无速度传感器感应电机转子断条的故障诊断

Fault Diagnosis for Broken Bar of Speed Sensorless Induction Motor

在基于定子电流信号进行异步电机故障诊断时,转子断条故障特征频率分量常常被电流的基频分量淹没.针对这种情况,文中提出一种新型无速度传感器感应电机矢量控制转子断条故障方法.该方法通过转子反电动势与电流矢量的叉乘构建无功功率,然后对无功功率进行频谱分析,其中特征频率2sf被用作转子断条的故障诊断判据.同时利用该无功功率进行速度辨识和磁场定向校正,消除传统MRAS速度辨识定子磁链方程中定子电阻和积分项的影响.实验结果表明,该方法能有效进行转子断条故障诊断,并提高速度辨识精度,改善矢量控制性能.

During the fault diagnosis of asynchronous motor based on stator current signals,the fault feature frequency component of broken bar always hides behind the fundamental component in the spectrum of the stator current.In order to solve this problem,a novel fault diagnosis method for the broken bar of speed sensorless induction motor is proposed based on the vector control.In this method,the reactive power is constructed by using the cross production of the rotor back electromotive force and the current vector,and then the corresponding reactive power spectrum is analyzed,with the characteristic frequency 2s f as the fault diagnosis criterion for the broken bar.Meanwhile,the reactive power is used to identify the speed and correct the magnetic field orientation,thus eliminating the impacts of the stator resistance and integral term of the traditional model reference adaptive system speed identification equation of stator flux.Experimental results demonstrate that the proposed method is effective in the fault diagnosis of broken bars,and that it can improve the speed identification accuracy as well as the vector control performance.