Implementation of Three Phase AC Synchronous Motor Drive by Using Voltage Source Converter

Abstract

The aim of the project is to develop a voltage source converter whose input is single phase variable frequency AC supply but the output is three phase fixed frequency AC. For this we first rectified the AC voltage using bridge rectifier. Then the rectified DC voltage is across the two terminals of DC link capacitor. Dc link capacitor reduces the ripple and distortion from the DC voltage. This capacitor is also called a bypassing capacitor, it is not only used to short the ripple with frequency to ground but also to leave the frequency of the DC to appear at the ground. Then, this DC supply is fed to the inverter and converts DC to AC power supply. It consists of MOSFET (IRFBC40G) and gate drive is given by microcontroller (PIC16F72) through driver circuit. Microcontroller (PIC16F819) is also used for frequently changing switching sequence. Microcontroller PIC16F72 is used in our proposed model. It is connected to power supply to operate it and programmed to provide a gate pulse to MOSFETs which are used in inverter circuit. It provides a gate pulse of 120° and at a time two MOSFET conducts in three phase inverter circuit. We have tried to run a three phase synchronous AC motor with 9 steps. It is seen that the motor runs correctly without any trouble.