INTELLIGENT CONTROLLER FOR REDUCTION OF TOTAL HARMONICS IN SINGLE PHASE INVERTERS

Singh Singh

doi:10.3844/ajassp.2013.1378.1385

Abstract

Due to the increased use of nonlinear loads, the problem of power harmonics becomes more and more complex. This work investigates the reduction of Harmonics in voltage controlled single phase full bridge inverter. The mapping state-space equations are generated by examining the single phase full bridge inverter. The PI and fuzzy logic controllers are used for the experimental simulation in this study. Experimental simulation clearly indicates that fuzzy logic controller reduces the total Harmonic distortion better than the conventional PI controller.

Highlights

Single-phase Inverters are generally used in the case of power failures, to deliver power to critical loads such as UPS, Induction heating, variable speed drives demand pure Sinusoidal voltage at the specified magnitude, frequency and low total harmonic distortion (Selvajyothi and Janakiraman, 2010)
The mapping state-space equations are generated by examining the single phase full bridge inverter
Experimental simulation clearly indicates that fuzzy logic controller reduces the total Harmonic distortion better than the conventional PI controller

Summary

INTRODUCTION

Single-phase Inverters are generally used in the case of power failures, to deliver power to critical loads such as UPS, Induction heating, variable speed drives demand pure Sinusoidal voltage at the specified magnitude, frequency and low total harmonic distortion (Selvajyothi and Janakiraman, 2010). The inherently nonlinear characteristics of dc-ac converters have drawn great attention in research for applying nonlinear control principles for reducing total harmonics in single phase Inverters. Harmonics due to nonlinear loads causes non sinusoidal voltages or currents in power converters (Moreno and Pigazo, 2007). Non linear loads cause voltage and current distortions. In an inverter a Sliding-Mode Control (SMC) Scheme is applied to deliver a.c power with low output voltage distortion as well as excellent voltage regulation under loading conditions (Tai and Chen, 2002)

System Description of Single Phase Full Bridge Inverter

Model of PI control Strategy

Simulink Block Diagram of Inverter using Fuzzy Logic Controller