互感线路接地距离保护定值灵敏度影响分析及其整定优化

从整定的角度建立互感线路感受阻抗分析完整模型,并对模型中各因素影响互感线路接地距离保护测量阻抗的机理进行定性分析和定量验证,提出了求取测量阻抗极值的简化模型条件。在此基础上结合电网中典型极值工况进一步对互感线路感受阻抗的助增影响进行分析。最后,根据分析结论提出了接地距离保护定值的整定优化策略,该整定策略已在广东电网全面应用,实际应用结果表明该整定策略能够提高接地距离保护定值的适应性,改善了接地距离保护定值的性能。

Sensitivity Impact Analysis and Optimal Setting of Grounding Distance Protection of Transmission Lines with Mutual Inductance

A complete detecting impedance analysis model of transmission lines with mutual inductance is developed from the angle of setting. In the model, the influence mechanism of various factors on the measured impendence of grounding distance protection is qualitatively analyzed and quantitatively validated. With these results, the conditions for the simplified model which can calculate the extreme values of the measured impendence are proposed. On this basis and by referring to typical extreme value cases in the power system, the sideline current addition influence of the detecting impendence of transmission lines with mutual inductance is further analyzed. Finally, the optimal relay setting strategy for the grounding distance protection based on the analysis results is proposed. The strategy is implemented in Guangdong power grid. Actual application results show that the optimal strategy is able to improve the adaptability and performance of grounding distance protection.