Delay-dependent robust stability analysis of power systems with PID controller

Abstract

This study examines the robust stability of a power system, which is based on proportional-integral-derivative load frequency control and involves uncertain parameters and time delays. The model of the system is firstly established, following which the system is transformed into a closed-loop system with feedback control. On this basis, a new augmented Lyapunov-Krasovskii (LK) functional is established for using the new Bessel-Legendre inequality to estimate the derivative of the functional, which can provide a maximum lower bound. A stability criterion is then derived by employing the LK functional and Bessel-Legendre inequality. Finally, numerical examples are used to demonstrate the validity and superiority of the proposed method.