VEHICLE CHARGING DEVICE, VEHICLE CHARGING CONTROL METHOD, AND VEHICLE CHARGING SYSTEM

Abstract

The present invention relates to a vehicle charging device, a vehicle charging control method, and a vehicle charging system. According to one aspect of the present invention, a charging circuit is provided, the charging circuit being connected to a vehicle drive battery in the order of a DC / DC converter of which the input side is connected to an external power supply via a first switch and the output side is connected to an auxiliary battery, and a second switch. When the voltage of the auxiliary battery decreases, the second switch is open and the charging circuit is activated to start charging of the auxiliary battery, and then the second switch is closed and charging of the vehicle drive battery is started. Thereby, it is possible to stably charge the vehicle drive battery even when the voltage of the auxiliary battery is low, while ensuring charging safety.

Description

[Technical field]

[0001] The present invention relates to a vehicle charging device, a vehicle charging control method, and a vehicle charging system. [Background technology]

[0002] The vehicle charging device of Patent Document 1 includes a charging circuit that converts AC voltage supplied from an external power source via EVSE (Electric Vehicle Supply Equipment) into DC voltage and charges a battery with the DC voltage, a charging control unit that controls the charging circuit and changes the potential of a signal line of a pilot signal output from a CPLT (Control Pilot) control circuit provided in the EVSE, and a capacitor C that is charged by the pilot signal until the CPLT control circuit starts communicating with the charging control unit. If the power supply cannot be secured when the charging control unit is started up, the power stored in the capacitor C is supplied to the charging control unit as a driving power supply. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-082849 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a vehicle charging device, a switch (relay) that electrically disconnects the vehicle driving battery is sometimes provided to safely charge the vehicle driving battery and operate the DC / DC converter. However, when the voltage of the auxiliary battery drops, it is difficult to stably operate the high-voltage switch using only auxiliary power, such as the power of the capacitor charged by the pilot signal, and there is a risk that the vehicle drive battery will not be able to be charged.

[0005] The present invention has been made in consideration of the current situation, and its purpose is to provide a vehicle charging device, a vehicle charging control method, and a vehicle charging system that can stably charge a vehicle drive battery even when the voltage of the auxiliary battery is low, while ensuring the safety of charging. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a charging circuit for charging a vehicle drive battery, the input side of which is connected to an external power source via a first switch, and the output side of which is connected to a DC / DC converter connected to an auxiliary battery that is a drive source for on-board equipment, a second switch, and then the vehicle drive battery, the charging circuit comprising: a charging control unit that controls the charging circuit, the charging control unit being connected to a signal line of a pilot signal output from an opening / closing control circuit that controls the first switch; an external power supply permission circuit connected to the signal line and changing the potential of the signal line; and a power supply unit that supplies power to the charging control unit. Effect of the Invention

[0007] According to the present invention, it is possible to stably charge a vehicle drive battery even when the voltage of the auxiliary battery is low, while ensuring the safety of the charging. [Brief description of the drawings]

[0008] [Figure 1] 1 is a configuration diagram showing one embodiment of a vehicle charging system including a vehicle charging device; [Diagram 2] 4 is a flow chart illustrating a first embodiment of a charging process. [Diagram 3] 5 is a flow chart illustrating a second embodiment of a charging process. [Figure 4] FIG. 11 is a configuration diagram showing another example of the power supply unit. [Diagram 5] 10 is a flow chart illustrating a third embodiment of a charging process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a vehicle charging device, a vehicle charging control method, and a vehicle charging system according to the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a vehicle charging system 100 for use with electric vehicles and the like.

[0010] The vehicle charging system 100 comprises a vehicle driving battery 1 mounted on a vehicle 101, an external power source 2 and an EVSE (Electric Vehicle Supply Equipment) 3 outside the vehicle 101, and a vehicle charging device 4, a DC / DC converter 5, a PCM (Powertrain Control Module) 11, switches S4, S5, and an auxiliary battery 7 provided on the vehicle 101. Here, the EVSE 3 is connected to an external power source 2, and the vehicle charging device 4 is detachably connected to the EVSE 3 via a charging cable. Furthermore, switches S4, S5 are disposed between the DC / DC converter 5 and the vehicle driving battery 1, and the auxiliary battery 7 is connected to the DC / DC converter 5.

[0011] The vehicle drive battery 1 is a high-voltage battery used as a drive source for the running motor of the vehicle 101, and is made up of a secondary battery such as a lithium-ion battery. The external power source 2 is an AC power source for general household use or an AC power source provided in a charging facility installed outdoors.

[0012] The EVSE 3 is an electrical circuit switching unit connected to an external power source 2 outside the vehicle 101, and has switches S6, S7 that open and close the connection circuit between the external power source 2 and the vehicle charging device 4 (charging circuit 41 described later), and a CPLT (Control Pilot) control circuit 32 as an opening and closing control circuit that controls the switches S6, S7. The switches S6 and S7 are formed of, for example, relays, and electrically connect or disconnect the external power source 2 and the vehicle charging device 4 of the vehicle 101 (a charging circuit 41, described later). The CPLT control circuit 32 controls the on / off (opening / closing) of the switches S6 and S7, and generates a pilot signal CPLT.

[0013] The vehicle charging device 4 mounted on the vehicle 101 includes a charging circuit 41, a charging control unit 42, an external power supply permission circuit 43, and a capacitor charging circuit 44. The input side of the charging circuit 41 is connected to the external power source 2 via switches S6 and S7.

[0014] The charging circuit 41 is composed of known circuits including a power factor correction circuit, a DC / DC converter, a rectifier circuit, etc., and converts the AC voltage supplied from the external power supply 2 into a predetermined DC voltage based on a control signal from the charging control unit 42. The charging control unit 42 includes a microcomputer, and controls the charging circuit 41 so that the vehicle driving battery 1 is charged based on the power supplied from the external power source 2.

[0015] The charging control unit 42 is connected to the CPLT control circuit 32 via a pilot signal line LP equipped with a diode D3, and receives the pilot signal CPLT generated by the CPLT control circuit 32 via the pilot signal line LP. The diode D3 is connected to the pilot signal line LP so that the anode is on the CPLT control circuit 32 side and the cathode is on the charge control unit 42 side.

[0016] The external power supply permission circuit 43 is a circuit for selectively lowering the potential of the pilot signal line LP to a specified voltage, and has a series circuit (first potential change circuit) in which a resistor R2 (second resistor) and a switch S2 (second switch) are connected in series, and a series circuit (second potential change circuit) in which a resistor R3 (third resistor) and a switch S3 (third switch) are connected in series, which are connected in parallel with the charging control unit 42. The switches S2 and S3 of the external power supply permission circuit 43 are formed of semiconductor switches such as transistors, and the on / off of the switches S2 and S3 is controlled by the charging control unit .

[0017] The charging control unit 42 controls the on / off of the switches S2 and S3 to change the potential of the pilot signal line LP. Such a change in the potential of the pilot signal line LP is configured to serve as a power supply permission command to the CPLT control circuit 32.

[0018] The capacitor charging circuit 44 is provided on a charging path that connects the pilot signal line LP between the diode D3 (third diode) and the external power supply permission circuit 43 and the power supply terminal 42A of the charging control unit 42. The capacitor charging circuit 44 has a series connection circuit in which a resistor R1 (first resistor), a normally closed switch S1 (first switch), and a diode D1 (first diode) are connected in series, and a capacitor C (capacitor) provided in a circuit connecting the series connection circuit and the power supply terminal 42A and the ground GND.

[0019] That is, in the charging path, a resistor R1, a switch S1, and a diode D1 are arranged in this order from the pilot signal line LP side, and the diode D1 is connected so that the anode is on the switch S1 side and the cathode is on the charging control unit 42 side. A capacitor C is disposed in a circuit connecting the charging path between the diode D1 and the power supply terminal 42A and the ground GND.

[0020] A capacitor charging circuit 44 including a capacitor C, a resistor R1, a switch S1, and a diode D1 constitutes a power supply unit that supplies power to the charging control unit 42. The charge control unit 42 controls the on / off of the switch S1, and when the switch S1 is turned on, a charge is stored in the capacitor C.

[0021] Furthermore, the power supply terminal 42A of the charging control unit 42 is connected to the auxiliary battery 7 via a diode D2 (second diode). The diode D2 is disposed so that its anode is on the auxiliary battery 7 side and its cathode is on the power supply terminal 42A side. When the auxiliary battery 7 is depleted, the capacitor C is used as the power source for the charge control unit 42 in place of the auxiliary battery 7.

[0022] The DC / DC converter 5 steps down a predetermined DC voltage output by the charging circuit 41 and the voltage of the vehicle driving battery 1. The auxiliary battery 7 is a drive source for various in-vehicle devices such as an ECU (Electronic Control Unit) and auxiliary devices, and is made up of a secondary battery such as a lead storage battery. The auxiliary battery 7 is charged by the output voltage of the DC / DC converter 5 .

[0023] The ECUs that use the auxiliary battery 7 as a power source include a vehicle ECU 8 that controls the operation of the vehicle 101, a battery ECU 9 that monitors the vehicle drive battery 1, and other ECUs 10. The battery ECU 9 measures the voltage, current, temperature, etc. of the vehicle drive battery 1 and performs cooling management of the vehicle drive battery 1.

[0024] The switches S4, S5 arranged between the DC / DC converter 5 and the vehicle driving battery 1 are controlled by the vehicle ECU 8 to be turned on and off (open and closed). A PCM 11 is provided between the DC / DC converter 5 and the switches S4 and S5, and the PCM 11 collectively represents a power conversion device that receives power from a drive battery and serves as a driving force, such as an inverter for driving a motor.

[0025] As described above, the input side of the charging circuit 41 is connected to the external power source 2 via switches S6 and S7, and the output side of the charging circuit 41 is connected to the vehicle drive battery 1, in the order of the DC / DC converter 5 connected to the auxiliary battery 7, and switches S4 and S5. In other words, the DC / DC converter 5 is arranged between the charging circuit 41 and the vehicle driving battery 1, switches S6 and S7 are arranged between the DC / DC converter 5 and the vehicle driving battery 1, and the auxiliary battery 7 is connected to the DC / DC converter 5.

[0026] In other words, the DC / DC converter 5 is electrically connected directly to the output side of the charging circuit 41 without passing through switches S4 and S5, while the vehicle driving battery 1 is electrically connected to the output side of the charging circuit 41 and the DC / DC converter 5 via switches S4 and S5. Thus, the vehicle charging system 100 includes switches S4, S5 that electrically disconnect the vehicle driving battery 1 from the charging circuit 41 and the DC / DC converter 5 connected to the charging circuit 41.

[0027] According to this configuration, when switches S4, S5 are off (open), the vehicle driving battery 1 is electrically disconnected from the output side of the charging circuit 41 and the DC / DC converter 5, but since the DC / DC converter 5 is electrically connected to the output side of the charging circuit 41, the DC / DC converter 5 can step down the output voltage of the charging circuit 41 to charge the auxiliary battery 7. On the other hand, when switches S4 and S5 are on (closed), the vehicle drive battery 1 is electrically connected to the output side of the charging circuit 41 and the DC / DC converter 5, so that the vehicle drive battery 1 can be charged by the output of the charging circuit 41, and the DC / DC converter 5 can step down the high voltage of the vehicle drive battery 1 to charge the auxiliary battery 7.

[0028] The flowchart in FIG. 2 shows a charging process for the vehicle drive battery 1 and the auxiliary battery 7 when the EVSE 3 is connected to the vehicle 101, in other words, a first embodiment of a process of a vehicle charging control method executed by the vehicle charging device 4. In step S201, the EVSE 3 is connected to the vehicle 101 via a charging cable. At this time, since the switches S6 and S7 of the EVSE 3 are in the OFF state (open state), an electric path electrically connecting the external power supply 2 and the charging circuit 41 is not formed.

[0029] On the other hand, when the EVSE 3 is connected to the vehicle 101, the CPLT control circuit 32 and the pilot signal line LP on the vehicle 101 side are connected, and the CPLT control circuit 32 outputs a pilot signal CPLT of 12 V DC to the pilot signal line LP. Then, in step S202, the 12V pilot signal CPLT output from the CPLT control circuit 32 to the pilot signal line LP is applied to the capacitor C through a charging path consisting of the diode D3, the resistor R1, the normally closed switch S1, and the diode D1, and the capacitor C is charged by the pilot signal CPLT.

[0030] Next, in step S203, the charging control unit 42 is started up. Here, if the voltage of the auxiliary battery 7 at the time when the EVSE 3 is connected to the vehicle is sufficient to drive the microcomputer of the charging control unit 42, the microcomputer of the charging control unit 42 can be started using the auxiliary battery 7 as a power source.

[0031] On the other hand, if the voltage of the auxiliary battery 7 at the time when the EVSE 3 is connected to the vehicle is not sufficient to drive the microcomputer of the charging control unit 42, a power source sufficient to start the charging control unit 42 will not be secured. However, when the EVSE3 is connected to the vehicle, charging of the capacitor C begins using the pilot signal CPLT. As the charging of the capacitor C progresses and the charging voltage of the capacitor C exceeds the voltage required for the operation of the charging control unit 42, the charging control unit 42 is started up by the power supply from the capacitor C.

[0032] In step S204, the started charging control unit 42 controls the switch S1 of the capacitor charging circuit 44 to be turned off to stop charging the capacitor C, and also controls the switch S2 of the external power supply permission circuit 43 to be turned on. When the switch S2 is turned on, the potential of the pilot signal line LP is changed from 12V to 9V, for example. The CPLT control circuit 32 detects this change in potential of the pilot signal line LP as a state in which the vehicle charging device 4 of the vehicle 101 is connected.

[0033] In step S205, communication is started between the CPLT control circuit 32 and the charging control unit 42, and the CPLT control circuit 32 outputs a pulsed pilot signal CPLT to the pilot signal line LP. Here, the pulse width of the pilot signal CPLT output by the CPLT control circuit 32 is set to a value according to the supply current capacity of the external power source 2, and the charging control unit 42 detects the supply current capacity of the external power source 2 from the pulse width of the acquired pilot signal CPLT. In other words, the CPLT control circuit 32 performs PWM (Pulse Width Modulation) to change the pulse width of the pilot signal CPLT in accordance with the supply current capacity of the external power supply 2.

[0034] Furthermore, the charging control unit 42, which has started communication with the CPLT control circuit 32, executes a fault diagnosis. In this failure diagnosis, the charging control unit 42 diagnoses whether or not there is an abnormality in the charging circuit 41 of the vehicle charging device 4 and the like.

[0035] In step S206, the charging control unit 42 determines whether the voltage of the auxiliary battery 7 is lower than a set voltage (allowable minimum voltage). Then, if the voltage of the auxiliary battery 7 is below the set voltage, in other words, if charging of the auxiliary battery 7 is necessary, in step S207, the charging control unit 42 turns on switch S3 of the external power supply permission circuit 43 while keeping switch S2 of the external power supply permission circuit 43 on, thereby further reducing the potential of the pilot signal line LP, for example, from 9 V to 6 V.

[0036] When the CPLT control circuit 32 detects that the potential of the pilot signal line LP has reached 6 V, it recognizes that the charging control unit 42 has permitted power supply from the external power source 2, and controls the switches S6 and S7 to be on (closed). In other words, when the conditions for starting power supply from the external power source 2 are met, the charging control unit 42 turns on the switch S3 and switches the potential of the pilot signal line LP to a specified voltage, thereby instructing the CPLT control circuit 32 to start power supply. When the CPLT control circuit 32 controls the switches S6 and S7 to be on, the external power source 2 and the input side of the charging circuit 41 are electrically connected, and the supply of AC voltage from the external power source 2 to the charging circuit 41 begins.

[0037] In step S208, the charging control unit 42 starts the operation of the charging circuit 41 and the DC / DC converter 5. As a result of the operation of the charging circuit 41 and the DC / DC converter 5, the charging circuit 41 converts the AC voltage supplied from the external power source 2 into a predetermined DC voltage, and further, the DC / DC converter 5 steps down the predetermined DC voltage output by the charging circuit 41, and the auxiliary battery 7 is charged by the output voltage of this DC / DC converter 5.

[0038] At this time, since switches S4 and S5 are kept in the off state (open state), charging of the vehicle drive battery 1 is not performed, and charging of the auxiliary battery 7, whose voltage has dropped, is performed before charging of the vehicle drive battery 1. In other words, when the voltage of the auxiliary battery 7 is low, after charging of the auxiliary battery 7 starts, switches S4 and S5 are closed and charging of the vehicle drive battery 1 by the charging circuit 41 starts.

[0039] In step S209, the charging control unit 42 determines whether or not the auxiliary battery 7 has been charged until its voltage reaches or exceeds a set voltage. If the charge of the auxiliary battery 7 is insufficient, the charge control unit 42 continues the charging operation of the auxiliary battery 7. On the other hand, when the auxiliary battery 7 is charged until its voltage reaches or exceeds the set voltage, the charging control unit 42 temporarily stops the operation of the charging circuit 41 in step S210.

[0040] In step S211, the charging control unit 42 starts up the vehicle ECU 8, the battery ECU 9, and the like, which are driven by the auxiliary battery 7. In other words, the charging control unit 42 outputs a trigger signal to start up the vehicle ECU 8, the battery ECU 9, and the like. Then, the battery ECU 9 that has been started up performs diagnosis of the vehicle drive battery 1 and the like. The vehicle ECU 8 and the battery ECU 9 are activated by a signal from the main switch of the vehicle 101 or the like, except when the vehicle drive battery 1 is being charged.

[0041] In step S212, the charges stored in the capacitors provided in the charging circuit 41 and the DC / DC converter 5 are discharged. Next, in step S213, the vehicle ECU 8 controls the switches S4, S5 to the on state (closed state) and connects the vehicle drive battery 1 to the output side of the charging circuit 41, thereby making the vehicle drive battery 1 available for charging.

[0042] Then, in step S214, the charging control section 42 operates the charging circuit 41 again to start charging the vehicle driving battery 1. In other words, when the voltage of the auxiliary battery 7 is low, the vehicle charging device 4 first charges the auxiliary battery 7, and when charging of the auxiliary battery 7 is completed, it temporarily stops operation of the charging circuit 41, and then operates the charging circuit 41 after switches S4 and S5 are turned on to start charging the vehicle drive battery 1.

[0043] On the other hand, if in step S206 the charging control unit 42 determines that the voltage of the auxiliary battery 7 is equal to or higher than the set voltage, in other words, if it determines that charging of the auxiliary battery 7 is not necessary, in step S215 the charging control unit 42 starts up the vehicle ECU 8, battery ECU 9, etc., which use the auxiliary battery 7 as a driving source. Next, in step S213, the vehicle ECU 8 controls the switches S4, S5 to the on state (closed state) and connects the vehicle drive battery 1 to the output side of the charging circuit 41, thereby making the vehicle drive battery 1 available for charging.

[0044] In step S217, the charging control unit 42 turns on the switch S3 of the external power supply permission circuit 43 while keeping the switch S2 of the external power supply permission circuit 43 on, thereby further reducing the potential of the pilot signal line LP from 9V to 6V. When the CPLT control circuit 32 detects that the potential of the pilot signal line LP has reached 6 V, it recognizes that the charging control unit 42 has permitted power supply from the external power source 2, and controls the switches S6 and S7 to be on (closed). Next, in step S214, the charging control unit 42 operates the charging circuit 41 to start charging the vehicle driving battery 1.

[0045] According to the vehicle charging device 4, vehicle charging control method, and vehicle charging system 100, the vehicle drive battery 1 can be stably charged even when the voltage of the auxiliary battery 7 is low, while ensuring the safety of charging. In other words, since the charging circuit 41 and the vehicle drive battery 1 can be electrically separated by the switches S4 and S5, the vehicle drive battery 1 can be charged safely.

[0046] In addition, when the voltage of the auxiliary battery 7, which serves as the power source for driving the switches S4 and S5 to open and close, drops, the auxiliary battery 7 is first charged by the external power source 2, thereby enabling stable control of the high-voltage switches S4 and S5. Therefore, even if the voltage of the auxiliary battery 7 is low when the EVSE 3 is connected to the vehicle 101, the switches S4 and S5 can be reliably controlled to start charging the vehicle drive battery 1.

[0047] For example, in a system in which a switch is placed between the vehicle drive battery 1 and DC / DC converter 5 and the charging circuit 41, and charging of the auxiliary battery 7 and the vehicle drive battery 1 are performed in parallel, if the auxiliary battery 7 is in a low voltage state, even if the EVSE 3 is connected to the vehicle, there is a possibility that charging will not be possible because there may not be enough power source for controlling the switches S4 and S5. In other words, if a user who owns vehicle 101 leaves vehicle 101 unattended and auxiliary battery 7 becomes discharged and enters a low voltage state, even if a home charger is connected, charging cannot be performed because switches S4 and S5 cannot be controlled, and auxiliary battery 7 may need to be replaced.

[0048] In contrast, according to the vehicle charging device 4, vehicle charging control method, and vehicle charging system 100 described above, if the auxiliary battery 7 is in a low voltage state when the EVSE 3 is connected, the auxiliary battery 7 is first charged by the external power source 2, and a power source for controlling the switches S4 and S5 (in other words, a power source for the charging control unit 42, the vehicle ECU 8, and the battery ECU 9 that execute the charging control) is secured, and then the switches S4 and S5 are turned on to start charging the vehicle drive battery 1. Therefore, even if the auxiliary battery 7 is in a low voltage state, the vehicle driving battery 1 can be charged without replacing the auxiliary battery 7.

[0049] Incidentally, in the charging process shown in the flowchart of FIG. 2, when charging of the auxiliary battery 7 is completed, the operation of the charging circuit 41 is temporarily stopped and then the switches S4 and S5 are controlled to be turned on, and then the operation of the charging circuit 41 is resumed, thereby preventing an overcurrent from flowing when the switches S4 and S5 are turned on. In contrast, if the charging control unit 42 controls the switches S4 and S5 to be turned on while setting the output voltage of the charging circuit 41 to be equal to the voltage of the vehicle drive battery 1, the switches S4 and S5 can be turned on while preventing the flow of overcurrent and continuing the operation of the charging circuit 41.

[0050] The flow chart of FIG. 3 shows a second embodiment of the charging process in which switches S4 and S5 are turned on while the charging circuit 41 continues to operate. 2. The processing contents in steps S301 to S307 in the flowchart of FIG. 3 are the same as steps S201 to S207 in the flowchart of FIG. 2, and the processing contents in steps S314 to S316 in the flowchart of FIG. 3 are the same as steps S215 to S217 in the flowchart of FIG. For this reason, detailed descriptions of the processing contents of steps S301 to S307 and steps S314 to S316 will be omitted, and the following description will mainly focus on the processing contents of steps S308 to S313.

[0051] When the supply of AC power from the external power supply 2 is started while the voltage of the auxiliary battery 7 is low, the charging control unit 42 starts the operation of the charging circuit 41 and the DC / DC converter 5 in step S308. Then, in step S309, the charging control unit 42 starts up the vehicle ECU 8 and the battery ECU 9 that use the auxiliary battery 7 as a drive source, and causes the battery ECU 9 to execute diagnosis of the vehicle driving battery 1 and the like.

[0052] Next, in step S310, the charging control unit 42 acquires a signal indicating the voltage value of the vehicle driving battery 1 from the battery ECU 9. In step S311, the charging control unit 42 controls the charging circuit 41 to make the output voltage value of the charging circuit 41 the same potential as the voltage value of the battery 1 for driving the vehicle.

[0053] Then, in step S312, when the output voltage value of the charging circuit 41 and the voltage value of the vehicle driving battery 1 are at the same potential, the vehicle ECU 8 controls the switches S4 and S5 to the on state (closed state) and connects the vehicle driving battery 1 to the output side of the charging circuit 41, thereby making it possible to charge the vehicle driving battery 1. In step S313, the vehicle driving battery 1 is charged by the output voltage of the charging circuit 41.

[0054] According to this charging process, when the output voltage value of the charging circuit 41 and the voltage value of the vehicle driving battery 1 are at the same potential, the switches S4 and S5 are controlled to the on state, thereby preventing an overcurrent from flowing through the switches S4 and S5 when they are switched from off to on. Furthermore, according to the charging process described above, although charging of the auxiliary battery 7 is started first, charging of the vehicle drive battery 1 is started without waiting for the completion of charging of the auxiliary battery 7, so that charging of the vehicle drive battery 1 starts earlier and the time until charging of the vehicle drive battery 1 is completed is shortened.

[0055] Furthermore, after charging starts, the charging control unit 42 does not need to perform a process of diagnosing the charge amount of the auxiliary battery 7. Furthermore, by speeding up the start-up of the battery ECU 9 and other components that use the auxiliary battery 7 as a power source, the charging state can be quickly notified to the operator performing the charging operation.

[0056] Incidentally, the vehicle charging device 4 shown in FIG. 1 includes a capacitor charging circuit 44 as a power supply unit that supplies power to the charging control unit 42 in place of the auxiliary battery 7, but the power supply unit is not limited to the capacitor charging circuit 44. For example, instead of the capacitor charging circuit 44, the vehicle charging device 4 can include a battery power supply unit as the power supply unit, which supplies power from a battery to the charging control unit 42. As the battery in the battery power supply unit, a primary battery, a rechargeable dry battery, or the like is used.

[0057] FIG. 4 is a configuration diagram of a main part of a vehicle charging system 100 showing a third embodiment in which a battery power supply unit is used as the power supply unit. Battery power supply unit 45 shown in FIG. 4 is one form of power supply unit replacing capacitor charging circuit 44, and includes a battery 46 and supplies power from battery 46 to charging control unit 42. Battery power supply 45 includes a battery 46, a switch S8, a switch S9, a switch S10, and a diode D4.

[0058] In detail, a switch S8, a switch S10, and a diode D4 are connected in series in the power supply path connecting the battery 46 and the power supply terminal 42A of the charging control unit 42, in that order from the battery 46 side. Furthermore, a switch S9 is connected in parallel to the series circuit of the switches S8 and S10.

[0059] Moreover, the diode D4 is arranged so that the anode is on the battery 46 side and the cathode is on the charge control unit 42 side. Battery power supply unit 45 switches between supplying and stopping power from battery 46 to charging control unit 42 depending on whether switch S8, switch S9, and switch S10 are on or off. The switch S8 is configured to be turned on when the pilot signal CPLT is at a high potential.

[0060] Switches S9 and S10 are turned on and off by the charging control unit 42. Switch S9 is a normally open switch that is off when the control is stopped, and switch S10 is a normally closed switch that is on when the control is stopped. As will be described later, when pilot signal CPLT becomes a pulsed signal and switch S8 cannot be stably maintained in the on state by pilot signal CPLT, charging control unit 42 turns on switch S9 to continue power supply from battery 46 to charging control unit 42.

[0061] The flow chart of FIG. 5 illustrates a third embodiment of a charging process by a vehicle charging device 4 including the battery power supply 45 shown in FIG. The process contents in steps S409 to S420 in the flowchart of FIG. 5 are the same as those in steps S206 to S217 in the flowchart of FIG. For this reason, detailed description of the processing contents of steps S409 to S420 will be omitted, and the following description will mainly focus on the processing contents of steps S401 to S408.

[0062] In step S401, the EVSE 3 is connected to the vehicle 101 via a charging cable. When the EVSE 3 is connected to the vehicle 101, the CPLT control circuit 32 and the pilot signal line LP of the vehicle 101 are connected, and the CPLT control circuit 32 outputs a pilot signal CPLT of 12 V DC to the pilot signal line LP.

[0063] Due to the output of the pilot signal CPLT, in the next step S402, the switch S8 is switched from off to on, and power is supplied from the battery 46 to the charging control unit 42 via the switch S8, the normally closed switch S10, and the diode D4. Then, in step S403, the charging control unit 42 is started up by the power supply from the battery 46 (in other words, the power is turned on).

[0064] In step S404, the charging control unit 42 determines whether the voltage of the auxiliary battery 7 is below a set voltage (allowable minimum voltage). If the voltage of auxiliary battery 7 is below the set voltage and charging of auxiliary battery 7 is required, in step S405, charging control unit 42 turns on switch S9 of battery power supply unit 45 and turns off switch S10.

[0065] As a result, the power supply path from the battery 46 to the charging control unit 42 is switched from the path passing through the switches S8 and S10 to the path passing through the switch S9, bypassing the switches S8 and S10. If power is supplied from the battery 46 to the charging control unit 42 via the switch S9, even if the pilot signal CPLT becomes a pulse signal and the switch S8 cannot be turned on stably, a stable power supply can be achieved from the battery 46 to the charging control unit 42.

[0066] When charging of the auxiliary battery 7 begins with the AC power supplied from the external power source 2, the charging control unit 42 turns off the switch S9 to cut off the power supply from the battery 46 to the charging control unit 42. Also, if the voltage of the auxiliary battery 7 is equal to or higher than the set voltage and charging of the auxiliary battery 7 is not necessary, in step S406, the charging control unit 42 turns off switch S10 of the battery power supply unit 45 and cuts off the power supply path from the battery 46 to the charging control unit 42.

[0067] After the switch control in step S405 or step S406, in step S407, the charging control unit 42 turns on the switch S2 of the external power supply permission circuit 43 to reduce the potential of the pilot signal line LP from 12V to 9V. In step S408, the CPLT control circuit 32 detects a drop in the potential of the pilot signal line LP, thereby starting communication between the CPLT control circuit 32 and the charging control unit 42, and the CPLT control circuit 32 outputs a pulsed pilot signal CPLT to the pilot signal line LP. Furthermore, the charging control unit 42, which has started communication with the CPLT control circuit 32, executes a fault diagnosis on the charging circuit 41 and the like.

[0068] The technical ideas described in the above embodiments can be used in any suitable combination as long as no contradiction occurs. Furthermore, although the contents of the present invention have been specifically described with reference to preferred embodiments, it is obvious that a person skilled in the art can adopt various modified embodiments based on the basic technical concept and teachings of the present invention.

[0069] For example, in vehicle charging system 100 shown in FIG. 4, a configuration can be adopted in which an operator performing charging operations operates a manual switch or the like provided on the vehicle to turn switch S8 on and off. Furthermore, in vehicle charging system 100 shown in FIG. 4, a configuration can be adopted in which, when a charging cable is connected to the vehicle, a contact is mechanically moved to turn on switch S8. [Explanation of symbols]

[0070] 1...vehicle drive battery, 2...external power source, 3...EVSE (electric circuit switching section), 32...CPLT control circuit (switching control circuit), 4...vehicle charging device, 41...charging circuit, 42...charging control section, 43...external power supply permission circuit, 44...capacitor charging circuit (power supply section), 5...DC / DC converter, 7...auxiliary battery, 8...vehicle ECU (on-board device), 9...battery ECU (on-board device), 100...vehicle charging system, 101...vehicle, S4, S5...switch (second switch), S6, S7...switch (first switch)

Claims

1. A vehicle charging device for charging a vehicle drive battery mounted on a vehicle from an external power source outside the vehicle, comprising: a charging circuit for charging the vehicle drive battery, the charging circuit having an input side connected to the external power supply via a first switch and an output side connected to a DC / DC converter connected to an auxiliary battery that is a drive source for on-vehicle equipment, a second switch, and the like, in that order; A charging control unit that controls the charging circuit and is connected to a signal line of a pilot signal output from a switching control circuit that controls the first switch; an external power supply permission circuit connected to the signal line and changing a potential of the signal line; a power supply unit that supplies power to the charging control unit; A vehicle charging device comprising:

2. 2. The vehicle charging device according to claim 1, When the voltage of the auxiliary battery drops, the charging control unit operates the charging circuit with the second switch open, thereby starting charging of the auxiliary battery by the DC / DC converter; Vehicle charging device.

3. 3. The vehicle charging device according to claim 2, after the charging control unit starts charging the auxiliary battery, the second switch is closed and the charging circuit starts charging the vehicle drive battery. Vehicle charging device.

4. 4. The vehicle charging device according to claim 3, After the charging control unit stops the charging circuit, the second switch is closed, After the second switch is closed, the charging control unit operates the charging circuit to start charging the vehicle drive battery. Vehicle charging device.

5. 4. The vehicle charging device according to claim 3, after the output voltage of the charging circuit is set to the same potential as the voltage value of the vehicle drive battery, the second switch is closed and charging of the vehicle drive battery is started by the charging circuit. Vehicle charging device.

6. 2. The vehicle charging device according to claim 1, The external power supply permission circuit changes the potential of the signal line under control of the charging control unit. Vehicle charging device.

7. 2. The vehicle charging device according to claim 1, The power supply unit is a capacitor charging circuit that is provided in a charging path that connects the signal line and the charging control unit and supplies power to the charging control unit. Vehicle charging device.

8. 8. The vehicle charging device according to claim 7, The capacitor charging circuit includes: A first resistor; A first switch; a first diode arranged such that the first switch side is an anode and the charging control unit side is a cathode; A capacitor; A vehicle charging device comprising:

9. 9. The vehicle charging device according to claim 8, a second diode disposed in a path connecting the auxiliary battery and the charge control unit so that the second diode is an anode on the auxiliary battery side and a cathode on the charge control unit side; Vehicle charging device.

10. 10. The vehicle charging device according to claim 9, a third diode is provided on the signal line, the third diode being disposed on the opening / closing control circuit side relative to a connection between the external power supply permission circuit and the capacitor charging circuit, the third diode being disposed on the opening / closing control circuit side as an anode and on the charging control unit side as a cathode; Vehicle charging device.

11. The vehicle charging device according to claim 10, The external power supply permission circuit includes: a first potential changing circuit having a second resistor and a second switch; a second potential changing circuit having a third resistor and a third switch; A vehicle charging device comprising:

12. A vehicle charging control method executed by a vehicle charging device mounted on a vehicle in order to charge a vehicle driving battery mounted on the vehicle from an external power supply external to the vehicle, comprising: The vehicle charging device includes: a charging circuit for charging the vehicle drive battery, the charging circuit having an input side connected to the external power supply via a first switch and an output side connected to a DC / DC converter connected to an auxiliary battery that is a drive source for on-vehicle equipment, a second switch, and the like, in that order; A charging control unit that controls the charging circuit and is connected to a signal line of a pilot signal output from a switching control circuit that controls the first switch; an external power supply permission circuit connected to the signal line and changing a potential of the signal line; a power supply unit that supplies power to the charging control unit; Equipped with When the voltage of the auxiliary battery drops, the charging control unit operates the charging circuit with the second switch open, thereby starting charging of the auxiliary battery by the DC / DC converter; After the charging of the auxiliary battery is started, the second switch is closed and the charging circuit starts charging the vehicle drive battery. A method for controlling vehicle charging.

13. A vehicle drive battery mounted in the vehicle; an external power source external to the vehicle; an electrical circuit opening and closing unit connected to the external power supply, the electrical circuit opening and closing unit having a first switch and a switching control circuit that controls the first switch; A vehicle charging device connected to the circuit opening / closing unit, a charging circuit connected to the first switch; a charging control unit connected to a signal line of a pilot signal output from the switching control circuit and controlling the charging circuit; an external power supply permission circuit connected to the signal line and changing a potential of the signal line; a power supply unit that supplies power to the charging control unit; The vehicle charging device having a DC / DC converter disposed between the charging circuit and the vehicle drive battery; a second switch disposed between the DC / DC converter and the vehicle drive battery; an auxiliary battery serving as a power source for an in-vehicle device connected to the DC / DC converter; A vehicle charging system comprising:

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