A Karnaugh mapping technique for the modeling of single phase multi string multi level inverter

The main objective of this paper is to study a seven level multi string converter topology for distributed energy resources based DC-AC conversion system. This paper proposes the Karnaugh mapping technique (which was rarely used in power electronic converters) for modeling the multi string seven level converter. The proposed method can also be extended to `n´ level converter. This paper also proposes the double Fourier series analysis to determine the expressions for modulation signals with particular reference to seven level design. This paper also compares the switching losses between cascaded and multi string multi-level inverters. The studied multi string inverter topology offers strong advantages such as less switching losses, improved output voltage waveforms, lower EMI and lower THD.