Energy efficient control of induction motor driving system

This paper deals with energy optimal control of induction motor dives. When motor operate at given steady-state operation point, the optimum control efficiency is acquired by seeking the different voltage-frequency ratio so that the active power absorbed by the motor is minimization, that is improve operational efficiency and achieve the purpose of energy saving. But the minimum active power also depend on the modulation strategy of the voltage-inverter. In this paper, the search of the optimum active power is achieved for pulse trains modulation strategy which allows motor developing high torque at low shaft speeds with respect to V/f control. Several numerical results of comparative analysis and experimental shows that-the optimized strategy can improve the motor efficiency (In particular, the efficiency of low speed areas).