Speed-sensorless induction motor control with torque compensation

This paper addresses the problem of controlling a three-phase induction motor without speed measurements and with torque compensation. A nonlinear feedback linearization control was designed for a fifth order induction motor model including electrical and mechanical dynamics. The proposed control scheme, which is an indirect field oriented control technique (IFOC) based on feedback linearization control (FLC), is made up of flux-speed controllers. In order to provide an estimated rotor speed for the control system, a model reference adaptive system (MRAS) algorithm based on reactive power was applied. This estimation passes through a Kalman filter, which is also used for the torque estimation. Some experimental results with TMS 320F2812 DSP are provided to verify the proposed system performance in a low speed over load variation conditions.