Dynamic Stability Analysis of Large-scale Power System by the Frequency Response Method

Abstract

A frequency response method has been proposed to analyze a dynamic stability on power oscillations of large interconnected power systems. However, its application to large-scale power systems is severely limited because of its long computation time. In this paper, several measures were proposed to remove this disadvantage. A method of directly calculating the determinant of an operational transfer matrix was first proposed in order to shorten the computation time at each frequency. The determinant is efficiently obtained by utilizing sparsity natures of three intermediate matrices. Multiple step sizes of frequency were next introduced instead of a fixed step size in order to reduce the number of frequency points to be scanned. These measures were applied to an example system with 107 generators. The computation time for each frequency response was reduced to 1

22 of the usual method. The number of frequency points was reduced to 28% of the usual method. The total computation time was reduced to 17.1 seconds, which corresponds to 1

75 of the usual method. These results verify the effectiveness of the proposed measures.