Comparison analysis for pure torque loop control of brushless DC motor

In this paper, a pure torque loop control method without flux linkage observer and a modified double closed loop control method with a couple of derived simple equations for the control of the stator flux linkage amplitude were proposed for direct torque control (DTC) of brushless DC motor (BLDCM), using a 2-phase conduction mode. The objectives of the novel control strategies are trying to simplify the control structure and to improve the control performance. The strategy and the equations were validated through the simulation analysis and the comparisons of the experimental results with the conventional DTC method. The reduction of torque ripples is also proved to be obvious.