This article is concerned with the problem of observer-based dynamic event-triggered control for a networked control system (NCS) under a class of power-constrained denial-of-service (DoS) attacks that aim at impeding the network communication from time to time. First, by carefully modeling such DoS attacks as aperiodic pulse-width-modulated (PWM) jamming signals, a switching observer, adapting to the DoS attacks, is delicately constructed to deal with the unavailability of full-state information. Second, to economize the limited bandwidth resources, a dynamic event-triggered communication scheme is designed under the aperiodic DoS jamming attacks, whose duration and frequency are assumed to be restricted. Third, a switching system model with artificial state delay is formulated, which characterizes the effects of the aperiodic DoS attacks and event-triggered communication scheme in a unified framework. Then, the asymptotic stability analysis and controller/observer synthesis conditions of the resulting switching system are obtained by using a piecewise Lyapunov-Krasovskii functional approach. Furthermore, a co-design method of the dynamic triggering parameters, controller, and observer gains is presented. Finally, an example is employed to verify the effectiveness of the obtained results.

This paper is concerned with the attack-resilient event-triggered controller design problem of a DC microgrid with multiple nonlinear constant power loads and intermittent denial-of-service (DoS) attacks. First, for a resource efficiency purpose, an event-triggering communication scheme is delicately devised in such a way to only invoke the data transmission over the communication line when the DoS attack is inactive. Second, via characterizing the DoS active and inactive time intervals, a new switching piecewise system model for the nonlinear DC microgrid system is presented. Third, a numerically efficient design criterion on the existence of the desired attack-resilient event-triggered controller is established. It is further shown that various performance indices including resource efficiency, attack resilience, robustness against disturbance, sampling performance of the DC microgrid system can be evaluated in a unified framework. Finally, an illustrative example is given to verify the effectiveness of the proposed control design method for the DC microgrid.

Resilient distributed coordination control is studied on multiarea power systems with low inertia under hybrid attacks, including denial-of-service (DoS) attack and deception attack. The communication among various areas under the DoS attack is deteriorated to switching residual topologies whose time characteristic is modeled by model-dependent average dwell time (MDADT). Deception attack with malicious strategy targeting at negative feedback control is modeled by a sign function. To obtain resilience performance of the power system under low inertia and hybrid attacks, resilient distributed scheme combining load-frequency control (LFC) with virtual inertia control (VIC) is proposed. Then, resilient frequency control problem of the studied power system is converted to $H_{\infty }$ control of the switched nonlinear system. By employing the Lyapunov stability theory and switched system method, the resilient conditions are given by the lower bound of the average dwell time of each residual topology and the upper bound of deception attacks. Furthermore, a linear matrix inequality (LMI) technique is used to design the distributed resilient control gains of the LFC-VIC scheme. Finally, a simulation of four-area power systems is carried out to verify the validness of our theory.

Secure frequency control of multi-area hybrid power systems with wind power is a research problem involving active defense, vulnerability, and resilience. Considering the scenario that Denial-of-Service (DoS) attack intrude into the control channels of thermal power and wind farm, the hybrid power system is modeled by a switched system with four subsystems. Then, the exponential stability of hybrid power system is studied under arbitrary DoS attack. An active defense scheme is proposed to design switched control gains by Lie algebra method achieved by a distributed consensus method. Furthermore, following the resulted exponential stability, the load disturbance attenuant performance of frequency control is studied by the proposed concepts of vulnerability point and resilience point. Under a class of event-DoS attack model, the estimation method of vulnerability point and resilience point is given. Finally, simulations of a three-area hybrid power system and NE39bus test system are carried out to verify our theories.

This note is concerned with bandwidth allocation-based switched dynamic triggering control under DoS attacks and time delay. To prevent DoS attacks from causing open-loop unstable operation of the system with single-channel transmission, we present a primary-redundancy (PR) communication structure on the basis of limited bandwidth allocation; the correlation of communication delay bound between PR channels is introduced. To save the limited bandwidth, we propose a dynamic the event-triggered mechanism (DETM). Then, a switched delay system model is established to describe system dynamic driven by primary channel control, redundancy channel control, and unstable operation under DoS attacks. Further, by using the convex combination method, a switching law for PR channel is designed with the aim of keeping the concealment of the redundancy channel. With the switching law, a criterion of exponential stability is obtained by using piecewise Lyapunov-Krasovskii functional method. A co-design method is proposed to obtain feedback control gains, DETM parameters and switching law parameters. Finally, two simulation examples are illustrated to verify the validness of our proposed method.

An indirect–direct secure control (IDSC) method is proposed for load frequency control (LFC) of multi-area power system under false data injection attacks. In the indirect secure control, based on the inherent local security of primary frequency control, an estimation system in power plant is established to reconstruct LFC commands. In the direct secure control, PI-based LFC scheme is adopted with a new robust performance index. Thus, a complementary secure strategy realized by IDSC is developed from combining resilience to cyber-physical disturbances and elimination of attack intrusion. We adopt mixed $H_{\infty }/H_{2}$ control method to formulate and design interconnected IDSC and decentralized IDSC. Simulations of the three-area power systems are carried out to verify the validness of our proposed IDSC method.