Method for detecting zero-sequence voltage circuit of transformer substation

Abstract

The invention discloses a method for detecting a zero-sequence voltage circuit of a transformer substation. A voltage transformer can be added with a 220V single-phase test voltage for one time before the transformer substation is in charged production, by the adoption of a high-accuracy universal meter, a zero-sequence voltage amplitude value between a terminal of a zero-sequence voltage outlet line L and the terminal of a grounding line N of a terminal box is detected to be ULN1, a voltage amplitude value between the terminal of the zero-sequence voltage outlet line L and the added test voltage A is detected to be ULA, and the voltage amplitude value between the test voltage A and the grounding line N is detected to be UAN; then, the voltage transformer can be added with a 380V three-phase symmetrical positive phase sequence line voltage for one time, and the voltage amplitude value between the zero-sequence voltage outlet line L and the grounding line N is detected to be ULN2; at last, the measured data can be analyzed, the polarity of outlet lines L of zero-sequence voltage secondary windings of a grounding terminal is the same as that of a high-voltage side of a primary winding if UAN=ULN1+ULA, a zero-sequence secondary winding a, a zero-sequence secondary winding b and a zero-sequence secondary winding c can be judged to be in like polarity connection in series if the voltage amplitude value ULN2 is 0, and thus whether the zero-sequence voltage connection of the terminal box is correct or not can be judged. According to the method disclosed by the invention, the connection of a zero-sequence voltage secondary circuit of the transformer substation can be detected, a zero-sequence voltage circuit which is in leaked connection and misconnection can be found, the inspection for the zero-sequence voltage secondary circuit can be more comprehensive to implement, convenience is provided for the operation, and the effectiveness and the reliability of the inspection are high.

Description

technical field [0001] The invention belongs to the technical field of electric engineering, in particular to a test method for ensuring the correctness of zero-sequence voltage circuit wiring by conducting tests before substations are put into production. Background technique [0002] Today, electricity has become an indispensable necessity for people's life. Substation is an important part of power transmission. Whether its zero-sequence voltage circuit is correct or not will affect the safety and stability of the power grid, the normal supply of power and the normal life of people. . Errors in the zero-sequence voltage circuit will lead to electromagnetic resonance hazards, affecting the correct action of the grid relay protection and other adverse consequences. [0003] Single-phase ground fault is the most common fault type in 110kV transmission and distribution network. After single-phase grounding, the zero-sequence voltage of the system will rise. During operation, ...

AI Technical Summary

Problems solved by technology

[0007] After the zero-sequence winding is put into operation, the zero-sequence voltage will not be generated during normal operation, and the polarity of the zero-sequence voltage wiring cannot be confirmed in depth. When the grid system fails, incorrect zero-sequence voltage will be provided, which will cause the grid relay Protection against misuse accidents

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