带限流模式直流断路器在柔性直流输电系统中的应用

Application of DC Circuit Breaker with Current Limiting in Flexible DC Transmission System

直流断路器的设计与研发是直流系统实际应用中的难点。对此,提出了一种具备故障限流模式的混合式直流断路器,该断路器具有正常运行、限流运行和故障隔离三种工作状态,通过三种状态之间的相互转换可实现正常工作时以低电抗方式运行、故障时进入限流状态以高电抗方式运行限制故障电流,最终隔离故障,可起到保护系统设备的作用,并对该断路器进行了闸组内的电压、电流应力分析。最后通过在PSCAD/EMTDC上搭建的仿真模型验证了该断路器的可行性和有效性。

The design and development of DC circuit breaker is a difficult point in the practical application of DC system.In this paper,a hybrid DC circuit breaker with current limiting mode was proposed.The circuit breaker has three operating conditions:normal operation,current limiting operation and circuit breakage.Through the mutual conversion between the three states,it can operate in the low reactance mode and enter the current limiting state when it works in the normal work.The fault current is restricted by the high reactance mode,and the fault can be isolated,and it can play the role of the protection system equipment.The voltage and current stresses in the circuit breaker were analyzed.Finally,the simulation model built on the PSCAD/EMTDC verified the feasibility and effectiveness of the circuit breaker.