基于RLC模型参数辨识的配网电缆单相接地故障的单端时域测距方法

摘要

This paper presents a single-ended time domain fault location method for distribution network cable single-phase earth fault based on RLC model. The method uses the transient information at a distribution network cable single-phase ground fault to establish the time-domain ranging equation combining with fault state network and fault zero-mode network. The transition resistance and the equivalent capacitance to ground are identified and evaluated. The algorithm avoids the effect on the location accuracy by such factors as weak steady-state residual current caused by the fault arc suppression coil compensation, transition resistance, fault initial angle and the neutral point operation mode. EMTP digital simulation results verify the correctness of the algorithm, and show it has a high accuracy of identification and location. The ranging average error is within 10 m, the maximum relative error is less than 0.113%, and the maximum relative error of calculating the transition resistance is less than 1. 637%, which meets the needs of practical application.%提出了一种基于RLC模型的配网电缆单相接地故障的单端时域测距方法。该方法利用配网电缆单相接地故障后的暂态信息并结合故障状态网络与零模网络，建立时域测距方程，实现故障测距，且对过渡电阻及其两侧的等值对地电容进行了辨识求值。该算法避免了故障后消弧线圈补偿使得稳态残流微弱、过渡电阻、故障初始角及中性点运行方式等因素对测距精度的影响。大量的EMTP数字仿真结果验证了该算法的正确性，且具有较高的测距辨识精度。测距平均误差在10 m内，最大相对误差小于0.113%，计算过渡电阻的最大相对误差小于1.637%，满足实际工程应用需求。