Direct Torque Control of Permanent Magnet Synchronous Motor

Abstract

Permanent Magnet Synchronous Motors (PMSM’s) are used in places that require fast torque response and high-performance operation of the machine. The Direct Torque Control (DTC) technique is different from methods which use current controllers in an proper reference frame to control the motor torque and fluxe values. The DTC technique does not any current controllers. DTC controls the Voltage source Inverter states on the basis of difference between the required and obtained torque and flux values. This is done by selecting one out of the six voltage vectors obtained by the Inverter (VSI) to have torque and flux fluctuations in between the limits of 2 hysteresis bands. This thesis obtains the modelling of the Direct Torque Control (DTC) system of PMSM using MATLAB/Simulink®. Speed control of PMSM using Field Oriented Control technique and Direct Torque Space Vector Pulse Width Modulation technique is also analysed and compared with traditional DTC. Simulation results are presented to help analyse the system performance and PI controller parameters influence on the system performance. The analysis is also done with fuzzy logic controller.