JPH07123517A - Charger for electric automobile - Google Patents

Abstract

PURPOSE:To prevent a potential from appearing on the car body due to leak from the internal wiring even under a state where a ground line associated with an external power supply is separated from the earth due to discontinuity of wiring or insufficient connection. CONSTITUTION:An electromagnetic relay 28 is interposed between an external AC power supply 16 and a connector 18. And an electromagnetic relay 30 is provided in a vehicle 10. The exciting coil 28c of the electromagnetic relay 20 has one end grounded 100 through a ground line 32 and the other end being applied with 12V through a contact 30a of the electromagnetic relay 30. The exciting coil 30b of the electromagnetic relay 30 has one end being applied with 12V and the other end connected with the body 20. When the ground line 26 is discontinued power supply to the exciting coil 28c is interrupted to open the contacts 28a, 28b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device for charging a battery mounted on an electric vehicle.

[0002]

2. Description of the Related Art An electric vehicle is a vehicle having a motor as a driving source, and a battery is mounted as a power source for driving the motor. Since this battery is discharged as the vehicle runs, it is necessary to charge the battery at a predetermined frequency. For this reason, an electric vehicle is equipped with an in-vehicle charger called an onboard charger. This on-board charger converts an AC current supplied from the external AC power supply into a DC current suitable for charging a battery when the external AC power supply is connected through the connector.

FIG. 3 shows the configuration of a charging device according to a first conventional example. In the device shown in this figure,
A battery 10 and an onboard charger 14 are mounted on a vehicle 10 configured as an electric vehicle, and the output side of the onboard charger 14 is connected to the battery 12.

On the other hand, an external AC power supply 16 is provided outside the vehicle 10. One of the AC wirings 17 drawn from the external AC power supply 16 is grounded to the ground 100. Further, the external AC power supply 16 is connected to the input side of the onboard charger 14 when the connector 18 is connected. Therefore, when the connector is connected, the AC current supplied from the external AC power source 16 is converted into the DC current by the onboard charger 14, and the battery 12 is charged by this current.

However, in this configuration, when a leak occurs from the AC wiring 17 connecting the external AC power supply 16 and the onboard charger 14 to the vehicle body 20, the vehicle body 20 receives an AC potential (for example, AC 100
(V, 200V, etc.) will appear, which is not preferable.

Therefore, there has been conventionally proposed a structure in which an earth leakage breaker is provided outside the vehicle 10 (Jitsuko Sho 61-1).
6761). FIG. 4 shows a second conventional example having this type of configuration.

In this figure, an earth leakage breaker 22 is provided between the external AC power source 16 and the connector 18. Further, the vehicle body 20 is connected via the connector 18 and the ground wire 24,
It is connected to the ground wire 26 of the external AC power supply 16. The earth leakage breaker 22 detects an increase in the electric potential of the vehicle body 20 due to the leak when an AC wiring connecting the external AC power supply 16 and the on-board charger 14 leaks to the vehicle body 20, and in response to this, the external AC power supply 16 and connector 18
Open the connection between. Therefore, according to such a configuration, an AC potential does not appear in the vehicle body 20 due to a leak, and a safer charging device can be obtained.

[0008]

However, in such a configuration, the earth leakage breaker functions when the ground wire for grounding the external AC power source to the ground is cut or a connection failure related to the ground wire occurs. There is a problem that an AC potential appears in the vehicle body when a leak occurs from the AC wiring to the vehicle body in this state.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and even when a ground wire related to an external power source has a broken wire or a connection failure,
The purpose is to open the connection between the external power supply and the connector in response to a leak from the in-vehicle wiring to the vehicle body.

[0010]

In order to achieve such an object, the charging device for an electric vehicle according to the present invention has an external power source, one end of which is grounded and is provided outside the vehicle, and an on-vehicle device. The in-vehicle wiring for charging the battery and the connector used to connect the external power supply to the in-vehicle wiring when charging the in-vehicle battery, and the vehicle body and the ground are electrically connected according to the connection of the connector. A first grounding wire provided so as to be connected to the vehicle, an opening / closing means for opening / closing the connection between the external power source and the connector, and an opening / closing means when the first grounding wire normally connects the vehicle body and the ground. And an opening / closing control means that closes and opens when the connection is broken.

Further, in the charging device for an electric vehicle according to the present invention, the opening / closing means includes a contact provided between the external power source and the connector, and an exciting coil for opening / closing the contact.
Control in which the opening / closing control means connects one end of the exciting coil of the opening / closing means to the ground and connects a second ground wire different from the first ground wire and the other end of the exciting coil to a vehicle-mounted control power source via a connector. A power supply connecting member, and a closed circuit is configured by the second ground wire, the exciting coil, the control power supply connecting member, and the control power supply when the connector is connected.

[0012]

In the present invention, when the vehicle body is normally grounded to the ground by the first grounding wire, the connection between the external power source and the connector is maintained by the opening / closing means. On the other hand, if the ground is open due to a break in the ground wiring of the external power supply or a connection failure, the opening / closing means opens,
The connection between the external power supply and the connector is opened. Therefore,
When the grounding of the external power supply to the ground is opened, the voltage is not supplied from the external power supply to the vehicle side, so even if there is a possibility that a leakage path from the in-vehicle wiring to the vehicle body may occur,
No electric potential appears on the car body.

Further, in the present invention, the contact of the opening / closing means is disposed between the external power source and the connector, and this contact is opened / closed by the exciting coil. One end of this exciting coil is grounded to the ground by a second ground wire different from the first ground wire, and the other end is connected to a vehicle-mounted control power supply (for example, auxiliary battery) via a connector by a control power supply connecting member. To be done. Therefore, when the connector is connected, a closed circuit is constituted by the control power source, the control power source connecting member, the exciting coil, the second ground wire, the ground, the first ground wire and the vehicle body, and the exciting coil closes the contact of the opening / closing means. Enables charging of onboard batteries.
When the grounding to the ground by the first grounding line becomes defective, the closed circuit is not established and charging is not performed, so that the vehicle body potential does not occur due to the leakage from the in-vehicle wiring.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. The same components as those of the first and second conventional examples shown in FIGS. 3 and 4 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows the configuration of a charging device according to the first embodiment of the present invention. In this embodiment, an electromagnetic relay 28 is provided between the earth leakage breaker 22 and the connector 18. Contact points 28a and 28b of the electromagnetic relay 28
Is an AC wiring 1 from the external AC power supply 16 to the connector 18.
7 are provided. When the contacts 28a and 28b are closed, the wiring 17 related to the external AC power supply 16 is connected to the onboard charger 14, and when it is opened, the connection is opened. Further, one end of the exciting coil 28c of the electromagnetic relay 28 is grounded to the ground 100 by a grounding wire 32 different from the grounding wire 26 of the external AC power supply 16, and the other end is connected to the on-vehicle electromagnetic relay via the connector 18. The contact 30 is connected to one end of the contact 30a.
At the other end of the in-vehicle electromagnetic relay 30, there is a direct current 12
V is applied (from an auxiliary battery or the like). This direct current 12
The minus side of the V power source (auxiliary battery, etc.) is grounded to the vehicle body 20. Further, the exciting coil 3 of the electromagnetic relay 30
This 12V is also applied to one end of 0b, and the other end of the exciting coil 30b is connected to the collector of the transistor 34. The emitter of the transistor 34 is the vehicle body 20.
The base is supplied with a control signal from an ECU (electronic control unit) 36. The ECU 36 inputs a command to charge the battery 12, the state of the onboard charger 14, and the like.

In this embodiment, when a command is given to the ECU 36 after the connector 18 is connected, the ECU 36 checks the state of each part of the device such as the onboard charger 14 and if the condition is normal, the transistor 34 should be turned on. A control signal to the effect is supplied. When the transistor 34 is turned on in response to this, a current flows through the exciting coil 30b and the contact 30a is closed. If the ground wire 26 is in a normal state, + 12V control power source → contact 30a → excitation coil 28c → ground wire 32 → ground wire 26 → ground wire 24 → body 2
A closed circuit related to the control power supply is formed by the path of 0.
Therefore, in this state, a current flows through the exciting coil 28c, the contacts 28a and 28b are closed, and the battery 12 is charged. When a leak occurs from the AC wiring 17 to the vehicle body 20 inside the vehicle 10, the earth leakage breaker 22 operates according to the generation of the potential in the vehicle body 20, and the connection between the external AC power source 16 and the onboard charger 14 is established. Be refused.

Further, in the present embodiment, the ground wire 26
When is disconnected from the ground 100 (when the wiring is broken or the connection is defective), the electromagnetic relay 28 operates to disconnect the connection between the external AC power supply 16 and the onboard charger 14.

That is, in the state where the ground wire 26 is separated from the ground 100, the above-mentioned closed circuit is not established, so that no current flows through the exciting coil 28c. As a result, the contacts 28a and 28b are opened, and the current supply from the external AC power supply 16 to the onboard charger 14 is cut off. Therefore, in this state, the AC wiring 17 is temporarily provided inside the vehicle 10.
Even if a leak from the vehicle to the vehicle body 20 may occur, the AC potential does not appear in the vehicle body 20. Thus, in this embodiment, a safer charging device can be obtained.

In addition, in this embodiment, since the exciting coil 28c is not energized when the connector 18 is not connected, the contacts 28a and 28 of the electromagnetic relay 28 are connected.
b is in an open state, and no AC voltage appears on the electrodes of the external AC power source side connector piece (plug or jack).
From this point of view, the charging device has high safety.

In the above description, the ECU 36 checks the function of each part of the device before charging, but this may be omitted. In this case, the electromagnetic relay 30 can be eliminated.

FIG. 2 shows the configuration of a charging device according to the second embodiment of the present invention which is constructed without using the electromagnetic relay 30. In the present embodiment, one end of the exciting coil 28c of the electromagnetic relay 28 is connected to the wiring relating to the external AC power source 16, and the other end is connected to the vehicle body 20 via the connector 18. Therefore, also in this embodiment, the ground wire 2
When 6 is separated from the ground 100, the exciting coil 28c
The potential at one end of the contact floats, which causes the contact 28a
And 28b are opened to open the connection between the external AC power supply 16 and the onboard charger 14. Therefore, also in this embodiment, the same effect as in the first embodiment can be obtained.

Further, the present invention is not limited to the configuration using a vehicle-mounted charger (on-board charger) as the charger. That is, it can be applied to a configuration in which the output of the external AC power source is converted into DC by a charger (off-board charger) outside the vehicle and the DC current is supplied to the battery through the connector and the in-vehicle wiring. More specifically, when using an off-board charger that does not have separate input / output wiring (that is, changes in the ground potential on the input side also reflect on the output potential), the The present invention can be applied to prevent the occurrence of leakage even when the ground wire of the external AC power supply has a poor contact or the like.

[0023]

As described above, according to the present invention,
Since the connection between the external power supply and the connector is opened when the ground from the external power supply to the ground is released, even if the ground wire related to the external power supply has a broken wire or a connection failure, A potential does not appear in the vehicle body due to a leak from the in-vehicle wiring to the vehicle body, and a safer and more reliable device can be obtained.

Further, according to the present invention, since the opening / closing means is composed of the electromagnetic relay, the above effects can be obtained with a relatively simple circuit structure.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a charging device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a charging device according to a second exemplary embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a charging device according to a first conventional example.

FIG. 4 is a block diagram showing a configuration of a charging device according to a second conventional example.

[Explanation of symbols]

 10 vehicle 12 battery 14 on-board charger 16 external AC power supply 17 wiring 18 connector 20 vehicle body 22 earth leakage breaker 24, 26, 32 ground wire 28, 30 electromagnetic relay 28a, 28b, 30a contact 28c, 30b exciting coil 34 transistor 36 ECU ( Electronic control unit) 100 Earth

Claims (2)

[Claims] 1. An external power source whose one end is grounded and is provided outside the vehicle, wiring inside the vehicle for charging a vehicle battery, and when charging the vehicle battery, the external power source and the vehicle interior A charging device for an electric vehicle, comprising: a connector used for connecting to a wiring; a first grounding wire provided to electrically connect a vehicle body and the ground in accordance with the connection of the connector; and an external power supply. An opening / closing means for opening / closing the connection between the connector and the connector, and an opening / closing control means for closing the opening / closing means when the first ground wire normally connects the vehicle body and the ground and opening the connection when the connection is broken. A charging device for an electric vehicle, comprising: 2. The charging device for an electric vehicle according to claim 1, wherein the opening / closing means includes a contact provided between the external power source and the connector, and an exciting coil for opening / closing the contact. Means for connecting one end of the exciting coil of the opening / closing means to the ground and a second ground wire different from the first ground wire, and a control power supply connection for connecting the other end of the exciting coil to a vehicle-mounted control power supply via a connector And a control power source, a control power source connecting member, an exciting coil, a second ground wire, the ground, the first ground wire and a vehicle body when the connector is connected to form a closed circuit. Charging device.