Application of phasor measurement units for monitoring power system dynamic performance

This Working Group is a sequel to a previous working group on Wide Area Monitoring and Control for Transmission Capability Enhancement, which published the Technical Brochure 330 in 2007. Since then the synchrophasor technology has advanced rapidly and many utilities around the world have installed hundreds of PMUs in their networks. In this Technical Brochure, we look at the current state of the technology and the extent to which it has been used in the industry. As the technology has matured, it is also important to understand the communication protocols used in synchrophasor networks and their relevant cyber-security issues. These concerns are briefly discussed in the brochure. The applications of Phasor Measurement Units (PMU) measurements reported here are divided into three categories: (a) applications already installed in utility networks, (b) applications that are well-tested, but not yet installed, and (c) applications that are beneficial to the industry, but not fully developed yet. The most common and mature applications are wide area monitoring, state estimation, and model validation. Out of these three applications, wide area monitoring is well established in the industry. The protection and control applications are emerging as evident from the reported examples. The experience of using remote synchrophasor measurements as feedback control signals is not widely reported by the industry. In parallel to this Working Group, Study Committee B5 had a Working Group on “Wide area protection and control technologies.” The Technical Brochure 664 published by this Working Group in September 2016 reviews synchrophasor technology and discusses the industry experience with wide area protection and control. The North American synchrophasor Initiative (NASPI) is another technical group that has gathered and reported a wide range of PMU experiences of industry and researchers. In summary, the field-tested applications presented in this Technical Brochure are a testimony to the confidence of utilities in the synchrophasor technology. The progress in state estimation techniques indicates that synchrophasor measurements will become a standard part of energy management and security assessment systems in the near future

Applications of Real-Time Simulation Technologies in Power and Energy Systems

Real-time (RT) simulation is a highly reliable simulation method that is mostly based on electromagnetic transient simulation of complex systems comprising many domains. It is increasingly used in power and energy systems for both academic research and industrial applications. Due to the evolution of the computing power of RT simulators in recent years, new classes of applications and expanded fields of practice could now be addressed with RT simulation. This increase in computation power implies that models can be built more accurately and the whole simulation system gets closer to reality. This Task Force paper summarizes various applications of digital RT simulation technologies in the design, analysis, and testing of power and energy systems

Relationship between personality traits and reaction to negative performance feedback

Pētījuma mērķis bija noteikt, kādas ir korelatīvas sakarības starp „Lielā piecinieka” faktoriem un trim reakcijas veidiem uz negatīvu atgriezenisko saiti par darba izpildi, lai noskaidrotu, kuras personības iezīmes būtu noteicošie kritēriji, veicot valodnieku atlasi. Datu ieguvei izmantotas divas anketas: „BFI” (Big Five Inventory), lai noteiktu 100 respondentiem raksturīgās personības iezīmes un anketa „Reakcija uz negatīvu atgriezenisko saiti par darba izpildi”. Iegūtie rezultāti norāda, ka pieņemot darbā jaunus tulkus un redaktorus, būtu ieteicams izvēlēties kandidātus, kuriem, papildus nepieciešamajām profesionālajām kompetencēm, būtu raksturīgi augstāki labvēlīguma rādītāji un zemāki ekstraversijas rādītāji.The objective of the study was to determine the correlative relationship between „Big Five” factors and three reaction types to negative performance feedback in order to find out which personality traits are the key criteria in the recruitment of linguists. Two questionnaires were used to obtain data for the research: „BFI” (Big Five Inventory) to determine the characteristic personality traits of 100 respondents and questionnaire „Reaction to negative performance feedback”. The results of the study suggest that during the recruitment of new translators and editors it would be advisable to select candidates who besides the required professional skills demonstrate higher ratings of Agreeableness and lower ratings of Extraversion

iTesla Power Systems Library (iPSL): A Modelica library for phasor time-domain simulations

The iTesla Power Systems Library (iPSL) is a Modelica package providing a set of power system components for phasor time-domain modeling and simulation. The Modelica language provides a systematic approach to develop models using a formal mathematical description, that uniquely specifies the physical behavior of a component or the entire system. Furthermore, the standardized specification of the Modelica language (Modelica Association [1]) enables unambiguous model exchange by allowing any Modelica-compliant tool to utilize the models for simulation and their analyses without the need of a specific model transformation tool. As the Modelica language is being developed with open specifications, any tool that implements these requirements can be utilized. This gives users the freedom of choosing an Integrated Development Environment (IDE) of their choice. Furthermore, any integration solver can be implemented within a Modelica tool to simulate Modelica models. Additionally, Modelica is an object-oriented language, enabling code factorization and model re-use to improve the readability of a library by structuring it with object-oriented hierarchy. The developed library is released under an open source license to enable a wider distribution and let the user customize it to their specific needs. This paper describes the iPSL and provides illustrative application examples. Keywords: Modelica, Power system, Simulatio

PMU-based Voltage Instability Detection through Linear Regression

Timely recognition of voltage instability is crucial to allow for effective control and protection interventions. Phasor measurements units (PMUs) can be utilized to provide high sampling rate time-synchronized voltage and current phasors suitable for wide-area voltage instability detection. However, PMU data contains unwanted measurement errors and noise, which may affect the results of applications using these measurements for voltage instability detection. The aim of this article is to revisit a sensitivities calculation to detect voltage instability by applying a method utilizing linear regression for preprocessing PMU data. The methodology is validated using both real-time hardware-in-the-loop simulation and real PMU measurements from Norwegian network.Comment: This paper has been withdrawn by the author due to a crucial sign error in equation

A Phasor-Data-Based State Estimator Incorporating Phase Bias Correction

With amplitude and phase information, time-synchronized measured phasor data of bus voltages and line currents can be used to calculate, without iterations, the voltage phasor on neighboring buses. In some phasor measurement units (PMUs), it has been observed that the voltage and current phasors exhibit phase biases, which can corrupt the conventional state estimator solution if it is augmented with such biased phasor data. This paper presents a new approach for synchronized phasor measurement-based state estimation, which can perform phasor angle bias correction given measurement redundancy. In this approach, polar coordinates are used as the state variables, because the magnitude and phase are largely independent measurements. The state estimation is formulated as an iterative least-squares problem, and its application to portions of the AEP high-voltage transmission system is illustrated.© 2011 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.QC 2012012

Vulnerability of synchrophasor-based WAMPAC applications' to time synchronization spoofing

This paper experimentally assesses the impact of time synchronization spoofing attacks (TSSA) on synchrophasor-based wide-area monitoring, protection and control (WAMPAC) applications. Phase angle monitoring, anti-islanding protection, and power oscillation damping applications are investigated. TSSA are created using a real-time (RT) IRIG-B signal generator and power system models are executed using an RT simulator with commercial phasor measurement units (PMUs) coupled to them as hardware-in-the-loop. Because PMUs utilize time synchronization signals to compute synchrophasors, an error in the PMUs' time input introduces a proportional phase error in the voltage or current phase measurements provided by the PMU. The experiments conclude that a phase angle monitoring application will show erroneous power transfers, whereas the anti-islanding protection mal-operates and the damping controller introduces negative damping in the system as a result of the time synchronization error incurred in the PMUs due to TSSA. The proposed test-bench and TSSA approach can be used to investigate the impact of TSSA on any WAMPAC application and to determine the time synchronization error threshold that can be tolerated by these WAMPAC applications