Modified cascaded multilevel inverter for renewable energy systems with less number of unidirectional switches

Abstract

This study presents, a novel topology for multilevel inverter based on series connection of basic modules. The suggested topology is utilize for symmetrical and asymmetric source system, which can be used for fuel cell and photovoltaic systems. In the symmetrical multilevel inverter, the values of input dc are equal. However, the magnitude of dc supplies for basic modules are unequal in asymmetrical multilevel inverter and their magnitudes are achieved from binary and trinary progression. Comparison results prove that the proposed topology needs a less components, reduced power loss and improve the efficiency of the inverter. Moreover, the peak-inverse-voltage on switches is also lower in proposed circuits. A detailed analysis of the suggested circuit is explained through the example of a 11-level, 15-level and 19-level inverter. The performance of the proposed circuit topology is analysed through MATLAB/SIMULINK environment and validated via experiment conducted on a laboratory prototype with real time controller dSpace 1104. The proposed inverter can be implemented for low-medium power in renewable energy systems.