Power Management and Control for PV-Battery Standalone System

Today solar energy is one of the famous nonconventional energy sources present. But use of solar energy for the power generation is not reliable due to the discontinuity in its availability. This problem can be eliminated by the use of other energy sources in parallel to the photovoltaic array. The integration of two or more energy sources to meet the load demand is known as hybrid energy system. In this paper a PV array is used along with a battery as a backup source to a resistive load. Extra power generated by the PV array is used for the charging of the battery. When the load demand rises the battery shares the load with the PV array. The load is supplied by the battery alone when the PV array is absent. A buck boost converter has been employed that is connecting the PV array to dc link. A bidirectional DC-DC converter connects the battery to the dc link. The mathematical modeling of both the converters has been done in this paper. A robust control topology has been developed for the charging and discharging of the battery. The scheme also helps in keeping the actual dc link voltage constant at required dc link voltage. The overall control topology of the proposed system is implemented in MATLAB Simulink and the simulation results for different cases by changing various parameters have also been included.