Current Limiting Characteristics of Integrated Superconducting Generator Circuit Breaker

The installation of generator circuit breaker at the generator outlet can ensure the safe as well as stable operation of the power plant, and increase the availability of the unit. However, with the increasing capacity of the generator unit, it puts higher requirements on the breaking capacity. Superconductors can effectively suppress the rise rate of fault current and reduce its peak value. Therefore, in order to solve the problem that generator circuit breakers are difficult to break large capacity short-circuit current, this paper proposes an integrated superconducting circuit breaker topology. The circuit and Cassie arc model are built in Matlab/Simulink to simulate the breaking process of the circuit breaker. Through simulation, the relationship between arc voltage and arc current is obtained under AC voltage of 30kV and current of 200kA. The current limiting characteristics of the topology under different superconducting tape lengths and different fault currents are compared and analyzed, which can achieve good current limiting effect and can be reliably turned off. Thus, the rationality of the structure is verified, which provides a theoretical basis for the study of short-circuit fault of generator circuit breaker.