An induction motor Field-Oriented Control system with optimal PWM using observer-based fundamental current estimation method

In order to lower the switching losses many high power motor drive systems use synchronous optimal PWM. As the switching angles are precalculated offline, the dynamic performance of optimal PWM is poor. The way to integrate optimal PWM with Field-Oriented Control(FOC) is studied in this paper. By adding a stator current observer in the FOC, the harmonics of the feedback currents are decreased and the voltage disturbances generated from the current control loop are reduced. Simulation results show that both the static and the dynamic performance of the motor drive system using optimal PWM are acceptable.