Selection of Appropriate DC Voltage Level Solar Powered for DC Residential Rural Area (Case Study Tullu Gudo)

Abstract

This thesis presents a selection of appropriate DC voltage levels used for DC in residential remote area. The DC bus is the common link between distributed sources and loads. The most common voltage values nowadays are 24V, 48V and 120V DC. Several criteria have be considered, such as efficiency and reliability, voltage drop and power losses through the cables connecting loads to DC bus. The final choice of the DC voltage was a single bus of 120V DC. This paper also presents a detailed model of DC home system solar powered in Tullu Gudo. The system is composed of a Photovoltaic array, Maximum Power Point Tracker (MPPT) Controller, DC-DC converters, charge controller and battery. The modeling carried out by estimating the required load, selecting and determining the proper specifications of the components involved in the system. The daily average load demand is 8.835 kWh/day. This load demand can be met by the solar array of 18 panels with a backup of 30 units of the battery having a capacity of 276 Ah. The system implemented in MATLAB/simulink platform with the solar radiation and temperature. The voltage regulation of 120V DC is 3.09 and its efficiency is 99.4%. Simulated results indicate that the proposed DC home system model meet the load demand and show good performance.