Switching Method Based Load Frequency Control for Power System with Energy-Limited DoS Attacks

Abstract

A load frequency control (LFC) scheme for modern power systems employs an open communication network to transmit control/measurement signals. The usage of the open communication network in power system makes the LFC scheme more vulnerable to communication network attacks, for example, a denial-of-service (DoS) attack. This attack will prevent a certain amount of transmission of the signals so as to degrade the performance of LFC scheme, or even lead to instability of power system. Therefore, this paper concerns LFC scheme for single-area power system with energy-limited DoS attack based on switching method. Compared with the latest schemes only considering duration of a DoS attacks, the proposed LFC takes fully into account both the duration and attack frequency of the DoS attack. A switching LFC model for a single-area power system is firstly constructed based on the characteristic of periodical sampling and DoS attacks. Then, an exponential stability criterion is developed in terms of the duration and frequency of a DoS attack. Next, a feasible controller of LFC scheme is derived by solving linear matrix inequalities in the criterion. Finally, a detailed design algorithm of LFC scheme is presented for a known DoS attack or an unknown DoS attack. The effectiveness of the proposed LFC scheme is evaluated on a single-area power system under DoS attacks. The proposed LFC scheme is compared with a robust LFC scheme and an event-triggered H∞ LFC scheme. The obtained contrasting results demonstrate that the proposed LFC scheme can defend DoS attacks with limited energy, and can perform better control effect in the presence of load fluctuations.