H∞ performance for load frequency control systems with random delays

• Main Authors: Nan Wang, Wei Qian, Xiaozhuo Xu
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2021-01-01
• Series: Systems Science & Control Engineering
• Subjects: random delays; $ {h_\infty } $ performance; load frequency control (lfc) systems; lyapunov-krasovskii functional (lkf); extended reciprocally convex matrix inequality
• Online Access: http://dx.doi.org/10.1080/21642583.2021.1893860

This paper investigates the problem of $ {H_\infty } $ performance analysis for PI-type load frequency control (LFC) of power systems with random delays. By taking the probability distribution characteristic of communication delays into account in the LFC design, the power systems with a PI controller are modelled as stochastic time-delay systems. Furthermore, a delay-product-type augmented Lyapunov-Krasovskii functional (LKF) is constructed, and a new extended reciprocally convex matrix inequality combining Wirtinger-based integral inequality with convex combination approach is utilized to reduce the conservatism of main results. As a result, less conservative $ {H_\infty } $ performance criteria are derived, which guarantee the asymptotically stable in the mean-square of the considered systems. Numerical examples are also provided to illustrate the superiority of our proposed methods.