This paper presents the problem of robust H∞ load frequency controller design and robust H￥ based approach called advanced frequency control (AFC). The objective is to split the task of balancing frequency deviations introduced by renewable energy source (RES) and load variations according to the capabilities of storage and generators. The problem we address is to design an output feedback controller such that, all admissible parameter uncertainties, the closed-loop system satisfies not only the prespecified H∞ norm constraint on the transfer function from the disturbance input to the system output. The conventional generators mainly balance the low-frequency components and load variations while the energy storage devices compensate the high- frequency components. In order to enable the controller design for storage devices located at buses with no generators, a model for the frequency at such a bus is developed. Then, AEC controllers are synthesized through decentralized static output feedback to reduce the complexity. The conditions for the existence of desired controllers are derived in terms of a linear matrix inequality (LMI) algorithm is improved. From the simulation results, the system responses with the proposed controller are the best transient responses.
 Barton, J.P. and Infield, D.G. (2014) Energy Storage and Its Use with Intermittent Renewable Energy. IEEE Transactions on Energy Conversion, 19, 441-448. http://dx.doi.org/10.1109/TEC.2003.822305
 Zhu, D. and Hug-Glanzman, G. (2012) Coordination of Storage and Generation in Power System Frequency Control using an Hα Approach. IET Generation, Transmission & Distribution, 7, 1263-1271. http://dx.doi.org/10.1049/iet-gtd.2012.0522