JP6160742B2 - Non-contact power transmission system - Google Patents

Description

The present invention relates to a non-contact power transmission system.

  Japanese Patent Laying-Open No. 2013-135572 (Patent Document 1) discloses a non-contact charging system that transmits power from a vehicle to a charging station in a non-contact manner. In the non-contact charging system, alignment between the power transmission unit of the charging station and the power reception unit of the vehicle is performed in order to increase the efficiency of power transmission and reception.

JP 2013-135572 A JP2013-154815A JP2013-146154A JP2013-146148A JP 2013-110822 A JP 2013-126327 A

  In the above publication, the charging station is provided with one power transmission side control unit, and one power transmission unit (power transmission coil) is controlled by the power transmission side control unit.

  However, as a type of charging station, a type in which one control unit controls a plurality of power transmission units can be considered.

  Here, it is conceivable that a new vehicle enters the charging station to be charged in a situation where the vehicle is stopped at some power transmission units among the plurality of power transmission units. When the charging station supplies power to the already stopped vehicle from the power transmission unit, the charging station can determine that the vehicle is present in the power transmission unit. On the other hand, it is conceivable that charging of the vehicle has been completed, but the vehicle is still on the power transmission unit without moving. In such a state, it cannot be known from the charging station side whether or not the vehicle is stopped at the power transmission unit.

  As a result, there is a problem that the charging station cannot determine to which power transmission section the vehicle newly entering the charging station should be guided.

  If a vehicle position confirmation sensor or the like is provided in each parking frame, the installation cost of the charging station is increased and the construction is troublesome.

An object of the present invention is to provide a contactless power transmission system capable of guiding the vehicle newly arrived to the charging station, the power transmission unit vacant.

  In summary, the present invention is a non-contact power transmission system including first and second vehicles and a charging station. The charging station includes a plurality of power transmission units that can transmit power to the vehicle without contact and a power transmission control unit that controls power transmission from the plurality of power transmission units. When the power transmission control unit receives the power transmission request signal from the first vehicle, the power transmission control unit transmits weak power from the first power transmission unit that is not transmitting power among the plurality of power transmission units. When the second vehicle is parked at a position where power can be received from the first power transmission unit, and the second vehicle receives weak power from the first power transmission unit, the second vehicle has a parking position. An occupancy signal that can specify that the position corresponds to the first power transmission unit is transmitted to the power transmission control unit. When receiving the occupation signal from the second vehicle, the power transmission control unit guides the first vehicle to a power transmission unit other than the first power transmission unit.

  With the above configuration, for example, the second vehicle occupies the first power transmission unit even when the second vehicle is stopped at the first power transmission unit without moving after charging. Since the charging station is notified, the charging station can guide the first vehicle that has transmitted the power transmission request signal to a power transmission unit other than the first power transmission unit.

  Preferably, the power transmission control unit executes power transmission by changing the power characteristics of the weak power from the plurality of power transmission units for each power transmission unit, and the second vehicle uses the occupancy signal according to the power characteristics of the received weak power. Is transmitted to the power transmission control unit.

  With such a configuration, it is possible to know what kind of power transmission unit the power transmission unit in which the second vehicle is stopped is based on the power characteristics of the weak power received. And the information which can specify the power transmission part by the second vehicle can be returned to the charging station.

  More preferably, the power characteristic varied for each power transmission unit is a supply time of weak power, and the second vehicle transmits a signal indicating the supply time as an occupation signal.

  More preferably, the power characteristic that is different for each power transmission unit is the number of times the weak power is switched on / off, and the second vehicle transmits a signal indicating the number of times of switching as an occupation signal.

  Preferably, the second vehicle retains information indicating that the power transmission unit used at the time of charging is the first power transmission unit among the plurality of power transmission units even after the end of charging. When the second vehicle receives weak power when parked at a position corresponding to the first power transmission unit after the end of charging, the second vehicle transmits an occupancy signal based on the stored information.

  According to the above configuration, the second vehicle can transmit the occupancy signal without performing processing that varies the power characteristics for each power transmission unit during transmission of weak power.

  Preferably, the second vehicle includes a power reception device capable of receiving power from any of the plurality of power transmission units, a power storage device, a charging relay provided between the power reception device and the power storage device, a distance detection unit, A power reception control unit that controls the charging relay and the distance detection unit. The distance detection unit includes a resistor and a distance detection relay that connects the resistor between the output line pair of the power receiving device. When charging the power storage device, the power reception control unit sets the charging relay in a conductive state while setting the distance detection relay in a non-conductive state and, after completing the charging of the power storage device, sets the charging relay in a non-conductive state. Connect the distance detection relay with.

  With the above configuration, the vehicle can receive the weak power separately from the charging of the power storage device, and can suitably detect the distance by the received voltage generated by the weak power.

  In another aspect, the present invention is a charging station capable of non-contact power transmission to the first and second vehicles, a plurality of power transmission units capable of non-contact power transmission to the vehicle, and a plurality of power transmission units A power transmission control unit that controls power transmission. When the power transmission control unit receives the power transmission request signal from the first vehicle, the power transmission control unit transmits weak power from the first power transmission unit that is not transmitting power among the plurality of power transmission units. When the second vehicle is parked at a position where power can be received from the first power transmission unit, and the second vehicle receives weak power from the first power transmission unit, the second vehicle has a parking position. An occupancy signal that can specify that the position corresponds to the first power transmission unit is transmitted to the power transmission control unit. When receiving the occupation signal from the second vehicle, the power transmission control unit guides the first vehicle to a power transmission unit other than the first power transmission unit.

  With the above configuration, for example, the second vehicle occupies the first power transmission unit even when the second vehicle is stopped at the first power transmission unit without moving after charging. Since the charging station is notified, the charging station can guide the first vehicle that has transmitted the power transmission request signal to a power transmission unit other than the first power transmission unit.

  In another aspect, the present invention provides a vehicle, a power receiving device capable of receiving power from a charging station in a non-contact manner, a power storage device, a charging relay provided between the power receiving device and the power storage device, and distance detection And a power reception control unit that controls the charging relay and the distance detection unit. The distance detection unit includes a resistor and a distance detection relay that connects the resistor between the output line pair of the power receiving device. When charging the power storage device, the power reception control unit sets the charging relay in a conductive state while setting the distance detection relay in a non-conductive state and, after completing the charging of the power storage device, sets the charging relay in a non-conductive state. Connect the distance detection relay with.

  With the above configuration, the vehicle can receive the weak power separately from the charging of the power storage device, and can suitably detect the distance by the received voltage generated by the weak power.

  According to the present invention, a vehicle that has newly arrived at a charging station can be guided to a vacant power transmission unit while avoiding a power transmission unit already parked in another vehicle.

1 is an overall configuration diagram of a non-contact power transmission system that is an example of an embodiment of the present invention. It is a figure for demonstrating a mode that a vehicle (1st vehicle) parks in the parking position in a charging station. It is a figure for demonstrating a mode that a vehicle (2nd vehicle) parks in the parking position in a charging station. It is a flowchart for demonstrating the outline of the process which vehicle 10A or 10B and the charging station 90 perform when performing non-contact electric power transmission. It is a flowchart for demonstrating the detail of the power transmission coil selection process performed in step S540 of FIG. 6 is a timing chart showing changes in transmitted power and received voltage that change in the process of FIG. 4 and FIG. 5. It is a figure for demonstrating the modification of an occupation confirmation process or a pairing process.

  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.

(Outline of contactless power transmission system)
FIG. 1 is an overall configuration diagram of a non-contact power transmission system which is an example of an embodiment of the present invention. 2 and 3 are diagrams for explaining a state in which the vehicle is parked at the parking position in the charging station. First, an outline of the present embodiment will be described with reference to FIGS.

  Referring to FIG. 1, the non-contact power transmission system of the present embodiment includes vehicles 10A and 10B and a charging station 90. Charging station 90 includes a plurality of power transmission units 700A and 700B that can transmit power to a vehicle in a contactless manner, and a power transmission control unit (power supply ECU 800) that controls power transmission from the plurality of power transmission units 700A and 700B.

  As shown in FIG. 2, consider a case where the first vehicle 10B is parked on the power transmission unit 700B in order to charge. The vehicle 10B uses the weak power from the power transmission unit 700B as an alignment test signal. For this reason, the vehicle 10B transmits a power transmission request signal to the charging station. When the charging station receives the power transmission request signal, the charging station transmits weak power from a power transmitting unit that does not transmit power among the plurality of power transmitting units 700A and 700B. In the case of FIG. 2, since the vehicle is not parked in any of the plurality of power transmission units 700A and 700B and is not transmitting power, weak power is transmitted from both of the power transmission units 700A and 700B. When the vehicle 10B selects the power transmission unit 700B and approaches the power transmission unit 700B, the weak power starts to be detected by the power reception unit 100, and thus alignment is performed based on the strength of the weak power (power reception voltage VR).

  Here, as shown in FIG. 3, even when charging of the vehicle 10B is completed, the case where the vehicle 10B has not moved from the power transmission unit 700B is considered. As shown in FIG. 3, when power supply ECU 800 receives a power transmission request signal from vehicle 10A, power supply ECU 800 transmits weak power from a power transmission unit that does not transmit power among a plurality of power transmission units 700A and 700B. For example, when charging from the power transmission unit 700B to the vehicle 10B has been completed, weak power is transmitted from both of the plurality of power transmission units 700A and 700B.

  When the vehicle 10B is parked at a position where power can be received from the power transmission unit 700B and the vehicle 10B receives weak power from the power transmission unit 700B, the parking position of the vehicle 10B corresponds to the power transmission unit 700B. Is transmitted to the power supply ECU 800. The transmission is executed via the communication unit 510 and the communication unit 810 of FIG. The power supply ECU 800 stops the transmission of the weak power from the power transmission unit 700B when receiving an occupancy signal of the power transmission unit 700B from the vehicle 10B, and the power transmission unit other than the power transmission unit 700B, that is, the power transmission unit 700A in the case of FIG. To the vehicle 10A.

  With the above configuration, for example, even when the vehicle 10B is stopped without being moved after charging in the power transmission unit 700B, the vehicle 10B notifies the charging station 90 that the power transmission unit 700B is occupied. Charging station 90 can guide vehicle 10A that has sent a power transmission request signal to a power transmission unit other than power transmission unit 700B (power transmission unit 700A in FIG. 3).

  Preferably, power supply ECU 800 executes power transmission by changing the power characteristics of weak power from a plurality of power transmission units 700A and 700B for each power transmission unit. The vehicle 10B transmits an occupancy signal of the power transmission unit 700B to the power supply ECU 800 according to the power characteristics of the received weak power.

  With such a configuration, the vehicle 10B can know what kind of power transmission unit the power transmission unit that the vehicle 10B has stopped is based on the power characteristics of the weak power received. Information that allows the vehicle 10 </ b> B to identify the power transmission unit can be returned to the charging station 90.

  More preferably, the power characteristic varied for each power transmission unit is the supply time (TA, TB in FIG. 6) of the weak power, and the vehicle 10B supplies the power as the occupation signal of the power transmission unit 700B (TB in FIG. 6). A signal indicating is transmitted.

  More preferably, the power characteristic varied for each power transmission unit is the number of times of weak power on / off switching (see FIG. 7), and the vehicle 10B transmits a signal indicating the number of switching as an occupancy signal of the power transmission unit 700B. To do.

  In addition, even if it does not perform the power transmission which made the characteristic of weak electric power different for every power transmission part, when the vehicle 10B specifies a power transmission part by pairing before charging, the information at that time is retained even after the end of charging. If so, information that can identify the power transmission unit may be returned to the charging station 90 in response to all the power transmission units transmitting the same weak power or receiving communication from the communication unit 810. .

  That is, preferably, vehicle 10B is configured to retain information indicating that the power transmission unit used at the time of charging is power transmission unit 700B among the plurality of power transmission units even after the end of charging. When the vehicle 10B receives weak power when parked at a position corresponding to the power transmission unit 700B (parking position B in FIG. 2) after the end of charging, the vehicle 10B outputs an occupancy signal based on the stored information. Send.

  Preferably, each of vehicles 10A and 10B includes a power receiving device 120 capable of receiving power from any of a plurality of power transmission units, power storage device 300, and charging relay 210 provided between power receiving device 120 and power storage device 300. And a distance detection unit 204, and a power reception control unit (vehicle ECU 500) that controls the charging relay 210 and the distance detection unit 204. The distance detection unit 204 includes a resistor 201 and a distance detection relay 202 that connects the resistor 201 between the output line pair of the power receiving device 120. When charging power storage device 300, vehicle ECU 500 sets charging relay 210 to a conductive state while disabling distance detection relay 202, and after charging power storage device 300 is completed, charging relay 210 is not conductive. While making the state, the distance detection relay 202 is turned on.

  With the above-described configuration, the vehicle can receive the weak power separately from the charging of the power storage device 300, and the distance detection based on the received voltage VR generated by the weak power can be suitably performed.

Next, details of each component of the non-contact power transmission system will be further described.
(Detailed configuration of contactless power transmission system)
Referring to FIG. 1, the contactless power transmission system according to the present embodiment includes vehicles 10A and 10B equipped with power receiving device 120 configured to be able to receive power without contact, and a power transmission device that transmits power to power receiving unit 100 from the outside of the vehicle. And a charging station 90 having 20A and 20B.

  Vehicle 10A includes a power receiving device 120, a power storage device 300, a power generation device 400, a communication unit 510, a vehicle ECU 500, and a display unit 520. The power receiving device 120 includes a power receiving unit 100, a filter circuit 150, and a rectifying unit 200. The vehicle 10B has the same configuration as the vehicle 10A, although the inside is not shown.

  Charging station 90 includes an external power supply 900, power transmission devices 20A and 20B, a communication unit 810, and a power supply ECU 800. Power transmission devices 20A and 20B include power supply units 600A and 600B, filter circuits 610A and 610B, and power transmission units 700A and 700B, respectively.

  For example, as shown in FIG. 2, power transmission devices 20A and 20B are provided on the ground surface or underground of parking positions A and B, respectively, and power reception device 120 is disposed at the lower part of the vehicle body. Note that the location of the power receiving device 120 is not limited to this. For example, if the power transmission devices 20A and 20B are provided above or on the side of the vehicle 10, the power receiving device 120 may be provided on the upper part of the vehicle body or on the vehicle body peripheral surface (front surface, rear surface, side surface).

  Power receiving unit 100 includes a secondary coil for receiving power (alternating current) output from any of power transmitting units 700A and 700B of power transmitting devices 20A and 20B in a non-contact manner. The power receiving unit 100 outputs the received power to the rectifying unit 200. The rectifying unit 200 rectifies the AC power received by the power receiving unit 100 and outputs the rectified power to the power storage device 300. The filter circuit 150 is provided between the power reception unit 100 and the rectification unit 200, and suppresses harmonic noise generated when receiving power from either the power transmission unit 700A or 700B. The filter circuit 150 is configured by an LC filter including an inductor and a capacitor, for example.

  The power storage device 300 is a rechargeable DC power supply, and is configured by a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The voltage of power storage device 300 is, for example, about 200V. The power storage device 300 stores power output from the rectifying unit 200 and also stores power generated by the power generation device 400. Then, power storage device 300 supplies the stored power to power generation device 400. Note that a large-capacity capacitor can also be used as the power storage device 300. Although not particularly illustrated, a DC-DC converter that adjusts the output voltage of the rectifying unit 200 may be provided between the rectifying unit 200 and the power storage device 300.

  Power generation device 400 generates traveling driving force for vehicle 10 </ b> A using electric power stored in power storage device 300. Although not particularly illustrated, power generation device 400 includes, for example, an inverter that receives electric power from power storage device 300, a motor driven by the inverter, a drive wheel driven by the motor, and the like. Power generation device 400 may include a generator for charging power storage device 300 and an engine capable of driving the generator.

  Vehicle ECU 500 includes a CPU (Central Processing Unit), a storage device, an input / output buffer, and the like (none of which are shown), and inputs signals from various sensors and outputs control signals to each device, and vehicle 10A. Control each device in. As an example, vehicle ECU 500 executes traveling control of vehicle 10 </ b> A and charging control of power storage device 300. Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  Note that a relay 210 is provided between the rectifying unit 200 and the power storage device 300. Relay 210 is turned on by vehicle ECU 500 when power storage device 300 is charged by power transmission devices 20A and 20B. A system main relay (SMR) 310 is provided between the power storage device 300 and the power generation device 400. SMR 310 is turned on by vehicle ECU 500 when activation of power generation device 400 is requested.

  Further, a relay 202 is provided between the rectifying unit 200 and the relay 210. The voltage VR across the resistor 201 connected in series with the relay 202 is detected by the voltage sensor 203 and sent to the vehicle ECU 500.

  The vehicle ECU 500 communicates with the communication unit 810 of the charging station 90 using the communication unit 510 when charging the power storage device 300 by the power transmission devices 20A and 20B, and displays information such as charging start / stop and the power reception status of the vehicle 10A. Interact with power supply ECU 800.

  Referring to FIGS. 1 and 2, the secondary coil in power receiving device 120 is set to 1 in power transmitting device 20A due to power received by a vehicle-mounted camera (not shown) or test power transmission (power transmission by weak power) 700A. The vehicle 10A or the charging station 90 determines whether or not the position is aligned with the next coil, and the display unit 520 notifies the user. Based on the information obtained from the display unit 520, the user moves the vehicle 10A so that the positional relationship between the power receiving device 120 and the power transmitting device 20A is favorable for power transmission and reception. Note that the user does not necessarily have to perform a steering wheel operation or an accelerator operation, and the vehicle 10A may automatically move to adjust the position, and the user may watch it on the display unit 520.

  In addition, it is preferable that the test power transmission with weak power is set to an output (about 1/100 or less of the main power transmission used for charging) that is used in a so-called specific low-power radio station.

  Referring to FIG. 1 again, power supply units 600A and 600B receive power from external power supply 900 such as a commercial power supply, and generate AC power having a predetermined transmission frequency.

  Power transmission units 700A and 700B include a primary coil for transmitting power to power reception unit 100 in a contactless manner. The power transmission units 700A and 700B receive AC power having a transmission frequency from the power supply unit 600A and transmit the AC power to the power reception unit 100 of the vehicle 10A in a non-contact manner via an electromagnetic field generated around the power transmission units 700A and 700B.

  Filter circuits 610A and 610B are provided between power supply units 600A and 600B and power transmission units 700A and 700B, and suppress harmonic noise generated from power supply units 600A and 600B. Filter circuits 610A and 610B are constituted by LC filters including inductors and capacitors.

  The power supply ECU 800 includes a CPU, a storage device, an input / output buffer, and the like (all not shown), and inputs signals from various sensors and outputs control signals to each device. Take control. As an example, power supply ECU 800 performs switching control of power supply units 600A and 600B so that power supply units 600A and 600B generate AC power having a transmission frequency. Note that these controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  When power is transmitted to vehicle 10A, power supply ECU 800 communicates with communication unit 510 of vehicle 10A using communication unit 810, and exchanges information such as charging start / stop and power reception status of vehicle 10A with vehicle 10A. .

  AC power having a predetermined transmission frequency is supplied from power supply units 600A and 600B to power transmission units 700A and 700B via filter circuits 610A and 610B. Each of power transmission units 700A and 700B and power reception unit 100 of vehicle 10A includes a coil and a capacitor, and is designed to resonate at a transmission frequency. The Q value indicating the resonance intensity of power transmission units 700A and 700B and power reception unit 100 is preferably 100 or more.

  When AC power is supplied from the power supply units 600A and 600B to the power transmission units 700A and 700B via the filter circuits 610A and 610B, the primary coil included in one of the power transmission units 700A and 700B and the secondary of the power reception unit 100 Energy (electric power) moves from one of the power transmission units 700A and 700B to the power reception unit 100 through an electromagnetic field formed between the coils. Then, the energy (electric power) that has moved to power reception unit 100 is supplied to power storage device 300 via filter circuit 150 and rectification unit 200.

  Although not particularly illustrated, in power transmission devices 20A and 20B, an insulating transformer is provided between power transmission units 700A and 700B and power supply units 600A and 600B (for example, between power transmission units 700A and 700B and filter circuits 610A and 610B). May be. Also in vehicle 10A, an insulating transformer may be provided between power reception unit 100 and rectification unit 200 (for example, between power reception unit 100 and filter circuit 150).

(Procedure for contactless power transmission)
FIG. 4 is a flowchart for explaining an outline of processing executed by the vehicle 10A or 10B and the charging station 90 when executing non-contact power transmission.

  Referring to FIGS. 1 and 4, in the vehicle, it is determined in step S10 whether or not a non-contact charging switch that specifies whether or not to perform non-contact charging is in an ON state. Although not particularly limited, it is preferable that the non-contact charging switch is automatically set to the ON state when the vehicle is activated, and the vehicle is configured so that the user can switch the setting to the OFF state. .

  In step S510, power supply ECU 800 of charging station 90 broadcasts a signal notifying that charging is possible when there is an empty parking position.

  In step S20, when the vehicle ECU 500 of the vehicle 10A receives this signal, the process proceeds to step S30, and a request for weak power transmission is transmitted to the charging station 90.

  In step S530, power supply ECU 800 of charging station 90 receives the power transmission request.

  In step S530, when the charging station 90 receives a power transmission request from the vehicle, in step S540, a power transmission coil selection process is executed in the charging station.

  FIG. 5 is a flowchart for explaining details of the power transmission coil selection process executed in step S540 of FIG. The process of this flowchart is executed by power supply ECU 800 of charging station 90. With reference to FIGS. 1 and 5, first, in step S701, it is determined whether or not power transmission unit 700A is transmitting power. In step S701, when power transmission unit 700A is transmitting power, the process proceeds to step S702, and when power transmission unit 700A is not transmitting power, the process proceeds to step S703.

  In step S702, it is determined whether power transmission unit 700B is transmitting power. In step S702, if the power transmission unit 700B is transmitting power, the process proceeds to step S712. If the power transmission unit 700B is not transmitting power, the process proceeds to step S704.

  In step S703, it is determined whether power transmission unit 700B is transmitting power. In step S703, if the power transmission unit 700B is transmitting power, the process proceeds to step S705. If the power transmission unit 700B is not transmitting power, the process proceeds to step S706.

  When the process proceeds to step S704, power supply ECU 800 selects power transmission unit 700B as a power transmission candidate. When the process proceeds to step S705, power supply ECU 800 selects power transmission unit 700A as a power transmission candidate. When the process proceeds to step S706, power supply ECU 800 selects power transmission units 700A and 700B as power transmission candidates.

  If a power transmission candidate is determined in any of steps S704 to S706, weak power transmission is executed from the selected power transmission unit in step S707. This weak power transmission is a test signal for confirming whether any one of the power transmission units is occupied by another vehicle. For example, as shown in FIG. 3, when the power transmission unit 700A is occupied by the vehicle 10A that has been charged, the vehicle 10B requests transmission of weak power for alignment in order to perform charging. The weak power is transmitted from both of the power transmission units 700A and 700B.

  At this time, the vehicle 10A can immediately receive the weak power from the power transmission unit 700A. The vehicle 10A corresponds to “another vehicle” in step S708. The vehicle 10A stands by in a state where it can receive weak power from the power transmission unit 700A even when charging is completed. Then, when receiving weak power from the power transmission unit 700A, the vehicle 10A transmits a signal notifying that the power transmission unit 700A is occupied to the power supply ECU 800 of the charging station 90. When vehicle 10A occupies power transmission unit 700B, vehicle 10A transmits to power supply ECU 800 a signal (occupation signal) notifying that power transmission unit 700B is occupied.

  In step S708, power supply ECU 800 confirms the content of the occupancy signal received from other parked vehicles (vehicles other than vehicles that have requested the transmission of weak power for charging).

  In the present embodiment, an example is shown in which the vehicle receives weak power and returns an occupancy signal to the charging station 90. However, after transmitting the weak power, the charging station 90 side determines whether or not each power transmission unit is occupied. It may be detected. For example, when a vehicle is present at a position where power can be received, effective power on the transmission side increases. Therefore, the active power at the time of weak power transmission may be detected by a current sensor and a voltage sensor provided in each power transmission unit, and an occupation signal of the occupied power transmission unit may be generated on the charging station side.

  Subsequently, in step S709, it is determined whether or not the power transmission unit 700A is occupied or being transmitted. In step S709, if the power transmission unit 700A is occupied or transmitting power, the process proceeds to step S710. If the power transmission unit 700A is not occupied or transmitted, the process proceeds to step S711. It is done.

  In step S710, it is determined whether power transmission unit 700B is occupying or transmitting power. In step S710, if power transmission unit 700B is occupied or transmitting power, the process proceeds to step S712. If power transmission unit 700B is not occupied or transmitting power, the process proceeds to step S713. It is done.

  In step S711, it is determined whether power transmission unit 700B is occupying or transmitting power. In step S711, if power transmission unit 700B is occupied or transmitting power, the process proceeds to step S714. If power transmission unit 700B is not occupied or transmitting power, the process proceeds to step S715. It is done.

  With the above selection process, the process is assigned to one of steps S712 to S715. When the process proceeds to step S712, since any power transmission unit is transmitting or occupying, the alignment request from the vehicle newly coming to the charging station 90 is rejected. When the process has proceeded to step S713, the power transmission unit 700B is selected as a target for transmitting weak power for alignment. When the process proceeds to step S714, the power transmission unit 700A is selected as a target for transmitting weak power for alignment. When the process has proceeded to step S715, power transmission units 700A and 700B are selected as targets for transmitting weak power for alignment.

  When one of the processes in steps S712 to S715 is completed, the process proceeds to step S716, and the control is returned to the flowchart of FIG.

  FIG. 6 is a timing chart showing changes in transmitted power and received voltage that change in the process of FIGS. 4 and 5.

  In FIG. 6, as illustrated in FIG. 3, weak power for alignment from the vehicle 10 </ b> A in a situation where the vehicle 10 </ b> B occupies the power transmission unit 700 </ b> B after completion of charging (a state where the power transmission unit 700 </ b> B is not transmitting power). The operation waveform when there is a power transmission request is shown.

  In response to a request for transmission of weak power from vehicle 10A (step S30 in FIG. 4), weak power is transmitted from power transmission unit 700A of power transmission device 20A and power transmission unit 700B of power transmission device 20B at time t1.

  Preferably, the weak power transmission at this time is transmitted so as to have different power characteristics for each power transmission unit. As an example of making the power characteristics different for each power transmission unit, it is conceivable to vary the power transmission supply time, such as the supply time TA from the power transmission unit 700A and the supply time TB from the power transmission unit 700B. In addition, as another example in which the power characteristic is different for each power transmission unit, power may be transmitted so that the number of on / off times is different for each power transmission unit as illustrated in FIG.

  In the example illustrated in FIG. 6, the vehicle 10 </ b> B receives the weak power of the supply time TB from the power transmission unit 700 </ b> B from time t <b> 1 to t <b> 2. When the vehicle 10B returns a signal indicating the supply time TB to the charging station, the charging station recognizes that the power transmission unit 700B corresponding to the supply time TB is occupied. The vehicle 10B may recognize that the power is transmitted from the power transmission unit 700B, and may return a signal indicating the occupation of the power transmission unit 700B.

  From time t11, it is shown that power transmission unit 700B is excluded from the power transmission unit capable of guiding vehicle 10A, and alignment with power transmission unit 700A is performed.

  Referring to FIG. 4 again, when the coil selection processing in step S540 is completed, in charging station 90, weak power transmission for alignment with the power transmission device including the selected power transmission unit and power reception device 120 is executed in step S550. To do. In the waveform example of FIG. 6, since the power transmission device 20B is occupied by the first vehicle 10B, weak power transmission is executed only from the power transmission device 20A.

  In step S50, the vehicle 10A performs alignment by moving the vehicle 10A automatically or manually (see time t11 in FIG. 6). At the time of alignment, vehicle ECU 500 causes relay 202 to conduct, and acquires the magnitude of received voltage VR generated at both ends of resistor 201 detected by voltage sensor 203. Since this voltage is smaller than that during full-scale power transmission, vehicle ECU 500 sets relay 210 in an off state so that it is not affected by power storage device 300 during detection.

  On the vehicle side, when the magnitude of the received voltage VR exceeds the threshold value TH in step S60, the vehicle ECU 500 notifies the fact using the display unit 520. Thereby, the user recognizes that the alignment is successful. Thereafter, when the user informs that the parking position is OK by pressing the parking switch in the vehicle 10A, the process proceeds to step S70 (see time t12 in FIG. 6).

  In step S <b> 70, vehicle ECU 500 transmits a weak power transmission stop request for alignment to charging station 90. In step S570, the power supply ECU 800 of the charging station 90 receives the weak power transmission stop request, and the weak power transmission for alignment by the power transmission devices 20A and 20B is completed (see time t13 in FIG. 6).

  In step S80 and step S580, vehicle ECU 500 and power supply ECU 800 execute a pairing process for confirming whether or not alignment with one of power transmission devices 20A and 20B has been reliably performed.

  As shown at times t14 to t15 in FIG. 6, in step S540, when the power transmission device 20A is selected as a power transmission target, the power supply ECU 800 performs test power transmission for pairing from the power transmission unit 700A of the power transmission device 20A. Run.

  On the other hand, in step S540, when the power transmission device 20B is selected as the power transmission target, the power supply ECU 800 executes test power transmission for pairing from the power transmission unit 700B of the power transmission device 20B.

  Note that the test power transmission used in the pairing process should be an output that is used at a so-called specific low-power radio station (less than 1 / 100th of the main power transmission used for charging), as in the case of positioning. Is preferred.

  In FIG. 6, the power supply ECU 800 varies the duration of transmission power on for each power transmission device. That is, when power transmission is performed by the power transmission device 20A, power transmission is performed with the transmission power turned on for the TA time (see time t14 in FIG. 6). Further, when the power transmission device 20B is not occupied by the vehicle 10B, power transmission is performed by turning on the transmission power for the TB time from the power transmission device 20B as indicated by a broken line (time points t14 to t16 in FIG. 6). See).

  In steps S90 and S100, vehicle ECU 500 measures the duration time during which the received power is turned on and notifies power supply ECU 800 of the duration time during which the received power is measured in step S110. In the example of FIG. 6, the power receiving device 120 receives the transmitted power from the power transmitting device 20A. Vehicle ECU 500 notifies power supply ECU 800 that the duration of on-time of the received power is TA. Thus, power supply ECU 800 can reliably confirm that vehicle 10A has been aligned with power transmission device 20A.

  In step S620, the charging station 90 performs full-scale power transmission processing by the power transmission device that has been aligned and for which target identification has been confirmed by pairing (see time t17 in FIG. 6). In the example of FIG. 6, the power transmission device 20A performs power transmission processing. In step S <b> 120, vehicle 10 </ b> A performs full-scale power receiving processing by power receiving device 120 and charges power storage device 300 with the received power. When the charging of power storage device 300 is completed, the processing on the vehicle side and the charging station ends.

  In addition, in t1-t2 of FIG. 6, the example which performs the power transmission which made the characteristic of weak electric power differ for every power transmission part was shown. However, even if the vehicle 10B identifies the power transmission unit by pairing before charging without performing power transmission with different weak power characteristics for each power transmission unit, the information at that time is retained even after the end of charging. If so, information that can identify the power transmission unit may be returned to the charging station 90 in response to all the power transmission units transmitting the same weak power or receiving communication from the communication unit 810. .

(Occupation confirmation process and pairing modification)
FIG. 7 is a diagram for explaining a modification of the occupation confirmation process or the pairing process. In FIG. 7, power supply ECU 800 varies the on / off switching cycle of transmitted power for each power transmission device. That is, power transmission device 20A switches transmission power on and off for each cycle ΔTA, and power transmission device 20B switches transmission power on and off for each cycle ΔTB.

  Vehicle ECU 500 notifies power supply ECU 800 of the number of times the received power is switched on and off. In the example of FIG. 7, vehicle ECU 500 counts how many times the on / off switching has occurred at times t <b> 20 to t <b> 21 and notifies power supply ECU 800. As a result, the power supply ECU 800 knows which power transmission device the vehicle occupies and which power transmission device has been aligned.

  In addition, although the modification of FIG. 7 was a modification which performs an occupancy confirmation process or pairing using transmitted power, it is not limited to this. Pairing is possible with various technologies. For example, pairing is performed by using an RFID (Radio Frequency IDentification) technology and providing an RFID tag and an RFID reader in the vehicle and the power transmission unit, respectively. Also good.

  The embodiments disclosed this time are also scheduled to be implemented in appropriate combinations. The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  10A, 10B Vehicle, 20A, 20B Power transmission device, 90 Charging station, 100 Power receiving unit, 120 Power receiving device, 150, 610A, 610B Filter circuit, 200 Rectifier, 201 Resistance, 202, 210 Relay, 203 Voltage sensor, 300 Power storage device , 400 power generation device, 500 vehicle ECU, 510,810 communication unit, 520 display unit, 600A, 600B power supply unit, 700A, 700B power transmission unit, 800 power supply ECU, 900 external power supply.

Claims (1)

A non-contact power transmission system,
First and second vehicles;
A charging station,
The charging station is
A plurality of power transmission units capable of transmitting power to a vehicle in a contactless manner;
A power transmission control unit that controls power transmission from the plurality of power transmission units,
The power transmission control unit, when receiving a power transmission request signal from the first vehicle, causes weak power to be transmitted from the plurality of power transmission units,
The vehicle performs alignment with the power transmission unit based on the received voltage of the weak power,
  When the vehicle completes alignment with the power transmission unit, it sends a parking completion notification to the charging station,
When the charging station receives the parking completion notification, the charging station stops the transmission of weak power from the plurality of power transmission units,
The charging station, after stopping the transmission of the weak power, for each predetermined time, changing a switching cycle between a state of transmitting power and a state of not transmitting power for each of the power transmitting units, To send weak power from
The vehicle transmits power reception information regarding the number of times of switching of the weak power received to the charging station,
The said charging station is a non-contact electric power transmission system which specifies the power transmission part which the said vehicle stopped from the said power receiving information.

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