Power-Efficient Control of an Induction Motor: Methods of Increasing Its Dynamics

Abstract

To improve the efficiency of an electric drive system under low speed conditions, a control strategy optimized for maximal torque per ampere (MTPA) is used in the vector control system of an induction motor. MTPA is a control method of motor excitation that significantly reduces the torsion torque dynamics due to the influence of the rotor time constant. Traditionally, for such a control strategy, steady-state motor conditions are considered, but transient modes are not. MTPA control strategies for an induction motor with and without use of a rotor flux controller are compared. New approaches to improving the dynamics of MTPA control are proposed. The transient modes are described and compared.