基于PSCAD/EMTDC的大规模交直流电网实际故障再现

针对2010年11月7日南方电网发生的北郊一增城甲线短路故障导致5回直流同时发生换相失败事件,基于电磁暂态仿真软件PSCAD/EMTDC,根据实际电网结构等值系统搭建了含直流详细模型的电磁暂态仿真模型.为保证交直流大电网的快速且准确的建模,确定了建模规模,提出了直流系统建模、发电机调节系统自定义与校核、大规模交直流电网分区建模调试等工程实用方法.在此基础上,对此次故障进行了仿真研究,成功再现了实际故障过程.通过仿真结果与实际故障录波的对比,证明了建模方法的有效性和所建模型的准确度.最后使用所建模型对广东500 kV重要站点进行了典型故障仿真分析,确定了不同故障类型下可能引起5回直流同时发生换相失败的故障区域.

Simulating Reappearing of an Actual Fault in Large-Scale AC/DC Power System Based on PSCAD/EMTDC

Aimed at analyzing the actual short-circuit fault on the Beijiao-Zengcheng line which led to simultaneous commutation failures in 5 DC lines of China Southern Power Grid,the electromagnetic transient simulation model including detailed DC models was built according to the equivalent model of the actual grid based on the electromagnetic transient simulation software PSCAD/EMTDC.In order to ensure fast and accurate modeling to reflect real failure process,the main difficulties were analyzed and corresponding solutions during the large-scale AC/DC power system modeling process were also proposed,in which some engineering solving methods,such as the modeling scale,DC system modeling,user-defined model,accurate and fast modeling of large-scale system,etc.,were defined.On this basis,the fault was simulated successfully by using the PSCAD/EMTDC model,which reproduced the actual failure process.By comparing the simulation results with the actual recorded wave results,it was demonstrated that the modeling method is practical and effective to make the grid model accurate and reliable and able to truly reflect the actual dynamics of the system.With the model,the fault scan of Guangdong 500kV important sites was carried out to determine the fault areas those may cause simultaneous commutation failures in 5 DC lines.