区分发电机不对称运行和定子绕组匝间短路的故障检测

摘要

In order to effectively detect the stator winding inter-turn short-circuit of synchronous generator, the frequency,amphtude and phase of inductive potential in the parallel branches of stator winding and the harmonic characteristics of inductive potential in rotor winding are analyzed based on AC machine winding theory for stator winding inter-turn short-circuit. The fault characteristics of stator winding inter-turn short-circuit and asymmetrical operation of generator are calculated for the fault simulation generator. It indicates that,the change trend of generator field current harmonics,4 times and 6 times of fundamental frequency of armature current,during stator winding inter-turn short-circuit is different from that during asymmetrical operation. It is proposed to apply the even harmonics of generator field current to distinguish stator winding inter-turn short-circuit from asymmetrical operation. Dynamic simulation is carried out for five fault conditions,which verifies its effectiveness.%为了有效检测和辨识发电机定子绕组匝间短路故障,应用交流电机绕组理论分析了定子绕组匝间短路时并联支路感应电动势的频率、幅值和相位以及转子绕组感应电动势的谐波特征.以试验所用的故障模拟发电机为例,分别对发电机不对称运行和定子绕组匝间短路进行了故障特征计算.发现在发电机不对称运行和定子绕组小匝数匝间短路不断恶化时,发电机励磁电流频率为4倍和6倍电枢电流基频的谐波成分的变化趋势不同,从而提出了基于发电机励磁电流偶数次谐波的辨识发电机不对称运行和定子绕组匝间短路的故障检测方法.应用故障模拟发电机组进行了不同故障情况的动模试验.通过分析、比较算例和试验结果验证了故障检测方法的有效性.