Indirect torque control of PMSM using hybrid system approach

In this paper, a PMSM drive under space vector modulation scheme supplied through an inverter is modelled as an hybrid system combining discrete event system and continuous dynamics. The system model is derived for each state and based on the inverter switching pattern, the flux applied and the torque developed are computed giving rise to error flux and error torque using which the next switching pattern is determined. In effect, the system derived is an indirect torque control of PMSM. A speed feedback is also used to avoid the drift in the control system. Simulation results of our proposed approach are compared with those of direct torque control scheme.