Adaptive Droop Control in Energy Storage Systems for Battery Protection Microgrid Applications

This paper proposes an alternative strategy to control the generated power within an isolated ac microgrid with distributed RES. The proposal is to control the terminal voltage of the existing battery banks below or equal its maximum allowable value. This is done by limiting the amount of power that each energy source can generate at each instant. The microgrid frequency is used to characterize the state of charge of the battery bank and quantify to the converters’ control systems how much power they need or can generate to maintain under control the internal power balance of the microgrid. The control of the battery banks’ terminal voltage implies indirectly the control of their SOC.