适用于直流电网的新型机械式直流断路器

Novel Mechanical DC Circuit Breaker Suitable for DC Grids

直流断路器是保证直流电网安全稳定运行的关键器件。为此,提出了一种新型机械式直流断路器拓扑,并介绍了其工作原理以及参数设计方法。利用PSCAD/EMTDC仿真平台搭建了四端直流电网模型,仿真验证该直流断路器的故障电流和负荷电流开断能力。最后,将该直流断路器与其他3种典型的直流断路器进行了对比。仿真结果表明:快速机械开关的分闸时间为3.5ms时,该直流断路器开断时间<4ms。与传统机械式直流断路器相比,所提新型机械式直流断路器无需额外的预充电电源,可以更好地应用于直流电网。

DC circuit breaker is a vital device to ensure the safe and stable operation of DC grids.Consequently,we proposed a novel DC circuit breaker topology,and introduced the working principle and parameter design of the proposed DC circuit breaker.A four-terminal DC grid model was built on the PSCAD/EMTDC simulation platform,and the model was used to verify the breaking abilities of fault current and load current of the proposed DC breaker.Finally,the DC breaker was compared to three other typical DC breakers.The simulation results show that,when the operation time of the fast mechanical switch is 3.5 ms,the proposed DC circuit breaker has an interruption time of less than 4 ms.The proposed DC circuit breaker does not require an additional pre-charging power supply,thus,it is more suitable for DC grids compared with the traditional mechanical DC circuit breaker.