线路故障对SVC的影响及保护整定分析

The analysis of line fault effect on SVC and protection setting

强直弱交的超高压电网采用SVC作动态无功补偿,可增强系统稳定性和安全性。负荷线路故障引起SVC保护误动作,会加剧系统运行工况。从几种典型线路故障特征出发,分析故障后TCR支路电流电压特征;故障期间TCR直流分量对晶闸管触发导通的影响。指出当前SVC欠电压保护的不足,提出SVC欠电压保护的整定调整方案及TCR支路故障整定的改进方向,可显著改善SVC保护可靠性。结合实际案例及仿真验证,证明方法的有效性。对改善SVC保护整定具有一定意义。

SVC is used for dynamic reactive power compensation, which can significantly enhance the stability and security of the system. Load line fault caused by SVC protection malfunction, will exacerbate the operating conditions of the system. Based on the characteristics of several typical circuit faults, the TCR branch current voltage characteristic is analyzed, and the influence of the TCR DC component on the thyristor trigger conduction is analyzed during the fault period. It points out the deficiency of the current SVC under voltage protection, and puts forward the adjusting scheme of SVC under voltage protection and the improvement direction of TCR branch fault setting, which can significantly improve the reliability of SVC protection. Combined with the actual case and the simulation, the effectiveness of the method is proved to be effective in improving the SVC protection setting.