Resilient Event-Triggered Output Feedback Control for Load Frequency Control Systems Subject to Cyber Attacks

Abstract

This paper considers the problem of load frequency control (LFC) design for multi-area power systems. Owing to the multi-area power system with a feature of spatial distribution, it becomes necessary to use the network as a signal transmission medium. The following two problems need to be addressed: 1) the transmission signals transmitted over the communication network are vulnerable to be attacked by adversaries. How to ensure the security of the control system and 2) multi-area power systems have a large amount of data need to be exchanged via the network, how to guarantee the network quality of service and the control performance under the limited network bandwidth. To address these problems, in this paper, a resilient output feedback control strategy in secure means is proposed for LFC systems based on the security criteria. Moreover, a new event triggered mechanism (ETM) is developed, under which the average data releasing rate is much lower than the one using the conventional data transmission mechanism, while it becomes high when the system encounters some external disturbances. To validate the effectiveness of the proposed approach, simulations are performed on a 3-area power system. The results show that the proposed control strategy can maintain the LFC system with a satisfactory control performance in the presence of stochastic cyber-attacks, and the average data releasing rate is of a lower level to save communication and computation resources.