Arun Babu K and M.Vijayakumar
Brush Less Direct Current (BLDC) motors are attaining higher priority in industrial automation, computers, aerospace, military, household appliance and traction applications because of its high efficiency, high power density and low maintenance cost. This makes the control of BLDC motor in all the four quadrants very vital. To control a BLDC machine, it is generally required to measure the speed and position of rotor by using the sensor. Using the measured value of rotor position, each inverter phase acting at precise time will be commutated. This paper deals with the digital control of three phase BLDC motor in all four quadrant operation. The motor is controlled in all the four quadrants without any loss of power; in fact energy is conserved during the regenerative period. This energy is stored in a battery storage system during regenerative period and can be fed back to the inverter mains during shortage of supply from the source. The FPGA controller is implemented which is more advantageous over other conventional controllers as it is computationally intensive, highly parallelizable tasks, best in class accuracy, reliability and maintenance. A PI controller in closed loop configuration is used for speed control. The torque ripple in each quadrant operation is also reduced using a closed loop operation with the aid of a low pass filter. The operation modes of the proposed system are simulated using MATLAB and results are validated.