基于预充电电容的新型混合直流断路器

A Novel Hybrid DC Circuit Breaker Based on Pre-charged Capacitors

混合型直流断路器技术因速度快、可靠性高,是目前直流领域断路器的重要研究方向,但现有方案存在成本高、限流效果差等缺陷。为解决上述问题,该文提出一种基于预充电电容的新型混合直流断路器,故障转移支路主要采用晶闸管代替传统的IGBT,预充电电容的投入一方面可使得晶闸管强迫关断,另一方面可有效抑制故障电流。该方案在短路线路切除过程中,较好地抑制了故障电流,同时减少了全控器件的使用,大大降低了设备成本。文中详细描述该混合直流断路器的拓扑结构、工作原理、控制策略及与现有方案的经济技术性对比,并最终通过在PLECS软件中搭建仿真模型验证其可行性和有效性。

Hybrid DC circuit breaker （DCCB） is prominent in DC grid due to its fast speed and high reliability. However, the existing hybrid DCCB schemes suffer from high cost and current-limiting shortage. To solve these problems, this paper proposed a novel hybrid DCCB based on pre-charged capacitors, which mainly employs thyristors instead of IGBTs. Pre-charged capacitors can not only realize reliable turn-off of thyristors, but also suppress fault current effectively. The proposed DCCB has the advantages of fault current suppression and low cost due to its pre-charged capacitors and reduced IGBTs. Topology structure, operating principle and control strategy were demonstrated in detail. The economic and technical comparison between the proposed and existing schemes was carried out. The effectiveness and stability of the novel DCCB were validated by the simulation in PLECS.