昆柳龙三端直流系统故障后断路器动作特性

Action Characteristics of Circuit Breakers After the Faults of Kunliulong Three-Terminal DC System

混合多端直流输电系统通过各直流断路器配合实现运行方式转换、隔离故障以及保护等功能,研究各种故障后直流断路器动作特性,对于发现系统潜在风险具有非常重要的意义。构建了昆柳龙(昆北-柳州-龙门)特高压三端混合直流系统及直流断路器PSCAD/EMTDC仿真模型,遍历系统交流侧、站内及直流侧典型故障,针对不同故障恢复过程中断路器动作特性进行分析,并得出各断路器最严重故障状态。研究结果将有助于发现系统薄弱环节,为系统运维和调度提供参考和依据。

The hybrid multi-terminal DC transmission system realizes operation mode conversion,fault isolation and protection functions through the cooperation of various DC circuit breakers,and studying the action characteristics of DC circuit breakers after various faults is of great significance for discovering potential risks of the system.This paper constructs the Kunliulong(Kunbei-Liuzhou-Longmen)UHV three-terminal hybrid DC system and DC circuit breaker PSCAD/EMTDC simulation model,traverses the typical faults on the AC side,inner station and DC side of the system,and analyzes the operating characteristics of the circuit breaker in different fault recovery processes.The most serious fault state of each circuit breaker is obtained.The research results will help to find the weak parts of the system,and provide reference and basis for the system operation and maintenance and dispatching.