基于电压畸变观测的PMSM逆变器故障检测方法

PMSM inverter fault detection method based on voltage distortion observation

针对永磁同步电机(PMSM)驱动系统中脉宽调制(PWM)电压源型逆变器(VSI)容易发生开路故障的问题,提出一种简单且低成本的开路故障检测方法。首先,对PWM逆变器中功率开关发生开路故障时引起的对应端电压变化进行分析,构建开路故障与各相电压波形畸变的关系模型。然后,通过观测各相的电压畸变,并与阈值进行比较来构建各相的布尔错误模型。最后,基于布尔错误模型和错误检测时间来检测故障状态并识别故障开关。同时对检测时间进行分析,避免故障误报。实验结果表明:该方法能够快速且有效地进行故障诊断,具有良好的可行性和实用价值。

To address the issue that the pulse width modulation (PWM) voltage source inverter (VSI) in driving system of permanent magnet synchronous motor (PMSM) is prone to the open- circuit fault, a simple and low-cost open-circuit fault detection method was proposed. Firstly, the voltage change of corresponding terminal caused by the open-circuit fault of power switch in PWM inverter was analyzed to build the relational model between open-circuit fault and voltage waveform distortion of each phase. Then, Boolean error model of all phases was built by observing the voltage distortion of each phase and comparing it with the threshold. Finally, the fault state was detected and fault switch was identified based on Boolean error model and error detection time. At the same time, the detection time was also analyzed to avoid the fault alarm. The test results show that this method can effectively and quickly carry out fault diagnosis. Thus, it is of excellent feasibility and practical value.