Mehrdad Jafarboland - Malek-Ashtar University of Technology
Meysam Hoseintabar - Malek-Ashtar University of Technology
Mohammad Hadi Rismani - Malek-Ashtar University of Technology

This paper describes the strategy to control a brushless dc (BLDC) motor with Direct TorqueControl (DTC) technique and two control methods including maximum torque per ampere(MTPA) and flux weakening methods are used in this technique in order to reducing statorcurrent and extend the maximum speed of the BLDC motor. MTPA control method findsoptimal d-and q-axis stator currents that produce desired electromagnetic torque whileminimizing stator current magnitude. In this strategy stator flux linkage is indirectly controlledusing d-axis current. Therefore, operation in flux weakening region is possible. In this study,the motor parameters are converted to dq and αβ reference frames using Line-to-Line Parkand Clarke transformations and this DTC method is based on three-phase conduction mode.This control technique is described clearly and simulation results are presented to illustrate itseffectiveness. Matlab/Simulink software is used to implement this control method.

Direct Torque Control (DTC), brushless dc (BLDC), maximum torque per ampere (MTPA), flux- weakening region