一种限流型混合直流断路器拓扑

A Topology of Current-limiting Hybrid DC Circuit Breaker

针对目前大多数混合直流断路器不具备限流功能且造价过高的问题,提出一种低成本限流型混合直流断路器。当故障发生后,并联在两侧的高速机械开关(ultra-fast disconnector, UFD)断开,电容C充电完成后断开两侧支路,电路由并联转为串联。随后,短路电流降低为单个支路电流,电感串联可限制电流的增长速度。IGBT阀组通过二极管桥式电路连接来实现双线关断,可减少绝缘栅双极晶体管(IGBT)数量。在相同参数下进行仿真计算,和传统的断路器相比IGBT使用数量降低83%。最后通过PSCAD/EMTDC和实验平台验证此拓扑的有效性。

To solve the problem that most of the current hybrid DC circuit breakers do not have the current limiting function and the cost is too high,a low-cost current limiting hybrid DC circuit breaker is proposed.When the fault occurs,the ultra-fast disconnector(UFD)connected in parallel on both sides is disconnected,and the branches on both sides are disconnected after the capacitor C is charged,and the circuit is converted from parallel to series.Subsequently,the short-circuit current is reduced to a single branch current,and the inductance in series limits the rate of increase of the current.The IGBT valve group is connected by a diode bridge circuit to achieve two-wire turn-off,which can reduce the number of insulated gate bipolar transistors(IGBTs).The simulation calculation is carried out under the same parameters,and the number of IGBTs used is reduced by 83%compared with the traditional circuit breaker.Finally,the validity of this topology is verified by PSCAD/EMTDC and experimental platform.