Reactive Power-Residual-Based Stator Interturn Fault Detection in PMSM Drive

Stator interturn fault is one of the most common failures in electrical machines, which leads to catastrophic results if no prompt detection is implemented. This work proposes a novel method to detect interturn fault for permanent magnet machine drive system, based on instantaneous reactive power residual. Here, the motor is operating in the sensorless control manner. The required rotor speed and position information for PMSM drive system and interturn fault detection scheme is estimated from stator voltages and currents. The reactive power residual is generated from the
dq
-reference frame currents and voltages obtained from the faulty permanent magnet synchronous machine prototype, and analytical model of healthy permanent magnet synchronous machine. Here, the proposed fault indicator is defined based on the magnitude of dc components which are extracted from negative-sequence instantaneous reactive power residuals. Compared to
dq
-axis current residuals, and the instantaneous reactive power, the instantaneous reactive power residual is observed to have enhanced fault signature, aiding incipient diagnosis. The reliability and robustness of the proposed fault detection scheme under different operating conditions, and under certain parameter variations, has been investigated and validated on a permanent magnet synchronous machine drive system.