Descriptive Model of Generic WAMS

The Department of Energy’s (DOE) Transmission Reliability Program is supporting the research, deployment, and demonstration of various wide area measurement system (WAMS) technologies to enhance the reliability of the Nation’s electrical power grid. Pacific Northwest National Laboratory (PNNL) was tasked by the DOE National SCADA Test Bed Program to conduct a study of WAMS security. This report represents achievement of the milestone to develop a generic WAMS model description that will provide a basis for the security analysis planned in the next phase of this study

Construction of system restoration strategy with PMU measurements

This journal issue is the Proceedings of International Conference on Smart Grid and Clean Energy Technologies (ICSGCE 2011)Power system restoration is well-recognized as one of the major technologies to improve system reliability. A high efficient restoration strategy is established and implemented with accurate information acquisition. Phasor measurement unit (PMU) provides a state-of-the-art information monitoring technology. In this paper, with PMU measurements, several algorithms are proposed to ensure complete observability of systems under regular operating conditions and during system restoration process. Case studies on IEEE 14, 30, 57, 118 and 300 - bus systems validate efficiency of the proposed algorithms. © 2011 Published by Elsevier Ltd.postprintThe 2011 IEEE International Conference on Smart Grid and Clean Energy Technologies (IEEE ICSGCE 2011), Chengdu, China, 27-30 September 2011. In Energy Procedia, 2011, v. 12, p. 377-38

Metric indices for performance evaluation of a mixed measurement based state estimator

With the development of synchronized phasor measurement technology in recent years, it gains great interest the use of PMU measurements to improve state estimation performances due to their synchronized characteristics and high data transmission speed. The ability of the Phasor Measurement Units (PMU) to directly measure the system state is a key over SCADA measurement system. PMU measurements are superior to the conventional SCADA measurements in terms of resolution and accuracy. Since the majority of measurements in existing estimators are from conventional SCADA measurement system, it is hard to be fully replaced by PMUs in the near future so state estimators including both phasor and conventional SCADA measurements are being considered. In this paper, a mixed measurement (SCADA and PMU measurements) state estimator is proposed. Several useful measures for evaluating various aspects of the performance of the mixed measurement state estimator are proposed and explained. State Estimator validity, performance and characteristics of the results on IEEE 14 bus test system and IEEE 30 bus test system are presented

Anomaly Detection In Electrical Power System Using Phasor Measurement Units

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2015Thesis (M.Sc.) -- İstanbul Technical University, Instıtute of Science and Technology, 2015Bu tez çalışması, Matlab PMU'lar modeli ile ölçülen PMU verilerini kullanarak öncü bir yaklaşım sağlamıştır. Bu çalışmada MATLAB SIMULINK'in simülasyon ortamında, özellik çıkarımı için çeşitli sinyal işleme teknikleri kullanılarak  bölgeler arası (inter-area) osilasyonlar, ferrorezonans vb gibi anormallikler tesbit edilmiştir. Çeşitli senaryoları simüle etme amacıyla bir sanal deney düzeneği (test-bed) sağlanarak, güç sistemi operasyonlarında herhangi bir istenmeyen durum tespit analizinin gerçekleştirilebilirliği amaçlanmıştır. Geniş Alan İzleme Sistemi ve kontrol gibi diğer uygulmalarla birlikte şebeke yönetimine bir bütün olarak bakıldığında, daha güvenilir bir şebeke yönetimi için umut verici bir gelecek sağlayacaktır. Elektrik kesintileri PMU'lar tarafından sağlanan durumsal farkındalık  yoluyla önlenebilir. Böylece şebeke geliştirilmiş güvenirliğe sahip olarak çalıştırılacaktır. Kısacası, WAMS güç sistemi salınımlarının güvenilir olarak izlenmesi ve tesbiti gelecekteki güç şebekelerinin en kritik uygulamalarından  biri olacaktır. Ayrıca, sistem operatörleri ve algılama algoritmaları için artan titreşimler ve istikrarsızlıklardan da  değerli bilgiler sağlanacaktır. Bu sistem gözetimin sağladığı bir deneyim olarak, operatörler için faydalı bir bilgiye dönüştürülebilir. Böylece operatörler eşzamanlı anlar sırasında oluşan veri ve olayları karşılaştırarak istikrarsızlığın ana nedenini bulmak üzere gözlem yapmak ve senkronize fazör ölçümlerini izlemek için uyarılabilir. Ayrıca, gelecekteki istikrarsızlıklardan korunmak için düzeltici eylemler de devreye alınabilir.In this study using MATLAB SIMULINK simulation environment is used to detect anomalies like inter-area oscillations, ferroresonance etc. utilizing several signal processing techniques for feature extraction. This will provide a virtual experimental setup (test-bed) to simulate various scenarios so that analysis can be carried out to detect any undesirable situation in the power system operation. It has been shown through the simulated scenarios i.e. detection of inter-area oscillations and ferroresonance phenomenon, that PMUs measurement can successfully achieved the desired results. These applications along with other similar one in Wider Area Monitoring System provides the promising future which will ensure better monitoring, control and grid management on the whole. Blackouts can be avoided through the situational awareness provided by the PMUs. Hence, grid can be operated with enhanced reliability. In short, WAMS reliable detection and monitoring of power system oscillations will be one of the most critical applications of the future power networks. So that a valuable information of increasing oscillations and instability be provided to the system operators and detection algorithms. In addition, operator can be alerted to observe and monitor the synchronized phasor measurements to find the root cause of instability by comparing the data and events occurred during the same time instants. Also, corrective actions can be taken to safe guard the further instability.Yüksek LisansM.Sc

Standards-based sensor web for wide area monitoring of power systems

The balance of supply and demand of energy is the key factor in the stability of power systems. A small disturbance in the supply demand relationship, if not properly handled, can cascade into a major outage, costing millions of dollars to the stakeholders. Proper monitoring and exchange of critical information in real time is the only solution to prevent the instability in this vulnerable system. But, the disparity in the protocols used by power utilities and the lack of infrastructure for information exchange are proving to be hindrance to obtaining a reliable de-regularized power industry. In this thesis, an emerging Sensor Web Enablement (SWE) has been adapted for the wide area monitoring of power systems. SWE and CIM provide a solution to both problems; the heterogeneity of data and the lack of central repository of the data for proper action. The sensor data from utilities that are published in CIM were modeled thorough a SensorML and exposed via a Sensor Observation Service (SOS). This provides a standard method for discovering and accessing the sensor data between utilities and facilitates rapid response functionality to handle contingences

Load Monitoring CEC/LMTF Load Research Program

This white paper addresses the needs, options, current practices of load monitoring. Recommendations on load monitoring applications and future directions are also presented

Desarrollo de software dirigido a la evaluación de las características de las Unidades de Medición Fasorial como dispositivos de medición y monitoreo y sus potenciales aplicaciones en sistemas eléctricos de potencia

Resumen: La implementación de Unidades de Medición Fasorial (PMU, por sus siglas en inglés) en los sistemas de energía eléctrica está masificándose alrededor del mundo ya que es una tecnología que permite una mejor observabilidad de las redes eléctricas mediante el monitoreo de las variables que allí interactúan representadas en magnitud y ángulo (Fasores). [1] Este documento inicia con algunas anotaciones históricas de las PMU y comenta acerca de su evolución. Luego, se presentan las bases teóricas de la representación de variables eléctricas como fasores y se explica cómo estos dispositivos logran mediciones fasoriales con la ayuda del sistema de posicionamiento global, GPS (Global Positioning System) que permite la sincronización de todos las PMU. [2] Además, se explica el concepto de concentrador de datos fasoriales (PDC, por sus siglas en inglés) y cómo funciona, sus características principales y cómo se organizan los datos recibidos desde las PMU conectadas en el sistema. También se trata el tema de la aplicabilidad que pueden tener estos dispositivos en los sistemas de potencia, el estado del arte y el futuro de los sistemas de monitoreo con PMU, donde se destacan la medición de frecuencia y magnitud de fasores, la estimación de estados, la predicción de inestabilidad, relés adaptativos, entre otras. [2] También, se hace alusión al software gratuito OpenPDC, en el cual se basa el desarrollo de la aplicación que se entrega como resultado en este trabajo, y los protocolos de comunicación que pueden ser usados con esta herramienta. Además se comenta cual es la función del OpenPDC en la herramienta y sus beneficios por ser un software de código libre. Teniendo en cuenta que el valor agregado de la aplicación desarrollada en este trabajo tiene que ver con las protecciones de las líneas de transmisión, se presenta un marco general de lo que son las protecciones de línea, como intervienen en la operación de los sistemas 12 eléctricos de potencia, tipos de protecciones y se profundiza en la protección distancia específicamente en la se conoce como “característica Mho”. Adicionalmente, el hecho de que este trabajo se dirija a crear una aplicación que necesariamente tendrá una interfaz de usuario, se hace una identificación de las más conocidas y usadas para el monitoreo de sistemas de potencia, como los Sistemas de Control, Supervisión y Adquisición de Datos (SCADA, por sus siglas en inglés) y se comenta acerca de su futuro. [3] Para finalizar, se presenta la descripción, composición, valor agregado y oportunidades de la aplicación desarrollada como producto de este informe y se presenta, como anexo, el artículo para publicar en una revista internacional que muestra la aplicación informática y la innovación en cuanto al uso de las PMU en sistemas eléctricos de potencia.Pregrad

Optimized Robust Adaptive Networks in Supervisory Control and Data Acquisition Systems

This thesis investigates the application of a Exponential Weighted Moving Average (EWMA) to be used as a memory buffer in conjunction with Special Protection Schemes (SPS) using the Electric Power and Communication Synchronizing Simulator (EPOCHS). It is proposed that using an SPS incorporating EWMA can compensate for the network layer lack of guarantee of packet delivery and provide for the stability and integrity of the power grid under a catastrophic event. The performance of the proposed SPS is evaluated using a discrete event computer simulation developed using the NS2 network simulator and the Power System Simulator for Engineering (PSS/E) power system simulator. Performance and metrics evaluated in terms of the SPS’s ability to properly calculate disturbance size and to react to the disturbance before the system reaches the minimum frequency threshold of 58.8 HZ and before 0.5 second threshold. Experimental results indicate that the proposed SPS with EWMA can be successfully be applied to ensure power grid stability regardless of network background traffic. The results indicate that the proposed EWMA SPS ensures the protection of the grid. The EWMA SPS has a significant impact on performance when applied to a heavy background traffic network without router reservation enabling it to be stable without the additional hardware cost. Overall, in the tested configuration, the new SPS system successfully maintained steady state operation under all traffic intensities

ARMAX-based transfer function model identification using wide-area measurement for adaptive and coordinated damping control

One of the main drawbacks of the existing oscillation damping controllers that are designed based on offline dynamic models is adaptivity to the power system operating condition. With the increasing availability of wide-area measurements and the rapid development of system identification techniques, it is possible to identify a measurement-based transfer function model online that can be used to tune the oscillation damping controller. Such a model could capture all dominant oscillation modes for adaptive and coordinated oscillation damping control. This paper describes a comprehensive approach to identify a low-order transfer function model of a power system using a multi-input multi-output (MIMO) autoregressive moving average exogenous (ARMAX) model. This methodology consists of five steps: 1) input selection; 2) output selection; 3) identification trigger; 4) model estimation; and 5) model validation. The proposed method is validated by using ambient data and ring-down data in the 16-machine 68-bus Northeast Power Coordinating Council system. The results demonstrate that the measurementbased model using MIMO ARMAX can capture all the dominant oscillation modes. Compared with the MIMO subspace state space model, the MIMO ARMAX model has equivalent accuracy but lower order and improved computational efficiency. The proposed model can be applied for adaptive and coordinated oscillation damping control