Battery Cells and a Super-capacitor Bank Storage System: Design Trend and Strategies for Renewable Power Applications

Abstract

The variability of critical load demands has led to an increasing push for a clean, sufficient and reliable power supply. Employing innovative techniques to address this need, is a feat yet to be met by several developing nations. Inverter systems based on battery storage provide the extra energy supply to these loads, due to the unavailability of the general power supply. Nevertheless, discharging/charging values of energy demands at peak levels notably affect the performance of batteries. Interestingly, an integrated energy system incorporating power and energy densities of high value can be supplied by combining batteries and other storage devices, in this context super-capacitors (SC). In light of the above, this paper presents the hybrid combination of battery cells and a super-capacitor bank storage system, highlighting its design as well as performance assessment aimed at improving the battery’s life span and its performance while on-load. A novel automatic switching system (ASS) is incorporated to establish a parallel connection between the battery and SC. The ASS detects energy signals from either source of power considered and engages the battery/super-capacitor hybrid system, either to charge or serve as a source of energy to the load. The results show that a significant initial value of transient current is supplied by the super-capacitor. The current draw at peak level is drastically reduced on the battery. This also results in economical savings in cost and increased reliability, which has been necessitated in the backup energy market.