Advanced Wide-Area Monitoring System Design, Implementation, and Application

Wide-area monitoring systems (WAMSs) provide an unprecedented way to collect, store and analyze ultra-high-resolution synchrophasor measurements to improve the dynamic observability in power grids. This dissertation focuses on designing and implementing a wide-area monitoring system and a series of applications to assist grid operators with various functionalities. The contributions of this dissertation are below: First, a synchrophasor data collection system is developed to collect, store, and forward GPS-synchronized, high-resolution, rich-type, and massive-volume synchrophasor data. a distributed data storage system is developed to store the synchrophasor data. A memory-based cache system is discussed to improve the efficiency of real-time situation awareness. In addition, a synchronization system is developed to synchronize the configurations among the cloud nodes. Reliability and Fault-Tolerance of the developed system are discussed. Second, a novel lossy synchrophasor data compression approach is proposed. This section first introduces the synchrophasor data compression problem, then proposes a methodology for lossy data compression, and finally presents the evaluation results. The feasibility of the proposed approach is discussed. Third, a novel intelligent system, SynchroService, is developed to provide critical functionalities for a synchrophasor system. Functionalities including data query, event query, device management, and system authentication are discussed. Finally, the resiliency and the security of the developed system are evaluated. Fourth, a series of synchrophasor-based applications are developed to utilize the high-resolution synchrophasor data to assist power system engineers to monitor the performance of the grid as well as investigate the root cause of large power system disturbances. Lastly, a deep learning-based event detection and verification system is developed to provide accurate event detection functionality. This section introduces the data preprocessing, model design, and performance evaluation. Lastly, the implementation of the developed system is discussed

Wide area protection and fault location : review and evaluation of PMU-based methods

Wide area protection (WAP) systems use multiple sources of information to improve trip times and reduce the complexity of protection settings. Therefore, such communications-enhanced schemes have the potential to replace conventional transmission system backup protection. Through review and assessment of the present state-of-the-art relating to WAP systems, this paper demonstrates how multiple synchrophasor data sources, and the associated communications systems, can be leveraged to enable new forms of supervisory protection. Two case studies are presented: a scalable WAP architecture for future decentralised power systems, and the validation a prototype WAP system, using the principle of distributed photonic sensing, highlighting how new tools can provide cost-effective solutions to emerging protection challenges

An Assessment of PIER Electric Grid Research 2003-2014 White Paper

This white paper describes the circumstances in California around the turn of the 21st century that led the California Energy Commission (CEC) to direct additional Public Interest Energy Research funds to address critical electric grid issues, especially those arising from integrating high penetrations of variable renewable generation with the electric grid. It contains an assessment of the beneficial science and technology advances of the resultant portfolio of electric grid research projects administered under the direction of the CEC by a competitively selected contractor, the University of California’s California Institute for Energy and the Environment, from 2003-2014

Security Analysis of Interdependent Critical Infrastructures: Power, Cyber and Gas

abstract: Our daily life is becoming more and more reliant on services provided by the infrastructures power, gas , communication networks. Ensuring the security of these infrastructures is of utmost importance. This task becomes ever more challenging as the inter-dependence among these infrastructures grows and a security breach in one infrastructure can spill over to the others. The implication is that the security practices/ analysis recommended for these infrastructures should be done in coordination. This thesis, focusing on the power grid, explores strategies to secure the system that look into the coupling of the power grid to the cyber infrastructure, used to manage and control it, and to the gas grid, that supplies an increasing amount of reserves to overcome contingencies. The first part (Part I) of the thesis, including chapters 2 through 4, focuses on the coupling of the power and the cyber infrastructure that is used for its control and operations. The goal is to detect malicious attacks gaining information about the operation of the power grid to later attack the system. In chapter 2, we propose a hierarchical architecture that correlates the analysis of high resolution Micro-Phasor Measurement Unit (microPMU) data and traffic analysis on the Supervisory Control and Data Acquisition (SCADA) packets, to infer the security status of the grid and detect the presence of possible intruders. An essential part of this architecture is tied to the analysis on the microPMU data. In chapter 3 we establish a set of anomaly detection rules on microPMU data that flag "abnormal behavior". A placement strategy of microPMU sensors is also proposed to maximize the sensitivity in detecting anomalies. In chapter 4, we focus on developing rules that can localize the source of an events using microPMU to further check whether a cyber attack is causing the anomaly, by correlating SCADA traffic with the microPMU data analysis results. The thread that unies the data analysis in this chapter is the fact that decision are made without fully estimating the state of the system; on the contrary, decisions are made using a set of physical measurements that falls short by orders of magnitude to meet the needs for observability. More specifically, in the first part of this chapter (sections 4.1- 4.2), using microPMU data in the substation, methodologies for online identification of the source Thevenin parameters are presented. This methodology is used to identify reconnaissance activity on the normally-open switches in the substation, initiated by attackers to gauge its controllability over the cyber network. The applications of this methodology in monitoring the voltage stability of the grid is also discussed. In the second part of this chapter (sections 4.3-4.5), we investigate the localization of faults. Since the number of PMU sensors available to carry out the inference is insufficient to ensure observability, the problem can be viewed as that of under-sampling a "graph signal"; the analysis leads to a PMU placement strategy that can achieve the highest resolution in localizing the fault, for a given number of sensors. In both cases, the results of the analysis are leveraged in the detection of cyber-physical attacks, where microPMU data and relevant SCADA network traffic information are compared to determine if a network breach has affected the integrity of the system information and/or operations. In second part of this thesis (Part II), the security analysis considers the adequacy and reliability of schedules for the gas and power network. The motivation for scheduling jointly supply in gas and power networks is motivated by the increasing reliance of power grids on natural gas generators (and, indirectly, on gas pipelines) as providing critical reserves. Chapter 5 focuses on unveiling the challenges and providing solution to this problem.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Machine Learning Based Detection of False Data Injection Attacks in Wide Area Monitoring Systems

The Smart Grid (SG) is an upgraded, intelligent, and a more reliable version of the traditional Power Grid due to the integration of information and communication technologies. The operation of the SG requires a dense communication network to link all its components. But such a network renders it prone to cyber attacks jeopardizing the integrity and security of the communicated data between the physical electric grid and the control centers. One of the most prominent components of the SG are Wide Area Monitoring Systems (WAMS). WAMS are a modern platform for grid-wide information, communication, and coordination that play a major role in maintaining the stability of the grid against major disturbances. In this thesis, an anomaly detection framework is proposed to identify False Data Injection (FDI) attacks in WAMS using different Machine Learning (ML) and Deep Learning (DL) techniques, i.e., Deep Autoencoders (DAE), Long-Short Term Memory (LSTM), and One-Class Support Vector Machine (OC-SVM). These algorithms leverage diverse, complex, and high-volume power measurements coming from communications between different components of the grid to detect intelligent FDI attacks. The injected false data is assumed to target several major WAMS monitoring applications, such as Voltage Stability Monitoring (VSM), and Phase Angle Monitoring (PAM). The attack vector is considered to be smartly crafted based on the power system data, so that it can pass the conventional bad data detection schemes and remain stealthy. Due to the lack of realistic attack data, machine learning-based anomaly detection techniques are used to detect FDI attacks. To demonstrate the impact of attacks on the realistic WAMS traffic and to show the effectiveness of the proposed detection framework, a Hardware-In-the-Loop (HIL) co-simulation testbed is developed. The performance of the implemented techniques is compared on the testbed data using different metrics: Accuracy, F1 score, and False Positive Rate (FPR) and False Negative Rate (FNR). The IEEE 9-bus and IEEE 39-bus systems are used as benchmarks to investigate the framework scalability. The experimental results prove the effectiveness of the proposed models in detecting FDI attacks in WAMS

Wide-Area Measurement-Driven Approaches for Power System Modeling and Analytics

This dissertation presents wide-area measurement-driven approaches for power system modeling and analytics. Accurate power system dynamic models are the very basis of power system analysis, control, and operation. Meanwhile, phasor measurement data provide first-hand knowledge of power system dynamic behaviors. The idea of building out innovative applications with synchrophasor data is promising. Taking advantage of the real-time wide-area measurements, one of phasor measurements’ novel applications is to develop a synchrophasor-based auto-regressive with exogenous inputs (ARX) model that can be updated online to estimate or predict system dynamic responses. Furthermore, since auto-regressive models are in a big family, the ARX model can be modified as other models for various purposes. A multi-input multi-output (MIMO) auto-regressive moving average with exogenous inputs (ARMAX) model is introduced to identify a low-order transfer function model of power systems for adaptive and coordinated damping control. With the increasing availability of wide-area measurements and the rapid development of system identification techniques, it is possible to identify an online measurement-based transfer function model that can be used to tune the oscillation damping controller. A demonstration on hardware testbed may illustrate the effectiveness of the proposed adaptive and coordinated damping controller. In fact, measurement-driven approaches for power system modeling and analytics are also attractive to the power industry since a huge number of monitoring devices are deployed in substations and power plants. However, most current systems for collecting and monitoring data are isolated, thereby obstructing the integration of the various data into a holistic model. To improve the capability of utilizing big data and leverage wide-area measurement-driven approaches in the power industry, this dissertation also describes a comprehensive solution through building out an enterprise-level data platform based on the PI system to support data-driven applications and analytics. One of the applications is to identify transmission-line parameters using PMU data. The identification can obtain more accurate parameters than the current parameters in PSS®E and EMS after verifying the calculation results in EMS state estimation. In addition, based on temperature information from online asset monitoring, the impact of temperature change can be observed by the variance of transmission-line resistance

Machine learning approach for dynamic event identification in power systems with wide area measurement systems

Orientador: Prof. Dr. Alexandre Rasi AokiCoorientador: Prof. Dr. Ricardo SchumacherDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia Elétrica. Defesa : Curitiba, 13/02/2023Inclui referênciasResumo: Ao longo dos últimos dez anos, a disponibilidade de WAMS (Wide Area Measurement Systems) tem constantemente aumentado e, com isso, a necessidade de se otimizar seu uso em relação a uma ampla gama de capacidades requeridas nos centros de operação. Concorrentemente, o sistema brasileiro tem observado diversos eventos em múltiplos níveis de criticalidade e, portanto, formas de rapidamente identificar irregularidades na rede elétrica têm sido requisitadas pelos operadores. Todavia, mesmo com tal diversidade de eventos registrados por PMUs (Phasor Measurement Unit), há dificuldades em se consolidar um banco de dados de eventos e, ademais, sistemas diferem uns dos outros - isto é, os volumes de dados requeridos para machine learning e a especificidade de cada sistema criam desafios para a construção de aplicações para detecção e identificação de eventos em uma dada rede. De tal maneira, o presente trabalho propõe uma forma de endereçar tais restrições e habilitar o uso de modelos de machine learning na vida real ao modelar um sistema real, simular uma grande quantia de eventos (como medição de PMU) e executar o processo de aprendizado de máquina com esses dados simulados. Tendo posse de qualquer conjunto de dados que contenha medições de evento da mesma PMU simulada, uma validação da aplicabilidade e performance do modelo obtido pode ser feita. Assim, um processo reprodutível e escalável foi definido pelo trabalho a partir de um estudo de caso no corredor Salto Caxias, um subsistema da rede elétrica paranaense operado pela COPEL, que forneceu três conjuntos de dados contendo eventos registrados em uma PMU dessa área. Alguns componentes como barras, linhas de transmissão, transformadores, geradores, PSSs, excitadores e controles de turbina foram modelados dentro da Power System Toolbox, embasada em MATLAB, para simulação de eventos. O algoritmo de machine learning selecionado para provar o conceito estabelecido foi rede neural artificial, definindo-se quatro classes possíveis para reconhecimento - "Curto-circuito", "Perda de Carga", "Perda de Linha" e "Normal". Com o modelo de machine learning definido e treinado, se aplicaram os dados de eventos reais nele. Os resultados mostram que as métricas da rede neural no processo de aprendizado foram geralmente suficientes para aplicação em vida real, mas que sua performance nos conjuntos de dados de eventos reais foi abaixo da registrada com os dados simulados. Todavia, considerando-se que os dados reais providenciados são de eventos longínquos à PMU observada e ao próprio sistema modelado, distorções e atenuações de sinal são inerentes. Assim, pode-se dizer que o método proposto é aplicável, com mais etapas de pré-processamento de dados, a qualquer dado sistema - caso ele seja minuciosamente modelado e haja disponibilidade de conjuntos de dados de eventos internos ao sistema.Abstract: Over the last ten years, the availability of WAMS (Wide Area Measurement Systems) has steadily increased and, with it, the need to optimize its usage concerning a large array of capabilities required at the operation centers. Concurrently, the Brazilian system has witnessed various events at multiple levels of criticality, and, thus, ways to quickly identify irregularities in the grid have been more and more requested by power transmission and distribution companies. The introduction of machine learning models and algorithms in such a context has been explored by the scientific community. However, even with such a diversity of events and their PMU (Phasor Measurement Unit) measurements, there is hardship in consolidating an event database and systems differ from each other - that is, the data volume required for machine learning and the specificity of each power system create challenges in constructing applications for detection and identification of events in a given grid. As such, the present work proposes a way to address those constraints and further enable the real-life application of machine learning models in a power system with WAMS through the modeling of a real-life system, simulating a large database of events as if they were registered through a PMU in said system and training machine learning models on this simulated data. If one has any dataset containing event measurements from the same PMU (which was simulated), a validation of model performance and applicability can be performed. A reproducible and scalable process was defined to achieve this through one case study for the Salto Caxias subsystem of the Paraná state grid, operated by COPEL, who provided the author with three event datasets captured from a PMU in the aforementioned system. Some components of the system were modeled in MATLAB-based Power System Toolbox for dynamic simulation, such as generators, PSSs, exciters, and turbine governors in addition to buses, transmission lines, and transformers. The selected algorithm for this proof-of-concept was artificial neural network, defining four distinct possible classes it can recognize - "Short-circuit", "Load Loss", "Line Loss" and "Normal". With the machine learning model defined and trained, its application was executed on real event datasets. The results show that the metrics of the neural network model on the learning process were generally sufficient for real-life solutions, but its performance on the real event datasets was below that of the performance on simulated data. However, considering that the provided datasets were from events that happened far away from the selected PMU and its modeled system, signal distortions and attenuations are present. Thus, it can be stated that the proposed method is applicable, with further data preprocessing, to any given system - as long as it is thoroughly modeled and there is availability of datasets of events that happened within it

Automated Anomaly Detection in Distribution Grids Using uPMU Measurements

The impact of Phasor Measurement Units (PMUs) for providing situational awareness to transmission system operators \ has been widely documented. Micro-PMUs (uPMUs) \ are an emerging sensing technology that can provide similar \ benefits to Distribution System Operators (DSOs), enabling a \ level of visibility into the distribution grid that was previously \ unattainable. In order to support the deployment of these \ high resolution sensors, the automation of data analysis and \ prioritizing communication to the DSO becomes crucial. In this \ paper, we explore the use of uPMUs to detect anomalies on \ the distribution grid. Our methodology is motivated by growing \ concern about failures and attacks to distribution automation \ equipment. The effectiveness of our approach is demonstrated \ through both real and simulated data

Electric Power Grid Resilience to Cyber Adversaries: State of the Art

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. The smart electricity grids have been evolving to a more complex cyber-physical ecosystem of infrastructures with integrated communication networks, new carbon-free sources of powergeneratio n, advanced monitoring and control systems, and a myriad of emerging modern physical hardware technologies. With the unprecedented complexity and heterogeneity in dynamic smart grid networks comes additional vulnerability to emerging threats such as cyber attacks. Rapid development and deployment of advanced network monitoring and communication systems on one hand, and the growing interdependence of the electric power grids to a multitude of lifeline critical infrastructures on the other, calls for holistic defense strategies to safeguard the power grids against cyber adversaries. In order to improve the resilience of the power grid against adversarial attacks and cyber intrusions, advancements should be sought on detection techniques, protection plans, and mitigation practices in all electricity generation, transmission, and distribution sectors. This survey discusses such major directions and recent advancements from a lens of different detection techniques, equipment protection plans, and mitigation strategies to enhance the energy delivery infrastructure resilience and operational endurance against cyber attacks. This undertaking is essential since even modest improvements in resilience of the power grid against cyber threats could lead to sizeable monetary savings and an enriched overall social welfare