A COMPARATIVE STUDY BETWEEN DIRECT TORQUE CONTROL AND PREDICTIVE TORQUE CONTROL FOR AXIAL FLUX PERMANENT MAGNET SYNCHRONOUS MACHINES
Mohsen Siami – S. Asghar Gholamian – Mosayeb Yousefi
This paper presents a comparative study between direct torque control (DTC) and predictive torque control (PTC) of Axial Flux Permanent magnet Machines (AFPM). In conventional DTC method for permanent magnet machines, only six actives voltage vectors of inverter are used to control torque and flux of machine. But in predictive torque control, in addition to six active voltage vectors, zero voltage vectors are used to control machine. So number of voltage vectors to control AFPM increases that leads to lower ripple of torque and flux. In predictive torque control, the response of torque and flux are computed for all possible switching states of inverter at every sample time according to discrete time model of machine, and then the switching state that optimizes ripple of torque and flux, will be applied in next discrete-time interval. Simulation results which compare the results of implementation of both methods and confirm the good performance of the proposed predictive torque control are presented.
Keywords: axial flux permanent magnet machine, direct torque control, predictive control, synchronous machine drives, torque ripple