Harmonics Reduction in AC Drives

Abstract

A variable speed drive (VFD) is used to control the speed and torque of AC Induction motor by varying input voltage. Conventional motor drive convert AC to DC then DC to AC. This conversion made the drive one of the largest sources of harmonic distortion. The aim of this project is to reduce this issue. This is done by using different methods of harmonic mitigation techniques. This study is very important for the power companies because of their growing concern of the power quality issue and its effect on their system stability and its quality. On the other hand, this research is also of major importance to the industrial sector because they must keep their harmonic distortion under standard limits. In this project, a variable speed drive had been used to drive a three phase induction motor, the drive is connected to a three phase source, MATLAB/SIMULINK tool had been used to simulate the whole system, the results are then obtained and analyzed. ETAP (electrical transient analysis program) had been used for the validation of the results. The obtained results show the jeopardy of having a VFD without mitigation, also it highlights the properties and advantages of each mitigation technique.