一起直流单极连续3次闭锁故障仿真分析

宁夏电网目前已接入3回直流,其中第1回直流为±660 kV接入,容量为4 GW;第2回直流为±800 kV,容量为8 GW;第3回直流为±800 kV,容量为10 GW,并正式形成了送端直流群。随着特高压直流的接入,宁夏电网发生直流故障的次数逐渐增多。针对第2回直流某次典型单极连续3次闭锁故障,详细介绍了事故发生的过程和故障前后宁夏电网运行方式及系统动态特性的变化情况。利用PSASP程序建立宁夏电网仿真模型,还原了故障前电网运行方式,并仿真再现了故障后的电网动态过程。通过仿真与实测结果的对比,进一步明确了直流故障期间电网特性的变化情况,同时验证了仿真模型的准确性。

Simulation and analysis of consecutive three times blocking failures for a DC unipolar

Ningxia power grid has connected with three HVDC transmission lines.The first is connected with 660 kV and 4 GW.The second and third are connected with ±800 kV, the capacities are separately 8 GW and 10 GW.With the access of UHVDC, the frequency of DC transmission system faults for Ningxia power grid increases gradually.Aiming at the typical consecutive three times unipolar blocking failures for a second DC transmission line, the process of the failure, the changes of power system operating conditions and dynamic characteristics before and after the fault were introduced in detail.The simulation model of Ningxia power grid was built by PSASP program.With PSASP, the dynamic characteristics of power grid after the faults were reproduced.By comparing with the PMU results, the characteristics of power grid during the faults were clarified, and the accuracy of the simulation model was verified.