Application of improved on-line monitoring method using PMU data in recent European blackout

The objective of the project discussed in this paper is to introduce and implement Phasor Measurement Units (PMUs) in Jordanian National Grid to establish Wide Area Monitoring System (WAMS) and increase situational awareness for real-time operations. The project focused on the southern zone of National grid, where PMUs were deployed at Aqaba and Qatrana substations. The PMUs were installed and commissioned at both locations, providing real-time voltage and current phasors from 400 KV and 132 KV circuits through the available PTs and CTs at the stations. The PMUs were tested and synchronized with Global Position System (GPS). Data is then transmitted from substation PMUs to the enhanced Phasor Data Concentrator (ePDC) which acts as the central PDC at NEPCO control Center. ePDC collect the real-time measurements from PMUs, time-align the measurements, and then stream the PMU data to the Wide Area Monitoring System Located at the NEPCO control center over pre-existing communication system. The paper also presented a post-fault analysis for a selected event using PMU s.

The modern power systems are becoming increasingly complex due to the large-scale interconnections, the integration of renewable energy sources, and the dynamic changes in loads, which require the sophisticated monitoring and control systems. Phasor Measurement Units (PMUs) have led to the creation of Wide-Area Monitoring, Protection, and Control (WAMPAC) systems, capable of transforming the grid, boosting its reliability, stability, and operational efficiency. PMUs are also used to offer time-synchronized measurements (synchro phasors) that can offer real-time insight into the dynamics of a system, which was not possible with traditional SCADA systems. This paper provides an extensive overview of the PMU technology and its application in Wide-Area Monitoring Systems (WAMS), their structure, essential elements, and communication structure. It also discusses key applications like real-time monitoring, state estimation, oscillation detection, fault location, voltage stability assessment, and wide-area control. The study also addresses some of the critical challenges, such as high implementation costs, data management complexities, cybersecurity threats, and communication latency, as well as interoperability issues. Further recent developments, including the combination of PMUs with smart grids, artificial intelligence, cloud computing, and Wide-Area Control Systems (WACS) are discussed, as well as future research directions, including optimization of costs, improved security, and autonomous operation of grids. In general, PMU-based WAMS is found as a foundational technology in terms of designing intelligent, resilient, and sustainable power system.

A comprehensive review of wide-area protection, control and monitoring systems.- Introduction to WAMS and Its Applications for Future Power System.- Information and communication infrastructures in modern wide-area systems.- Wide-Area Monitoring Systems and Phasor Measurement Units.- Optimal selection of Phasor Measurement Units.- Coordinated designs of fuzzy PSSs and load frequency control for damping power system oscillations considering wind power penetration.- Wide-area monitoring of electromechanical oscillations on large interconnected power systems based on simultaneous processing spatio-temporal data.- Electromechanical mode estimation in power system using a novel nonstationary approach.- Small Signal Stability Improvement of Pumped Storage Hydropower using Wide Area Signal Considering Wind Farm.- Impact Analysis and Robust Coordinated Control of low frequency oscillations in wind integrated power system.- Frequency Stability of Two-Area Interconnected Power System with Doubly Fed Induction Generator Based Wind Turbine.- Wide-Area Measurement-Based Voltage Stability Assessment by Coupled Single-Port Models.- Adaptive WAMS-Based Secondary Voltage Control.- Applications of Decision Tree and Random Forest Methods for Real-Time Voltage Stability Assessment Using Wide Area Measurements.- Superseding Mal-operation of Distance Relay Under Stressed System Conditions.- Real-time voltage stability monitoring using machine learning-based PMU measurements.- Wide Area Transmission System Fault Analysis Based on Three-phase State Estimation with Considering Measurement and Parameter Errors.- Data-driven Wide-Area Situation Analyzer for power system event detection and severity assessment.- Techno-economic analysis of WAMS based islanding detection algorithm for microgrids with minimal PMU in smart grid environment.- Independent Estimation of Generator Clustering and Islanding Conditions in Power System with Microgrid and Inverter-based Generation.- Resilience in Wide Area Monitoring Systems for the Smart Grid.- Cyber Kill Chain-based Intrusion Detection Systems for Cyber-Physical Security in Smart Grid.

Optimal phasor measurement unit placement for power system observability using teaching–learning based optimization

The electrical power system is becoming more and more complex with the increasing demand of the electricity across the world, as the world is becoming the global village. The electrical power system must be reliable and safe enough to fulfil the energy requirements with the continuous supply of energy. The chances of power system's blackouts and outages are increasing with its increased complexity. So, there is a need of an efficient control system to make the power system more safe, efficient and reliable. Wide Area Monitoring, Protection and Control system (WAMPAC) is becoming an emerging technology for an efficient monitoring, protection and control of power system. Phasor measurement unit (PMU) is an integrated part of wide area monitoring, protection and control (WAMPAC) system, which can be used for monitoring, protection and control of complex electrical power systems. PMU gives the synchronized phasor measurements of voltage and current and can easily monitor and control even small disturbances in power system to protect the power system from any blackouts and outages before any fault occurs. In the proposed paper a PMU model is designed in MATLAB/Simulink and then PMU is used for power system protection and the comparative analysis are done with the conventional protection technique for an interconnected two-area network power system.

The Wide Area Monitoring System (WAMS) is an effective monitoring system that must be used in the electricity system due to the ever-increasing issues it faces. Considering that Phasor Measurement Units (PMUs) can deliver synchronized Phasor Measurement Units of voltages and currents in real-time at widely various locations is important. This paper studies the optimal allocation of PMUs in order to achieve a fully operable system utilizing Discrete Water Cycle Optimization (DWCO) with minimal number of PMUs and initial investment. In radial power systems the PMUs allocation can be applied directly. On the other hand, PMUs allocation on power system mesh, loop network needs some prearrangement before starting the process. One of the mythologies, which can be used in preparing the system is the tree search method using shortest path. The PMUs optimal allocation takes place utilizing two different methodologies which are tree search method with shortest path and discrete water cycle algorithm. These algorithms were tested on IEEE-14 and IEEE-30. As the PMUs number is reduced, the data capacity will be reduced. The models’ results are satisfied specially for Water Cycle Optimization.

The electric grids are complex, large and highly interconnected with numerous generation power stations delivering power to major load centers. This has led to increasing need for real-time monitoring of grids. Wide area monitoring systems (WAMS) equipped with new era information and communication technology provides real-time situational awareness through synchrophasor technology. WAMS allow monitoring the grid and transmission system conditions over large areas. The phasor measurement units (PMU) are integral to WAMS, as they provide synchrophasors of analogue quantities from different locations of the grid. This paper proposes a modeling technique of PMU using Petri nets (PNs) for reliability assessment. The PN based reliability model captures dynamic behaviour as well as minute functional details of PMU and its modules. Additionally, the model provides information regarding normal, alert and emergency situations of the PMU modules. The reliability indices are obtained using PN-Markov approach, which are found complying with the existing m ethods.

In recent years, with the rapid development of Wide Area Monitoring System (WAMS) and Wide Area Monitoring Analysis Protection-control (WAMAP) in China, more and more synchronized Phasor Measurement Units (PMU) have been put into services. So far nearly all the regional power systems have established systems to meet the requirement of sharing PMU synchrophasors among multiple parties. As PMU plays a significant role in the power system, selecting the models with excellent performance is of great importance. Therefore, PMU testing and evaluation have become a concerned subject by many professionals. A testing and evaluation (T&E) architecture should be built to do the integrated evaluation, including testing platform, testing method and result evaluation. This paper also put forward specific testing method and procedure for PMU, which are comprised of static performance testing and dynamic performance testing. Three testing sub-platforms will be introduced in this paper: the environment adaptability testing platform, Electromagnetic Compatibility (EMC) testing platform and performance testing platform. What's more, the evaluation method for PMU is described in detail in this paper, and examples of PMU device tested on these platforms is described in the paper.

Synchrophasor systems are being added to modern power systems to facilitate improved wide area monitoring and wide area protection schemes. As synchrophasor systems are installed utilities must decide if new cyber devices, phasor measurement units and phasor data concentrators, will be declared as The US National Electric Reliability Council (NERC) Critical Infrastructure Protection (CIP) cyber critical assets. This paper explores the potential impact of reconnaissance attacks, packet injection attacks, and denial of service attacks on wide area monitoring systems and wide area protection systems. This paper was written to accompany a panel presentation and discussion and was not intended to provide new research results.

In recent years, wide area monitoring systems’ (WAMS) communication infrastructure plays a crucial role in the transformation to smart grid for real-time delivery of data with low latency. The advancement of WAMS has to be meticulously designed by optimizing the power systems and communication infrastructure. The performance of the communication infrastructure relies on the optimal placement of phasor measurement units (PMUs) in the power system. In the modified IEEE 14 bus system the optimal PMU placement and its backbone communication network has been designed and analyzed. With optimum number of PMUs for complete observability and minimal distance between PMUs and control centers effective monitoring is achieved for the stable operation of the grid. The minimal path between the PMUs to the control centers were obtained by Dijkstra algorithm. Finally using opnet the communication network has been analyzed using different routing protocols. The simulation results are analyzed and it shows that Multiprotocol Label Switching (MPLS) based PMU data transfer provides better performance.

Wide Area Monitoring System (WAMS) with Phasor Measurement Unit (PMU) has the capability to do real time monitoring including fast system condition changes. On the other hand, Supervisory Control and Data Acquisition (SCADA), which is vulnerable to that condition, are still widely used in wide world power system because of its capability and maturity. This paper proposes the framework in transforming SCADA into WAMS by installing required additional PMU while keeping the conventional measurement from SCADA. Moreover, the real time state estimation procedure in managing the initial state variable and weighting factor re-weight strategy is also proposed. The result shows that the proposed WAMS hybrid warrants better estimation accuracy and faster state estimation process than SCADA. In addition, the voltage stability monitoring as WAMS application can also successfully be obtained.

Phasor measurement unit (PMU) is a modern device that could be used as both protection and wide area monitoring in a power system. Throughout the wide area monitoring system (WAMS), all the synchronized data acquired by the PMUs in multiple locations were analyzed by phasor data concentrators (PDC). This control support system could determine a suitable protective control and a preventive correction in the case of a contingency plan based on PMUs measurement data. Subsequently, the allocation of PMUs is important due to constraints such as the cost of PMUs itself. Therefore, the objective of most research in this area is to determine the optimal PMUs placement (OPP) that can achieve full observability of the power system with minimal number of PMUs. In this paper, using particle swarm optimization (PSO) algorithm, the effect of PSO parameters is investigated. A binary concept of PSO is used to determine PMUs optimal location for IEEE 30-bus system. The tests were divided into five cases and the simulation results show the importance of parameters used for PSO algorithm. In the tests, the use of linear decreasing inertia weight or constriction factor can prevent the particles from being trapped in local optima.

In recent days electrical power system experiencing a rapid change thereby inclusion of advanced equipment and expansion of transmission/distribution network. Besides the modernisation of existing power system network, a number of renewable energy sources such as wind parks and solar parks etc., have been integrated to balance growing power demand due to the industrialization and digitalization. However, a secure and dependable operation of power system network is not so easy because of its complex nature in terms of control, operation and maintenance of various components in wide-area network. Inspite of gigantic developments in power system operations, components and protection technologies, today’s power systems are more susceptible to blackouts than ever before. In this context some of the recorded major blackout incidents have been classified according to the time and location as of research reference purpose. As per the survey the frequency of occurrence of blackouts is increased over time. Practically, it is not possible to avoid blackouts completely; though, various research studies and number of research articles were acknowledged that by taking some rationally gainful measures, incidence of the blackouts could be abated and/or their effects could be mitigated. The forthright approach is to minimize the peril of unplanned disturbances thereby extenuating opportune paradigms to the extent that possible, the root causes of the disturbances through analyses and audits followed by initiating various preventive and corrective actions. In view of the preventive and corrective actions to avoid wide-area disturbances, a new paradigm has been embraced with Wide-Area Protection, Control and Monitoring (WAPCAM) system. With the rapidly growing capabilities in advanced computer and communication technologies such as Intelligent Electronic Devices (IEDs) enabled Remote Terminal Units (RTUs), Global Positioning System (GPS) enabled Phasor Measurement Units (PMUs); opportunities are now being available to adopt the Wide-Area Protection, Control and Monitoring (WAPCAM) system. Such systems receive wide-range of data or information e.g. system-wide bus voltages, angles, active and reactive power flows, etc., and by analysing them, can estimate whether the system is at stressed condition or not. By taking coordinated actions, the power system network can be saved from proceeding to total collapse, or even, mitigate the wide-area disturbance effects upon the system. WAPCAM system has different level of hierarchies in realization of preventive and corrective actions such as local feeder level, sub-station level and central/regional level. One of the recommended preventive plans against the wide-area disturbances and the blackouts is Wide-Area Protection and Control (WAPC) system that includes Special Protection Schemes (SPS) (or) System Integrated Protection Schemes (SIPS) (or) Remedial Action Schemes (RAS) based on an advanced communication infrastructure etc. To mitigate the impact of wide-area disturbances, the remedial/corrective actions have been initiated by implementing Wide-Area Stability and Control (WASC) system that embraces power system stabilizers (PSS) and ON-Load Tap Changers (OLTC) and Wide-Area Monitoring and Control (WAMC) system. It also includes out-of-step (OSS) bus splitting and optimal islanding schemes etc. Although; the power system exhibits unstable dynamic phenomena at stressed conditions such as Transient Angle Instability, Voltage Instability and Frequency Instability, the WAPCAM has to bring back the power system to normal restorative condition as soon as possible. This chapter enlightens a comprehensive research review and explicates different type of WAPCAM systems that can address the major blackouts to improve stability, reliability and security of power system networks. A comparative assessment has been explicated by summarizing various recently reported conventional and intelligent schemes. It also enlightens the research insights to power system researchers and protection engineers while planning and designing of stable, reliable and secured power system networks.

In India Power system monitoring is based mainly on measurements provided by Remote Terminal Unit (RTU). For power system measurement synchronized phasor or Phasor Measurement Unit (PMU) is popular choice in abroad and its popularity is increasing day by day because of its several feature. Synchrophasor technology was first introduced in india in 2011-12[7],[8],[9]. Direct measurement of voltage or current phasor is possible because of PMU which was not possible earlier. Global positioning system (GPS) provides time synchronized data. In this paper a new approach is used for optimal placement of PMU, counting their number & time elapsed. The approach is applied on IEEE-14 bus system bus system .Here all the bus which are taken into consideration is either completely observable or at some depth of un-observability is also taken into account. Index Terms— PMU, Observability, Phasor, IEEE-14 Bus system

National Grid, the Transmission System Operator for Great Britain, has recently installed a Wide Area Monitoring System (WAMS), to improve the real-time view of the power system. Phasor Measurement Units (PMUs) have been installed, primarily through upgrades to digital fault recorders, as an extension to dynamic system monitoring. This paper reviews the development of WAMS on the GB System and presents the experiences so far, detailing both existing and future applications of synchrophasor technology, such as oscillation analysis, model validation and improved situational awareness.