With pace of time there is a huge development in technologies. In recent time there is a concern of energy as right now fossil fuel is used but as population increasing in near future to meet demand it would be very tough that why we are focusing on renewable energy. Distributed energy resources based micro grid and Nano-grid framework is most technically viable bottom-top approach to sustainably meet ever-increasing demand of rural and urban communities. Recently the growth of DC operative home appliances like mobile and lap top chargers, ovens and hair dryer’s etc. are increasing and therefore a DC/DC converter is an efficient way to meet the electricity need from the local DER and helps in improving the system efficiency. In our dissertation we took three different section of solar panel and after that simulation carried out with help of buck boost converter and besides this MPPT algorithm (P & O method) for solar PV module and closed loop PI control system also used. The proposed methodology is to extract maximum DC power from solar PV system and it is directly fed to DC load or DC Nano grid. The simulation results demonstrate the buck boost converter application for maintain constant voltage at DC bus irrespective of variation of solar PV generation. Also it improves the system efficiency by reducing no. of conversions. In our dissertation work analysis of ploy crystalline, mono crystalline and thin film crystalline is done and got different simulation result.