Optimal Tuning of Digital PID Controllers for Commercial BLDC Motors Using the Nelder–Mead Method

Abstract Brushless DC (BLDC) motors are widely used in various applications due to their high efficiency and reliability. Many sensorless BLDC motor drivers, developed using zero-crossing detection of back electromotive force (EMF), eliminate the need for position sensors such as Hall sensors. The speed of a BLDC motor can be conveniently controlled using the trapezoidal control method, in which pulse-width modulation (PWM) is applied to the input DC voltage of the converter to regulate motor speed. Although Proportional-integral-derivative controller (PID) controllers are commonly used, accurately tuning their parameters remains difficult and challenging. Therefore, this study explores the use of the Nelder–Mead optimisation method for tuning digital PID controllers in commercial outer-rotor BLDC motors. Simulation and experimental results demonstrate that the Nelder–Mead method is highly effective for PID tuning in commercial BLDC motor drives, resulting in significant reductions in settling time and system overshoot.