A novel LMI criterion for power system stability with multiple time-delays

This paper presents a novel LMI criterion for electric power system stability with multiple time-delays. Initially, the linear time-invariant model of the power system with multiple delays is constructed, subsequently, the former criteria and the novel criterion of this paper are demonstrated in this paper, and the novel criterion is fully proved according to Lyapunov direct method. Specifically, the proposed criterion utilizes a properly simplified Lyapunov-Krasovskii functional, and no free-weighting matrix is introduced in the formation of new criterion, as a consequence, the calculation efficiency is remarkably enhanced. A typical second-order delay system, a single-generator-infinite-bus system and the WSCC 3-generator-9-bus delay system are taken to validate the effectiveness and efficiency enhancement of the proposed criterion. The numerical results indicate that the criterion of this paper can generate the same stability margin with the former ones. Further, the numerical results also verify that the proposed criterion's efficiency is substantially boosted and calculation time is greatly curtailed.