Power management strategy research for a photovoltaic-hybrid energy storage system

Abstract

This paper presents a power management strategy of a hybrid microgrid, which is composed of a Photovoltaic (PV) system, a Lithium-ion (Li) battery system and a Supercapacitor (SC) system. The microgrid energy is mainly generated by the Photovoltaic system, which normally uses a maximum power point tracking (MPPT) technique to continuously deliver the highest power. However, the variations in irradiation and temperature often make the PV power become stochastic. So the hybrid energy storage system is introduced for the internal power flow balance and energy storage. The microgrid control center generates power strategy refers to the state of charge (SOC) of Li system. Furthermore, a load control strategy is proposed to assist power management. Finally, the proposed power management method will keep power balance inside the microgrid and keep the hybrid energy storage system always operating at a healthy state. The improved performance will be tested in Matlab simulation.