stand 1 is received. . On the other hand, the vehicle A cannot receive the power from the stand 2 for the power transmission request signal transmitted by specifying the stand 2. At this time, since the power transmission request signal is not output for the vehicle B, the power supplied from the stand 2 is not received by the vehicle B, and therefore the power transmission success notification is not transmitted from the stand 2. Thereby, in the vehicle A, it can be specified that the stand 1 is a corresponding power transmission unit. In the stand 1 as well, it can be recognized that power transmission has succeeded in response to the power transmission request signal specifying the stand from the vehicle A, so that the vehicle to be transmitted can be specified as the vehicle A.

  Conversely, for the vehicle B, the power transmission request signal transmitted by specifying the stand 2 is appropriately charged and a power transmission success notification is received from the stand 2, but the power from the stand 1 is No power is received and no power transmission success notification is received. As a result, both the vehicle B and the stand 2 can identify each other.

  As described above, when a plurality of power transmission success notifications are received in response to a charging request signal transmitted without specifying the counterpart power transmission unit on the vehicle side, each vehicle receives the power transmission success notification. It is possible to specify pairing of vehicles and power transmission units more efficiently than sending power transmission requests individually to all power transmission units by sending a separate power transmission request to candidates only. It becomes.

  In the above, when the vehicle receives only the power transmission success notification from one stand in response to the charge request signal transmitted without specifying the other party's stand, the individual power transmission request specifying the stand is not performed. But at this stage, the other party's stand is identified.

  If a power transmission request specifying a stand executed in each vehicle is executed in a plurality of vehicles at the same timing, a plurality of power transmission success notifications may be received again in each vehicle. For this reason, it is preferable that the power transmission request to be performed by specifying a stand is performed at a random timing, for example, by adjusting the transmission timing between vehicles.

  Note that the contactless power supply system in the above description has been described by taking the case where the power receiving device is a vehicle as an example, but the power supply target is not limited to the vehicle, and can be applied to any electric system including a chargeable power storage device. is there.

  In the above description, “test power transmission” has been described as a case where a small amount of electric power is transmitted compared to a normal charging operation, but other power transmission states may be employed as “test power transmission”. For example, although the power is the same as that at the time of charging, the case where pulsed short-time power transmission is performed is also included in “test power transmission”.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  10, 10A vehicle power supply system, 20, 20A power transmission device, 30 management server, 31, 160, 230 communication unit, 89 power transmission system, 90, 220 power transmission unit, 91, 110 power reception unit, 92, 93, 96, 97 coil 94, 99, 111, 221 Resonant coil, 95, 98, 112, 222 Capacitor, 100, 100A, 100B Vehicle, 113, 223 Electromagnetic induction coil, 115 SMR, 118 Electric load device, 120 PCU, 130 Motor generator, 140 Power transmission gear, 150 drive wheels, 155 drive device, CHR 170, 180 rectifier, 190 power storage device, 195 voltage sensor, 196 current sensor, 200, 200A to 200C power transmission unit, 210 power supply device, 250 power supply unit, 260 matching unit, 270 Vehicle detection Part, 300 vehicle ECU, 400 commercial power supply.

Claims (20)

A power transmission unit that supplies power to a power receiving device in a contactless manner,
A power transmission unit that supplies power to the power receiving device in a contactless manner;
A communication unit that performs wireless communication with the power receiving device;
A control unit,
In response to the power transmission request from the power receiving device, the control unit executes test power transmission for identifying the power receiving device to be transmitted from the power transmission unit,
The control unit is a case where the power supplied by the test power transmission is received, and when the power reception apparatus receives only one power reception success signal indicating that the power reception is successful, the power reception apparatus transmits the power. A power transmission unit that identifies a power reception device to be executed and performs the test power transmission again when the power reception success signal is received from a plurality of power reception devices. A plurality of power transmission units according to claim 1 are provided,
The power transmission request is transmitted from the power receiving apparatus to the power transmission units all at once.   The power transmission device according to claim 2, wherein each power transmission unit executes the test power transmission in concert with another power transmission unit in response to the power transmission request.   The power transmission device according to claim 2, wherein the control unit executes the test power transmission at a timing different from that of other power transmission units when the test power transmission is performed again.   The power transmission unit according to claim 1, wherein, when the power receiving device to be transmitted is specified, the control unit outputs a signal for identifying the power transmission unit to the specified power receiving device.   The control unit does not execute the test power transmission even when the power transmission request is received when power is transmitted to another power receiving device other than the power receiving device that has transmitted the power transmission request. The power transmission unit described in 1.   The control unit, when power transmission to another power receiving device other than the power receiving device that transmitted the power transmission request is completed, and when the other power receiving device exists in a power transmission possible range of the power transmission unit, The power transmission unit according to claim 1, wherein the test power transmission is not executed even when received. The power transmission unit further includes a detection unit that detects the presence or absence of a power receiving device in a power transmission possible range of the power transmission unit,
The control unit does not execute the test power transmission even when the power transmission request is received when the detection unit indicates that there is no power receiving device in the power transmission possible range. The power transmission unit according to claim 1. The power receiving device includes a power receiving unit that receives power from the power transmission unit in a contactless manner,
The power transmission unit according to claim 1, wherein a difference between the natural frequency of the power transmission unit and the natural frequency of the power reception unit is ± 10% or less of the natural frequency of the power transmission unit or the natural frequency of the power reception unit. The power receiving device includes a power receiving unit that receives power from the power transmission unit in a contactless manner,
The power transmission unit according to claim 1, wherein a coupling coefficient between the power transmission unit and the power reception unit is 0.1 or less. The power receiving device includes a power receiving unit that receives power from the power transmission unit in a contactless manner,
The power reception unit includes a magnetic field that vibrates at a specific frequency formed between the power reception unit and the power transmission unit, and an electric field that vibrates at a specific frequency formed between the power reception unit and the power transmission unit. The power transmission unit according to claim 1, wherein the power transmission unit receives power from at least one of the power transmission units. A power transmission device that supplies power to a power receiving device in a contactless manner,
A plurality of power transmission units;
A wireless communication with the power receiving device, and a control device for controlling the plurality of power transmission units,
The control device, in response to a power transmission request from the power receiving device, causes the plurality of power transmission units to simultaneously execute test power transmission for identifying the power receiving devices to be transmitted by each of the plurality of power transmission units,
The control device has one power transmission unit that has received power supplied by the test power transmission among the plurality of power transmission units, and one power reception success signal indicating that power reception has been successful from the power reception device. If it is received only, the power receiving device is identified as the power receiving device that should transmit power from the power transmission unit,
When the control device receives the power reception success signal from a plurality of power reception devices, the control device individually causes the test power transmission to be executed again for a power transmission unit that has received power supplied by the test power transmission. The power transmission device further includes a plurality of control units corresponding to the plurality of power transmission units,
The power transmission device according to claim 12, wherein the control device is a management server that manages the plurality of control units. A power receiving device that receives power from a power transmission device including a plurality of power transmission units in a contactless manner,
A power receiving unit that receives power in a contactless manner from one of the plurality of power transmitting units;
A communication unit for performing wireless communication with the power transmission device;
A control device,
The control device transmits to the power transmission device a first power transmission request for executing test power transmission for specifying a power transmission unit that performs power transmission to the power receiving unit, and is supplied by the test power transmission transmitted from the power transmission device. Based on a power transmission success signal indicating that the received power has been received, a power transmission unit candidate for transmitting power to the power receiving unit is determined, and the test power transmission is individually re-executed for the power transmission units included in the candidate A power receiving device that transmits a second power transmission request for causing the power receiving unit to transmit power to the power receiving unit according to a power receiving state of power supplied by the test power transmission in response to the second power transmission request.   The power receiving device according to claim 14, wherein the first power transmission request is a signal that causes the plurality of power transmission units to perform the test power transmission all at once.   The power receiving device according to claim 14, wherein a difference between the natural frequency of the power transmission unit and the natural frequency of the power reception unit is ± 10% or less of the natural frequency of the power transmission unit or the natural frequency of the power reception unit.   The power receiving device according to claim 14, wherein a coupling coefficient between the power transmitting unit and the power receiving unit is 0.1 or less.   The power reception unit includes a magnetic field that vibrates at a specific frequency formed between the power reception unit and the power transmission unit, and an electric field that vibrates at a specific frequency formed between the power reception unit and the power transmission unit. The power receiving device according to claim 14, wherein the power is received from the power transmission unit through at least one of the following. The power receiving device according to any one of claims 14 to 18,
A power storage device capable of charging the power received by the power receiving device;
A vehicle comprising: a driving device for generating a driving force using electric power from the power storage device. A non-contact power feeding system that transmits power in a non-contact manner between a power transmission device and a vehicle,
The power transmission device includes a plurality of power transmission units,
The power transmission device and the vehicle can perform wireless communication with each other,
The power transmission device, in response to a power transmission request from the vehicle, simultaneously performs test power transmission for identifying power transmission units that perform power transmission to the vehicle by the plurality of power transmission units,
In response to receiving power supplied by the test power transmission, the vehicle transmits a power reception success signal indicating that power reception has been successful to the power transmission device,
When the power transmission device has one power transmission unit that has received power supplied by the test power transmission among the plurality of power transmission units and only one power reception success signal is received, the power transmission When the unit is identified as a power transmission unit that transmits power to the vehicle that has transmitted the power reception success signal and receives the power reception success signal from a plurality of vehicles, the power transmission unit that has received power supplied by the test power transmission A non-contact power feeding system that individually executes the test power transmission again with respect to.

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