A Consensus Approach to Real-Time Distributed Control of Energy Storage Systems in Wind Farms

Today, the state-of-the-art wind generators (WGs) are double-fed induction generators that integrate storage devices into their systems. These WGs are expected to be among the largest producers of renewable energy worldwide in the coming years. In this paper, we propose a consensus approach to the distributed control of the energy storage systems (ESS) for carrying out real-time wind farm power output regulation with power-sharing among these storage devices. These two objectives can be attained when the controllers of the ESS and the grid-side converter (GSC) within a single WG are coordinated and the controllers of the GSCs of all WGs are coordinated with each other as well. Our approach is comprehensive, including a coordinated control architecture for the ESS and GSCs to attain the former objective and a consensus-based control architecture for coordinating all GSCs to attain the latter. Calling upon results from singular perturbation and Lyapunov's theories, we establish stability of the coupled closed-loop dynamics of the ESS and the consensus protocol. Lastly, we construct the control algorithms for the GSC and the DC-DC converter which yield accomplishment of the desired control objectives. Effectiveness of the proposed approach is demonstrated through numerical simulations on the IEEE 24-bus power system under critical scenarios.