Speed-Adaptive Droop Control for Doubly Fed Induction Generator-Based Gravity Energy Storage System

In order to ensure the reliable operation of a gravity energy storage system and reduce a converter’s cost and power rating, this paper proposes a gravity energy storage system (GESS) based on a doubly fed induction generator (DFIG). To address the issues of low inertia and limited grid-support capability, a speed-adaptive droop control strategy is introduced. The droop curve can be adjusted automatically according to the speed variation. Thereby, the GESS can effectively provide grid support through rotor-speed control. A simulation model of the DFIG-based GESS is developed in MATLAB/Simulink 2024b, and the grid-support capability of the proposed control strategy is verified under various operating conditions.