特高压直流双极相继故障再启动策略

Recovery Strategy for Bipolar Cascading Line Fault of Ultra-high Voltage Direct Current Project

直流故障再启动功能对于提高特高压直流输电工程的运行可靠性具有重要意义。首先,分析了已投运特高压直流再启动对交流系统安全稳定性的影响。在此基础上,针对特定的交流运行方式,对特高压直流双极相继故障时序及系统稳定特性进行了分析,并基于分析结果提出了三段式相继再启动策略分析方法,以此作为制定特高压直流双极相继故障再启动策略的理论依据。最后,以西南某回特高压直流工程为例,验证了所提三段式再启动策略的有效性。

The DC line fault recovery function is of great importance to ultra-high voltage direct current(UHVDC) projects in enhancing operational reliability.First,the impact of UHVDC recovery for the line fault on the security and stability of AC system is analyzed and described in detail by taking UHVDC projects in operation presently as examples.Secondly,both the time sequence of UHVDC bipolar cascading line fault and the system stability characteristics are analyzed,and a three-stage cascading fault recovery strategy is proposed based on the analysis results.The proposed strategy will provide a theoretical guidance for all DC projects to draw up their cascading fault recovery schemes.In the end,an UHVDC project in Southwestern China is taken as an example to verify the efficiency of the proposed strategy.