We study in this paper the theory and applications of a nonlinear control technique, i.e., so-called composite feedback control, for class linear systems with actuator nonlinearities. It consists law without any switching element. The part is designed to yield closed-loop system small damping ratio quick response, while at same time not exceeding limits desired command input levels. used increase as output approaches target reference reduce overshoot caused by part. shown that proposed...

Trustworthy and secure operation of the cyber-power system calls for resilience against malicious accidental failures. The objective a resilient is to withstand recover supply critical loads despite multiple contingencies in system. To take timely actions, we need continuously measure cyberphysical security We propose cyber-physical assessment metric (CP-SAM) based on quantitative factors affecting resiliency utilizing concepts from graph theoretic analysis, probabilistic model availability,...

With the increasing penetration of distributed energy resources (DERs) in grid edge, including renewable generation, flexible loads, and storage, accurate prediction generation consumption at consumer level becomes important. However, DER based on transmission customer-level data, either repeatedly or large amounts, is not feasible due to privacy concerns. In this article, a machine learning approach, federated (FL), proposed carry out forecasting using network Internet Things (IoT) nodes,...

Electric distribution grid operations typically rely on both centralized optimization and local non-optimal control techniques. As an alternative, system operational practices can consider distributed techniques that leverage communications among various neighboring agents to achieve optimal operation. With the rapidly increasing integration of energy resources (DERs), algorithms are growing in importance due their potential advantages scalability, flexibility, privacy, robustness relative...

The grid of the future will have a higher penetration edge devices that enable increased automation and intelligence. current models do not account for these grid-edge devices, creation cyber-physical is essential to understand impact devices. Although existing power system (CPPS) been developed using wide variety approaches, comprehensive review validity approaches their suitability modeling has performed. In CPPS, physical layer usually consists protection whereas cyber communication,...

In this paper, we show that by using two adaptive neural networks (NNs), each of which is tailored for a specific task, the tracking performance hard-disk-drive (HDD) actuator can be significantly improved. The first NN utilizes accelerometer signal to detect external vibrations and compensates its effect on HDD position via feedforward action. second designed compensate pivot friction. appealing advantage compensators design does not involve any information plant, sensor, disturbance...

Recent cyber attacks on the power grid have been of increasing complexity and sophistication. In order to understand impact cyber-attacks system resiliency, it is important consider an holistic cyber-physical specially with industrial automation. this study, device-level resilience properties various controllers their microgrid resiliency studied. addition, a metric considering vulnerabilities, model, proposed. Resiliency defined as ability provide energy critical loads even in extreme...

This paper provides an overview of the development a real-time cyber-physical testbed for analyzing impact cyber events on critical loads in microgrid. A real-time, co-simulation utilizing Real Time Digital Simulator (RTDS) simulating power system, Common Open Research Emulator (CORE) emulation communication network, and TCP/IP based interface is used this work. The to simulate Army microgrid model validation. Cyber-physical system simulation results demonstrates ability implement attacks analyze

In this paper we propose a distribution-level retail electricity market operated by Distribution System Operator (DSO), to permit participation for small-scale distributed energy resources (DERs) in real-time market. The is built upon Proximal Atomic Coordination algorithm, which solves the optimal power flow using convex nonlinear Branch Flow model, rendering spatially and temporally varying Locational Marginal Prices. A numerical study of structure carried out via simulations IEEE-123 node...

With increasing penetration of distributed energy resources (DER) in the distribution system, it is critical to design market structures that enable smooth integration DERs. A hierarchical local electricity (LEM) structure proposed this paper with a secondary (SM) at lower level representing feeders and primary (PM) upper level, feeders, order effectively use DERs increase grid efficiency resilience. The SM enforces budget, power balance, flexibility constraints accounts for costs related...

Resilience of safety-critical systems is gaining importance, particularly with the increasing number cyber and physical threats. Cyber-physical threats are becoming increasingly prevalent, as digital ubiquitous in critical infrastructure. The challenge determining resilience cyber-physical identifying a set metrics that can adapt to changing states system. A static metric lead an inaccurate estimation system state, result unintended consequences against In this work, we propose data-driven...

The electricity grid has evolved from a physical system to cyberphysical with digital devices that perform measurement, control, communication, computation, and actuation. increased penetration of distributed energy resources (DERs) including renewable generation, flexible loads, storage provides extraordinary opportunities for improvements in efficiency sustainability. However, they can introduce new vulnerabilities the form cyberattacks, which cause significant challenges ensuring...

In a typical disk drive servo system, two or more types of controllers are used for track seeking, following, and settling modes. This leads to the problem mode switching among these controllers. We present in this paper unified control scheme, discrete-time composite nonlinear feedback control, which can perform all above functions hard (HDD) systems with actuator saturation. The proposed scheme is composed by combining linear law law. designed yield fast response, while increase damping...

In this paper, we are interested in wireless scheduling algorithms for the downlink of a single cell that can minimize queue-overflow probability. Specifically, large-deviation setting, maximize asymptotic decay rate probability, as threshold approaches infinity. We first derive an upper bound on probability over all policies. then focus class collectively referred to "α-algorithms." For given α ≥ 1, α-algorithm picks user service at each time has largest product transmission multiplied by...

While there has been much progress in designing backpressure based stabilizing algorithms for multihop wireless networks, end-to-end performance (e.g., buffer usage) results have not as forthcoming. In this paper, we study the usage (sum of utilization along a flow path) over network with general topology and fixed, loop-free routes using large-deviations approach. We first derive bounds on best that any scheduling algorithm can achieve. Based intuition from bounds, propose class...

Natural disasters and cyber intrusions threaten the normal operation of critical electric grid infrastructure. There is still no widely accepted methodology to quantify resilience in power systems. In this work, system resiliency refers ability keep provide energy load even with adverse events. A significant amount work has been done for distribution Even though loads are located system, transmission play a role supplying feeder addition Distributed Energy Resources (DERs). This focuses on...

This study presents a tool to the cyber-physical resiliency (CyPhyR) of critical energy infrastructure system, in particular effect cyber attacks on microgrid's resiliency. The developed enables measuring using data from and physical systems suggests control decisions for resilient planning operation microgrid. microgrid is formulated based graph theory indices cyber-power system characteristics. A Common Vulnerability Scoring System metric called Cyber Asset Impact Potential used phase,...

This paper proposes a dynamic nonlinear control scheme to improve the seek-settling performance in hard disk drive servo system by combination of novel designed reference generator and feedback controller. The controller consists linear one for short rise time an associated small overshoot. In order settling stability due actuator saturation, trajectory is based on loop so that position error signal tracking stage decreased greatly, which effectively avoids saturation with high gain design....

In this paper, we study the queue-overflow probability of wireless scheduling algorithms. networks operated under queue-length-based algorithms, there often exists a tight coupling between service-rate process, system backlog arrival and stochastic process governing channel variations. Although one can use sample-path large-deviation techniques to form an estimate probability, formulation leads difficult multidimensional calculus-of-variations problem. present new technique address...

We consider the problem of link scheduling for efficient convergecast in a wireless system. While there have been many results on algorithms that attain maximum possible throughput such system, few provide are optimal terms some quality-of-service metric as probability end-to-end buffer usage exceeds large threshold. Using deviations framework, we design novel and low complexity algorithm attains asymptotic decay rate overflow sum-queue (i.e. total queue backlog entire system) threshold...