JP2011205755A - Charging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge remaining electric charges by a simple constitution.SOLUTION: A charging device includes a normal charging inlet 21 connected with a commercial AC power supply 71, a quick charging inlet 41 connected with a charging station 81, a charger 23 which is connected to the normal charging inlet 21 and converts the power of the commercial AC power supply 71 into charging power to a battery 11, a common charging cable run 50 connected to the battery 11, a first charging cable run 20 which connects the common charging cable run 50 and the charger 23, a second charging cable run 40 which connects the common charging cable run 50 and the quick charging inlet 41, and a common relay 53 which is arranged at the common charging cable run 50. The first charging cable run 20 includes a first positive-side charging cable run 27 and a first negative-side charging cable run 28, and a discharging circuit 30 with a switching transistor 31 and a discharging resistor 32 connected in series is connected between the first positive-side charging cable run 27 and the first negative-side charging cable run 28.

Description

  The present invention relates to a structure of a charging device.

  In an electric vehicle that travels by driving a motor with electric power charged in a secondary battery, it is necessary to charge the secondary battery with an external power source for traveling. For this reason, the electric vehicle is equipped with a charger that charges a secondary battery by connecting to a commercial external power supply of AC 100V or AC 200V. However, since a secondary battery for an electric vehicle has a large capacity, there is a problem that it takes several hours to charge a secondary battery by boosting a commercial power source. For this reason, a charging station that can supply DC power boosted to the charging voltage of the secondary battery mounted on the electric vehicle is installed, and the charging station and the secondary battery mounted on the electric vehicle are connected. However, rapid charging for charging secondary batteries in a short time has come to be performed. According to this rapid charging, the secondary battery of the electric vehicle can be charged in several tens of minutes. However, it is not preferable to charge the secondary battery at the same time by both the normal charging method and the rapid charging method in which the secondary battery is charged from a commercial AC power supply. Therefore, a signal line is attached to each of the normal charging and quick charging plugs to detect that each plug has been inserted, and even when both plugs are inserted, the secondary battery is charged only from one of the charging systems. A method has been proposed. In addition, the charging inlet for normal charging and the charging inlet for quick charging are integrated, and only one of the charging plugs can be connected to charge the secondary battery from only one charging system. A method has been proposed (see, for example, Patent Document 1).

  In addition, the charger is often provided with a capacitor for storing electric charges so that an overcurrent can be prevented and the secondary battery can be stably charged. Since charges are stored in the capacitor during charging, it is necessary to release the stored charges when charging is stopped. For this reason, the charger is often provided with a discharge resistor for discharging the electric charge accumulated in the capacitor (see, for example, Patent Document 2).

JP 2009-77557 A JP-A-8-103030

  By the way, a relay is provided between the charging system for the secondary battery and the power supply system of the electric vehicle to cut off the two electric systems when not charging. In the case of a system that performs normal charging, a relay is provided between the charger mounted on the electric vehicle and the power line of the electric vehicle. In the case of a system that performs quick charging, the quick charging inlet and the power line of the electric vehicle In many cases, a relay is provided between the two. However, providing relays at two locations complicates the configuration of the charging system, so in recent years, a charging system for secondary batteries is configured through a common charging line, and a common relay is provided on the common charging line. The system configuration may be simplified. In addition, when the normal charging inlet and the quick charging inlet are provided separately, if the quick charging inlet is opened so that charging is not performed from both charging inlets, the relay is turned off by the interlock and charging is performed. May be configured to stop. In this case, there is a problem that the electric charge of the capacitor inside the charger that is normally attached to the charging system cannot be discharged and becomes a residual electric charge, and a potential may be generated in the rapid charging inlet.

  In addition, the relay may be welded due to an inrush current during the on / off operation, but if charging is performed with the relay welded, the charging system connected to the external power supply and the power system of the electric vehicle cannot be shut off. There is a problem of end. For this reason, it is necessary for the relay to perform a welding check to check whether the relay is operating normally without welding. In order to check the welding of the relay, a voltage sensor for detecting the voltage is provided on the charging system side of the relay, and the positive and negative contacts of the relay are turned on one by one and the welding judgment is made from the voltage detected by the voltage sensor. There are many cases. However, if the welding check is performed by the voltage sensor, the number of parts increases, and the structure becomes complicated.

  An object of the present invention is to discharge residual charges with a simple configuration.

  The charging device of the present invention is a charging device for charging a power storage device, wherein a first charging inlet to which a first external power source is connected, a second charging inlet to which a second external power source is connected, A charger connected to the first charging inlet for converting the power of the first external power source into charging power for the power storage device; a common charging circuit connected to the power storage device; and the common charging circuit; A first charging circuit that connects the charger, a second charging circuit that connects the common charging circuit and the second charging inlet, and a common relay disposed in the common charging circuit. The first charging circuit includes a first plus side charging circuit and a first minus side charging circuit, and a switching element is provided between the first plus side charging circuit and the first minus side charging circuit. Discharge resistor connected in series It was connected electric circuit, characterized by.

  The charging device of the present invention includes a control unit that turns on and off the common relay and the switching element, and the second charging inlet is opened when the power storage device is charged by the first external power source. In this case, it is also preferable to have charging stop means for turning off the common relay and turning on the switching element.

  The charging device of the present invention includes a current sensor that detects a current from the power storage device, the common charging circuit includes a plus-side common charging circuit and a minus-side common charging circuit, and the common relay is the plus-side common Including a positive contact for turning on and off the charging circuit and a negative contact for turning on and off the common charging circuit for the negative side, and the control unit switches between the positive contact and the negative contact with the switching element turned on. It is also preferable to have relay welding detection means that alternately turns on and off so that one is turned on and the other is turned off, and detects the welding of the plus side contact or the minus side contact by the current detected by the current sensor. is there.

  The present invention has an effect that discharge of residual charges can be performed with a simple configuration.

It is a systematic diagram which shows the structure of the charging device in embodiment of this invention. It is a flowchart which shows operation | movement of the charging device in embodiment of this invention. It is a time chart which shows operation | movement of the charging device in embodiment of this invention. It is a flowchart which shows the forced stop operation | movement of the charging device in embodiment of this invention. It is a time chart which shows the forced stop operation | movement of the charging device in embodiment of this invention. It is a flowchart which shows the relay welding check operation | movement of the charging device in embodiment of this invention. It is a time chart which shows the relay welding check operation | movement of the charging device in embodiment of this invention.

  An embodiment of the present invention will be described with reference to FIG. The charging device 100 according to the present embodiment charges a battery 11, which is a chargeable / dischargeable power storage device mounted on an electric vehicle, with first and second external power supplies. A common charging circuit 50 connected to each of the side output lines 13, a common relay 53 provided in the common charging circuit 50, for turning on and off the common charging circuit 50, and a first connecting the common charging circuit 50 and the charger 23. The second charging line connecting the common charging line 50 and the quick charging inlet 41 as the second charging inlet, the normal charging inlet 21 as the first charging inlet connected to the charger 23, and the quick charging inlet 41 as the second charging inlet. The electric circuit 40 is included. The common charging circuit 50 includes a plus side common charging circuit 51 and a minus side common charging circuit 52, and the first charging circuit 20 includes a first plus side charging circuit 27 and a first minus side charging circuit 28. The second charging circuit 40 includes a second plus-side charging circuit 43 and a second minus-side charging circuit 44, and the plus-side common charging circuit 51 includes a first plus-side charging circuit 27, a second charging circuit 27, and a second charging circuit 27. And the negative common charging circuit 52 is connected to the first negative charging circuit 28 and the second negative charging circuit 44. The common relay 53 provided in the common charging electric circuit 50 includes a positive contact 54 that turns on and off the positive common charging electric circuit 51 and a negative contact 55 that turns on and off the negative common charging electric circuit 52.

  The first external power supply is a commercial AC power supply 71 of 100V or 200V, and is connected to the normal charging plug 75 via the connectors 72 and 73 and the normal charging cable 74. When the lid 22 attached to the normal charging inlet 21 is opened and the normal charging plug 75 is inserted into the normal charging inlet 21, the commercial AC power supply 71 and the charger 23 are connected. The second external power source is a high-voltage DC power source of 200 V or 400 V that is higher than the commercial AC power source supplied from the charging station 81. A quick charging cable 84 is connected to the charging station 81, and a quick charging plug 85 is attached to the tip of the quick charging cable 84. When the lid 42 attached to the rapid charging inlet 41 is opened and the rapid charging plug 85 is inserted into the rapid charging inlet 41, the high-voltage DC power source is connected to the second charging circuit. Further, the normal charging inlet 21 and the quick charging inlet 41 each have a built-in signal line for outputting a connection state when the normal charging plug 75 and the quick charging plug 85 are inserted and connected, respectively.

  The charger 23 includes a power conversion circuit 24 that converts AC power into high-voltage DC power for charging the battery. A diode 26 for preventing backflow is provided at the output terminal on the plus side. A capacitor 25 is connected between the positive output terminal and the negative output terminal. In addition, a switching transistor 31 and a discharge resistor 32 that are switching elements are connected in series between the first plus-side charging circuit 27 and the first minus-side charging circuit 28 of the first charging circuit 20. A discharge circuit 30 is provided.

  The positive output line 12 of the battery 11 is provided with a current sensor 63 that detects an input / output current of the battery 11. Further, the normal charging inlet 21 and the quick charging inlet 41 are provided with switches 61 and 62 for detecting opening and closing of the lids 22 and 42, respectively.

  The positive output line 12 and the negative output line 13 of the battery 11 are connected to a power control unit (PCU) 15, and the PCU 15 is connected to a motor generator 16 for driving the vehicle, and drives the vehicle with electric power charged in the battery 11. It is configured as follows. A system main relay 14 for turning on and off the plus side output line 12 and the minus side output line 13 is provided on the output line of the battery 11.

  The system main relay 14, the common relay 53, the switching transistor 31, and the charger 23 are each connected to the control unit 90 and configured to operate according to commands from the control unit 90. The common relay 53 is configured such that a plus-side contact 54 and a minus-side contact 55 are connected to the control unit 90, and the respective contacts 54 and 55 are independently turned on and off. Further, the signals of the current sensor 63, the normal charging inlet 21, the quick charging inlet 41, and the switches 61 and 62 are input to the control unit 90, respectively. The control unit 90 is a computer including a CPU that performs signal processing therein and a storage unit that stores a control program, control data, and the like.

  An operation when the battery 11 is charged by the charging apparatus 100 configured as described above will be described. First, when normal charging is performed, the connector 73 on the normal charging plug 75 side is inserted into the connector 72 of the commercial AC power supply 71 to connect the commercial AC power supply 71 and the normal charging plug 75. Then, the lid 22 of the normal charging inlet 21 is opened, the normal charging plug 75 is inserted into the normal charging inlet 21, and the commercial AC power supply 71 and the charger 23 are connected. When the normal charging plug 75 is inserted and connected to the normal charging inlet 21, a signal indicating that the connection state has been established is output from the normal charging inlet 21 to the control unit 90. The control unit 90 determines that the commercial AC power supply 71 and the charger 23 are connected by the signal as shown in step S101 of FIG. When the control unit 90 determines that the normal charging plug 75 is connected to the normal charging inlet 21 and the commercial AC power supply 71 and the charger 23 are connected, the control unit 90 has been turned on until then, as shown in step S102 of FIG. The switching transistor 31 is turned off, and the first plus-side charging circuit 27 and the first minus-side charging circuit 28 are disconnected. Then, as shown in steps S103 and S104 in FIG. 2, the control unit 90 turns on the common relay 53 and the system main relay 14 to connect the charger 23 and the battery 11, and as shown in step S105 in FIG. Then, the charger 23 is started. When the charger 23 is started, the AC power input to the charger 23 is converted into DC power by an internal power conversion circuit, and is boosted to a voltage necessary for charging the battery 11. After being stored as electric charge, it flows into the first charging circuit 20 from the output end. The high-voltage direct current flowing through the first charging circuit 20 flows through the common charging circuit 50 and the common relay 53 to the positive output line 12 and the negative output line 13 of the battery 11 to charge the battery 11. . At this time, a potential similar to that of the first charging electric circuit 20 is generated in the second charging electric circuit 40, but the lid 42 of the quick charging inlet 41 is closed, and the electric potential does not leak to the outside.

As shown in step S106 of FIG. 2, when the remaining capacity (SOC) of the battery 11 becomes equal to or greater than a predetermined threshold, the controller 90 stops the charger 23 as shown in step S107 of FIG. As shown in step S108 of FIG. 2, the system main relay 14 is turned off to disconnect the vehicle power supply system and the battery 11, and as shown in step S109 of FIG. 2, the common relay 53 is turned off to charge the electric vehicle and the electric vehicle. Disconnect from the power system. Then, as shown in step S110 in FIG. 2, the process waits until the normal charging plug 75 is pulled out. When the normal charging plug 75 is pulled out, there is no connection signal output from the normal charging plug 75 to the control unit 90. Therefore, the control unit 90 determines that the normal charging plug 75 has been pulled out, and proceeds to step S111 in FIG. As shown, a command to turn on the switching transistor 31 is output. In response to this command, the switching transistor 31 is turned on at time t ₂ shown in FIG. 3, and the first plus-side charging circuit 27 and the first minus-side charging circuit 28 are connected via the discharge resistor 32. Then, as shown in FIG. 3A, the residual charge remaining in the capacitor 25 flows to the first negative charge circuit 28 through the first positive charge circuit 27, the switching transistor 31, and the discharge resistor 32. Discharged. Even if the residual charge disappears and the discharge current becomes zero, the switching transistor 31 remains on. Finally, the lid 22 of the normal charging inlet 21 is closed to finish the charging operation. As described above, when the residual potential of the first charging circuit 20 is set to zero by turning on the switching transistor 31, the potential of the second charging circuit 40 connected to the first charging circuit 20 is also set to zero. Even when the lid 42 of the charging inlet 41 is opened and the quick charging inlet 41 is opened, it is possible to suppress damage to other external devices due to the remaining potential.

  Further, when charging the battery 11 by the charging station 81, the lid 42 of the quick charging inlet 41 is opened, the quick charging plug 85 is inserted into the quick charging inlet 41, and the charging station 81 and the second charging circuit 40 are connected. Connecting. When the charging station 81 and the second charging electric circuit 40 are connected, a signal indicating that the connection state has been established is output from the quick charging inlet 41 to the control unit 90. Based on the signal, control unit 90 determines that charging station 81 and second charging circuit 40 are connected. At this time, since the normal charging plug 75 is not inserted into the normal charging inlet 21, the switching transistor 31 is kept off, and the first plus-side charging electric circuit 27 and the first minus-side charging electric circuit 28 are It is in a blocked state. The diode 26 prevents the current from flowing from the second charging circuit 40 to the charger 23. The control unit 90 turns on the common relay 53 and the system main relay 14 to connect the charging station 81 and the battery 11, starts supplying high-voltage DC power from the charging station, and charges the battery 11. When the battery 11 is charged by rapid charging and the remaining capacity (SOC) exceeds a predetermined threshold value, the supply of DC power from the charging station 81 is stopped, and then the rapid charging plug 85 is removed from the rapid charging inlet 41. The lid 42 of the quick charge inlet 41 is closed to finish the charging operation.

  Next, the operation for forcibly stopping charging during normal charging will be described. In the present embodiment, current flows from the charger 23 to the battery 11 during normal charging through the first charging circuit 20 and the common charging circuit 50. However, since the common charging circuit 50 is connected to the second charging circuit 40, when the battery 11 is charged from the first charging circuit 20, the second plus of the second charging circuit 40 is used. A potential is generated between the side charging circuit 43 and the second minus side charging circuit 44. For this reason, when the lid 42 of the quick charging inlet 41 is opened during normal charging, the external device may be damaged by the potential of the second charging circuit 40. For this reason, in the charging apparatus 100 of this embodiment, when the lid 42 of the quick charge inlet 41 is opened during normal charging and the quick charge inlet 41 is opened, normal charging is detected by detecting that fact. Built-in interlock to stop.

As shown in step S201 of FIG. 4, the control unit 90 stands by without performing a forced stop operation when normal charging is performed normally. Then, as shown in step S <b> 202 of FIG. 4, when the cover 42 of the quick charge inlet 41 is opened during normal charging, the switch 62 operates and a signal is input to the control unit 90. When this signal is input, the controller 90 determines that the lid 42 of the quick charge inlet 41 is opened during normal charging, stops the charger 23 as shown in step S203 of FIG. S204, as shown in time _{t 4} in FIG. 5, with disconnects the power supply system and the battery 11 in the vehicle turns off the system main relay 14, step S205 in FIG. 4, as shown in time _{t 4} in FIG. 5, the common Relay 53 is turned off to disconnect the charging system and the power system of the electric vehicle. As shown in FIG. 5, the normal charging plug 75 remains inserted into the normal charging inlet 21 during this period. Then, the control unit 90 turns on the switching transistor 31 as shown in step S206 in FIG. ₄ and time t4 in FIG. Then, as shown in FIG. 5A, the residual charge remaining in the capacitor 25 flows to the first negative charging circuit 28 through the first positive charging circuit 27, the switching transistor 31, and the discharge resistor 32. Discharged.

  As described above, in the present embodiment, when the lid 42 of the quick charge inlet 41 is opened during normal charging, charging is forcibly stopped and the switching transistor 31 is turned on to discharge the capacitor 25. In addition, no charge remains in the first and second charging electric circuits 20 and 40, and even when charging is forcibly stopped, it is possible to prevent other external devices from being damaged.

Next, an operation for checking the welding of the common relay 53 by the charging device 100 of the present embodiment will be described with reference to FIGS. When the welding check of the common relay is performed, charging is stopped and the switching transistor 31 is on. As shown in step S <b> 301 of FIG. 6, the control unit 90 first turns on the system main relay 14. Then, step S302 in FIG. 6, as shown in time t ₅ in FIG. 7, the plus-side contact 54 of the common relay 53 is turned on and an off state and the minus side contact 55. At this time, if the minus side contact is welded and cannot be opened even by an off command from the control unit 90, the plus output line 12 from the plus side of the battery 11, the system main relay 14, The plus side common charging circuit 51, the plus side contact 54 of the common relay 53 that is turned on, the first plus side charging circuit 27, the switching transistor 31, the discharge resistor 32, the first minus side charging circuit 28, and the welded The current flows to the negative side of the battery 11 via the negative side contact 55 of the common relay 53, the negative side common charging circuit 52, and the negative side output line 13 of the battery 11, and is indicated by a dotted line a in FIG. The current is detected as follows. In this state, the control unit 90 acquires the current value detected by the current sensor 63 provided in the positive output line 12 of the battery 11 as shown in step S303 of FIG. 6, and the process proceeds to step S304 of FIG. As shown, when the current value is larger than the threshold value, it is determined that the negative contact 55 of the common relay 53 is welded. When the current value is smaller than the threshold value, the negative side of the common relay 53 is determined. It is determined that the contact 55 is normal without welding. If it is determined that the minus side contact 55 is not normal and is welded, the control unit 90 outputs a common relay abnormality signal, as shown in step S310 of FIG. 6, and then, as shown in step S309 of FIG. Then, the system main relay 14 is turned off and the welding check of the common relay 53 is finished.

  On the other hand, when determining that the minus side contact 55 is normal, the control unit 90 turns off the plus side contact 54 and turns on the minus side contact 55 as shown in step S305 of FIG. In this case, if the plus contact 54 is welded, a current flows from the battery 11 as described above, and the current is detected by the current sensor 63 as shown by a solid line b in FIG. As shown in step S306 in FIG. 6, the control unit 90 acquires this current value. As shown in step S <b> 307 in FIG. 6, the control unit 90 determines whether or not the positive contact 54 is welded based on the current value of the current sensor 63. When it is determined that the plus side contact 54 is normal and not welded, since the respective contacts 54 and 55 of the common relay 53 are normal, a common relay normal signal is output. If it is determined that the plus side contact 54 is not normal and is in a welded state, as shown in step S310 of FIG. 6, after a common relay abnormality signal is output, as shown in step S309 of FIG. Then, the system main relay 14 is turned off to end the welding check.

  In the present embodiment described above, since the welding check of the common relay 53 can be performed using the current sensor 63 that detects the output current of the battery 11, it is easy to use other instruments such as a voltage sensor for the welding check. It can be set as a simple structure.

  11 Battery, 12 Positive output line, 13 Negative output line, 14 System main relay, 15 Power control unit (PCU), 16 Motor generator, 20 First charging circuit, 21 Normal charging inlet, 22, 42 Lid, 23 Charger, 24 power conversion circuit, 25 capacitor, 26 diode, 27 plus side charging circuit, 28 minus side charging circuit, 30 discharging circuit, 31 switching transistor, 32 discharging resistor, 40 second charging circuit, 41 rapid charging inlet, 43 plus side charging circuit, 44 minus side charging circuit, 50 common charging circuit, 51 plus side common charging circuit, 52 minus side common charging circuit, 53 common relay, 54 plus side contact, 55 minus side contact, 61, 62 switch, 63 Current sensor, 7 A commercial AC power supply, 72, 73 connector, 74 normal charging cable, 75 normal charging plug, 81 charging station 84 fast charging cable, 85 rapid charging plug, 90 control unit, 100 charging apparatus.

Claims (3)

A charging device for charging a power storage device,
A first charging inlet to which a first external power source is connected;
A second charging inlet to which a second external power source is connected;
A charger connected to the first charging inlet for converting the power of the first external power source into charging power for the power storage device;
A common charging circuit connected to the power storage device;
A first charging circuit that connects the common charging circuit and the charger;
A second charging circuit that connects the common charging circuit and the second charging inlet;
A common relay disposed in the common charging circuit,
The first charging circuit includes a first plus side charging circuit and a first minus side charging circuit,
Connecting a discharge circuit in which a switching element and a discharge resistor are connected in series between the first plus-side charging circuit and the first minus-side charging circuit;
A charging device. The charging device according to claim 1, wherein
A control unit for turning on and off the common relay and the switching element;
When charging the power storage device with the first external power source, when the second charging inlet is opened, the common relay is turned off and the charging device is turned off to turn on the switching element. Having means,
A charging device. The charging device according to claim 2,
Including a current sensor for detecting a current from the power storage device;
The common charging circuit includes a plus side common charging circuit and a minus side common charging circuit,
The common relay includes a positive contact that turns on and off the positive common charging circuit, and a negative contact that turns on and off the negative common charging circuit,
In the state where the switching element is turned on, the control unit alternately turns on and off either the plus side contact or the minus side contact so that the other is turned off, and the current detected by the current sensor, Having relay welding detection means for detecting the welding of the plus side contact or the minus side contact;
A charging device.

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