Three Phase Harmonics Elimination of Distribution System for Four Leg Voltage Source Inverter

Abstract

In recent decades there has been a rapidly growing demand for high quality, uninterrupted power. In light of this fact, this study has addressed some of the causes of poor power quality and control strategies to ensure a high performance level in inverter fed power systems. In particular, specific loading conditions present interesting challenges to inverter-fed, high power systems. No-load, unbalanced loading, and nonlinear loading each have unique characteristics that negatively influence the performance of the Voltage Source Inverter (VSI). Ideal, infinitely stiff power systems are uninfluenced by loading conditions; however, realistic systems, with finite output impedances, encounter stability issues, unbalanced phase voltage, and harmonic distortion.  The suggested placement of the harmonic reduction unit dictates the use of a special controller structure that uses the harmonics magnitude in the d-q reference frame. In the proposed control algorithm, the required amount of attenuation for harmonics is determined to meet the total harmonic distortion.  Fast and efficient algorithm for phase detection irrespective of the presence of harmonics has been utilized for the system. The effectiveness of proposed method is further implemented by connecting induction motor to the output and performance of the motor is studied using Matlab/Simulink software.