Magnetic controlled shunt reactor exciting winding casing tube flashover detecting method and circuit

Abstract

The invention relates to a flashover detecting method and circuit for the bushing of the excitation winding of a magnetic control shunt reactor. The method of the invention includes the following steps: 1) mounting a circuit sensing element at the point grounding location of an overvoltage protection loop of the magnetic control shunt reactor; 2) judging to be normal when no circuits are detected by the circuit sensing element; 3) judging that the bushing of the excitation winding has a direct earth flashover fault when a circuit is detected by the circuit sensing element. The method can detect the fault circuit at the point grounding location of the overvoltage protection loop through the circuit sensing element no matter the flashover fault happens at any place of the bushing of the excitation winding; therefore, the invention is simple to be collocated; the level requirement on the insulating location is low; the detecting cost is low; the invention has great significance for the industrialization development of the magnetic control shunt reactor.

Description

technical field [0001] The invention relates to a relay protection detection method and circuit, in particular to a magnetically controlled shunt reactor excitation winding bushing flashover detection method and circuit. Background technique [0002] In ultra-high voltage and ultra-high voltage power grids, controllable reactors can effectively solve the contradiction between limiting overvoltage and reactive power compensation. They are indispensable technical means for ultra-high voltage and ultra-high voltage power grids, and have broad application prospects. The magnetically controlled shunt reactor changes the magnetic saturation degree of the iron core by changing the magnitude of the DC excitation current, so that the reactance value can be adjusted continuously, smoothly and quickly, so it has very superior control performance. However, since the magnetic control shunt reactor is a high-impedance transformer type, the short-circuit impedance is very large (it can be ...

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Problems solved by technology

However, since the magnetic control shunt reactor is a high-impedance transformer type, the short-circuit impedance is very large (it can be designed to reach or approach 100%), and the short circuit of the excitation winding belongs to one of the working conditions of the magnetic control shunt reactor. In the case of ground flashover and insulation damage due to overvoltage, it is difficult to detect the fault by conventional means, so it cannot effectively provide reliable protection for the reactor, which has become a difficult problem in the popularization and application of the magnetic control shunt reactor.

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