Economic Control of Quality of Manufactured Product.

In this paper, we mainly review the topics in consensus and coordination of multi-agent systems, which have received a tremendous surge of interest and progressed rapidly in the past few years. Focusing on different kinds of constraints on the controller and the self-dynamics of each individual agent, as well as the coordination schemes, we categorize the recent results into the following directions: consensus with constraints, event-based consensus, consensus over signed networks, and consensus of heterogeneous agents. We also review some applications of the very well developed consensus algorithms to the topics such as economic dispatch problem in smart grid and k -means clustering algorithms.

Recent Advances in Consensus of Multi-Agent Systems: A Brief Survey

The electricity industry is now at the verge of a new era—an era that promises, through the evolution of the existing electrical grids to smart grids, more efficient and effective power management, better reliability, reduced production costs, and more environmentally friendly energy generation. Numerous initiatives across the globe, led by both industry and academia, reflect the mounting interest around not only the enormous benefits but also the great risks introduced by this evolution. This paper focuses on issues related to the security of the smart grid and the smart home, which we present as an integral part of the smart grid. Based on several scenarios, we aim to present some of the most representative threats to the smart home/smart grid environment. The threats detected are categorized according to specific security goals set for the smart home/smart grid environment, and their impact on the overall system security is evaluated. A review of contemporary literature is then conducted with the aim of presenting promising security countermeasures with respect to the identified specific security goals for each presented scenario. An effort to shed light on open issues and future research directions concludes this paper.

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Survey in Smart Grid and Smart Home Security: Issues, Challenges and Countermeasures

Transition to a sustainable energy environment results in aggregated generator and load dynamics in the distribution network. State estimation is a key function in building adequate network models for online monitoring and analyzes. The requirements of distribution system state estimation (DSSE) is becoming stringent because of the needs of new system modeling and operation practices associated with integration of distributed energy resources and the adoption of advanced technologies in distribution network. This paper summarizes the state-of-the-art technology, major hurdles, and challenges in DSSE development. The opportunities, paradigm shift, and future research directions that could facilitate the need of DSSE are discussed.

A Review on Distribution System State Estimation

Distribution System Modeling and Analysis

This article provides a survey on state estimation (SE) in electric power grids and examines the impact on SE of the technological changes being proposed as a part of the smart grid development. Although SE at the transmission level has a long history, further research and development of innovative SE schemes, including those for distribution systems, are needed to meet the new challenges presented by the requirements of the future grid. This article also presents some example topics that signal processing (SP) research can contribute to help meet those challenges.

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State Estimation in Electric Power Grids: Meeting New Challenges Presented by the Requirements of the Future Grid

This paper presents the analysis and simulation of the performance of fault location and isolation (FLI) in an automated power distribution feeder. This system is composed of two coupled networks: a power system consisting of a distribution feeder with multiple load buses, and an unreliable communication network of the distributed intelligent agents in the system, namely, the substation automation and fault protection units separating segments of the feeder. We provide a complete specification of a distributed algorithm for FLI and an exact characterization of the time from the occurrence of a fault to its location and isolation. Both apply to a distribution feeder with an arbitrary number of buses. These models are then refined into a hybrid simulation that combines three models executing in parallel: a power system model based on dc power flow, a distributed automation system model for the intelligent agents constructed using the IEC 61499 distributed automation standard, and an abstract communication network model that unreliably links the physically distributed agents. The results demonstrate the effect of communication network reliability at two levels of design abstraction, the correspondence of results at the two levels, and the use of a modern cosimulation framework to verify the performance of distributed smart grid automation algorithms.

Automated Fault Location and Isolation in Distribution Grids With Distributed Control and Unreliable Communication

This paper presents a state estimation method for power systems when not all state variables are observable with phasor measurement units (PMU), namely, incomplete PMU observability. Realizing that PMU measurements are generally more accurate than conventional ones, the proposed approach estimates PMU unobservable states and PMU observable states separately. The latter are estimated from PMU measurements using a linear estimator. Those estimates are then used along with conventional measurements in a reduced-order nonlinear estimator for the PMU unobservable states. The proposed decoupled approach features reduced computational complexity and greater numerical stability, when compared to existing combined approaches. We show analytically that the performance of the proposed method is comparable to that of existing approaches if PMU measurements are sufficiently accurate. In this paper, we also study the impact of time-skew errors in conventional measurements on the performance of hybrid state estimators using both conventional and PMU measurements. We propose a model that incorporates such errors into conventional measurements. We show that our proposed method is more robust than existing approaches in the presence of time-skew errors. Our analytical findings are verified by simulations on standard IEEE test systems.

Power System State Estimation Under Incomplete PMU Observability—A Reduced-Order Approach

Phasor measurement units (PMUs) are being increasingly deployed in power systems where they are used for state estimation (SE) among other applications. In this paper, we present a computationally efficient approach to SE based on model-order reduction. The proposed algorithm operates separately on PMU measurements and on conventional measurements, using reduced-dimension matrices. This approach reduces the computational load considerably without significantly affecting accuracy. Moreover, this scheme supports distributed implementation and is numerically stable. The performance of the proposed estimation algorithm is examined with the IEEE 14-bus system and compared with existing schemes in the literature.

Reduced-order synchrophasor-assisted state estimation for smart grids

This paper presents a distributed estimation scheme as a possible solution to multi-area state estimation for power systems. The proposed estimation scheme features data-dependent selective sensing and estimation, namely, event-triggered estimation and communication. The triggering event is characterized by the innovation received by the measurements. The proposed scheme can potentially reduce the overhead costs that include communication (bandwidth), data processing and interference, leading to more effective use of the resources.

Neelabh Kashyap

Papers

State Estimation in Electric Power Grids: Meeting New Challenges Presented by the Requirements of the Future Grid

Automated Fault Location and Isolation in Distribution Grids With Distributed Control and Unreliable Communication

Power System State Estimation Under Incomplete PMU Observability—A Reduced-Order Approach

Reduced-order synchrophasor-assisted state estimation for smart grids

Event-triggered multi-area state estimation in power systems