A new control scheme for the spleed control of PMBLDC motor drive

The design of current and speed controllers for permanent magnet brushless DC (PMBLDC) motor drive remains to large extent a mystery in the motor drives field. A precise speed control of PMBLDC motor is complex due to non linear coupling between winding currents and rotor speed as well as non-linearity present in the developed torque due to magnetic saturation of the rotor. This paper presents a new control scheme to the conventional PMBLDC motor, aimed at improving control system robustness via complete decoupling of the design and performance of the control loops that ensures robustness by minimizing the mutual influence among the speed and current control loops. This robust decoupling control scheme would be applicable to both static and dynamic aspects. The effectiveness of the proposed robust speed control scheme is verified by simulation at different values of inertial load variations.