Design of Fractional Order Adaptive Sliding Mode Observer for Induction Motor Drive

Abstract

The main objective of this work is to enhance the performance of synergetic sensorless speed vector control for Induction Motor (IM). In the first part, the induction motor is modeled along with its power supply, which primarily consists of a voltage inverter controlled via current regulation using hysteresis PWM. Subsequently, the principles of vector control as applied to IM are presented. In the second phase, a synergetic control strategy is proposed for speed regulation of IM. Various numerical simulations are conducted to illustrate and analyze the effectiveness of the proposed control method. In the final phase, to reduce the chattering phenomenon, a sensorless speed vector control approach is developed using a fractional order sliding mode adaptive observer. The proposed observer replaces the switching term in the conventional adaptive sliding mode observer with a fractional-order integral term, while preserving its advantages. The observer estimates the rotor flux components in the stationary reference frame based on the IM’s measurable quantities, and the mechanical speed is estimated using a Lyapunov-based function.