基于电压钳位原理的多端口限流式直流断路器

Multi-port Current Limiting DC Circuit Breaker Based on Voltage Clamp Principle

随着直流电网技术的广泛运用,直流断路器作为关键保护设备已成为相关领域研究重点。提出一种基于电压钳位原理的多端口限流式直流断路器,具有通态损耗低、经济性良好、重合闸速度快等优点。首先,提出新型断路器的拓扑结构及动作策略,通过电压钳位原理切除故障,而后利用LC振荡关断支路晶闸管;其次,分别对母线和线路故障进行解析推导,进而针对其关断过程设计参数;最后,利用PSCAD/EMTDC中的三端直流电网模型验证其有效性与适用性,并分别对两种故障仿真加以分析,通过故障电流、系统电压及支路电压对比分析等验证该断路器可代替多个常规断路器,减少了主断路器需求。

With the wide application of DC power grid technology, as a key protection device, the DC circuit breaker has become the research focus in the related fields. This paper presents a multi-port current limiting DC circuit breaker based on the voltage clamping principle, which has the advantages of low on-state loss, good economy and fast reclosing speed. Firstly, the topology and operation strategy of the new circuit breaker are proposed, in which the fault is removed by the voltage clamping principle and then the branch thyristors are turned off by LC oscillation. Secondly, the bus and line faults are analyzed and deduced,respectively, and then the parameters are designed according to the shutdown process. Finally, the effectiveness and applicability of the proposed circuit breaker are verified by three-terminal DC network model in PSCAD/EMTDC, and two kinds of fault simulation are analyzed. Through the comparative analysis of fault current, system voltage and branch voltage, it is verified that the proposed circuit breaker can replace several conventional circuit breakers, which can reduce the demand for main circuit breakers.