超高压线路波过程及高频暂态电流保护性能分析

探讨了超高压输电线路发生故障后传输线波阻抗不均匀处暂态量的反射及透射情况,利用Peterson法则推导了保护安装处暂态电流的复频域表达式。明确了故障后影响各频率分量传播的主要因素,指出若选取合适的频段,则基于高频暂态电流高低频段能量比的保护对于不同故障时刻、过渡电阻及故障类型均有良好的自适应性。大量的仿真实验验证了所得出的结论。

Analysis of Transmission Process of Fault-Generated Travelling Wave along EHV Transmission Lines and Performance of Transient Current Protection

The reflection and refraction of fault-generated travelling waves at the position where the wave impedance is non-uniform are researched. The Peterson principle is applied to deduce the expressions of transient currents in complex frequency domain at the position where the protection is installed. The main factors influencing the propagation of all components of different frequencies are explicated, and it is pointed out that choosing appropriate frequency bands can make the transient current protection based on the energy ratio of a high frequency band to a low one have good adaptability to different fault inception angles, fault resistances and fault types. The obtained conclusions are verified by a lot of simulation results.