Robust Model-Based Interturn Fault Detection in DTC-SVM PMSM Drive

Stator interturn faults are the most common failure in electrical machines and, if not detected quickly, can have disastrous results. This work, proposes a robust model based interturn fault detection technique in direct torque control with space vector modulator (DTC-SVM) permanent magnet machine (PMSM) drive to detect the interturn fault (ITF), which is insular for speed and load variations, based on negative-sequence instantaneous reactive power (IRP) distortions. The IRP distortion is obtained from <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i>-reference frame voltage distortions and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i>-reference frame current distortions. The obtained IRP distortions are transformed to negative-sequence IRP distortions. Based upon the vector magnitude of the dc components, which are presented in the negative-sequence IRP distortions, the novel fault indicator (FI) is proposed. The proposed FI obtained from negative-sequence reference frame IRP distortions, shows invariant signature for DTC-SVM PMSM drive speed and load variations. The robustness of the proposed model based ITF detection technique has been validated under various operating speed and load conditions, on a DTC-SVM PMSM drive system. The proposed model based ITF detection technique ensures improved reliability and availability of the motor drive system in critical applications.