Protection method of power distribution network for coal mine

Abstract

The invention relates to a protection method of a power distribution network for a coal mine. The protection method comprises the following steps of: if any section in the power distribution network is subjected to short circuit, respectively tripping the main protection detection fault outlet of a superior switch closest to a fault section, if failure current still exists after the inherent action time of a main protection tripping fault switch, showing that the fault switch refuses operating; and then tripping the intelligent backup protection direct outlet of a superior switch adjacent to the fault switch, and removing the fault. The method has the following beneficial effects: the current conditions of circuits in all levels are judged, thereby ensuring that backup protection of the superior protection drives tripping without time delay when a switch cabinet in each level refuses operating, effectively shortening the protective fault removal time of the superior switch when the fault switch refuses operating, being conductive to removing the fault rapidly, and being conductive to the safety of the whole power distribution network.

Description

technical field [0001] The invention relates to the technical field of power system backup protection, in particular to a distribution network protection method for coal mines. Background technique [0002] Power protection is an electrical application technology that acts on the tripping of switches in the system when electrical equipment fails or does not work normally in the power system, also known as relay protection. In the tree-shaped distribution network, if a short-circuit fault occurs on a line protected by a lower-level relay protection device, all the relay protection devices at the upper level may detect the fault due to the short distance of the power supply line or the insufficient sensitivity of the relay protection device. The phenomenon of false tripping due to short-circuit current is called leapfrog tripping. In power system power supply, skipping trips have been a problem that has plagued the power system for many years, and skipping trips often occur. ...

AI Technical Summary

Problems solved by technology

That is to say, the fault discrimination and action tripping of the existing power backup protection are only determined according to the fault measurement information and action delay of the respective protected components, and the action delay is coordinated by the step-shaped time difference. The action time limit of the backup protection is the shortest, and the action time limit of the highest-level backup protection is the longest, that is to say, the closer the power components are to the power supply, the longer the protection action time is, causing the faults close to the power supply cannot be removed quickly, and it is easy to cause damage to the power supply. It has caused huge losses to the power system, so it cannot meet the requirements of the power system for rapid protection

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