Delay-Dependent Stability Analysis of Multi-Area Load Frequency Control Systems with Multiple Renewable Energy Structures

This paper investigates the delay-dependent stability of time-delayed load frequency control (LFC) systems with multiple energy structures based on Lyapunov theory and linear matrix inequality (LMI) technology. Firstly, a multi-area delayed LFC model considering multiple renewable energy structures is established. Then, in order to improve the computation efficiency of stability analysis of large scale LFC systems, a new reconstruction technique for system model is proposed. Next, the improved delay-dependent stability criteria are established based on reconstructed model by using the Lyapunov stability theory. Finally, case studies are based on two-area LFC systems. Comparing with the criterion based on the original model without reconstruction, the calculation efficiency of proposed stability criteria has been greatly improved with the cost of small accuracy, and the calculation accuracy is better than the previous methods.