A Low-Cost Control Architecture for Buck Converter Fed VSI Based BLDC Motor Drive

In this paper, a novel low-cost digital controller to drive a buck converter fed voltage source inverter (VSI) based brushless DC (BLDC) machine has been proposed. This controller is designed to be implemented solely in digital platforms and has multiple numbers of predefined discrete duty ratios. In conjunction with buck converter fed VSI, the controller is beneficial to enhance the speed and resultant torque profile of BLDC motor drive as compared to conventional bang-bang or on-off controller. The controller also incorporates a current limiter to avoid the over-current loading of the motor. The sampling time and the design of the current limiter are mathematically derived in the paper. The working efficiency of the developed controller for the BLDC motor drive has been examined for various vital and steady-state conditions. The speed ripples, settling time, tolerance to the commanded speed, and load variations are validated and presented in this paper. The proposed controller has been performed and implemented in the field-programmable gate array platform and compared to generic pre-existing controllers to validate the cost-effectiveness of the controller.