Research on Gain Fault Diagnosis of Current Sensor for Doubly Salient Electromagnetic Motor at Standstill

Fault diagnosis of current sensor is the key technology to improve the reliability of doubly salient electromagnetic motor (DSEM) drive system. In some occasions, such as initial position estimation of position sensorless, the motor is at standstill. However, there is no method addressing the fault diagnosis of current sensor for DSEM at standstill. To solve this problem, three methods are proposed to realize gain fault diagnosis of current sensor for DSEM at standstill in this article. One method is realized by detecting excitation current during excitation field building, and the other two are realized by detecting phase currents during the injection of specific current pulses. Then, there is a comparison of three fault diagnosis methods. The proposed method does not require the values of motor parameters, and it can be used either as part of an initial debugging or periodic testing of the system, which can also improve the reliability of initial position estimation to avoid startup failure of motor. Finally, the experimental results validate the effectiveness of the proposed method.