负载振动与气隙偏心下电机电流调制机理分析

分别分析了感应电机负载转矩振动和气隙偏心对定子电流的调制机理,同时针对转矩振动频率与电机转子转频一致时,两者对定子电流调制结果在频域上难以区分开的特点,利用Wigner时频域分析方法,计算了负载转矩振动和气隙偏心时电流边频分量的相位差,指出二者时频分布特征的区别,为有效、准确地进行电机气隙偏心故障诊断提供理论依据。

Stator current modulation mechanism analysis of induction motor under load torque vibration and gap eccentricity

The modulation on stator current signal of induction motor under the situation of load torque vibration and gap eccentricity is analyzed respectively.In view of that the modulation results in these two cases are difficult to be distinguished in frequency domain while the vibration frequency and rotor frequency are consistent, the Wigner time-frequency domain analysis method is used to calculate the phase difference of side-frequency current.The work in this paper points out the difference of modulation effects between load torque vibration and gap eccentricity in time-frequency domain, which provides theoretical basis for motor air-gap eccentric fault diagnosis.