Transient Stability Analysis of Large-Scale Power System by Lyapunov´s Direct Method

In this paper, a method for reducing computation memory required by Lyapunov´ s direct method has been presented. This requirement gets critical when the direct method is applied to transient stability studies of large-scale power systems containing more than 100 generators. Firstly, the system equations, the Lyapunov function, and the linear equations associated with the calculation of the stable equilibrium state, have been formulated in such way that the extreme sparcity of the network admittance matrix could be taken advantage of. Secondly, the programming techniques such as optimally ordered triangular factorization and efficient storage scheme of sparse matrices have been introduced. Lastly, the effectiveness of the method has been investigated with the 107-generator and 363-bus power system represented by the detail generator model including automatic voltage regulators ard power system stabilizers.