和应涌流对继电保护误动的分析及对策

Analysis and Measures of Sympathetic Inrush Cause Protection Equipment Misoperation

通过采用波形对比法,查找和分析发电机差动保护误动的故障原因。介绍了和应涌流产生的机理、特征和非周期分量对电流互感器(TA)暂态饱和的影响。通过切磋减小或消除和应涌流对策的不同观点,结合现场实际,将发电机差动保护整定值由0.09pu调整至0.25pu,并对二次回路负载阻抗、TA伏安特性进行试验,检验TA伏安特性、TA精度和二次回路负载能否满足误差要求,用以减小系统突变时和应涌流对相邻设备继电保护装置的误动。

Cause Analysis on the misoperation of Generator Differential Protection by means of comparing with wave form. Introduce the principle and features of sympathetic inrush, influence of non-periodic components on transient saturation of current transformer. Through the different view on reducing the sympathetic inrush and actual onsite, adjust Generator Differential Protection setting from 0.09pu to 0.25pu, and test the second- ary circuit load impedance and Volt-Ampere Characteristic. Through Inspecting TA Volt-Ampere Characteris- tic,the accuracy of TA, the secondary circuit load to meet the error requirement, reduce the misoperation of neighbor protection equipment by sympathetic inrush when system happen sudden change.