Torque Control of Induction Motors with Minimal Ripples Based on Continuous Control Set-MPC in a Wide Speed Range

Abstract

This paper proposes a novel continuous control set model predictive control (CCS-MPC) method for torque control of induction motors (IMs). A systematic way to define a reference state for the given torque reference is provided. The reference state is determined according to the operational modes to yield the highest possible efficiency. Maximum torque per ampere (MTPA) operation is adopted considering Ohmic loss minimization below and above the base speed. MTPA in field- weakening region is adopted. In the proposed CCS-MPC, a cost index is defined using the derived reference state and the optimal control input is determined considering the input constraints. The proposed control method is implemented and validated by simulation and experimental studies. The results confirm that the proposed approach gives a very good dynamic performance overall speed with minimal torque and current ripples.