Stability Analysis of Photovoltaic and Battery Energy Storage Systems Integrated to Weak Grid

This paper investigates the stability of photovoltaic(PV) and battery energy storage systems integrated to weak grid. In order to analyze the stability issue, a small-signal model of PV and battery energy storage inverter systems connected to the weak grid is established. The effects of output power of PV under the condition of constant power generation of PV and battery energy systems and grid strength on the stability of PV and battery energy storage systems are analyzed. Analysis results show that, with the decrease of grid strength, stability of PV and battery energy storage systems declines, and with the increase of output power of PV, stability of PV and battery energy storage systems declines, too. Finally, the time-domain model of PV and battery energy storage systems connected to the weak grid is built to verify the correctness of the analysis.