Criterion and Delay Optimization of Circuit Breaker Failure Protection Based on Tail Current Recognition

When the circuit breaker acts, the current on the primary side of the current transformer suddenly decreases, and the inductive effect will form a tail current on secondary side, which will cause the time of return of the failure protection to be too long, resulting in the failure protection maloperation. A comprehensive criterion for the identification of circuiter failure protection based on tail current is proposed to improve the reliability of identification. Firstly, the working principle of the current transformer is analyzed, and the mechanism of the influence the tail current on the failure protection of the circuit breaker is explored. Secondly, the minimum algorithm and Fréchet distance algorithm are combined to construct a fast and reliable of the tail current comprehensive judgment criteria; Finally, according to the action delay and requirements of the circuit breaker failure protection, the delay of the circuit breaker failure protection optimized. The proposed method can effectively avoid the maloperation of the circuit breaker failure protection.