基于基波电势分布特征的大型发电机定子接地故障定位方法

提出一种基于基波电势分布特征的定子接地故障定位方法，该方法按各相各分支定子线圈的实际连接关系，确定发电机中性点至接地故障点的基波电势，建立了该基波电势、机端三相基波电压、基波零序电压、接地过渡电阻阻值之间的数学关系，准确定位定子接地故障，并对波绕组发电机故障定位中的特殊情况进行了分析。采用基于准分布电容参数的定子接地故障仿真模型验证了所提方法的有效性。最后对现场实际故障案例进行分析，进一步验证了所提方法的准确性，其可大幅缩短现场故障检修的时间。

Stator grounding fault location method based on distribution characteristics of fundamental wave potential

A stator grounding fault location method based on potential distribution characteristics of fundamental wave is proposed. The fundamental wave potential between the neutral point of the generator and the grounding fault point is determined according to the actual connection relationship of the stator coils of each branch of each phase. The mathematical relationship of the fundamental wave potential, three-phase fundamental wave voltage of the machine terminal, fundamental wave zero-sequence voltage and grounding transition resistance is established, by which, the stator grounding fault is accurately located. The special situation in the fault location of the wave winding generator is analyzed. Then, a stator grounding fault simulation model based on quasi-distributed capacitance parameters is used to verify the effectiveness of the proposed method. Finally, the actual fault cases in the field are analyzed, and the results further verify the accuracy of the proposed method and that it can greatly shorten the on-site trouble shooting time.