A mine-used explosion-proof low-voltage selective leakage protector

Abstract

The invention relates to a mining flame-proof type selective leakage protector. The mining flame-proof type selective leakage protector is characterized in that the mining flame-proof type selective leakage protector comprises a single chip microcomputer, a power supply unit, a liquid crystal display module, a signal detecting and processing circuit, a communication module and a drive tripping circuit. The power supply unit is connected with the single chip microcomputer and the liquid crystal display module and supplies power for the single chip microcomputer and the liquid crystal display module, the single chip microcomputer is connected with a zero-sequence current mutual inductor arranged on a power supply system through the signal detecting and processing circuit to achieve an electric leakage detecting function, the single chip microcomputer is connected with a tripping executing mechanism on the power supply system through the drive tripping circuit to achieve a tripping control function, and the single chip microcomputer is connected with a remote monitoring host machine to achieve a remote monitoring function. The mining flame-proof type selective leakage protector is reasonable in design, achieves the function of classified selective electric leakage protection of a trunk line and a branch line of the power supply system with no neutral ground in an underground coal mine, improves the automation degree and the power supply quality of the coal mine, and better ensures personal safety and the safety of machinery equipment.

Description

technical field [0001] The invention belongs to the technical field of earth leakage protectors, in particular to a mine flameproof low-voltage selective earth leakage protector. Background technique [0002] Underground electrical equipment in coal mines is usually powered by the mine's low-voltage power grid. At present, the power supply system in which the neutral point of the transformer is not grounded (neutral point insulated power supply network) is generally used underground in coal mines in my country. Such as image 3 As shown, in the neutral point insulated power supply network, cables are used as carriers in the underground, and the three-phase wires are insulated from the ground. The insulating material has a certain value of resistance R1, R2, R3 (that is, insulation resistance to the ground). The longer the total length, the smaller the insulation resistance; in addition, the three wires also have certain distributed capacitances C1, C2, and C3 to the ground;...

AI Technical Summary

Problems solved by technology

In order to avoid equipment damage or personal injury caused by the leakage of the power supply network system, a leakage protection device is usually installed in the power supply system. The existing leakage protection device usually has low detection accuracy, low reliability, poor selectivity, false tripping of the main switch, communication Single protocol, poor anti-interference ability and other problems, it is difficult to meet the power supply requirements of selective leakage protection in coal mines

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