Generator transformer bank grid-connected circuit breaker flashover protection method

Abstract

The invention discloses a generator transformer bank grid-connected circuit breaker flashover protection method. Aiming at the problem of long action delay of the existing circuit breaker flashover protection method, the invention provides an instantaneous action flashover protection method, and the method adopts the action condition of the phase angle difference between the terminal voltage and the main transformer high-voltage side bus voltage as well as a phase current action element, so that the protection reliability can be ensured. The relay protection method provided by the invention is simple and reliable in principle and relatively high in feasibility, conforms to the basic'four-property 'principle of relay protection, namely, the reliability, sensitivity, selectivity and quick action principle, is extremely low in implementation cost, can greatly improve the rapidness and reliability of flashover protection of the grid-connected circuit breaker of the generator transformer bank, and has a relatively high application value.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a flashover protection method for a grid-connected circuit breaker of a generator transformer set. Background technique [0002] Faults in the power system can be divided into transverse faults and longitudinal faults, such as single-phase grounding, two-phase grounding, three-phase grounding and phase-to-phase faults are all transverse faults. If the equipment element is equipped with differential protection, it can ensure fast removal of transverse faults. For longitudinal faults, such as circuit breaker flashover, differential protection cannot operate, and such faults usually use single-ended electrical quantity criterion and are removed after a delay. [0003] During the process of synchronous paralleling of the generator transformer group or when the generator is disconnected and out of operation, the voltage acting on the breaker...

AI Technical Summary

Problems solved by technology

After a delay of 0.1s to 0.2s, when the flashover protection acts on de-excitation, compared with the initial no-load excitation voltage, the excitation voltage and excitation current at this time need to go through a longer de-excitation process, which leads to flashover Persistence of network failure

[0008] Although the protection method of circuit breaker flashover protection tripping adjacent circuit breakers proposed in the article "Analysis of the Coordination Relationship between Circuit Breaker Flashover Protection and Transformer Stability Capability" can remove flashover faults and protect the main equipment, but this sacrifices The selectivity of the protection is improved, that is, the loss of power to the adjacent equipment is caused

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