Direct torque control of three-phase induction motor based on constant voltage per frequency control with simple controller

Direct torque control of three-phase induction motor based on constant voltage per frequency control preserves the conventional direct torque control transient merits, furthermore, produces better quality steady-state performance in a wide speed range. In this paper, the simple controller is introduced to substitute the original PI controller for speed, torque and stator flux magnitude control. The concept of proposed controller adapts from the concept of variable step size maximum power point tracking for photovoltaic system. The simulation results have confirmed the validity of the proposed controller as well as shown good dynamic and steady-state responses of this control system.