Sensorless Speed and Flux Regulation of Induction Motors: A Sliding Mode Approach
Abstract
A novel sliding mode observer for current-based sensorless speed control of induction motors is presented in this paper. The control objective is to guarantee asymptotic tracking of respecified speed and rotor flux references without mechanical sensors. To this end, an adaptive sliding mode speed and flux observer is introduced: it is based on a different and original approach with respect to the widely used equivalent control techniques. As regards the control algorithm, the problem of chattering, typical of sliding mode controllers, is overcome since the derivative of the stator currents are used as discontinuous forcing actions, while the actual control signals are continuous, thus limiting the mechanical stress.
