高压直流断路器系统开断条件仿真研究

Simulation Study on the Breaking Conditions of HVDC Circuit Breaker

为分析高压直流断路器在实际高压直流输电系统中的各种故障情况及其开断条件,笔者利用PSCAD/EMTDC仿真软件,根据高压直流输电系统的结构和控制方式,搭建了背靠背高压直流输电系统仿真模型。仿真研究了单端高压直流输电系统不同位置发生单相、异相、三相及直流母线短路等故障情况下的暂态特性。仿真结果表明,该仿真模型有很好的动态响应特性,能够有效模拟单端高压直流输电系统的各种短路情况。同时,结合高压直流系统的控制方式对各种短路情况进行了研究分析,找出了在系统中对高压直流断路器的开断较为苛刻的情况。经过参数分析得到了各种不同故障情况下对直流断路器的开断影响较大的故障电流峰值、最大故障电流上升率等系统参数。从而为多端高压直流输电网络建模分析、高压直流断路器型式试验及其标准的制定、高压直流断路器的发展提供借鉴。

To analyze the faults and the breaking conditions of HVDC circuit breaker in the real HVDC transmissionsystem, according to the structure and control mode, the author uses PSCAD/EMTDC and builds the model of back-to-back HVDC transmission system. The simulation study on the transient characteristic of the single end HVDCtransmission system under the faults conditions of single phase, double phase, three phases short-circuit faults andDC bus short-circuit. The result shows the model has a good dynamic response and can simulate various short-circuit conditions of single end HVDC transmission system effectively. Meanwhile, combined with the control modeof HVDC system the analysis of the various short-circuit conditions are carried out, the relatively harsh condition tothe breaking of HVDC circuit breaker in the system are found. After analyzing the results, the system parameters,which has large influence on the breaking of HVDC circuit break, such as the peak of the fault current and themaximum fault current are obtained. Thus, the references for multiterminal HVDC transmission network modelinganalysis, HVDC circuit breaker type test, standards formulation and HVDC