Design of Standalone PV System with Battery Storage for DC Load

Abstract

A SAPS standalone PV system with battery storage generally needs a complex control circuit to operate in various operating modes according to irradiation, battery condition, load change. In many applications, a advanced controller is required to make the change of the control architecture according to the mode. This project work presents a simple control circuit for a Standalone PV power system with battery. The proposed circuit contains a boost converter (BC) with two loop control and a bidirectional DC/DC converter with two loop control, connected to the PV side of the Boost DC/DC converter. The BC regulates the output voltage across DC load and provide constant power. The bidirectional dc/dc converter(BDC) facilitate lead acid battery charge or discharge and maximum power point tracking(MPPT). Therefore, the previously needed complex supervisory controller is eliminated. The Fractional Open Circuit Voltage MPPT algorithm is used here. This work will give the constant power to dc loads and maintain constant voltage across it. In this work simulation were done in MATLAB simulink and verify the different modes of operation in standalone PV system.