雷击对行波故障测距的影响及识别

Lighting Strike Identification and Its Effects on the Traveling Wave Fault Location

雷击是影响行波测距装置精度的主要因素之一,雷击故障的识别是解决输电线路雷击干扰的基础。通过对雷击故障和短路故障电流行波的暂态特性分析可知,雷击故障电流具有以下特点:雷击故障电流具有更大的陡度;非故障相的电流行波也具有更大的暂态能量。据此,提出利用小波变换提取故障电流陡度和利用相电流行波暂态能量进行雷击故障识别的新方法,以及相应的识别判据。EMTDC仿真及实例验证证明了文中所述雷击识别方法的正确性。

Lightning strike is one of the major factors that affect the precision of traveling wave fault location devices. Identification of lighting strike is key to mitigate the lighting strike influences on the transmission lines. In comparison with short circuit currents, lighting fault currents are more acute in gradients and the non-fault phase currents carry much more transient energy in their traveling waves. Based on this, a new wavelet transform method is proposed to identify lighting faults by extracting the gradients of fault currents and transient energy in the non-fault phase currents. Also, the corresponding criteria are proposed. EMTDC simulation and experimental results verify the correctness of the proposed method.