Effect of Supercapacitor Contribution on Discharge Performance and Efficiency in a Battery–Supercapacitor Hybrid Energy Storage Architecture
Keywords:
Hybrid energy storage system, Battery, Supercapacitor, OpenModelica, Power sharing, State of charge, Energy efficiency, Battery stress reductionAbstract
Hybrid energy storage systems (HESS) that combine batteries and supercapacitors are becoming increasingly important as they reduce the load on the batteries by offloading peak loads to the supercapacitor. This increases system efficiency and extends battery life. Although the configuration of the HESS is important, there are only a few studies that have investigated the influence of power distribution on battery capacity, energy conservation and system efficiency using simulations. Therefore, this study created a dynamic model of a battery-supercapacitor HESS using OpenModelica and simulated the discharge process for three power distribution patterns (battery only: α =0, Hybrid with low supercapacitor proportion: α =0.3, Hybrid with high supercapacitor proportion: α =0.6). In this model, a Parameter α is introduced that divides and determines the load, What proportion of the total load current is absorbed by the supercapacitor? The Simulation was conducted with a fixed load current of 5.0 A and a discharge time of 10 minutes. The results show that as the proportion of supercapacitor increases, the battery consumption decreases and the system efficiency increases. In pure battery operation, the residual charge after discharge dropped to 16.67 %, and the system efficiency remained at 32.43 %. In the hybrid configuration with a higher supercapacitor proportion, the residual charge remained at 66.67 %, and the initial system efficiency reached 85.04 %. The remaining battery energy at end of simulation increased from 2,220 J (battery only) to 8,880 J (hybrid configuration with high supercapacitor proportion) — a fourfold improvement in energy retention. This study clearly demonstrates the performance advantages of the HESS configuration and shows that OpenModelica is an effective platform for dynamic simulations of hybrid electrochemical energy storage systems.
