Power Smoothing of Large Solar PV Plant Using Hybrid Energy Storage

Abstract

This paper proposes a power smoothing strategy for a 1-MW grid-connected solar photovoltaic (PV) power plant. A hybrid energy storage system (HESS) composed of a vanadium redox battery and a supercapacitor bank is used to smooth the fluctuating output power of the PV plant. The power management of the HESS is purposely designed to reduce the required power rating of the SCB to only one-fifth of the VRB rating and to avoid the operation of the VRB at low power levels, thus increasing its overall efficiency. The PV plant including the HESS has been modeled using MATLAB/Simulink and PLECS software environment. The effectiveness of the proposed power control strategy is confirmed through extensive simulation results.