调相机失磁保护励磁电压判据性能分析与改进

新一代调相机在中国特高压直流换流站中逐步得到应用。正在运行的调相机失磁保护励磁电压判据采用励磁电压平均值作为保护动作量,难以可靠区分调相机深度进相运行和全失磁故障2种工况,也不能识别大部分脉冲丢失的部分失磁故障。文中提出了励磁电压方均根值判据,与平均值判据协同作用解决调相机深度进相运行和全失磁故障的区分问题;提出了脉波方均根值判据,解决丢失脉冲的部分失磁故障的识别问题。阐述了方均根值判据、平均值判据和脉波方均根值判据定值的整定方法。动模试验和现场试验结果验证了所提判据及定值整定方法的可行性和有效性。

Performance Analysis and Improvement of Excitation Voltage Criterion for Loss of Excitation Protection of Condenser

The new generation of condenser is gradually used in the ultra-high-voltage direct current (UHVDC) station. Because the excitation voltage criterion of loss of excitation protection of the condensers in operation uses the average value of excitation voltage as its protection action value, it is difficult to distinguish the deeply leading phase operation and complete loss of excitation of the condenser reliably, and cannot distinguish most of the partial loss of excitation with pulse missing. The root mean square (RMS) criterion of excitation voltage is proposed to solve the problem of distinguishing deeply leading phase operation and complete loss of excitation of the condenser with the coordination of the average value criterion. The pulse RMS criterion is proposed to solve the problem of distinguishing partial loss of excitation with pulse missing. The method to calculate the settings of the RMS criterion, average value criterion and pulse RMS criterion is expounded. Results of the dynamic simulation test and on-site test verify the feasibility and validity of the criterion and the method of setting calculating.