JPS5910862A - Monitoring device of deterioration in insulation - Google Patents

Abstract

PURPOSE:To monitor deterioration in insulation in the hot-line state of a main circuit and to discriminate a fault point of the deterioration in insulation without stopping system operation, by grounding the case sheath of every circuit block at one point and providing an insulation deterioration detecting part to every block. CONSTITUTION:The sheaths of all cables 4 of circuit blocks each consisting of a primary wiring breaker 2, secondary bus 6, secondary wiring breaker 5, etc., are grounded at one point through detecting parts 9. Then, a direct current flowing through a primary bus from a signal applying part 8 flows through the impedance between the main circuit and ground of every cable 4 in the same block and is detected by the detecting part 9 as a current corresponding to the circuit block unit, and a discrimination and display part 10 discriminates the insulation deterioration of every circuit block. This constitution allows the monitoring of insulation deterioration in the hot-line state of the main circuit and discriminates a position of insulation deterioration, block by block, without stopping the system operation.

Description

DETAILED DESCRIPTION OF THE INVENTION C. Technical Field of the Invention The present invention relates to an improvement of an insulation deterioration monitoring device that constantly monitors insulation deterioration of a cable system in a live line state.

[Technical background of the invention]

Conventionally, devices having the configuration shown in FIG. 1 have often been adopted as devices for monitoring insulation deterioration in cable systems. In the figure, reference numeral 1 denotes an AC power source that is supplied to the primary bus 2. A cable 4 is connected to each of the secondary busbars 2 through two primary power distribution breakers 3, and one of the cables 4 is connected to a cable 4 through three secondary power distribution breakers 5, respectively. It is connected to the connected secondary bus 6. ″1f
rC, each cable sheath 7 is individually grounded.

On the other hand, this monitoring device is composed of a signal application section 8, a detection section 9, and a judgment display section 10. In other words, the signal application unit 8 rectifies the power of the auxiliary power supply 11 into a DC signal, and applies the DC signal between the main circuit and the ground via a reactor (not shown). The applied direct current flows through the impedance between the main circuit of the equipment and cable and the ground to the detection section 9 installed between the signal application section 8 and the ground, and an error is detected based on the magnitude of the output of the detection section 9. The display section 10''C is used to display an alarm.

[Problems with background technology]

In the conventional insulation deterioration monitoring device mentioned above,
- When all of the secondary and secondary distribution circuit breakers 3 and 5 are closed, even if the insulation of the entire system connected to these circuit breakers 3 and 5 can be monitored, the insulation If deterioration is detected, it is not possible to determine where the insulation deterioration is, so investigating the insulation deterioration location not only involves stopping system operation;
There is a problem in that it requires time.

[Purpose of the invention]

The present invention was made in view of the unforeseen circumstances.
The purpose is to provide an insulation deterioration monitoring device that can monitor insulation deterioration while the main circuit is live, and can also determine the location of insulation deterioration at the circuit block level without stopping system operation.

[Summary of the invention]

In order to achieve the above object, the present invention monitors insulation deterioration of a circuit while the main circuit is live, and includes the following features:
connects cable sheaths for each circuit block consisting of multiple circuits, performs cable sheath grounding in the same circuit block at one point, and installs an insulation deterioration detection unit between each connected cable sheath and ground in the same circuit block. [Embodiment of the Invention] Hereinafter, an embodiment of the present invention shown in the drawings will be described.

FIG. 2 shows an example of the configuration of the insulation deterioration monitoring device according to the present invention. The same parts as in FIG.

In other words, Figure 2 focuses on the fact that accidents caused by insulation deterioration in the system are far more likely to be caused by insulation deterioration in cable parts, even in equipment areas such as switchboards. The cable sheaths 7 are connected, the connected cable sheaths 7 are grounded at one point, and a detection section 9 is provided between the connected cable sheaths and the ground in the same circuit block.

With this device configuration, the direct current applied from the signal application section 8 to the primary bus 2 flows through the impedance between the main circuit and the top and the ground of all the cables 4 in the same circuit block, and is converted into a current for each circuit block. It is detected by the detection section 9, and determined by the determination display section 10 as insulation deterioration of the unit circuit block.

In addition, although the circuits of all the branch breakers 5 connected to one primary power distribution and disconnector 3 are shown as one unit circuit block in the above, the circuits of the branch breakers 5 are each shown as a unit circuit block. If it is desired to make a determination as follows, the cable sheath 7 may be individually grounded, and a detection section may be provided between the cable sheath 7 and the ground.

Further, the judgment display section 10 may be constructed by using a circuit to switch inputs from a plurality of detection sections, or may be arranged in one-to-one correspondence as detection sections.

In addition, the present invention can be independently modified and implemented without changing the gist thereof.

〔Effect of the invention〕

As explained above, according to the present invention, insulation deterioration can be monitored while the main circuit is live, and the location of insulation deterioration can be determined on a circuit block basis without stopping system operation. A highly efficient insulation deterioration monitoring device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional insulation deterioration monitoring device, and FIG. 2 is a block diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...AC power supply, 2...-secondary bus, 3...-secondary power distribution breaker, 4...cable, 5...secondary distribution breaker, 6...secondary bus, 7 ...cable sheath, 8
...Signal application section, 9..Detection section, 10..Judgment display section, 1..Auxiliary power supply. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2

Claims (1)

[Claims] When monitoring circuit insulation deterioration while the main circuit is live, cable sheaths are connected for each circuit block consisting of a single circuit or multiple circuits, and the cable sheaths within the same circuit block are grounded at one point. Connection within block 71. An insulation deterioration monitoring device characterized in that an insulation deterioration detection section is provided between an fc cable sheath and a ground.