Design and Implementation of Transformer less Micro Inverter for PV-Grid Interface

Abstract

The need for energy is increasing day-by-day, which is a large part of total global energy consumption. The crises of fossil fuels and nuclear power will run out someday in the future. Therefore, we aim to develop energy from Renewable Energy Sources (RES) especially from solar. The growth of solar energy has increase day by day to meet the demand in the future. In this paper, modeling and analyzing of a transformer-less grid-connected inverter is proposed for solar photovoltaic (PV)-grid interface system. The scope of the transformer-less inverter is used to minimize ground leakage current in the grid. The inverter is directly connected to unbiased grid line and PV array inverting terminal to compensate the ground leakage current. The transformer-less grid connected inverter is used to compensate reactive power, extraction of high energy from PV array, and low grid current distortion. The inverter is also used to improve tracking output current reference, grid synchronization, and to provide a safety margin of forced direct current into the grid. In the control circuit the Proportional Resonant (PR) controller is used. Atmega328 based reduced rated hardware is developed for verifying the system enhancements and the experimental results are used to prove the proposed methodology for control of transformer less grid interactive inverter which supports both active and reactive power to the loads.