Modified DTC with Adaptive Compensator for Low-Speed Region of Induction Motor in Electric Vehicle Applications

Abstract

ABSTRACT In this paper, adaptive compensator-based Direct Torque Control (DTC) strategy is proposed for improved induction motor drive operation at low-speed region. The voltage drop across the stator resistance becomes significant against the stator input voltage during lower speed operations of motor. Hence, proper flux setup becomes difficult in the motor. Therefore, desired speed under low-speed region cannot be achieved using conventional DTC. Further, torque production as required for desired operation becomes difficult in low-speed region as different literature tried to calculate the exact value of stator resistance to compensate the adverse effects. In this paper, adaptive loop control is proposed to compensate stator flux using the speed error without estimating stator resistance. A proportional differential (PD) regulator is implemented to establish desired flux under low-speed region. The model considered for studied is simulated in MATLAB SIMULINK to analyze and compare the effectiveness of the proposed control scheme at low-speed operations against conventional DTC by incorporating variable operating conditions.