Photovoltaic based new multilevel inverter topology with minimum number of switching components [articol]

Abstract

Multilevel inverter (MLI) plays a strong role in low power photovoltaic (PV) applications to transfer large amount of high quality power. It offers less distortion and can be used in high power, medium voltage applications. The objective of this paper is to propose a photovoltaic based new multilevel inverter topology with reduced number of switches and voltage sources. The proposed inverter consists of two units namely basic unit which produces unidirectional output voltage and polarity changing unit which helps to change the polarity of the output voltage. The basic unit of the proposed inverter topology produces five level output voltage waveform during symmetric operation and nine level output voltage waveform during asymmetric operation. This topology can be extended with multiple dc sources to synthesize large output levels. The advantage of this topology is it uses minimum number of components and hence the cost and size of the inverter is reduced. In this paper, the dc source for the proposed inverter topology is modelled as a PV array. A mathematical model for the PV array is developed and implemented with the proposed multilevel inverter topology. The proposed inverter is simulated using MATLAB/Simulink software. The simulation results for different output levels are analysed and presented.