International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 03 | Mar-2016 www.irjet.net p-ISSN: 2395-0072 © 2016, IRJET ISO 9001:2008 Certified Journal Page 1878 Study of Micro Grid Topology and Design of Voltage Source Inverter and Charge Controller Priyanka Shintre 1 , Dr. A. M. Mulla 2 1 Student , ME Electrical Power System, ADCET, Ashta, Maharashtra, India 2 Professor, Head of institute, ADCET, Ashta, Maharashtra, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - This paper deals with the study, design analysis, and implementation of laboratory scale Micro grid. The overall system is simulated by using MATLAB and results are used for hardware implementation of the proposed system. The overall scheme consists of PV panel, Wind Turbine, Battery Bank, Buck Converter, Inverter, Charge Controller and various electrical loads. The various electrical loads are fed through an Inverter. Micro grid can operate in two modes of operation. First is Islanding Mode and other is Grid connected mode. Here only Islanding mode is taken into consideration and further grid connected mode can be implemented using a Smart Switch and a suitable Transformer. In the Micro grid, the Distributed Energy Resources(DERs) such as Wind Turbine, Solar PV panel, Diesel Generator set, Fuel cell units, Energy storage system and different loads are arranged as one unit connected to the Grid utility via Static Transfer Switch (STS). [1] All the DERs and variety of electrical loads which are located in close vicinity to each other and a battery bank are connected to a system via Power Electronic Interface. [2] Key Words: Micro Grid, Voltage Source Inverter, Charge Controller 1. INTRODUCTION Micro grid is operated in two modes viz. islanding or Stand-alone mode and Grid connected mode. In normal condition, the Micro grid is connected to a grid utility and operated in parallel with the grid. It exchanges the power according to the demand and supply. [7] But when fault occurs, the Micro grid transfers into Islanded mode of operation via STS and acts as Isolated Island. [1][7] In both the modes of operation, Micro grid should balance the power management. In Grid connected mode, the Micro grid exchanges the power to the grid and in islanding mode it should meet the power balance when there is load scheduling. [7] The produced Electricity by a low power Wind Turbines and PV panels can be utilized in several purposes such as Clinics, Homes, Schools, Telecommunication towers etc. However the low output can be raised and a new solution of use DC- DC Buck Converter can make the output suitable to charge controller for making the system simple, robust, and cost effective. This ensures the generator works at maximum power or close to it. [4][5] The battery is fed through a suitable designed charge controller which controls the battery voltage and current up to its specified limit. It is specially designed for Solar and Wind hybrid system. The Inverter employed is Voltage Source Inverter (VSI) and having PWM technique for controlling. When fault occurs, the STS open to isolate both the grids. i.e. Utility and Micro grid within a half frequency cycle. The DERs now have to fulfill the load requirement and to regulate the voltage regulation. The DERs should supply the continuous power to critical loads within the Micro grid and when fault is cleared, the Micro grid has to be resynchronized with utility grid before STS can reclosed to return smoothly back to the grid connected operation from Islanding mode. [2] 1.1 Desirable Features: The desirable features of the proposed scheme are as follows:  The Micro grid should perform both Grid connected and Islanding mode of operations satisfactorily.  The working of STC should be proper.  The charge controller should be able to control the battery voltage and battery current within its specified value.  There should be control on power transfer in both Grid connected mode and Islanding mode.  The Micro grid should be able to satisfy the load requirement when operated in only Islanding mode.