Design of Integral Droop Control for Hybrid Energy Storage System Considering Ramp Rate Characteristic

Abstract

Fuel cells and flow batteries are energy storage devices attracting attention due to their high energy density. However, rapid output power fluctuation is impossible due to their low-rated ramp rate. Therefore, supercapacitor hybrid systems with fast output power fluctuations are commonly constructed. Integral droop control methods have been proposed to control the hybrid energy storage systems. However, there is a limitation in that a strict design method based on the ramp rate is not presented. Therefore, this paper proposes a design method considering ramp rate characteristics. In addition, the cost and system efficiency according to the parameter change is analyzed. The analysis of this paper was verified through system prototype experiments using supercapacitors.