基于桥臂中点电压的双绕组永磁同步电机逆变器及相绕组故障诊断方法

In the motor drive system, there are the same fault characteristics for the open circuit (OC) fault of phase winding (OCFOPW) and the two OC fault types of power switch (OCFTOPS). However, there is no method addressing the diagnosis of both OCFOPW and OCFTOPS. In order to solve this problem, this article proposes a fault diagnosis method of inverter and phase winding for doubly salient electromagnetic motor (DSEM) based on the midpoint voltage of bridge arm. First, based on unidirectional conduction of diode and the variation characteristics of back electromotive force (EMF), fault diagnosis is realized by constructing a forward voltage on the antiparallel diode. Then, a voltage threshold is set to eliminate misdiagnosis caused by the conduction voltage drop on the device, and the variation rate of excitation current is varied to ensure effective diagnosis in the case that the back EMF is less than voltage threshold. Finally, the experiments on a 12/8-pole DSEM validate the effectiveness of the proposed method.