A Novel Digital Control Technique for Brushless DC Motor Drives: Steady State and Dynamics

This paper introduces a novel digital control for trapezoidal back-emf brushless DC (BLDC) motor drives. First, the over all concept is outlined followed by the steady state analysis and design procedure that is derived from Newton´s 2nd law of motion. Second, transient operation is presented, which makes use of a state observer. The state observer is used to estimate the load torque, which is necessary for the digital controller to calculate the appropriate control parameters. The design equations for the state observer are derived. Finally, a BLDC motor drive model is created in the MATLAB/Simulink environment to validate the developed control algorithm. The simulation results will show that the proposed controller is able to accurately track a commanded speed despite time varying torque disturbances