Delay-Dependent Stability Analysis and Controller Design for LFC System under Hybrid Attacks

This paper investigates the problem of load frequency control (LFC) for power systems with electric vehicle (EV) under hybrid attacks, including time-delay attacks (TDA) and denial-of-service (DoS) attacks. The open network communication environment makes the LFC system vulnerable to cyber attacks. First, a multiple time-varying delay linear model of the LFC system with EV under hybrid attack is modeled. Then, a less conservative asymptotic stability criterion is proposed through the Lyapunov-Krasovskii functional (LKF) and delay-dependent region partitioning approach. Additionally, the output feedback controller gain problem is also solved by the convex optimization method. Finally, a numerical example and the LFC model system are exploited to illustrate the effectiveness and superiority of the theoretical results.

I. INTRODUCTION

Load frequency control (LFC) plays a crucial role in power systems [1]. It ensures that the frequency of each area remains stable around a rated value and limits the fluctuation of power exchange on interconnections within a defined range [2], [3]. In modern interconnected power systems, the automatic generation control (AGC) system maintains the real-time balance of generation and load in the control area by adjusting the active power output of frequency-regulated generators and ensures planned power exchange between regions. Plug-in electric vehicles (EVs) are widely used in LFC systems due to the improved frequency compensation capability [4].