Analysis of the Influence of Fast Switch on Power Grid Relay Protection

The excessive short-circuit current restricts the development of the power grid. By using the fast switch to dynamically change the system topology structure during faults, the short-circuit current flowing through the conventional circuit breaker can be limit under the switchable current range, but the application of fast switch will affect the relay protection. In this paper, the flexible short-current suppression technology using the fast switch is introduced firstly. Then, the influence of fast switch on line protection, differential protection, distance protection and zero-sequence protection is discussed, and the optimized protection strategies are proposed. Finally, the simulation result is verified in RTDS.