A Feasible Delay Margin Sensitivity Analysis Method

Abstract

This letter proposes a method for calculating the sensitivity of delay margin with respect to system parameters. According to the property that the delay margin is achieved when the rightmost eigenvalues of the close-loop system locate exactly on the imaginary axis, a characteristic equation with inclusion of the delay margin is established. By differentiating the characteristic equation and further introducing normalization condition for the eigenvector, the sensitivity of the delay margin with respect to any given parameters can be obtained by solving a set of sparse linear equations. Due to the general differential and algebraic equation used in the derivation, the proposed delay margin sensitivity analysis method applies to various power system models and control problems.