Computation of all stabilizing PI controller parameters of hybrid load frequency control system with communication time delay

This paper presents an effective and simple graphical method to compute all stabilizing Proportional Integral (PI) controller gains of a hybrid load frequency control (LFC) system that contains time delays due to use of open and distributed communication network. The method is based on extracting stability region and the stability boundary locus in the PI controller parameters. The accuracy of the proposed method is verified by time-domain simulations.