基于电流残差的逆变器开路故障诊断方法

Open-circuit Fault Diagnosis Method for Inverter Based on Current Residual

逆变器是永磁同步电机驱动系统的重要组成部分,对其进行故障诊断具有重要意义.为了诊断逆变器开路故障,构造了正常逆变器驱动PMSM系统的健康状态观测器,通过比较实际PMSM与观测器的输出得到三相电流残差,分析单管和双管开路情况下的三相电流残差特征表达式,并判断故障特征所在区间,实现对故障开关的准确定位.仿真表明,该方法可以对逆变器单管及双管IGBT开路故障实现准确诊断,在电机转速突变与突加负载时不会造成误诊断.

Inverter is an important part of the permanent magnet synchronous motor （PMSM）drive system,whose fault diagnosis is of great significance. In order to diagnose open-circuit faultof inverter in PMSM system,a healthy state observer of PMSM system driven by normal inverteris constructed. Three- phase current residuals are obtained by comparing the output of actualPMSM with above mentioned observer. The characteristic expression of three-phase current residualsof single tube and double tube in the condition of open circuit is analyzed,and the intervalof fault characteristic is distinguished,then the position of fault switch is located accurately. Simulationverifies that the method can diagnose single tube and double tube IGBT inverter open-circuitfault accurately and will not result in a false diagnosis for motor speed mutation and suddenload.