A Robust Sensorless Induction Motor Drive for Alternative Energy Vehicular Application

This paper presents a field oriented induction motor drive system with two distinct features: a Fuzzy Model Reference Learning Controller (FMRLC) to improve the robustness of the speed regulator against the external disturbance and a closed loop Sliding Mode Flux and Speed Estimator (SMFSE) to estimate the flux and speed of machine. The FMRLC based speed regulator adaptively tunes its parameters when the command speed is changed making the speed regulator performance better as compared to linear as well as direct fuzzy controllers and avoiding the rigorous tuning required by the linear controller. The SMFSE is designed such that it estimates the rotor flux without requiring any knowledge of the rotor resistance thus making the proposed flux estimation insensitive to the rotor time constant. The rotor speed is estimated using the estimated rotor flux and the designed sliding mode observer. The complete drive system is shown to have a very good speed tracking performance and an accurate flux and speed estimation while subjected to sudden external disturbances. Extensive simulations are presented for performance evaluation and validation of the proposed drive system.