Denial of service attacks and communication latency pose challenges for the operation of control systems within power systems. Specifically, excessive delay between sensors and controllers can substantially worsen the performance of distributed control schemes. In this paper, we propose a framework for delay-resilient cyber-physical control of smart grid systems for transient stability applications. The proposed control scheme adapts its structure depending on the value of the latency. As an example, we consider a parametric feedback linearization (PFL) control paradigm and make it “cyber-aware.” A delay-adaptive design that capitalizes on the features of PFL control is presented to enhance the time-delay tolerance of the power system. Depending on the information latency present in the smart grid, the parameters and the structure of the PFL controller are adapted accordingly to optimize performance. The improved resilience is demonstrated by applying the PFL controller to the New England 39-bus and WECC 9-bus test power systems following the occurrence of physical and cyber disturbances. Numerical results show that the proposed cyber-physical controller can tolerate substantial delays without noticeable performance degradation.

In this paper, we consider a distributed energy storage system (ESS)-based control paradigm for transient stability of power systems. Utilizing a multi-agent control framework, we propose an effective virtual inertia measure for cyber-physical agents that includes both traditional synchronous generators and actuated ESSs. We derive the effective virtual inertia analytically for the case of general ESS-based control. We further consider the case of parametric feedback linearization control (PFL) as an application and investigate the proposed inertia measures after applying the PFL control. The utility of the proposed inertia measures is studied using the IEEE 68-bus test power system. Numerical results demonstrate the impact of storage limits, control scheme aggressiveness, and delay on the proposed inertia measures during a disturbance in the power system.

Security of smart power systems is a sound concern as more cyber elements are added to the power grid. In this paper, we focus on cyber attacks that target data integrity in smart grid systems. We specifically investigate the impact of false data injection (FDI) attacks on distributed transient stability control schemes. As an example, we focus on the parametric feedback linearization (PFL) controller, and we derive closed-form expressions for the errors in rotors’ speed and angle as a result of cyber attacks on data integrity. Furthermore, we investigate adaptive control strategies to eliminate or minimize the impact of FDI attacks on system dynamics. The IEEE 68-bus test power system is used to numerically evaluate the impact of example attacks and to draw valuable insights.

This work presents a new class of cyber-physical switching attacks that targets power transmission systems. The proposed approach relies on exciting inter-area oscillation modes in a coordinated manner to drive groups of system generators out of step. Our paradigm targets inter-area oscillations by switching a relatively small part (in the order of 2%) of the system load at a (low) frequency that resonates with one of the inter-area oscillation modes observed in the power system. The switching frequency of the targeted mode is chosen through measurement-based analysis of the frequency deviation at a select bus that is observable by the adversary. The inter-area switching attack is implemented as single-load switching and coordinated multi-load switching and is studied with a variety of switching signals. Numerical results show the potential and characteristics of the proposed switching exploitation when applied to the four-machine two-area power system and the Northeast Power Coordinating Council 68-bus system.

This work describes the utility of pyrazole-4-carbaldehyde 1 as starting material for the synthesis of a novel potent series of 5α-reductase and aromatase inhibitors derived from 1,2,3-triazole derivative. Condensation of 1 with active methylene and different amino pyrazoles produced the respective Schiff bases 2–4, 8 and 9. On the other hand, 1 was reacted with ethyl cyanoacetate and thiourea in one-pot reaction to afford the pyrazolo-6- thioxopyridin-2-[3H]-one (10). Moreover, α–β unsaturated chalcone derivative 11 was prepared via the reaction of compound 1 with P-methoxy acetophenone, which in turn reacted with each of ethyl cyanoacetate, malononitrile, hydrazine hydrate, and thiosemicarbazide to afford the corresponding pyridine and pyrazole derivatives 13, 14, 17, and 20. The structure of newly synthesized compounds was characterized by analytical and spectroscopic data (IR, MS and NMR). All new compounds were evaluated against 5α-reductase and aromatase inhibitors and the results showed that many of these compounds inhibit 5α-reductase and aromatase activity; compound 13 was found to be the highest potency among the tested samples comparing with the reference drugs.

In this work we propose an adaptive cyber-enabled parametric feedback linearization (PFL) control scheme for transient stability of smart grids. Based on feedback linearization control theory, the distributed PFL controller utilizes a distributed energy storage system (ESS) to modify the dynamics of the power system during transients. We consider cyber attacks on data integrity and availability in the smart grid, and propose to adapt the PFL controller's parameter to the cyber state of the smart grid. Specifically, the PFL control scheme adapts its aggressiveness parameter to the level of noise, communication latency, and data injection attacks. Further, depending on the severity of the physical disturbance, the controller adjusts the value of its parameter to speed up the stabilization process. The performance of the proposed control scheme is validated on the IEEE 68-bus test power system where the adaptive PFL controller is shown to efficiently stabilize the power system during physical and cyber disturbances.