定子绕组匝间短路时发电机电磁转矩分析

对定子绕组匝间短路时发电机的电磁转矩特性进行了研究。分析了在考虑电机振动偏心下，定子绕组匝间短路后同步发电机的气隙磁场变化特征，然后得到内部故障发生前后电磁转矩的变化特征，特别是瞬时转矩中的脉冲转矩分量幅值和频率的变化特征。同时分析了故障后发电机转子励磁电流的故障特征。利用动模实验，实测了1台容量为7.5kV×A的同步发电机不同程度定子绕组匝间短路时的电磁转矩并对其进行了离散傅里叶变换频谱分析，实验分析结果与理论分析基本一致。该结果对于电机瞬时转矩的测量、计算和运行中动态电磁转矩波形的描述具有较高的参考价值。

Analysis of Generator Eletro-magnetic Torque on Armature Winding Inter-turn Short Circuit Fault

This paper analyzes the electro-magnetic torque characteristic of generators caused by the stator winding inter-turn short circuit faults. The air-gap magnetic field characteristic of the synchronous generator is analyzed first with inter-turn short circuit fault, while considering the vibration eccentricity. Then the corresponding characteristics of electro-magnetic torque are obtained, especially the magnitudes and frequency variation of the instantaneous pulse torque. And the characteristic of excitation current after fault has also been studied. Using the dynamic simulative experiment, we acquire the instantaneous electro-magnetic torque data of the 7.5kVA synchronous generator with different stator winding inter-turn short circuit faults, then analyze these data by the Discrete Fast Fourier Transform technique.