Evaluation of Delays-based Stability of LFC Systems in the Presence of Electric ‎Vehicles Aggregator

Abstract

In the integrated electrical systems, frequency control service considering the electric vehicle (EV) aggregators could lead to time-varying delay in load frequency control (LFC) schemes. These delays influence the LFC system efficiency, and in some situations, the lack of a clear choice of a control strategy considering the time-varying delays causes power system instability. Thus, this paper illustrates different time-varying delays based on the stability of an LFC system in the EV aggregators presence. The LFC's delay-dependent stability study is executed for finding the stability region and, stability criteria is suggested using the linear matrix inequality (LMI) method and Lyapunov-Krasovskii theory. Also, Wirtinger-based improved inequality and bounding lemma are applied to compute the greatest allowable delay in the LFC system, including the EV aggregators.

Keywords

• time-varying delay
• lyapunov-krasovskii theory
• lmi
• load frequency control
• electric vehicles aggregator