Fuzzy direct torque control of permanent magnet synchronous motors

Abstract

In the traditional direct torque control of permanent magnet synchronous motors, the hysteresis control may cause great flux and ripples in the torque. As so to decrease ripples, the fuzzy control theory is applied to the direct torque control system in this paper by utilizing stator flux magnitude error, torque error and flux angle as the input to generate the error of flux and torque reasonably, and making use of the fuzzy strategy to optimize switch the state of inverter and simultaneously applying zero voltage vector to the fuzzy controller. It turns out that this approach makes the torque ripple smaller than the traditional direct torque control system. The simulation results show that this fuzzy direct torque control strategy based on the characteristics of permanent magnet synchronous motors can obtain better operation performance than the regular direct torque control.