Design Guidelines for Nonlinear Vector Control of Permanent Magnet Brushless DC Motor

Brushless DC motor drives are fast becoming an attractive alternative to DC and Induction motor drives, especially in the low speed, high power range. Different types of control schemes have been suggested for variable speed AC drives nourished from static power sources. A difficulty of the Field oriented control scheme when applied to induction motor drives is that the motor always operates at a lagging power factor. In this work, a generalized design strategy is suggested for the speed control loop of BLDC motor drive, in which, its intrinsic flexibility to generate the same torque for different combinations of currents is exploited, that can attain more general types of control. A suitable nonlinear and a robust controller using H- makes the drive with a better dynamic performance for a step change in speed corresponding to an incremental and decrement frequency at a constant torque and a step change in torque at constant speeds corresponding to a particular frequency. This paper gives more information regarding the design aspects of BLDC motor and simulation for closed loop system. The BLDC motor is extensively simulated using MATLAB software.