Abstract:

For the problem of override trip of coal mine power system, the paper proposed a scheme of preventing override trip based on short circuit locking control. The system is mainly composed of short-circuit locking controller, comprehensive protection device and signal line. Locking controller receives short-circuit current signal of the switch and blocks superior switch quick-break protection function. All levels of switch short-circuit blocking prevent override trip function in turn cascade,.Signal using point-to-point transmission.When the line appears short-circuit fault, device can realize no time limit quick-break protection function of selective and prevent the occurrence of override trip. Keywords：coal mine；override trip；quick break protection; selective

Key words: coal mine, override trip, quick break protection, selective