Power Management Strategy for Battery-Supercapacitor-Based HESS in a Residential Grid-Connected PV System

The rapid growth in electric vehicles and other residential loads requires renewable energy sources-assisted infrastructure to downsize the load on the utility grid. It becomes necessary to introduce grid-scale energy storage systems (ESSs) with renewable energy sources to increase the reliability of the power supply for critical loads. These ESSs may be electrochemical batteries, supercapacitors, flywheels, fuel cells, etc. The life cycle of these ESSs, especially for electrochemical batteries, starts to degrade during large transients during charging or discharging. This calls for hybrid energy storage systems (HESSs) which can reduce battery degradation of costly ESSs by incorporating supercapacitors. In this paper, a battery pack is combined with a supercapacitor to constitute a HESS for the residential grid-connected PV system. This configuration is preferable due to the high density of energy of the battery pack, and the high density of power of the supercapacitor. Moreover, a simplified power management scheme is proposed for effective coordination between the sources of the HESS. The proposed approach is proved to be effective by validation on the MATLAB® Simulink platform by analyzing the characteristics of the HESS under two different demand/generation scenarios.