混合式直流断路器模型及其操作暂态特性研究

Transient Model and Operation Characteristics Researches of Hybrid DC Circuit Breaker

该文围绕±10 kV柔性直流系统中的自然换流型混合式直流断路器操作暂态特性进行分析并建模仿真。首先简要分析直流断路器拓扑结构,提出一种基于绝缘栅双极型晶体管的自然换流混合式断路器。随后设计了断路器的动态模型,并整定了动作时序。接着讨论了断路器参数变化和故障特性对断路器分断性能的影响,利用PSCAD/EMTDC仿真软件分析了极间短路故障时直流断路器的暂态特性。仿真结果表明,电流转移过程能否正常进行对断路器开断有很大的影响,转移回路的杂散电感与电流转移时间接近线性关系,金属氧化物压敏电阻吸收电流持续时间对断路器成功开断故障有很大影响。此外,该文还设计了电流转移实验验证研究结果的正确性。研究结果可用于指导直流配电系统和断路器设计和电磁暂态分析。

This paper focused on the breaking transient characteristics analysis and simulation of hybrid DC circuit breaker in ±10 kV flexible DC system. Firstly, various existing DC breakers were compared. A hybrid breaker topology based on insulated gate bipolar transistor was proposed. Secondly, the dynamic branch models and operation timing of the DC breaker were designed. Then, the impact of breaker parameters and system fault characteristics on the breaking performance was discussed. The transient characteristics of DC circuit breaker under interpoles fault of DC system were analyzed using PSCAD/EMTDC. The results show that current transfer process has a greater impact on the breaking performance. There is nearly a linear relationship between transfer circuit stray inductance and current transfer time. And metal oxide varistor（MOV） current duration also has a significant impact on the breaker. Finally, a current transfer experiment was designed and the simulation results have been verified. It will be a valuable reference for the design and electro-magnetic analysis of DC distribution system and DC breaker.