Science and Education Publishing American Journal of Electrical and Electronic Engineering 2328-7357 4 6 2016 12 28 A New Approach to Enhance the Torque Handling Capacity of a PMBLDC Motor Drive 164 176 EN Protik Chandra Biswas Department of Electrical and Electronic Engineering, Khulna University of Engineering & Technology, Khulna, Bangladesh Bashudeb Chandra Ghosh AJEEE2016463 10.12691/ajeee-4-6-3 2016 8 13 2016 10 21 2016 12 26 Permanent Magnet Brushless DC (PMBLDC) Motors are trapezoidal shaped back EMF permanent magnet AC machine with high power density. Since the motor has a trapezoidal field pattern rather than sinusoidal it is desirable to study the motor behavior under different current fed conditions to analyze the developed electromagnetic torque. In this paper three different trapezoidal, square and sinusoidal current fed field oriented vector controlled PMBLDC motor drives are presented. The novel approach of this paper is that, the torque handling capacity of a PMBLDC motor can be increased up to its rated torque by only changing the pattern of reference current of a field oriented vector controlled PMBLDC motor drive. Adaptive PI controller based on motor speed error is also proposed in the paper to have a simplified drive system. When square and sinusoidal reference current fed vector controlled drives are used, the maximum torque handling capacity of a specified PMBLDC motor is 1.60 Nm and 1.55 Nm respectively. Only by using trapezoidal reference current fed drive, the maximum torque handling capacity of that specified motor can be increased to 2.0 Nm. The performance of these three different current drives are also compared on the basis of their torque pulsation. The dynamic performance of the vector controlled trapezoidal current fed drive is found outstanding than the square and sinusoidal current fed drives considering response time, load torque handling capacity, variable speed condition, settling time of the system.