Design and Analysis of Dual Level Boost Converter Based Transformerless Grid Connected PV System for Residential Applications

In this paper, a transformer-less grid-connected PV system using low voltage panels is designed and analyzed for residential applications. For this, dual-level dc-dc boost converter is used to obtain a higher voltage level at the output, and the system is integrated into the utility-grids/loads through a three-phase inverter. By this way, the designed system reduces the cost and dimension in comparison with a conventional system. In the designed system, the switching operation of dual-level dc-dc converter is achieved using perturb & observe maximum power point tracking method. In the performance/analysis section, the system is tested for different load groups and irradiation levels. The results show that the system increases the PV voltage to the desired voltage value. Also, the system is analyzed for three irradiation levels and two local load groups. In case studies, it is obvious that the excess power is supplied to the grids and the lacking power is provided from the grids to feed loads.