Abstract：The relay protection technology is becoming more and more mature for the traditional AC power grid, but with the formation of UHV AC and DC hybrid power network, the adaptability of AC protection to the characteristics of the power grid needs to be improved. In view of the breaker failure or the CT dead zone fault, the removal of the fault time is long, which may lead to the failure of the multiple DC continuous commutation, resulting in the serious consequences of the system. In this paper, two kinds of breaker dead zone (failure) protection optimization scheme is introduced, which shortens the excision time to less than 200ms when the breaker failure or the CT dead zone fault is broken down to prevent accidents caused by power grid stability damage. And it builds a test system. The performance index of the optimized breaker dead zone (failure) protection is examined in detail, and the action situation of the breaker dead zone (failure) protection in the abnormal operation condition is verified and tested, so as to guarantee the optimized breaker dead zone (failure) protection operation stability and reliability in power system.
2019, Vol. 20 
