Design optimization of a single phase inverter for photovoltaic applications

The objective for this paper is to present a novel inverter topology for photovoltaic (PV) applications, in particular for the AC-module. A modified version of the inverter proposed by Shimizu et al. solves a major problem within the original topology; regeneration of transformer leakage energy. Also presented is a decomposition of the currents and voltages inside the inverter. The decomposition is used to derive the stress and power losses, and hereby developing a tool for optimizing the inverter in terms of efficiency and ratings. Finally, the developed tool is used to design an inverter. The annual European efficiency is calculated to 81.8% for a 160 W inverter, which is regarded as high for an inverter for AC-module applications, as long the cost can be kept low.