Mine low voltage power network capacitative current automatic compensation device

Abstract

The utility model relates to an automatic capacitive current compensating device for a mine-used low-voltage power grid, which belongs to the technical field of underground leakage protection in coal mines. It is characterized in that the whole set of devices is composed of two parts: a capacitive current automatic compensation main circuit and a capacitive current automatic compensation control circuit. The biggest advantage is that it can automatically adjust the current of the inductance branch according to the change of the distributed capacitance of the actual power grid to the ground, and achieve the best compensation, so as to ensure the minimum leakage current or personal electric shock current. The system adopts single-chip microcomputer control to realize automatic compensation, without manual operation of opening the cover, and has the characteristics of good compensation effect, short cycle, convenient operation and high safety. It is mainly used in low-voltage power supply leakage protection where the neutral point is not grounded in underground coal mines.

Description

technical field [0001] The invention relates to an automatic capacitive current compensation device for a low-voltage power grid used in mines, which belongs to the technical field of automatic detection in coal mines, and specifically relates to an automatic capacitive current compensation device for an additional power supply DC detection leakage protector. The capacitive current automatic compensation of the 660V and 1140V low-voltage power supply leakage protection system without grounding overcomes the defect that the existing capacitive current compensation device cannot automatically and quickly adjust according to the operation change of the power grid, and can completely replace the capacitive current of the low-voltage power grid of the existing technology current compensation device. Background technique [0002] In the low-voltage power supply system where the neutral point is directly grounded, if a leakage accident occurs, a large current will be generated, eve...

AI Technical Summary

Problems solved by technology

When a leakage fault occurs in the power grid, effective protection measures must be taken, otherwise it will cause the following problems: personal electric shock accidents; leakage sparks generated at the grounding point cause gas and coal dust explosions; early detonation of electric detonators; long-term leakage may cause electrical equipment further deterioration of the insulation of the mine, causing short circuits between phases, electrical fires and other electrical failures that endanger mine safety

[0004] 1. The capacitor current compensation adjustment period is too long. Once the inductance value is determined, it cannot be adjusted in time with the change of the distributed capacitance parameters of the power grid. Therefore, the best compensation in the entire service cycle cannot be guaranteed. Once the distributed capacitance changes, it will appear. overcompensation or undercompensation, reducing the safety

[0005] 2. Each operation needs to open the cover, manually change the tap or manually adjust, through the visual ammeter and manual adjustment, the operation is inconvenient and the adjustment is cumbersome

In addition, opening the explosion-proof casing with electricity in the underground and adjusting it does not meet the requirements of explosion-proof technology, and may even cause new unsafe factors

[0006] 3. In order to meet the explosion-proof requirements, adjustments are generally carried out on the ground, and the best compensation for downhole parameters cannot be accurately realized

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