Performance enhancement of single phase multi level inverter fed from photo voltaic array for domestic applications

Abstract

Owing to the ever increasing energy consumption, rising public awareness on environmental protection, and steady progress in power deregulation, alternative (i.e., renewable and fuel cell based) Distributed Generation (DG) systems have attracted increased interest. Photo Voltaic (PV) power generations is one of the most promising Renewable Energy (RE) technologies. Power electronics technology plays a very important role in integrating RE to a grid or domestic loads. A single or multi stage power electronic converter is needed to convert RE generated power into useable power. In case of PV system, multi stage power conversion systems are generally used. A multi stage power conversion involves a DC-DC boost converter and a DC-AC inverter. In order to track the Maximum Power Point (MPP) and to improve the low voltage input to a fixed DC output a DC-DC boost converter is used. Similarly, a DC-AC inverter is used to obtain a sinusoidal output voltage for the grid or standalone systems. The modelling and control of a Photo Voltaic Energy Conversion System (PVECS) with a new multilevel inverter is described in this thesis. It is not easy to connect the power converters to the grid directly hence, for high newlinepower and moderate voltage networks a multilevel converter topology is introduced. A multilevel inverter not only provides high power but also enhances the utilization of RE sources. RE sources such as PV, wind energy and fuel cells can be effortlessly interfaced to a multilevel inverter system for the high power applications. Developing interest for medium and high power applications, Multi-Level Inverter (MLI) has attracted more consideration in PV systems. Generally, MLI comprises of power electronic switches to produce a staircase voltage waveform from multiple DC voltage inputs/sources. newline newline