基于小波变换的无刷直流电机逆变器故障诊断

摘要

Fault diagnosis is the premise of realizing the fauh tolerant control of motor.In order to improve the reliability of the motor system,and solve the open circuit fault of the inverter power tube in brushless DC motor driving system,the wavelet transform is proposed in this paper,which is adopted to analyze the three phase current signal of the motor.For the purpose of obtaining fault information quickly,the product of three or more layers of wavelet transform detail signals as detection signal is presented,which can locate the fault point precisely.The energy of the low frequency wavelet signal is regarded as the extraction feature to identify the fault of inverter power tube.This method has the advantage of high reliability and a simple algorithm for extracting the characteristic signal.The results of simulation and experiment show the effectiveness and accuracy of the proposed method.%故障诊断是实现电机容错控制的前提,为了提高电机系统的可靠性,针对无刷直流电机驱动系统中逆变器功率管的开路故障,采用小波变换对电机三相电流信号进行分析,为了能快速地提取故障信息,提出利用3层以上细节信号的乘积作为检测信号,根据乘积信号的小波变换能够准确找到故障点,以低频小波信号的能量值作为提取特征来识别发生故障的逆变器功率管.该方法故障识别可靠性高,信号特征提取算法简单.仿真及实验结果验证了所提方法的有效性和准确性.