Substation area differential protection method for intelligent substation

Abstract

The invention discloses a substation area differential protection method for an intelligent substation, which comprises a big differential protection mode taking the substation as the principal thing, and more than two small differential protection modes taking the substations as the principal things; the big differential protection mode serves as a starting element, any one small differential protection mode serves as an action element; when the two conditions are satisfied simultaneously, the differential protection outputs action; the small differential protection modes are still failure selecting elements; the range of the big differential protection mode is delimitated by high voltage side current of each transformer and all outlet current on the medium voltage side generating line and the low voltage side generating line, of the substation, (not comprising buscouple and segment); the ranges of the small differential protection modes are delimitated by corresponding high voltage side current of the transformer, and all corresponding outlet current on the generating lines connected with main change medium voltage side and low voltage side, (not comprising buscouple and segment). The method not only can thoroughly protect the substation, but also can close the failure transformer in a targeted manner, is small in influence range for the electricity using user, and is particularly suitable for the substation provided with two or more than two transformers to use.

Description

technical field [0001] The invention belongs to the field of relay protection automation of electric power engineering, and is used for improving the safety and reliability of power system operation, and particularly relates to a differential protection method of an intelligent substation. Background technique [0002] A substation is a power facility that combines some electrical devices to transform voltage, receive and distribute electrical energy, control the flow of electrical power, and adjust voltage. In a power system, a substation is an assembly point for power transmission and distribution. The main components of the substation are: feeder (incoming line, outgoing line) and busbar, isolating switch, grounding switch, circuit breaker, power transformer (main transformer), voltage transformer TV (PT), current transformer TA (CT), lightning rod. Substations can be mainly divided into: hub substations, terminal substations; step-up substations, step-down substations; ...

AI Technical Summary

Problems solved by technology

For example, Chinese Patent No. 200910025578.1 discloses a phasor differential protection method activated by sampled value differential current. This protection method combines the advantages of sampled value differential and phasor differential, and has high resistance to Interference and reliability, but still achieve the purpose of protecting the substation by controlling the input or output of the whole station

Although this protection method plays a role in protecting the entire substation, it also affects the power supply within the coverage of the entire substation, and cannot control the working status of one or some faulty transformers in the substation in a targeted manner.

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