Effect of parameter variations on the performance of direct current (DC) servomotor drives

Abstract

This paper describes the design and implementation of a proportional-integral-derivative (PID) controller and model reference adaptive controller (MRAC) for the brushless direct current (BLDC) servomotor drive system. The performance of the BLDC servomotor drive system is analyzed under different operating conditions such as change in inertia, resistance, load disturbance and change in reference speed. Simulation and experimental results are presented to prove that the parameter variations will considerably affect the performance of the PID controller based BLDC drive but not the MRAC based BLDC drive due to its inherent capability to adapt itself to the changing environment. Moreover, determining mechanical load parameters accurately for the small DC servomotor drives is a great challenge to the control system designers as they are very essential for the design of controllers. This paper also presents a simple and accurate method for determining the mechanical parameters of motor and load.