同步发电机定子绕组匝间短路下电磁转矩和振动分析

在考虑气隙偏心的情况下，分析了定子绕组匝间短路后同步发电机气隙磁场的变化特征，得到该内部故障前后电磁转矩和振动的变化规律，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．应用场路耦合法分析了内部故障与偏心双重条件下的电机端电流第17阶和第19阶分量特征．通过动模实验实测了一台容量为7．5kVA的发电机定子绕组匝间短路时的定子垂直方向振动加速度信号并对其进行了离散频谱分析．结果表明，发电机定子绕组匝间短路后，其2倍基频振动加速度变化大，第17阶和第19阶谐波电流幅值可作为检测未发生或发生内部故障的电机的动态偏心严重程度的特征值

Analysis of Synchronous Generator Electro-Magnetic Torque and Vibration with Armature Winding Fault

The air-gap magnetic field characteristic of the synchronous generator,caused by stator winding inter-turn short circuit fault,was analyzed in this paper with a consideration of the air-gap eccentricity. Then the characteristics of electromagnetic torque and vibration of generator were obtained,especially the magnitudes and frequency variation of the instantaneous pulse torque. And the characteristic of the 17th and 19th order component of terminal current under this condition was also analyzed by the coupled field-circuit method. Lastly,in the dynamic simulation experiment, the vibration acceleration data in the vertical direction of a 7.5 kVA generator with stator winding inter-turn short circuit fault were acquired,and then these data were analyzed by discrete fast Fourier technique. The results show that the change of the double frequency vibration acceleration is bigger when stator winding inter-turn short circuit faults occur and the 17th and 19th order component of terminal current can be used to detect the dynamic eccentricity of machines with or without internal faults.