Date of Publication :21st December 2018

Abstract: Brushless DC Motors (BLDCM) have found immerse applications in automobile, automation, consumer electronics, medical and industrial applications due to their high efficiency, long operating life ratio of torque delivered to the size and fast dynamic response. In a brushless motor, the rotor incorporates the magnets, and the stator contains the windings. Commutation is implemented electronically with electronic speed controller (ESC) which uses the semiconductor switches to change current in the windings based on the motor back EMF. PID controller is designed in MATLAB Simulink software and PID gains are tuned using auto tuning method. Digital PID controller is then implemented on FPGA as it provides greater flexibility and higher resources for implementing control algorithms. FPGA (PID controller) receives back EMF output from BLDC motor and generates the gate pulses which drive the switches of electronic speed controller. Actual speed of the motor is compared with the reference speed given and the error signal is processed in a PID controller to obtain the required pulse width. As the motor rotates, feedback (back EMF) signals are produced in accordance with rotor position. Three phase voltages are produced from ESC after they receive the decoded signals. These voltages are fed as input to the motor and it rotates at required speed.

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