Because of environmental factors and sustainability concerns, renewable energy sources are the state-of-art today. In energy conversion it is important, the output of the system to be suitable with standard applications, for both economical and compatibility issues. To fit the system output voltage and frequency with the international standards, battery packs and transformers are widely used. For modularity the major problem in this area is large physical dimensions. In this study a high frequency multi-winding transformer is used to reduce the size. Also a simple multi-level inverter which has fewer switching elements is proposed by taking account the same concern. And calculation of switching angles for the multilevel inverter is handled by a trigonometric method in order to reduce output harmonics.