Controle de velocidade de motor de corrente contínua por modulação de largura de pulso

Abstract

This paper presents the development and implementation of a closed-loop speed control system for a DC motor, utilizing pulse-width modulation (PWM) and a proportional-integral (PI) controller on a digital platform. An experimental setup consisting of a main motor coupled to a tachogenerator was used to mathematically model the plant; this was achieved through open-loop testing and black-box system identification, resulting in a first-order mathematical model. Based on this model, the PI controller was designed, discretized, and implemented on an Arduino microcontroller, which handled PWM signal generation and control logic execution. Experimental results demonstrated the system's ability to drive the speed to reference values, exhibiting low overshoot during upward transitions and virtually zero steady-state error. However, during downward transitions, the lack of an anti-windup strategy resulted in significant undershoot and a delay in control signal recovery. The system also demonstrated the ability to reject external disturbances and showed consistency between experimental and simulated responses.