Performance analysis of PV system for maximum utilization of solar radiation

Abstract

A detailed analysis of a photovolatic (PV) stand-alone system using a novel battery voltage regulator to maximize the utilization of solar radiation is presented. The basic idea of the novel battery voltage regulator is discussed in a previously published work. The proposed system disconnects the battery rather than the PV array when the battery is fully charged. When the battery is disconnected, the load is supplied through a chopper. Hence, instead of losing available solar energy-by disconnecting the array-the energy is supplied to the load. The analysis presented here shows that the PV array may be disconnected for a variable period, ranging between 4 and 5 h per day during the summer season. This result indicates that a significant energy loss, up to 50% of the available solar energy, may occur during the summer. An elaborate analysis for the chopper circuit is given in this work. The analysis showed that the chopper keeps the load voltage almost constant if the chopper parameters are carefully designed. The novel system preserves the battery charge during periods of high solar insolation, thus the battery state of charge is kept high for long periods during the year. Consequently, the battery lifetime is prolonged. In this work, the climatic conditions of Cairo, the Egyptian capital, are considered. The effects of cloudy days on the system performance were taken into consideration.