Robust H∞ load frequency control of power systems with two time delays.

Summary: This paper is concerned with the robust H∞ load frequency control (LFC) of power systems with two time delays in the presence of load disturbance. Firstly, the original power systems with the proportional‐integral (PI)‐type LFC are converted into an output feedback control system with two time delays. Secondly, an improved reciprocally convex inequality is proposed, and a less conservative robust H∞ criterion is derived, which can be used to design the PI‐type LFC with robust H∞ performance. Then, based on the robust H∞ criterion, an algorithm is provided to obtain the PI‐type LFC gain and the time delay margin, which effectively convert the coupled nonlinear terms into linear items without solving the inverse of the matrix with row full rank. Finally, simulations are shown to verify the superiority of the presented method. [ABSTRACT FROM AUTHOR]