Research on Time Delay Stability of Power System using Fault Chains and Markov Process

A new method based on fault chains and the Markov process for analyzing time-delay power system stability is proposed in this article. First, reasonable fault chains are formed using the fault chain generation method based on network power flow. Second, by combining the fault chains and Markov processes, a class of Lyapunov-Krasovskii functionals considering the Markov jump is established. Free weighting items constructed with the Markov process transfer rate matrix and Newton-Leibniz formula, respectively, are then introduced to the weak infinitesimal operators in the Lyapunov-Krasovskii functional. Meanwhile, to lower the conservativeness of the method, the whole time-varying time-delay interval has been divided into two subintervals. Finally, the time-delay upper bound that the power system can bear in the case of cascading faults is calculated by means of the generalized eigenvalue problem. The efficiency and feasibility of the proposed method in solving the maximum time delay in the case of cascading faults have been validated by the dynamic time-domain simulation results. Comparative results with other methods show the proposed method has low conservativeness.