Publication:

Diseño e implementación de un controlador de velocidad de motores de corriente alterna monofásicos

This thesis is about speed control of small domestic AC motors which will be used for home automation applications. First of all, a literature study about the different types of motor for domestic applications is carried out, which has led us to choose a Permanent Split Capacitor (PSC) motor to use in this project. Later, a literature study is performed about various methods of controlling the speed of the PSC motors and come to the conclusion that the best solution is using a three-phase inverter bridge. It is required the design of the motor controller, therefore an electric drive to vary the PSC motor speed was designed using the topology of a three-phase voltage source inverter (VSI). This system allows varying the induction motors speed, varying the frequency and voltage. It was made implementing PWM (Pulse Width Modulation) control algorithms in a PIC microcontroller. The PIC microcontroller generates the control signals which are firstly sent to the optocouplers, which achieve the isolation between the control system and the power system. Optocoupler output signals are sent to the MOSFETs driver and finally to the MOSFETs, where DC bus (generated by a rectifier) is synthesized to provide two sinusoidal voltages at 90 degrees out of phase with varying amplitude and varying frequency to fed the motor, according to the V/f profile.