A Lyapunov approach based on gravitational search algorithm for transient stability assessment of AC/DC systems with wind power

With large-scale wind farms connected to AC/DC network, the transient stability assessment (TSA) of power system becomes more and difficult. Among them, estimating region attraction (ROA) equilibrium point is a traditional but still challenging problem. Based on Lyapunov theory, this paper proposes new approach obtain enlarged estimation ROA. The optimization updating strategy shape function in sum squares (SOS) problem are studied reduce conservatism result. In proposed method, gravitational search algorithm (GSA) employed optimize coefficients initial improve performance. time-domain simulation (TDS) expected faults, fitness value for calculated using values state variables at fault clearing time information. Furthermore, optimal computed by introducing update condition adjusting iteration ROA algorithm. Finally, method applied two-machine-infinite-bus complex nine-bus with power. And effectiveness verified comparing existing methods.