Rotor Flux-Oriented Control of Three-Phase Induction Motor Using Sliding Mode Controller and Rotor Flux Estimator

The work focuses on implementing rotor flux-oriented control (RFOC) for controlling the rotational speed and torque of a three-phase squirrel cage induction motor (IM). The speed controller has been implemented based on sliding mode controller (SMC). SMC is a robust control scheme which provides a means of achieving the control objective in the presence of model uncertainties and disturbances arising externally. Two different sliding mode controllers have been proposed in this paper. The first scheme is based on a discontinuous control input law which poses some performance limitations which have been illustrated though the simulation results. The second controller is designed using continuous control input law which overcomes the performance constraints of the first controller. A rotor flux estimation technique has been proposed to determine rotor flux position required for implementing RFOC. The performance of the sliding mode controllers and rotor flux estimator has been verified using computer simulation in Simulink using the mathematical model of a three-phase IM.