异步电机断条故障诊断的细化包络方法

Fault diagnosis of induction motor with broken bar based on zoom envelope method

针对异步电机断条故障时电流细化频谱存在的故障频率成分较弱和幅值不对称问题,结合实调制细化算法与Hilbert变换算法,提出了一种新的细化包络算法。实调制细化算法基于移频调制原理实现了正负频段频谱的对称搬移,保证了细化谱与原始谱的一致,减少了计算量;经Hil-bert变换得到细化谱的包络谱,可以排除电网频率成分影响,提高包络谱的分辨率。仿真和实验结果表明,该方法使电机电流信号的故障特征频率更容易识别,克服了常规细化谱在电机断条故障诊断应用中的不足。

For the induction motor with broken bar, the fault frequencies component in stator current is weak and its amplitude of zoom spectrum unsymmetrical, combining real modulation zoom algorithm with the Hilbert transformation algorithm, a new algorithm to improve the detection of fault is proposed. With the real modulation zoom algorithm based on frequency shift and modulation principle, a symmetrical fre- quency spectrum convey in positive and negative frequency domain was realized, a coincidence between zoom spectrum and original spectrum was guaranteed, and the calculation amount was decreased. Through the Hilbert transformation, a zoom envelope spectrum was gotten, the influence of power net frequency component could be eliminated, and the resolution of envelope spectrum could be enhanced. Simulation and experimental results show that this method makes the identification of fault characteristic frequencies easy in motor current signal, and overcomes the disadvantages of normal zoom spectrum in motor broken bar fault diagnosis applications.