Delay-dependent stability analysis of power system considering communication delays

This paper proposes a new flexible methodology based on frequency domain approach for analyzing the delay-dependent stability of deregulated power system considering communication delays. The delay margin of the system is determined theoretically for different values of controller gains. The theoretical results are verified through simulation studies. The correlation between the delay margin and the controller gain is investigated, which helps the system operator in designing the controllers for stable operation of power system. The proposed method is more accurate, less conservative and takes less computation time as compared to the existing approaches. The proposed method is independent of the order of the system. To extend the analysis spectrum and to prove the feasibility of the proposed method for large scale interconnected power system, a case study has been carried out based on a reasonable size test system to design a wide area damping controller considering time delays.