EFFICIENCY OPTIMIZATION OF VECTOR-CONTROLLED INDUCTION MOTOR DRIVE

This paper presents a new approach that minimizes total losses and optimizes the efficiency of a variable speed three-phase, squirrel-cage, vector-controlled induction motor drive through optimal control, based on combined loss-model control and search control. The motor power factor is used as the main control variable. An improvement of efficiency is obtained by online adjusting the stator current according to the value of power factor corresponding to the minimum total losses at a given operating point. The drive system is simulated using Matlab SIMULINK models. A PIC microcontroller is used as minimum loss power factor controller. Simulation results show that the proposed approach significantly improves the efficiency and dynamic performance of the drive system at all different operating conditions.