无电压传感器逆变器开路故障诊断方法

为了提高永磁同步电机(PMSM)控制系统的可靠性,提出一种基于二阶滑模电压观测器和混合逻辑动态模型(MLD)的无电压传感器逆变器开路故障诊断方法。首先构建正常工作与故障状态下电压源逆变器的混合逻辑动态模型,并对两种状态下电机电压的残差进行分析。通过提取电压残差中所包含的故障信息,实现了逆变器开路故障的诊断与定位。同时,提出一种二阶滑模电压观测器对电机电压进行实时估计,避免电压传感器所带来的增加系统复杂性与成本的问题,减少系统潜在故障源。最后,通过实验验证了该方法的有效性。

Diagnostic method of open-switch faults in inverters without voltage sensor

To improve reliability of permanent magnet synchronous motor ( PMSM) system,a novel diag-nostic method for open-switch faults in inverters without voltage sensor using second-order sliding-mode voltage observer and Mixed Logical Dynamical ( MLD) model was proposed.The presented method was a-chieved by analysis of MLD model of the voltage source inverter under both healthy and faulty conditions. Due to the different phase voltage values of the machine under healthy condition from open switch faults, the residuals of phase voltage include information of switch faults,which can be used to detect the faults and identified the faulty switch of the voltage source inverter.Then,a second-order sliding-mode voltage observer was proposed to estimate voltage directly to get rid of high cost and complexity as a result of volt-age sensors.This observer estimates voltage exactly without the phase lag compensation and chattering phenomena existing in the conventional observer.Finally,experimental results show the validity of the pro-posed diagnostic approach.