Iterative Algorithm for Critical Energy Determination in Transient Stability of Power Systems

Abstract

Abstract In this paper an algorithm for determination of critical energy for analysis of power systems transient stability is presented, being des cribed by an electrical network with constant impedances and with generators represented through the classical model, aiming to obtain critical fault clearing times for short circuits eliminated through transmission line disconnection. The concepts of potential energy boundary surface (PEBS) and system energy function are both used, similar to Liapunov's function represented by integral form due to the electrical network renre sentation. with no reduction to the internal busses of feneration, and the trajectories of states are obtained through series Taylor expansion. Taking into account an algorithm nreviouslv developed, the compensation theorem is applied to determine a submatrix of the bus impedance matrix for the system configurations in pre. under and post-fault conditions. This aims better computational efficiency, besides the expansion of the computational program for large power systems. One example consisting of the analysis of 22 contingencies in a system with 45 generators. 340 busses and 684 transmission lines is included, within just one sinple processing with duration of about 9 minutes in the computer used.