瞬时功率频谱分析在牵引电机转子故障诊断的应用研究

Study on application of spectral analysis of instantaneous power to fault diagnosis of traction motor rotor

针对故障特征频率容易被基波频率淹没的问题,提出一种基于网侧瞬时功率的转子故障诊断方法。当交流调速系统牵引电机发生转子断条故障时,定子电流中故障特征频率(1±2s)f1分量通过变频器向变频器一次侧(网侧)传播。通过频谱分析发现,变频器网侧电流信号和定子电流信号都存在故障特征频率容易被基波频率淹没的问题。该方法选用网侧瞬时功率进行频谱分析,使得转子断条故障特征频率转换成2sf1的频谱分量,消除了基波频率影响,突出故障特征频率。且只需采集单相电流,简化了硬件结构。实验表明:该方法能对转子故障进行有效诊断。

A method for the rotor fault diagnosis was proposed based on the instantaneous power of the network side to resolve the problem which fault characteristic frequency drowned easily by base wave fre quency. When traction induction motor broken bar fault occur in the variable frequency drive system, the fault characteristic frequency components （1 ±2s）f1 propagated through converter to inverter side （net work side）. It was found that the network side current signal and the stator current signal had the same problem which fault characteristic frequency drowned easily by base wave frequency. The instantaneous power of the network side spectrum was selected and analyzed, the rotor broken bar fault characteristic frequency convert 2sfl spectral component was made, the base wave frequency effect was eliminated, the characteristic frequency was highlighted and the hardware structure for requiring only one phase current was simplified. Experimental results showed that the method can effectively diagnose the rotor fault.