JPH0614976U - Leakage detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an earth leakage detection device suitable for detecting electricity leakage in an electric vehicle or the like, capable of early and safely detecting earth leakage of high voltage. [Structure] In order to detect an electric leakage occurring in a power transmission path from a power source 1 through a power transmission cable 5 to a load, the power transmission cable 5
A detection wire 7 composed of a conductor coil wound along the outer skin is attached to part or all of the above. Detection line 7
Sensitively catches a leak current when a leak occurs, and generates an induced voltage V _i . This induced voltage V _i is applied to the comparator 11
When it exceeds the reference voltage V _f , the comparator 11 turns on the transistor 15. As a result, the relay switch 3 is opened to prevent leakage.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a device for detecting a high-voltage leak, and more particularly to a leak detection device suitable for detecting a leak in an electric vehicle equipped with a high-voltage battery.

[0002]

[Prior art]

 In general, leakage detection is a technology required in various fields of electric power use, but especially in electric vehicles and the like, the point of using a high-voltage battery and the generation of leakage that occupants experience are absolutely necessary. Therefore, it is necessary to detect even a subtle current leak early and safely and to prevent it reliably.

Conventionally, an earth leakage breaker is known as a main means for detecting earth leakage, but this has a large leak current value of 15 mA or more that can be detected and a response delay is so long that it cannot be ignored. It is difficult to meet the above requirements.

[0004]

[Problems to be solved by the device]

 As described above, the conventional earth leakage breaker is not satisfactory in that it can detect a high voltage earth leakage early even if it is a minute current.

Therefore, an object of the present invention is to provide a leakage detection device capable of early and safely detecting leakage of high voltage and suitable for detecting leakage in an electric vehicle or the like.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is to detect an electric leakage generated in a transmission path from a power source to a load through the transmission cable, and the electric cable is attached to the transmission cable and is connected to the outside of the transmission cable when the leakage occurs. The present invention is characterized by having a detection line that generates an induced voltage in response to a leak current leaking to the device, and an electronic circuit that receives an induced voltage from the detection line and performs a predetermined protection operation.

[0007]

[Action]

 When a leakage occurs in any part of the power transmission path, an induced voltage corresponding to the resistance of the leakage path is generated in the detection line in the middle of the leakage current path that leaks from the transmission cable to the outside of the transmission cable. Upon receiving this induced voltage, the electronic circuit immediately carries out protective operation such as cutting of the power transmission path.

[0008]

【Example】

 Hereinafter, an embodiment of the leakage detection device according to the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a high voltage battery of an electric vehicle, and one end of a high voltage cable 5 is connected to the high voltage battery 1 via a relay switch 3. The other end of this high-voltage cable 5 is connected to a traveling motor 6 of the electric vehicle.

A leak detection line 7 is attached to a part or the whole of the high voltage cable 5. The leak detection wire 7 is a conductor coil formed by winding a metal wire, a metal foil, a braided wire, conductive particles, or a conductive film along the outer cover of the high-voltage cable 5. The leak detection line 7 is a leak current leaking due to damage or moisture absorption of the high-voltage cable 5, that is, a leak leaking from the high-voltage cable 5 to the outside of the high-voltage cable in the radial direction thereof. An induced voltage is generated in response to an electric current. The outside of the leak detection line 7 is covered with a protective layer 9.

The induced voltage V _i generated from the leak detection line 7 is applied to one input terminal of a comparator 11 using an operational amplifier, and the other input terminal of the comparator 11 has a stabilized constant voltage for an electronic circuit. A reference voltage _Vf formed using the source is applied. The output of the comparator 11 is adapted to be added to the gate of the switching transistor 15 for turning on / off the relay coil 13.

Under such a configuration, when a leakage occurs in any part of the power transmission path from the battery 1 to the traveling motor via the cable 5, a current flows in the radial direction of the cable 5 at that moment. Since it leaks, the induced voltage V corresponding to the resistance of the leak path_iIs output from the leak detection line 7. According to this configuration, since the current flowing through the cable 5 under normal load has poor sensitivity, the leak detection line 7 has almost no induced voltage V. _i Does not cause

When the induced voltage V _i exceeds the reference voltage V _f , the comparator 11 turns on the transistor 15 and the relay coil 13 is energized to open the relay switch 3. As a result, the cable 5 is separated from the battery 1 to prevent electric leakage.

Here, by selecting an appropriate value as the reference voltage V _f , it is possible to reliably detect the leakage even with a minute leakage current. Further, the response of the comparator 11, the switching transistor 15 and the relays 13 and 3 is sufficiently fast, so that it is possible to detect the leakage early and safely prevent it.

However, if the above-described leakage detection device is attached to, for example, the high-voltage cable 5 of an electric vehicle, even if a leakage occurs in the vehicle, it can be detected at an early stage. If the circuit is properly protected, the occupants will never experience any sensations such as numbness due to electrical leakage, and sufficient safe driving of the vehicle can be ensured.

[0016]

[Effect of device]

 As described above, according to the present invention, the detection line provided in the power transmission cable sensitively catches the leak current of the power cable, and the power transmission path is cut by the electronic circuit that can ignore the response transmission. Therefore, even if the leak current is minute, it is possible to detect and prevent the leak early and safely.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a leakage detection device according to the present invention.

[Explanation of symbols]

 1 High-voltage battery 3 Relay switch 5 High-voltage cable 7 Detection line 9 Protective layer 11 Comparator 13 Relay coil 15 Switching transistor

Claims (1)

[Scope of utility model registration request] 1. A leakage detection device for detecting leakage occurring in a transmission path from a power source to a load via a transmission cable, which is attached to the transmission cable and responds to a leakage current leaking from the transmission cable to the outside of the transmission cable when a leakage occurs. An electric leakage detection device, comprising: a detection line that generates an induced voltage and an electronic circuit that receives an induced voltage from the detection line and performs a predetermined protection operation.