Delay margin computation for single area load frequency control system with time delay

Abstract

In this paper, the delay margin is computed for a load frequency control system with time delay of a single area using delay-independent stability analysis method. The delay-independent stability analysis method is used to consider some characteristics. The delay-independent stability of time-delayed systems may lose stability if their eigenvalue spectrum lies on the imaginary axis for delays. The stability is guaranteed for the delay margin, which must be known. A method for computing the delay margin for load frequency control system with delay is presented. In this method, the system's characteristic equation is converted into frequency-dependent equation. Then the spectral radius of the matrix pair is used to compute the crossing frequency at which eigenvalues cross the imaginary axis. The crossing frequencies and angles are computed using sweeping tests and binary recursive algorithm. At the end, the effectiveness of the proposed method is demonstrated using a case study of load frequency control system with delay of a single area.