基于电压偏差的三电平逆变器故障诊断与定位

Fault Diagnosis and Location of Three-level Inverter Based on Phase Voltage Deviation

针对二极管中点箝位(NPC)三电平逆变器的开关管开路故障,提出了一种基于三相电压偏差的诊断方法。该方法根据NPC三电平逆变器的混合逻辑动态(MLD)模型预估逆变器正常工作状态下的三相电压,将预估电压与实际电压进行比较得到电压偏差,通过分析三相电压偏差的表现特征实现开关管的故障诊断与定位。该方法无需增加额外的电压、电流传感器,具有诊断精准、迅速的优点。仿真和实验结果验证了所提故障诊断方法的有效性。

Aiming at the switch open circuit fault of diode neutral point clamped(NPC) three-level inverter,a diagnosis method based on three-phase voltage deviation is proposed.According to the hybrid logic dynamic(MLD) model of NPC three-level inverter,the three-phase voltage of the inverter under normal working state is estimated,the voltage deviation is obtained by comparing the estimated voltage with the actual voltage,and the fault diagnosis and location of the switch are realized by analyzing the performance characteristics of the three-phase voltage deviation.The method does not need additional voltage and current sensors,and has the advantages of accurate and rapid diagnosis.Simulation and experimental results verify the effectiveness of the proposed fault diagnosis method.