Wavelets and parity equations methods comparison for faulty encoder detection in PMSM drives

This paper aims to carry out a comparative study on techniques used for position sensor faults detection in PMSM drives. Fault detection algorithms are developed based on wavelets decomposition, and especially multiresolution analysis (MRA) technique, and parity equations method. The considered fault is the loss of encoder outputs information in a PMSM drive with flux oriented control (FOC). Simulation results carried out under MATLAB are discussed and comparison between the two fault detection methods is performed using as criteria effectiveness, rapidness, robustness to noise, and simplicity of real time implementation.