A New Multilevel Inverter Topology With Reduced Power Components for Domestic Solar PV Applications

Abstract

Power electronic converters are used to nullify the input fluctuations from a solar photovoltaic unit because of intermittent solar irradiance and to make the terminal voltage grid compatible with the desired frequency. The conventional two-level converters suffer from low power quality and high voltage stress. In this article, a new multilevel inverter topology called Dual Source Multilevel Inverter (DS-MLI) with fewer power switches is proposed for solar PV power conversion systems. It can operate in symmetric and asymmetric operating modes with no cascading. This reduces the switching components required to produce several levels in the staircase voltage waveform. A closed-loop control algorithm is designed using the state-space averaging technique, and we assess the dynamic behaviour of the system under step change. We carry the simulation out in MATLAB environment. The experimental prototype of DS-MLI rated 1 kW is fabricated using FGA25N120-ANTD IGBTs, and an eco-sense made solar PV emulator is used for analysing the performance of DS-MLI while interfacing with solar PV unit. We compare the suggested scheme with its conventional counterpart in the aspects of components required, cost and efficiency, and the results are presented.