An Improved Result on Stability Analysis of Delayed Load Frequency Control Power Systems

This paper investigates the stability of power systems with load frequency control considering time delays (constant and time-varying delays). A new criterion for ensuring the stability of the system is proposed on the basis of Lyapunov stability theory and a further strengthened inequality. Finally, taking a single-area load frequency control scheme with the proportional-integral controller as an example, according to the stability criterion obtained, the relationship between the maximum allowable delay and the gain of proportional-integral controller is discussed. Besides, in case studies, the effectiveness of our method is also demonstrated.