Design of Variable Frequency Drive with Vector Control

Abstract

Induction motor is the most widely used motor for domestic and for industrial purposes because it is the most rugged type of motor, has very simple construction and it needs the least amount of maintenance. The aim is to design and implement a Three Phase Variable Frequency Drive for Three Phase Induction motors. The motor drive is to generate sinusoidal currents using the technique of space vector PWM, in order to maximize the DC bus utilization. The motives behind the choice were to introduce speed control in three phase induction motors, making a customizable and a user friendly product, increasing the life of an induction motor by generating pure sin wave. Variable frequency drives are extensively used in industries to match the motor speed with the process speed. When a motor is loaded, the RPM of the motor falls. The motor drive, constantly monitoring the speed of the motor, robustly responds to the dip by increasing the frequency and amplitude of the three phase voltage so as to meet the load demand, ultimately making the motor match the process speed. The protection of the motor and the drive is of core importance. Our secondary goal will be to implement protections like the locked rotor protection, the over voltage and over current protection, inverter shoot through protection and performing insulation test on the motor before running the motor.