Development and demonstration of power management of hybrid energy storage for PV integration

The integration of hybrid energy storage system (ESS) with PV has been considered an effective solution to counteract its variable power generation. This paper proposes an on-line power management system of the hybrid Ultracapacitor-Battery ESS for PV power smoothing. The two-layer control framework with multi-rate operation mechanism is designed to coordinate the power sharing among these two energy storage elements dynamically based on the system status, the components´ energy status, and their dynamic characteristics, etc. The simulation studies are performed to demonstrate the effectiveness and advantages of the proposed control method by Matlab/Simulink. A small-scale experimental testbed is set-up and the control structure is implemented on-line to validate its effectiveness.