±800kV直流输电工程高端阀厅内部过电压仿真分析

Simulation Analysis on Overvoltage Inside High-End Valve Hall of ±800 kV UHVDC Project

换流站阀厅内部重要设备众多、空气间隙复杂、典型电极多,一直是±800kV特高压直流输电工程设计工作中的重点之一。研究阀厅内部过电压的分布和数值对科学、合理地设计阀厅具有重要意义。以±800kV向家坝—上海直流输电工程的仿真计算为基础,对系统在各种故障状态下的操作过电压进行了仿真研究和总结;结合换流站避雷器布置和送端复龙站高端阀厅内部空气间隙、电压关键点的实际位置和范围,得出了高端阀厅内部过电压的分布和最严重时刻数值。仿真结果表明,特高压直流输电阀厅内部过电压并非同一时刻出现,而是集中在几种严重故障发生时刻。

In view of complicated air gaps and multiple electrodes inside the valve hall of converter station for ±800 kV uHvDC project, where multi important equipment are installed, the design of the valve hall is one of the important key points of ±800 kV UHVDC project, so it is of significance for the reasonable design of the valve hall to research the distribution and numerical value of overvoltage inside the valve hall. Based on simulation calculation of ±800 kV UHVDC power transmission system from Xiangjiaba to Shanghai, the simulation research on switching overvoltages under various fault conditions occurred in ±800 kV UHVDC transmission system is performed and summarized. Combining with the attester layout as well as the air gap distribution, actual positions of voltage key points and their influencing spheres inside the high-end valve hall of Fulong converter station at the sending end of the UHVDC transmission system, the distribution of overvoltages inside the valve hall and their values at the most serious time are obtained. Simulation results show that overvoltages inside the valve hall do not appear at the same time, but concentratedly appear when some kinds of serious faults occur.