1107 / 2019-05-20 20:54:35

Coordination Strategies of Relay Protection for UPFC Integrated 500kV Power Network

unified power flow controller, relay protection, UPFC control-protection, reclosure

As a powerful flexible AC transmission equipment, Unified Power Flow Controller (UPFC) has been further extended in power system and gradually applied in the 500kV power network. As one of the devices integrated to power network, the UPFC and its control-protection must be cooperated with the adjacent equipment to ensure the safe operation of the grid. The relay protection of power grid, such as transmission line protection, circuit breaker protection, series transformer protection, etc., in 500kV power network with 3/2 connecting mode will face new application problems. This paper analysis the special functional requirements of relay protection in power system. Based on fast bypass technology, it designs the coordination requirement and strategies between the UPFC control-protection and relay protection of power network. More, the implementation scheme of UPFC protection and integrated power network protection strategy is put forward, which is applied in practical UPFC project of 500kV power network. Experimental results show that the line protection, circuit breaker protection, series transformer protection device involved are correct. The collaboration between UPFC control protection and AC protection is correct and reliable. The research improves operation reliability of UPFC system.