Improved Droop Control for Power Grid Considering State-of-charge of Battery Energy Storage

The constant droop coefficient (DC) in the traditional f-P and V-Q droop control is not conducive to the state-of-charge (SoC) management of the battery energy storage (BES) system. This paper proposes an improved droop control strategy (DCS) for the power grid which considers both the power frequency adjustment of the power system and the SoC management constraints of the BES. The proposed improved DCS is enabled to adjust the DC according to the SoC status of the BES. Case studies verify the effectiveness of the proposed DCS, which significantly reduces the frequency change deviation in the dynamic process of the weak power grid.