Protective circuit for expansion unit wiring system

Abstract

The invention relates to a protective circuit for an expansion unit wiring system. The protective circuit comprises a line protection device connected to a 110 kV power system through a voltage transformer and two transformers with 110kV voltage classes. The two transformers share the same circuit to be connected with the 110kV power system. In the circuit, the 110kV side of each transformer is provided with an isolating switch, a current transformer and a circuit breaker which are connected in series. The output end of the line protection device is connected with the two circuit breakers of the 110kV sides of the two transformers. The input end of the line protection device is connected with an overvoltage protection and transfer trip local discrimination device. The invention firstly provides the expansion unit wiring system with a protection method suitable for the two transformers with 110kV voltage classes sharing the same circuit of a transformer station and a power station boosting station, solves the application of the expansion unit wiring type in the 110kV voltage class power transformation system, and greatly shortens protection action time.

Description

technical field [0001] The present invention relates to protection circuits, in particular to protection circuits for extended unit wiring type systems. Background technique [0002] In the current 110kV voltage level power system of the substation or step-up station, when the scale is two main transformers and one circuit, the single-bus connection type is usually set. The single-bus connection type is equipped with confluence bus and corresponding bus voltage transformer, bus ground knife and other equipment. The 110kV incoming line interval and 110kV line interval of each main transformer are equipped with circuit breakers, isolating switches and current transformers. The single-bus connection type is also equipped with a line protection device and a transformer protection device, and is not equipped with a special circuit breaker protection device. The circuit breaker reclosing is realized by the line protection device, and the circuit breaker failure adopts the princip...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a protection circuit for the extended unit wiring type system to solve the application of the expanded unit wiring type in the 110kV voltage level transformation system, as well as the problems of circuit breaker reclosing and circuit breaker failure, shorten the protection action time, and Problems of overvoltage protection and local judgment of remote tripping, and joint tripping of transformer failure

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