New hybrid direct-torque control for a winding rotor synchronous machine

Abstract

In this paper, we present a novel control strategy for motor drivers, which we have called 'hybrid direct-torque control'. Based on models of both motor and inverters, the hybrid control uses a formal representation of inverter-machine behavior to determine the optimal switching state and vector application time. In contrast to conventional direct-torque control, which is based on the presence of hysteresis controllers and a switching table, the hybrid control involves tracking reference values of the electrical state in the state space. Observers and estimators of torque and flux are unnecessary. This control scheme is applied to a winding rotor synchronous motor.