Robust H∞ load frequency control of future power grid with energy storage considering uncertainty and time delay

Abstract

In future grid environment, the unpredictable fluctuating characteristics of the renewable energy (RE) sources will inevitably cause adverse impacts on the system dynamic performance such as jeopardizing the frequency stability. Meanwhile, the utilization of energy storage (ES) can play a positive and noteworthy role in dealing with above problems. In this paper, we analyze the dynamic model of the grid-connected ES and the closed-loop frequency-domain block diagram is developed. Then a novel controller is proposed based on rigorous linear matrix inequalities (LMI) theory to ensure the robustness and stability of the system, when taking into account the parametric uncertainty and random time delay in control channels in the complex environment. The system can utilize ES to participate in Load Frequency Control (LFC) process so as to assist conventional thermal units. Finally, comprehensive case studies are performed to demonstrate the effectiveness of the proposed methods. © 2014 IEEE.