基于消弧线圈补偿特征的故障选线新方法

为解决零序电流互感器极性不明确导致选线错误的问题,提出一种根据消弧线圈补偿特征的选线新方法。对于每条线路建立健全线路数学模型,利用零序电压电流暂态分量与基频分量求取相应的导纳参数。针对分量"湮没"问题,提出一种矩阵束的改进方法实现小幅值高频分量的精确提取。分析得到消弧线圈补偿作用规律:在确定频段内故障线路两参数符号相反或数值明显减小,健全线路两参数计算结果相近,可实现故障判断。仿真实验结果验证了该方法摆脱了零序互感器极性不同导致选线错误的限制,无需线路参数信息即可实现故障自判,适应性强。

Fault line selection approach based on compensation characteristics of extinction coil

Anti-polarity of zero sequence CT leads to failure of fault line selection in extinction coil grounding system. In order to overcome the drawback, a new approach using compensation characteristics of extinction coil is proposed. The healthy line mathematical model for each line is built and the transient component and steady component of zero sequence voltage and current are used to get corresponding admittance parameters. To solve the component annihilation, this paper presents an improved matrix pencil algorithm for the extraction of high frequency component of small amplitude. The rule of the compensation effect of extinction coil is obtained that in set frequency band two component parameters of fault line are opposite in sign or decrease significantly in numerical values and the calculation results for two parameters of healthy line are similar, the fault line selection is realized. Simulation results verify the correctness of the algorithm without the impact of anti-polarity of zero sequence CT, which has highly adaptive capacity for practical engineering.