A Micro Inverter Design for Micro Grids

Abstract

The usage of fossil-based fuels in electrical energy conversion systems causes irreversible damages to the environment. Due to the intensive use of these resources, their reserves are rapidly decreasing. So there are many studies on renewable energy sources and their usage in the literature. Micro grids within the smart grid structure provide the synchronization of the energy obtained from renewable sources with distributed generation within themselves or with the national grid. Photovoltaic panels (PV), which can easily transform energy without damaging the environment, come to the forefront the renewable energy sources. Panel structure, converter and inverter design have a great importance on the total efficiency of solar power generation. Therefore, the design of the converter and inverter and their instantaneous working status should be monitored. In this study, grid connected micro inverter design and analysis have been carried out for micro grids. In the boost converter design, the maximum power point is monitored with the Perturb&Observe (P&O) method and the switching signals of the isolated boost converter are provided to be monitored with the PI controller. Micro inverter is designed with H-bridge model controlled by 4 MOSFETs. The switching signals of the MOSFETs were realized with the phase-locking algorithm following the mains voltage. Synchronized energy to the grid is transferred to the load with the LCL filter used in the micro inverter output.