基于换流驱动电路的直流断路器关键技术研究

Research on Key Technology for DC Circuit Breaker Based on Current Commutation Drive Circuit

针对直流断路器存在的预充电系统电压过高、充电困难或运行损耗大、系统复杂等问题,本文提出一种适用于直流断路器的换流驱动电路。研究其工作原理,建立换流过程的状态方程形式的数学模型,研制了换流驱动电路的两大核心部件——自动供电系统和基于半导体器件的双向快速开关,通过短路故障开断实验验证了换流驱动电路在机械式和混合式直流断路器中的通用性,提高了换流驱动电路的工程实用性。相比现有换流技术,该拓扑具有微损耗、成本低且通用于机械式和混合式直流断路器的优势。

In view of the problems in DC circuit breakers(DCCBs)such as high pre-charging system voltage,difficulty in charging,large operating loss and system complexity,a current commutation drive circuit(CCDC)suitable for DCCBs was proposed in this paper.Its working principle was studied,and a mathematical model of the commutation process in the form of state equations was established.Then,two core parts(i.e.,the automatic power supply system and the bidirectional fast switch based on thyristor and diode)in the CCDC were developed,and the universality of CCDC in mechanical/hybrid DCCBs was verified by the short-circuit fault breaking test,thus improving the engineering applicability of CCDC.Compared with the existing current commutation technologies,the proposed topology has advantages of low loss,low cost,and universal use in mechanical/hybrid DCCBs.