PWM modulator for motor control for educational purposes

Abstract

The growth of the electric automotive sector is undeniable, which is why numerous applications for the control and interface of electric vehicles have been researched and developed, as well as improvements to their performance. This article presents an electric motor control system based on frequency-to-voltage conversion, which offers, among other features, very precise power regulation. The premise of all of the above is based on the use of pulse width modulation (PWM) of a square wave signal, which will be responsible for modifying its duty cycle at the user's request by means of a potentiometer, thus simulating the accelerator pedal of an electric vehicle, varying the operating frequency of the rest of the circuit responsible for controlling the power demand required by the electric motor at any given moment. The final design has been implemented on a board to avoid transfer losses between its components as much as possible and to ensure that everything results in a single solid block that is as compact as possible, so that it can be used in teaching, both for analysis and synthesis. The end result is a high level of control over the motor through PWM signal regulation, achieving maximum values of 12 V and 1.8 A, and a maximum power of 21.6 W.