MRAS speed estimator for speed sensorless IFOC of an induction motor drive using fuzzy logic controller

In this paper, a model reference adaptive system (MRAS) speed estimator for speed sensorless indirect field oriented control (IFOC) of an induction motor drive (IMD) using fuzzy logic controller (FLC) is implemented to replace the conventional constant gain proportional-integral-controller (PIC). Firstly, the MRAS speed sensor for IFOC of an IMD is implemented using PIC. The PIC offers satisfactory performance under ideal operation. However, the PIC unable to work effectively under sudden change in speed or load torque disturbances which causes high ripples in the stator flux and electromagnetic torque, respectively. Therefore, the FLC is considered to improve the performance and minimize the error dynamics and ripple contents of stator flux and electromagnetic torque under different loading conditions. The FLC based adaptation scheme offers better dynamic as well as steady state performance and robustness to sudden change in speed and load torque disturbances, respectively. The performance of each adaptation control schemes are simulated for sudden change in speed and various load torque disturbances, respectively. A detailed comparison of different control schemes are carried out in a MATALB/Simulink environment in speed sensorless modes of operation, when a IMD is operating in forward and reversal motoring under no-load, load, sudden change in speed condition.