Abstract:
This paper proposed a transformer less inverter for use in residential solar energy systems. There is a strong trend in the photovoltaic (PV) inverter technology to use transformerless topologies in order to acquire higher efficiencies combining with very low ground leakage current. The operation principle, control strategy and characteristics of the system are described. The new and traditional system configuration has compared in this paper. Analysis and simulation results will be presented to demonstrate the new features. An improvement in inverter efficiency and a reduction in cost have been achieved by omitting the 50 Hz power transformer (transformerless). The design and control issues associated with the development of a 40 W prototype single-phase stand alone photovoltaic system is discussed in this paper. Voltage level controller and PWM inverter systems have been realized by usingPIC16F877A microcontrollers. An experimental system was implemented to demonstrate the effectiveness of the proposed system. Simulation and experimental results are given to verify the system’s efficiency. Simulated model for system is designed using MATLAB Simulink. The paper focuses on some known problems and challenges for transformerless inverters. Topologies without transformers have big advantages like low weight, volume and cost. In addition they often reach higher efficiencies than topologies with transformers. Therefore they are important for future developments.

Keywords: DC–AC power conversion, photovoltaic (PV) systems, transformerless inverter, PIC microcontroller, DC- DC Converter, Solar energy