A robust current sensor fault detection scheme for sensorless induction motor drive

This article proposes a new current sensor fault detection scheme for speed sensorless field oriented control (FOC) of induction motor drive (IMD). Detection of the faulty signal, isolation of the faulty sensor and reconfiguration by proper estimation are the three steps involved in the present fault tolerant control (FTC) scheme. Third-difference operator (TDO) is used here for the detection of the faulty current sensor while the concept of vector rotation is employed to estimate the stator current from the reference d-q current. A decision-making logic circuit does the task of isolating the faulty signal and reconfiguring the control scheme by estimated signal. Model reference adaptive system (MRAS) based on reactive power is applied for estimating the rotor speed to make the control scheme speed sensorless. The effectiveness of the proposed scheme is shown by MATLAB/Simulation study. The experimental results in dSPACE-1103 based IM drive further validate the performance of the proposed scheme.