Non-contact charging control device

Abstract

The invention provides a non-contact charging control device which can restrain service life consumption of a charging relay. A non-contact charging control device is provided with a processor configured so as to transmit power in a non-contact manner from a power transmission device to a power reception device using wireless communication. When wireless communication is interrupted during charging in which a power receiving unit of the power receiving device receives power transmitted from the power transmitting device and charges a battery with the received power, transmission of power from the power transmitting device is stopped. The wireless communication is cut off in a state in which a relay for switching a connection state between the power receiving unit and the battery is connected, and after the wireless communication is restarted, the transmission of power from the power transmitting device is restarted in a state in which the relay is connected.

Description

Technical Field

[0001] The present disclosure relates to a contactless charging control device. Background Art

[0002] Patent Document 1 discloses a contactless power receiving device equipped with a charging relay that switches the connection between the power receiving device and the battery. When the power transmitting device charges the battery, the vehicle's ECU activates the charging relay. Furthermore, the power transmitting and receiving devices can communicate via a mutual communication unit.

[0003] [Prior art literature]

[0004] [Patent Document]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-059197 Summary of the Invention

[0006] [Problems to be Solved by the Invention]

[0007] In a contactless charging system that uses wireless communication between a power transmitting device and a power receiving device to transfer power contactlessly, if wireless communication between the two devices is interrupted during charging, the wireless communication is terminated after the charging relay is disconnected. Wireless communication is then reestablished, and the charging relay is reconnected to resume charging. In this case, the charging relay is turned on and off each time wireless communication is interrupted, which depletes the life of the charging relay.

[0008] The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a non-contact charging control device capable of suppressing the life consumption of a charging relay.

[0009] [Means for solving the problem]

[0010] A non-contact charging control device disclosed herein includes a processor configured to, in a non-contact charging system that uses wireless communication to transmit power from a power transmitting device to a power receiving device in a non-contact manner, stop power transmission from the power transmitting device when wireless communication is interrupted while a power receiving unit of the power receiving device is receiving power transmitted from the power transmitting device and charging a battery with the received power, disconnect wireless communication while a relay that switches the connection state between the power receiving unit and the battery is connected, and resume power transmission from the power transmitting device with the relay connected after wireless communication is resumed.

[0011] [Effects of the Invention]

[0012] According to the present disclosure, it is possible to realize a non-contact charging control device capable of suppressing the life consumption of a charging relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a block diagram showing a schematic configuration of a wireless power transmission system including a non-contact charging control device according to an embodiment.

[0014] Figure 2 This is a flowchart showing the processing in the non-contact charging control device.

[0015] Figure 3 This is a flowchart showing a method for determining whether to disable a position transmitter in a non-contact charging control device. DETAILED DESCRIPTION

[0016] A non-contact charging control device according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the components in the following embodiments include components that can be easily replaced by those skilled in the art, or components that are substantially the same.

[0017] (Implementation Method)

[0018] [Structure of wireless power transmission system]

[0019] Figure 1 This is a block diagram showing a schematic configuration of a wireless power transmission system including a non-contact charging control device according to an embodiment. Figure 1 The illustrated wireless power transfer system 1 includes an onboard device 11 as a power receiving device mounted on a vehicle 100 and a ground-based device 21 as a power transmitting device that transmits power from the ground to the vehicle 100 . Figure 1 The wireless power transmission system 1 shown uses wireless communication to transmit power from the ground device 21 to the vehicle-mounted device 11 in a contactless manner through magnetic field resonance, and uses magnetic field resonance coupling (magnetic field resonance) to realize power supply from the ground device 21 to the vehicle-mounted device 11 of the vehicle 100.

[0020] [Vehicle structure]

[0021] Next, the structure of vehicle 100 will be described. Vehicle 100 is an electric vehicle that can be charged with electricity supplied from an external power source, such as a battery electric vehicle (BEV) or a plug-in hybrid electric vehicle (PHEV). Vehicle 100 includes at least onboard equipment 11, a charging relay 12, a high-voltage battery 13, a shifter 14, and an ECU (Electronic Control Unit) 15, which serves as a contactless charging control device.

[0022] The in-vehicle device 11 includes a communication unit 111 , a position transmission unit 112 , and a power reception unit 113 .

[0023] The communication unit 111 is composed of an antenna and a predetermined communication module. Under the control of the ECU 15, the communication unit 111 wirelessly communicates with the communication unit 211 of the ground equipment 21 in accordance with a predetermined wireless communication standard. The predetermined wireless communication standard is a communication standard with a communication distance of less than 10 meters. Various short-range wireless communications with short communication distances can be used as the predetermined wireless communication standard. For example, it is used for communication in accordance with any communication standard established by IEEE, ISO, IEC, etc. Examples include Wi-Fi (registered trademark) and Bluetooth (registered trademark).

[0024] The position transmitter 112 is configured using a position transmitter. Under the control of the ECU 15 , the position transmitter 112 applies a voltage to the position transmitter to transmit electromagnetic waves for position detection.

[0025] The power receiving unit 113 receives power transmitted contactlessly from the power transmitting unit 213 and supplies the received power to the high-voltage battery 13. The power receiving unit 113 is electrically connected to the high-voltage battery 13 via the charging relay 12. The power receiving unit 113 is configured using a secondary coil and a resonant capacitor.

[0026] The charging relay 12 switches the connection state between the power receiving unit 113 and the high-voltage battery 13. The charging relay 12 is turned on by the ECU 15 during charging of the high-voltage battery 13 of the onboard equipment 11 from the ground equipment 21 and turned off when charging is completed.

[0027] The high-voltage battery 13 is an externally rechargeable vehicle-mounted battery and is composed of a secondary battery that stores electric power supplied from the power receiving unit 113 .

[0028] The shifter 14 is, for example, a shift lever of an AT vehicle, and appropriately switches the gears of the vehicle 100 according to the shift selected from the neutral gear "N" that cuts off the torque transmitted from the engine to the tires, the drive gear "D" that makes the vehicle 100 move forward, the reverse gear "R" that makes the vehicle 100 move backward, the parking gear "P" that stops the vehicle 100, etc.

[0029] ECU 15 is implemented using memory and a processor with hardware. Examples of this hardware include memory, a central processing unit (CPU), a digital signal processor (DSP), and a field-programmable gate array (FPGA). ECU 15 controls various components of vehicle 100.

[0030] If wireless communication is interrupted while the power receiving unit 113 of the onboard device 11 receives power from the power transmitting unit 213 of the ground device 21 and charges the high-voltage battery 13, the ECU 15 stops power transmission from the ground device 21 and disconnects wireless communication while the charging relay 12 is connected. After wireless communication is resumed, the ECU 15 resumes power transmission from the ground device 21 while the charging relay 12 is connected. Furthermore, the ECU 15 applies voltage to the position transmitter of the position transmitter 112 to transmit electromagnetic waves for position detection. The position detector 212 detects the transmitted electromagnetic waves to detect the positional offset between the ground device 21 and the onboard device 11. If wireless communication is interrupted during charging, the ECU 15 then disables the position transmitter and resumes power transmission from the ground device 21 after wireless communication is resumed. If the vehicle 100 remains parked, the ECU 15 resumes power transmission from the ground device 21.

[0031] [Structure of ground equipment]

[0032] Next, the structure of the ground device 21 will be described. The ground device 21 transmits power in a contactless manner to the vehicle 100 parked at a predetermined location, such as a parking space. The ground device 21 includes at least a communication unit 211, a position detection unit 212, a power transmission unit 213, and a metal detection unit 214.

[0033] The communication unit 211 is configured using an antenna and a predetermined communication module, and performs wireless communication with the communication unit 111 of the vehicle 100 in accordance with a predetermined wireless communication standard.

[0034] The position detection unit 212 detects the electromagnetic wave transmitted from the position transmission unit 112 to detect the positional relationship between the in-vehicle device 11 and the ground device 21 .

[0035] The power transmission unit 213 includes a primary coil and is disposed underground or on the surface of a parking lot, a road, etc. The power transmission unit 213 is electrically connected to an external AC power source and transmits power supplied from the AC power source in a contactless manner.

[0036] The metal detector 214 detects a metal foreign object between the power receiving unit 113 and the power transmitting unit 213 by detecting a change in an electric field or the like.

[0037] [Processing in the non-contact charging control device]

[0038] Next, the processing in the ECU 15 will be described. Figure 2 FIG. 1 is a flowchart showing the processing in the non-contact charging control device. Figure 2 As shown, the ECU 15 establishes wireless communication between the communication unit 111 of the in-vehicle device 11 and the communication unit 211 of the ground device 21 (step S1 ).

[0039] Next, the ECU 15 confirms that the position of the shifter 14 is the parking position and parking of the vehicle 100 is completed (step S2 ).

[0040] The ECU 15 then performs an alignment check (step S3) to confirm whether the onboard device 11 and the ground device 21 are aligned. The ECU 15 applies voltage to the position transmitter of the position transmitter 112 to transmit electromagnetic waves for position detection. The ECU 15 then receives the result from the position detector 212 from the communication unit 111, and determines whether the onboard device 11 and the ground device 21 are properly aligned. If the alignment check indicates that the onboard device 11 and the ground device 21 are properly aligned, the ECU 15 determines the alignment is OK. If the alignment is not satisfactory, the ECU 15 reports that the vehicle 100's position should be adjusted.

[0041] If the alignment check determines that the battery is OK, the ECU 15 turns on the charging relay 12 to electrically connect the power receiving unit 113 and the high-voltage battery 13 , thereby enabling charging (step S4 ).

[0042] Then, the ECU 15 starts power transmission (step S5 ). Specifically, the ECU 15 starts receiving power from the power transmission unit 213 via the power reception unit 113 and charges the high-voltage battery 13 with the received power.

[0043] Here, it is assumed that the ECU 15 detects that the wireless communication between the communication unit 111 and the communication unit 211 is interrupted during charging (step S6 ).

[0044] Then, the ECU 15 stops the power transmission (step S7 ). Specifically, the ECU 15 stops receiving power from the power transmission unit 213 via the power reception unit 113 .

[0045] Furthermore, the ECU 15 disconnects the electrical connection between the power receiving unit 113 and the high-voltage battery 13 by turning off the charging relay (step S8 ).

[0046] Then, the ECU 15 cuts off the wireless communication between the communication unit 111 and the communication unit 211 (step S9 ).

[0047] The ECU 15 then determines whether charging has ended (step S10). If the ECU 15 determines that charging has ended (step S10: Yes), the series of processes ends. On the other hand, if the ECU 15 determines that charging has not ended (step S10: No), the process returns to step S1 and repeats the process.

[0048] Here, when wireless communication is interrupted during charging, ECU15 stops the transmission of power from the ground equipment 21 and cuts off wireless communication while the charging relay 12 is connected. That is, in step S6, when wireless communication is interrupted during charging, Figure 2 As indicated by the middle dashed line, the ECU 15 stops the power transmission in step S7 , but does not perform the process of turning off the charging relay 12 in step S8 , and interrupts the wireless communication in step S9 .

[0049] Furthermore, after resuming wireless communication, ECU15 resumes the transmission of power from the ground equipment 21 while maintaining the state of connecting the charging relay 12. That is, returning from step S10 to step S1, after resuming wireless communication, as shown in FIG. Figure 2 As indicated by the middle dashed line, the ECU 15 does not need to turn on the charging relay 12 , and therefore does not perform the process of step S4 , but starts power transmission in step S5 .

[0050] By executing the above-described process, it is possible to prevent the charging relay 12 from being repeatedly turned on and off every time wireless communication is interrupted, thereby suppressing the life of the charging relay 12 from being depleted.

[0051] [Disabling the Position Transmitter]

[0052] In addition to not performing the on / off processing of the charging relay 12 when the wireless communication is disconnected / reconnected, the position transmitter may be disabled when the wireless communication is reconnected during the alignment check in step S3 .

[0053] Figure 3 This is a flowchart showing a method for determining whether to disable a position transmitter in a non-contact charging control device. Figure 3 The determination shown is performed, for example, before the alignment inspection in step S3 is performed.

[0054] First, during the alignment check, the ECU 15 determines whether there is a history record indicating that the alignment check between the onboard device 11 and the ground device 21 was successful (step S11). If the ECU 15 determines that there is a history record indicating that the alignment check was successful (step S11: Yes), the process proceeds to step S12. If the ECU 15 determines that there is no history record indicating that the alignment check was successful (step S11: No), the process proceeds to step S14.

[0055] Next, the ECU 15 determines whether the shifter 14 is in the parking position (step S12). If the ECU 15 determines that the shifter 14 is in the parking position (step S12: Yes), the process proceeds to step S13. If the ECU 15 determines that the shifter 14 is not in the parking position (step S12: No), the process proceeds to step S14.

[0056] In step S13 , the ECU 15 validates the determination history that the alignment check was OK (step S13 ).

[0057] On the other hand, in step S14 , the ECU 15 invalidates the determination history that the alignment check was OK (step S14 ).

[0058] Next, the ECU 15 determines whether wireless communication has been interrupted during charging (step S15 ). If the ECU 15 determines that wireless communication has been interrupted during charging (step S15 : Yes), the process proceeds to step S16 . If the ECU 15 determines that wireless communication has not been interrupted during charging (step S15 : No), the process proceeds to step S18 .

[0059] ECU 15 then determines whether the alignment check OK determination history is valid (step S16). If, in step S13, the alignment check OK determination history is valid, ECU 15 determines that the alignment check OK determination history is valid (step S16: Yes), and the process proceeds to step S17. On the other hand, if, in step S14, the alignment check OK determination history is invalid, ECU 15 determines that the alignment check OK determination history is invalid (step S16: No), and the process proceeds to step S18.

[0060] In step S17 , the ECU 15 sets a flag indicating a request to disable the position transmitter to a request status (step S17 ).

[0061] On the other hand, in step S18 , the ECU 15 sets the flag indicating the invalidation request of the position transmitter to no request (step S18 ).

[0062] After making the above-described determination, if the position transmitter disable request is received during the alignment check in step S3, ECU 15 disables the position transmitter during the alignment check and performs the alignment check using the position information from the previous alignment check. Specifically, after performing the alignment check, if wireless communication is interrupted during charging, ECU 15 disables the position transmitter and resumes power transmission from ground equipment 21 after wireless communication is resumed, provided that vehicle 100 remains parked (shifter 14 is in the park position).

[0063] Here, the metal detector 214 detects metal foreign objects by detecting changes in the electric field. Therefore, if the electric field changes when the charging relay 12 is turned on and voltage is applied, the metal detector 214 may mistakenly detect a metal foreign object. Similarly, if the electric field changes when voltage is applied to the position transmitter of the position transmitter 112, the metal detector 214 may mistakenly detect a metal foreign object. Furthermore, if voltage is applied to both the charging relay 12 and the position transmitter simultaneously, the metal detector 214 is more likely to misdetect.

[0064] The metal detector 214 cannot determine the source of the electric field, thus causing such erroneous detection. In addition, in order to prevent erroneous detection, the foreign body detection parameters of the metal detector 214 can also be set higher, but in this case, the foreign body detection function may not be fully utilized.

[0065] In contrast, the ECU 15 disables the position transmitter when power transmission is resumed after wireless communication is interrupted during charging. This prevents erroneous detection caused by simultaneous application of voltage to the charging relay 12 and the position transmitter.

[0066] Those skilled in the art will readily deduce further effects and variations. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Therefore, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0067] [Explanation of Reference Numerals]

[0068] 1 Wireless Power Transmission System

[0069] 11 Vehicle-mounted equipment

[0070] 12 Charging relay

[0071] 13 High-voltage battery

[0072] 14 gear shifter

[0073] 15 ECU

[0074] 21 Ground Equipment

[0075] 100 vehicles

[0076] 111, 211 Ministry of Communications

[0077] 112 Position Transmission Unit

[0078] 113 Receiving Unit

[0079] 212 Position detection unit

[0080] 213 Power Transmission Department

[0081] 214 Metal Detection Department

Claims

1. A non-contact charging control device comprising a processor, wherein the processor is configured to: In a contactless charging system that uses wireless communication to transfer power from a power transmitting device to a power receiving device in a contactless manner, When wireless communication is interrupted while the power receiving unit of the power receiving device is receiving power transmitted from the power transmitting unit and charging the battery with the received power, the power transmission from the power transmitting device is stopped, and wireless communication is disconnected while a relay for switching the connection state between the power receiving unit and the battery is connected. After wireless communication is resumed, the power transmission from the power transmitting device is resumed while the relay is connected.

2. The non-contact charging control device according to claim 1, wherein: The power receiving device is an on-board device mounted on a vehicle. The power transmission device is ground equipment that transmits electric power from the ground to the vehicle.

3. The non-contact charging control device according to claim 2, wherein: After the processor applies voltage to the position transmitter to transmit electromagnetic waves for position detection, and detects the position offset between the power transmitting device and the power receiving device by detecting the transmitted electromagnetic waves through the position detection unit, if wireless communication is interrupted during charging, after the wireless communication is resumed, if the vehicle continues to be parked, the position transmitter is set to invalid and power transmission from the power transmitting device is resumed.

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