高压直流输电线路极间耦合影响及故障选极方案

为了解决高压直流输电线路极间耦合引起的问题,提出了一种利用单极电气量的故障选极方案。耦合特性分析发现线路极间耦合程度与电气量的频率有关,且频率越高则耦合作用越显著。故障电气量频谱特性理论分析及仿真结果表明健全极电气量中低频信号含量远低于故障极。基于健全极与故障极低频信号差异,提出了仅利用单极电气量的故障极选择方法,并给出了故障选极判据。仿真结果及现场录波数据均验证了所提选极方法的可行性及有效性。

Analysis of inter-pole coupling effect and faulty pole selection for HVDC transmission line

Aiming at the inter-pole coupling effect of HVDC transmission line, a faulty pole selection scheme based on the electrical variables of single pole is proposed. The characteristic analysis of inter-pole coupling shows that, the coupling effect is related to the frequency of electrical variables: the higher the frequency is, the more obvious the coupling effect is. Theoretical spectrum analysis and simulative results show that, the content of low-frequency signals in the electrical variables of healthy pole is much lower than that of faulty pole, based on which, a faulty pole selection scheme based on the electrical variable of single pole is proposed and its criterion is given. The feasibility and validity of the proposed scheme are verified by the simulative results and field-recorded data.