Sliding Mode Observer-based MRAS for Sliding Mode DTC of Induction Motor: Electric Vehicle

Abstract

The current paper presents a new, Direct Torque and Flux Control strategy based on sliding mode control (SMC) and space-Vector Modulation (SVM) is proposed for induction motor Sensorless drives in order to solve existing problems in conventional control by Direct Torque Control (C-DTC); such as, high flux, torque and current ripple, and variable switching frequency. The presence of hysteresis comparators is the major reason for high torque and flux ripples in C-DTC. In SM-DTC, the hysteresis comparators and switching Table are replaced by sliding mode controller. The stability and robustness of the controller are proven analytically using the Lyapunov theory. To avoid the use of a mechanical sensor, the rotor speed estimation is made by a sliding mode observer (SMO) based model reference adaptive system (MRAS). The reference model is a Sensorless sliding mode observer and the adaptive model is a typical current model. Finally, the proposed schemes are simulated under Matlab / Simulink environment, and the simulation results show the effectiveness of the proposed Sensorless control.

Switching function parameter variation analysis of a quasi-sliding mode controlled induction motor drive

“…Hysteresis controller is used in the inner current loop. Classical fixed gain  ISSN: 2088-8694 proportional-integral (PI) controller based IFOC drives fail to provide the desired performance when load perturbations, parametric variations [11], external disturbances or modelling uncertainties [12] are there, making the torque sluggish and oscillatory [13], which may become critical in certain applications. To address this application-oriented challenge a sliding mode controller is proposed as the speed controller in this work.…”