Guaranteed cost load frequency control for a class of uncertain power systems with large delay periods

This paper investigates the problem of guaranteed cost load frequency control (LFC) for a class of uncertain power systems with large delay periods (LDPs). The model of LFC for power systems with LDPs has been firstly modeled as a switched delay system, which includes a potentially unstable subsystem caused by LDPs and a stable subsystem caused by small delay periods (SDPs). Based on the switching technique and under the constraint conditions of the length ratio and the frequency of LPD, the guaranteed cost load frequency controller can be obtained such that the closed-loop system is exponentially stable and a weighted guaranteed cost upper bound is achieved. Finally, an example is provided to demonstrate the applicability of the proposed method.