Change search
Refine search result
12345 101 - 150 of 201
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 101. Milano, F.
    et al.
    Vanfretti, L.
    Morataya, J. C.
    An Open Source Power System Virtual Laboratory: The PSAT Case and Experience2008In: IEEE Transactions on Education, ISSN 0018-9359, E-ISSN 1557-9638, Vol. 51, no 1, p. 17-23Article in journal (Refereed)
    Abstract [en]

    This paper describes the authors’ experience in the assessment of laboratory activities based on an open source software package for power system analysis, namely, Power System Analysis Toolbox (PSAT). PSAT is currently used in several universities for both undergraduate and graduate courses. PSAT has also its own Web forum, which provides support to students and researchers all around the world, thus resulting in an almost unique example of ldquovirtual laboratoryrdquo over the Internet. This paper attempts to answer through a variety of real-life examples the following open questions: What are the practical and pedagogical advantages of using an open source software with respect to proprietary software for power system analysis? What happens if a power system virtual laboratory is freely available on the Web? What is the difference between a class-based and a Web-based virtual laboratory?

  • 102. Milano, F.
    et al.
    Vanfretti, Luigi
    State of the art and future of OSS for power systems2009In: 2009 IEEE POWER & ENERGY SOCIETY GENERAL MEETING, VOLS 1-8, IEEE , 2009, p. 4859-4865Conference paper (Refereed)
    Abstract [en]

    This paper presents the main concepts of Free and Open Source Software (FOSS) that are relevant for power system analysis, research and education. The main FOSS projects for power system analysis are briefly introduced and discussed. The paper also provides some outlines about the future of FOSS for power systems and the activities of the IEEE Task force on Open Source Software.

  • 103.
    Milano, Federico
    et al.
    University College Dublin.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Role of non-commerical software in undergraduate electric energy systems programmes2015In: Edulearn15: 7th International Conference on Education and New Learning Technologies, IATED-INT ASSOC TECHNOLOGY EDUCATION A& DEVELOPMENT, , 2015, p. 318-328Conference paper (Refereed)
    Abstract [en]

    This paper describes the potential and challenges of open-source non-commercial software tools for undergraduate electric energy systems programmes, and their impact on student’s potential work opportunities. This paper also describes how different academic traditions have an impact on the choice of educational software, and how that has repercussions on the students' learning and the learning outcomes of programme modules. The matter presented in the paper is based on the authors' experience as both developers of open-source software tools, as PhD students and lecturers with several universities.

  • 104.
    Nordström, Lars
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Chenine, Moustafa
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Zhu, Kun
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Information and communication system architectures for wide-area monitoring and control applications2011Conference paper (Refereed)
    Abstract [en]

    This paper presents a review of work performed in the field of communication systems requirements for wide area monitoring and control applications. This includes studies performed both in the context of NASPI, the North American Syncrophasor Initiative, as well as other studies in the US and Europe. Presently a relatively large body of work has been done regarding the requirements on the communication infrastructure. Among the work included, are surveys among Transmission System Operators on the foreseen communication requirements, as well as other theoretical studies on acceptable delays and other performance characteristics, such as data loss, that Wide Area Control applications put on the Information and Communication System. Much of the above referenced work still needs verification either though experimental work or through simulations. It is especially important to simulate large scale communication infrastructures that consider background traffic under different operational conditions in the power system, such as under disturbances. The paper is concluded with some remarks on future direction of work within the field.

  • 105. Parniani, Mostafa
    et al.
    Chow, Joe H.
    Vanfretti, Luigi
    Department of Electrical, Computer, and Systems Engineering, RPI, NY Troy.
    Bhargava, Bharat
    Salazar, Armando
    Voltage Stability Analysis of a Multiple-Infeed Load Center Using Phasor Measurement Data2006In: Power Systems Conference and Exposition, 2006. PSCE ’06. 2006 IEEE PES, IEEE , 2006, p. 1299-1305Conference paper (Refereed)
    Abstract [en]

    Voltage stability is a security concern for modern power systems. It can be analyzed using detailed or equivalent models. In this paper a new approach is presented for voltage stability analysis using synchronized phasor measurement data. Simple equivalent models of the interconnected system and load side at a measurement point are estimated from the data, and then used for calculating PV curves and predicting the stability limit. Two different models are proposed, and compared based on the analyses performed on the event recordings from US western power system. Minimal modeling and formulation makes the method suitable for online calculations. The models are continuously updated to reflect the effects of different system components and changes

  • 106.
    Peric, Vedran
    et al.
    KTH, School of Electrical Engineering (EES).
    Bombois, Xavier
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Optimal Signal Selection for Power System Ambient Mode Estimation Using a Prediction Error Criterion2016In: 2016 IEEE POWER AND ENERGY SOCIETY GENERAL MEETING (PESGM), IEEE , 2016Conference paper (Refereed)
  • 107.
    Peric, Vedran S.
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Baudette, Maxime
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Gjerde, J. O.
    Løvlund, S.
    Implementation and testing of a real-time mode estimation algorithm using ambient PMU data2014In: 2014 Clemson University Power Systems Conference, PSC 2014, IEEE Computer Society, 2014, p. 6808116-Conference paper (Refereed)
    Abstract [en]

    This paper presents a software implementation of a real-time power system mode estimator application which uses ambient synchrophasor data. The software is built using Statnett's Synchrophasor Software Development Kit (SDK) as a platform for fast prototyping of real-time synchrophasor applications. The SDK extracts synchrophasor data received in the IEEE C.37.118 protocol and provides them as LabVIEW signals. These signals are preprocessed and mode frequencies and damping ratios are calculated by Yule-Walker's method. The implemented LabVIEW software employs state machine logics which enables modifications and upgrades to the algorithm.

  • 108.
    Peric, Vedran S.
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Power-System Ambient-Mode Estimation Considering Spectral Load Properties2014In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 29, no 3, p. 1133-1143Article in journal (Refereed)
    Abstract [en]

    Existing mode meter algorithms were derived with the assumption that load variations are accurately represented by white noise or an integral of white noise, which may not be satisfied in actual power systems. This paper proposes a mode meter algorithm which relaxes this assumption by explicitly taking into account spectral load characteristics. These characteristics can be either measured or estimated using the inverse of the existing power system model. The method is developed assuming an autoregressive moving average (ARMA) model of the system and incorporating estimated correlations between loads as inputs and synchrophasor measurements as outputs. Performances of the proposed method are compared with the Yule-Walker and N4SID methods using simulated synchrophasor data obtained from the KTH Nordic 32 test system. Finally, the effects of measurement noise on the proposed method are analyzed, as well as the effects of model uncertainty when the power system model is used to determine spectral load characteristics. It is shown that the proposed algorithm increases accuracy in mode estimates when the loads are described with nonwhite noise.

  • 109.
    Perić, Vedran S.
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Bogodorova, Tetiana
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Mete, A. N.
    Vanfretti, Luigi
    Statnett SF, Norway.
    Model order selection for probing-based power system mode estimation2015In: 2015 IEEE Power and Energy Conference at Illinois, PECI 2015, 2015Conference paper (Refereed)
    Abstract [en]

    The paper discusses model order selection for probing mode estimation algorithms. Four methods are analyzed and compared: 1) Residual analysis based model order selection, 2) Model order selection based on singular values, 3) Akaike Information Criterion, and 4) Variance-Accounted-For (VAF) as a measure of optimal fitting between measured data and model response. The methods are assessed using synthetic PMU measurements from the simulation of the KTH Nordic 32 Test system and the IEEE test system with 50 generators and 145 buses.

  • 110. Perninge, M.
    et al.
    Lavenius, Jan
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Approximating a post-contingency stable operation region in parameter space through time-domain simulation2013In: Proceedings of IREP Symposium: Bulk Power System Dynamics and Control - IX Optimization, Security and Control of the Emerging Power Grid, IREP 2013, IEEE , 2013Conference paper (Refereed)
    Abstract [en]

    Operating criteria for power systems, such as the (N - 1)-criterion, are often based on evaluating whether the system is vulnerable to a specific set of contingencies. Therefore, a major part of power system security is concerned with establishing regions in parameter space where the system is vulnerable to specific contingencies. In this article we exploit the possibility of using Monte Carlo simulations to build an approximation of the region, in parameter space, where the power system will remain stable following a given contingency.

  • 111.
    Rabuzin, Tin
    et al.
    KTH.
    Baudette, Maxime
    KTH.
    Vanfretti, Luigi
    Implementation of a Continuous Integration Workflow for a Power System Modelica Library2017In: 2017 IEEE POWER & ENERGY SOCIETY GENERAL MEETING, IEEE , 2017Conference paper (Refereed)
    Abstract [en]

    Traditional simulation tools for power system studies are, in general, shipped with built-in and closed model libraries. Typically, the models' implementation is not thoroughly documented, preventing the user to gain a full understanding of their implemented behavior. Previous efforts from the authors have focused on the development of an open source software library of power system components developed using Modelica: the Open-Instance Power System Library (OpenIPSL), which provides models that can easily be accessed and studied by the user. Recent developments have focused on the implementation of a software architecture facilitating collaborative developments on OpenIPSL. Employing the latest technologies available in the software development community, this paper details the implementation of a continuous integration workflow, providing automated testing and behavior verification of the library's models. This platform seeks to increase the library's stability and to provide more reliable models developed collaboratively by multiple individuals. Moreover, this software architecture only utilizes open source software, which can be hilly tailored to the specific needs of users and other library developers.

  • 112.
    Rebello, Eldrich
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Almas, Muhammad Shoaib
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Statnett, Norway.
    An Experimental Setup for Testing Synchrophasor-based Damping Control Systems2015In: Environment and Electrical Engineering (EEEIC), 2015 IEEE 15th International Conference on, IEEE conference proceedings, 2015, p. 1945-1950Conference paper (Refereed)
    Abstract [en]

    Prototype Wide-Area Power system OscillationDamping (WAPOD) controllers using synchrophasor data havebeen proposed, developed and tested in field demonstrationprojects. However, the development and testing process of thesecontrol systems has been confined to a few specific cases, thedetails of which have not been thoroughly reported in availableliterature. This paper details the development, construction andimplementation of a real-time, Hardware-in-the-loop (HIL) testset-up for such a control system. A general purpose, phasorbasedcontrol algorithm is deployed on a Compact ReconfigurableInput/Output (cRIO) controller from National Instruments. Thecomplete, closed-loop experimental set-up, the hardware used andthe rationale behind different design choices are also documented.As this test-set-up uses IEEE C37.118 data over a TCP/IPnetwork, the complete, real-time data path is examined. A realtimeHIL test with the implemented controller is also presentedand results are analysed.

  • 113.
    Rebello, Eldrich
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Statnett.
    Almas, Muhammad Shoaib
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    PMU-based Real-Time Damping Control System Software and Hardware Architecture Synthesis and Evaluation2015Conference paper (Refereed)
    Abstract [en]

    Low-frequency, electromechanically induced, interareaoscillations are of concern in the continued stability of interconnectedpower systems. Wide Area Monitoring, Protection andControl (WAMPAC) systems based on wide-area measurementssuch as synchrophasor (C37.118) data can be exploited to addressthe inter-area oscillation problem. This work develops a hardwareprototype of a synchrophasor-based oscillation damping controlsystem. A Compact Reconfigurable Input Output (cRIO) controllerfrom National Instruments is used to implement the realtimeprototype. This paper presents the design process followedfor the development of the software architecture. The designmethod followed a three step process of design proposal, designrefinement and finally attempted implementation. The goals ofthe design, the challenges faced and the refinements necessaryare presented. The design implemented is tested and validatedon OPAL-RT’s eMEGASIM real-time simulation platform and abrief discussion of the experimental results is included.

  • 114.
    Rebello, Eldrich
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Statnett.
    Almas, Muhammad Shoaib
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Software Architecture Development and Implementation of a Synchrophasor-based Real-Time Oscillation Damping Control System2015In: PowerTech, 2015 IEEE Eindhoven, IEEE conference proceedings, 2015, p. 1-6Conference paper (Refereed)
    Abstract [en]

    Low-frequency, electro-mechanically induced, interareaoscillations have in the past, posed a serious threat to thestability of interconnected power systems.Wide Area Monitoring,Protection and Control (WAMPAC) systems based on wideareameasurements such as synchrophasor (C37.118) data canbe exploited to address the inter-area oscillation problem. Thiswork develops a modular software architecture for a prototypeWAMPAC control system. A Compact Reconfigurable InputOutput (cRIO) controller from National Instruments is usedto implement the real-time prototype. This paper presents thedesign process followed for the development of the softwarearchitecture. The design method followed a three step processof design proposal, refinement and attempted implementation.Results from each iteration are used to improve the next. Thegoals of the design, the challenges faced and the refinementsnecessary are presented. The details of the final implementationin LabVIEW are also documented.

  • 115.
    Rogersten, Robert
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Statnett SF, R and D, Oslo, Norway.
    Li, Wei
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Towards Consistent Model Exchange and Simulation of VSC-HVdc Controls for EMT Studies2015In: 2015 IEEE POWER & ENERGY SOCIETY GENERAL MEETING, IEEE , 2015Conference paper (Refereed)
    Abstract [en]

    Design of voltage source converters (VSC) for high-voltage direct current (HVdc) systems requires extensive simulation tools that are accurate and reliable. Before the installation of VSC-HVdc links, different simulation-based studies need to be performed by different parties and using different electromagnetic transient (EMT) simulation platforms. Previous work shows that even with a pedantic re-implementation of the models from the ground up, simulation results are still inconsistent between different EMT tools. This paper demonstrates a methodology, which provides a higher consistency between the simulation tools Simulink and PSCAD. This methodology is complex and exposes several limitations. Hence, the is a need for the adoption of a standardized equation-based modeling language for EMT model exchange.

  • 116.
    Rogersten, Robert
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Li, Wei
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Zhang, Lidong
    ABB, Sweden.
    Mitra, Pinaki
    ABB, Sweden.
    A Quantitative Method for the Assessment of VSC-HVdc Controller Simulations in EMT Tools2014In: Innovative Smart Grid Technologies Conference Europe (ISGT-Europe), 2014 IEEE PES, IEEE conference proceedings, 2014, p. 1-5Conference paper (Refereed)
    Abstract [en]

    Voltage-Source Converter-Based High-voltage dc (VSC-HVdc) technology has received growing interest during recent years due to its benefits for separated active and reactive power control. Before the installation of VSC-HVdc links, different simulation-based studies need to be performed, usually by different parties and using different electromagnetic transient (EMT) simulation platforms. This paper provides a systematic method to assess discrepancies between simulation tools. Models of the VSC and its control systems are implemented from scratch in two different tools. A metric and a methodology to quantitatively assess the discrepancies between simulation results is proposed and illustrated. The paper shows that even with a pedantic re-implementation of the models from the ground up, simulation results are still inconsistent. The objective of this paper is to develop a quantification method for comparing the models developed in different EMT simulation tool and to emphasize differences that can arise with the numerical solvers in such tools.

  • 117.
    Segundo Sevilla, Felix Rafael
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    A Small-Signal Stability Index for Power System Dynamic Impact Assessment using Time-domain Simulations2014In: 2014 IEEE PES General Meeting - Conference & Exposition, IEEE Computer Society, 2014, Vol. 2014-October, article id 6938842Conference paper (Refereed)
    Abstract [en]

    In this paper, a three layer small-signal stability index to assess power system dynamic simulations is presented. The index is calculated from an estimate of the eigenvalues of the system, which are determined using time-series from dynamic simulations. The methodology assumes that no other information about the system (model) is available. In the first layer, which is the main future of the index, a scalar (positive or negative) indicates if any of the modes have a damping ratio less than a pre-defined value. In the second layer, a vector is used to specify which pre-defined damping ratios were violated and finally, in the third layer a matrix is used to retrieve precise information about which mode has violated the pre-defined damping requirements of the system. The proposed index is first illustrated using synthetic data and then the index is validated using simulation data from the KTH-Nordic32 system.

  • 118.
    Sevilla, Félix Rafael Segundo
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Static stability indexes for classification of power system time-domain simulations2015In: 2015 IEEE Power and Energy Society Innovative Smart Grid Technologies Conference, ISGT 2015, IEEE conference proceedings, 2015Conference paper (Refereed)
    Abstract [en]

    Two new static indexes that use time series from power system dynamic simulations are presented on this paper. The proposed indexes are used to check whether the time series from dynamic simulations will converge to a safe and stable equilibrium point and to measure the quality of the stability. They can also be used to classify simulations according to the severity of the contingency applied. The Integral Square Generator Angle (ISGA) index is used as a dynamic index to assess the validity of the proposed indexes and their use for classification of timedomain simulations. An illustrative example using the Klein-Rogers-Kundur's two-area system is presented and then the static indexes are validated trough several nonlinear simulations using the KTH-Nordic32 system.

  • 119.
    Singh, Narender
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Hooshyar, Hossein
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems. KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Feeder dynamic rating application for active distribution network using synchrophasors2017In: Sustainable Energy, Grids and Networks, ISSN 0284-4354, E-ISSN 2352-4677, Vol. 10, p. 35-45Article in journal (Refereed)
  • 120.
    Singh, Ravi Shankar
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Baudette, Maxime
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Hooshyar, Hossein
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems. Statnett.
    Almas, Muhammad Shoaib
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Løvlund, Stig
    Statnett.
    ‘In Silico’ Testing of a Decentralized PMUData-Based Power Systems Mode Estimator2016In: Power and Energy Society General Meeting (PESGM), 2016, IEEE conference proceedings, 2016Conference paper (Refereed)
    Abstract [en]

    This paper presents the software implementation ofa Phasor Measurement Unit (PMU) data-based mode estimationapplication in a decentralized mode estimation architecture. Thiswork builds from previous efforts in the development of a modeestimator implemented using a centralized architecture, meaninga set of modes were estimated for the whole system in a singleprocessing location. One drawback of mode estimators that usecentralized mode architecture is that the observability and thereforeestimation of important low-damped local electromechanicalmodes can be affected by the higher observability of otherdominant modes of the systems (e.g inter-area modes). This workproposes, implements and tests a decentralized architecture inorder to increase the observation capability to provide betterestimates of local low damped oscillations. In this architecture,the data from a single PMU or a group of local PMUs couldbe processed by a processor to estimate the modal parametersobserved at a specific part of the grid or observed by specificgroup of PMUs. The decentralized architecture and results oftests are presented in this paper together with comparison witha centralized architecture.

  • 121. Singh, Ravi Shankar
    et al.
    Hooshyar, Hossein
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Statnett SF, Norway.
    Assessment of Time Synchronization Requirements for Phasor Measurement Units2015Conference paper (Refereed)
    Abstract [en]

    This paper assesses time synchronization sources suitable for Phasor Measurement Unit (PMU) applications in power systems. The paper investigates PMU phase error due to PMU timing inaccuracy and the presence of current and voltage transformers. This paper also shows that in practical on-field applications of commercial PMUs, the required accuracy of the time source should be better than the 31.8μs limit mentioned in the IEEE Standard for Synchrophasor Measurements for Power Systems C37.118.1-2011 and could be well in the sub-microsecond range. The laboratory test set-up is discussed in brief.

  • 122.
    Singh, Ravi Shankar
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Hooshyar, Hossein
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Experimental real-time testing of a decentralized PMU data-based power systems mode estimator2017Conference paper (Refereed)
    Abstract [en]

    This paper presents the results and testing of a Phasor Measurement Unit (PMU) data-based mode estimation application deployed within a decentralized architecture using a real-time test platform. This work is a continuation of that in [1], which described a decentralized mode estimation architecture that enables the application to better detect local modes whose observability is affected by other more observable modes. The tests in this paper were carried out using an active distribution network (ADN) comprised of a high voltage network connected to a distribution grid including renewable energy resources (RES). The developed application was run in a decentralized architecture where each PMU was associated with its own processing unit which was running the application to estimate modes from the time-series data. The results of the decentralized mode estimation architecture are analyzed and compared with its centralized counterpart.

  • 123. Singh, Ravi Shankar
    et al.
    Hooshyar, Hossein
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Statnett SF, Norway.
    Laboratory Test Set-up for the Assessment of PMU Time Synchronization Requirements2015Conference paper (Refereed)
    Abstract [en]

    This paper presents the construction of a Hardware-in-the-loop laboratory test set-up designed to assess the time synchronization requirements of Phasor Measurement Units (PMUs). The test set-up also allows to investigate the effects of signal phase shifts caused by current and voltage transformers, errors in timing source and the impact of these errors when determining time synchronization compliance of PMUs. The paper also describes the structure of an IRIG-B time-sync real-time implementation, which allowed real-time hardware-in-the-loop simulation by providing a PMU with a high-accuracy timing source.

  • 124. Singh, Ravi Shankar
    et al.
    Hooshyar, Hossein
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Testing and analysis of centralized and decentralized mode estimation architectures for active distribution network monitoring2017In: 2017 IEEE Manchester PowerTech, Powertech 2017, IEEE conference proceedings, 2017, article id 7981163Conference paper (Refereed)
    Abstract [en]

    This paper presents the results of testing a Phasor Measurement Unit (PMU) data-based mode estimation application deployed within a decentralized architecture using a realtime test platform. By extending the author's previous work in [1], this paper shows that a decentralized architecture is effective in detecting local modes which are less observable in presence of other dominant modes when estimated in a centralized architecture. The tests in this paper were carried out that was coupled with actual PMUs, a Phasor Data Concentrator (PDC) and two types of mode estimation architectures. The is network comprised of a high voltage network connected to an Active Distribution Network (ADN) with Renewable Energy Resources (RES). In the decentralized architecture where each PMU was associated with its own processing unit running to compute mode estimates from the acquired time-series data. The results of the decentralized mode estimation architecture are analyzed and compared with centralized architecture.

  • 125.
    Sturk, Christopher
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Statnett SF, Res & Dev, Oslo, Norway.
    Chompoobutrgool, Yuwa
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Sandberg, Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Coherency-Independent Structured Model Reduction of Power Systems2015In: 2015 IEEE POWER & ENERGY SOCIETY GENERAL MEETING, IEEE , 2015Conference paper (Refereed)
  • 126.
    Sturk, Christopher
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Statnett SF Research and Development, Norway.
    Chompoobutrgool, Yuwa
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Sandberg, Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Coherency-Independent Structured Model Reduction of Power Systems2014In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 29, no 5, p. 2418-2426Article in journal (Refereed)
    Abstract [en]

    This paper proposes a new model reduction algorithm for power systems based on an extension of balanced truncation. The algorithm is applicable to power systems which are divided into a study area which requires a high-fidelity model and an external area, making up most of the power system, which is to be reduced. The division of the power system can be made arbitrarily and does not rely on the identification of coherent generators. The proposed algorithm yields a reduced order system with a full non-linear description of the study area and a reduced linear model of the external area.

  • 127.
    Sturk, Christopher
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Chompoobutrgool, Yuwa
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Sandberg, Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Structured Power System Model Reduction of Non-Coherent Areas2012In: Power and Energy Society General Meeting, 2012 IEEE, IEEE , 2012, p. 6344913-Conference paper (Refereed)
    Abstract [en]

    This paper demonstrates how structured model reduction can be used to reduce the order of power systems without the need to identify coherent groups of generators. To this end the Klein-Rogers-Kundur 2-area system is studied in detail. It is shown how different modes of the system are captured as the model order is varied, which is of interest in e.g. distributed controller design, where the objective is to damp these oscillations. The power system is divided into a study area and an external area and the proposed algorithm is used to reduce the external area to a low order linear system, while retaining the nonlinear description of the study area. It is shown that this approach permits greater deviations from the steady-state than if a reduced system that is entirely linear is used, while still yielding accurate simulation results.

  • 128.
    Sturk, Christopher
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Milano, Federico
    Sandberg, Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Structured Model Reduction of Power Systems2012In: 2012 American Control Conference (ACC), American Automatic Control Council , 2012, p. 2276-2282Conference paper (Refereed)
    Abstract [en]

    This paper shows how structured model order reduction can be applied to power systems. For power systems divided into a study area and an external area, the proposed algorithm can be used to reduce the external area to a low order linear system, while retaining the nonlinear description of the study system. The reduction of the external area is done in such a way that the study system is affected as little as possible. It is shown that a lower model order can be attained when information about the study system is taken into consideration, than if the external system is reduced independently of it

  • 129. Tounsi, B.
    et al.
    Henry, Alexandre
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Modelling and dynamic analysis of offshore wind farms according to the French TSO grid code2012In: IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society, IEEE , 2012, p. 1374-1380Conference paper (Refereed)
    Abstract [en]

    Offshore wind farms are growing rapidly in the North Sea, being installed at more distant locations and becoming larger in size. The French government has the ambition to build 6 GW of offshore wind farms by 2020. Dynamic analysis for the integration of these farms to follow such ambitious plans has to be carefully performed to ensure system security. Through this article, a proposed reference offshore wind farm has been defined and modelled. An interconnection study has been realized based on ENTSO-E1 offshore requirements and French Transmission System Operator (TSO) current requirements. The transmission system, which considers an AC submarine cable, has an important impact when fulfilling grid code requirements. Finally, using the IEEE 14-bus power system which integrates the reference offshore wind farm, stability studies have been also carried out.

  • 130. Ugalde Loo, Carlos Ernesto
    et al.
    Acha, Enrique
    Liceaga-Castro, Eduardo
    Vanfretti, Luigi
    Individual Channel Analysis of the Thyristor-Controlled Series Compensator Performance2010In: International Journal of Emerging Electric Power Systems, ISSN 2194-5756, E-ISSN 1553-779X, Vol. 11, no 2Article in journal (Refereed)
    Abstract [en]

    The TCSC is the electronically-controlled counterpart of the conventional series bank of capacitors. A mature member of the FACTS technology, the TCSC has the ability to regulate power flows along the compensated line and to rapidly modulate its effective impedance. In this paper its performance is evaluated using Individual Channel Analysis and Design. Fundamental analysis is carried out to explain the generator dynamic behavior as affected by the TCSC.

    Moreover, a control system design for the system is presented, with particular emphasis in the closed-loop performance and stability and structural robustness assessment. It is formally shown that the incorporation of a TCSC operating in its capacitive range improves the dynamical performance of the synchronous machine by decreasing the electrical distance and therefore considerably reducing the awkward switchback characteristic exhibited by synchronous generators.

    It is also formally proven in the paper that the inductive operation should be avoided as it impairs system operation. In general, the TCSC inclusion brings on fragility into the global system, making it non-minimum phase and introducing adverse dynamics in the speed channel of the synchronous machine. Moreover, it is shown that the minimum-phase condition may also be present in cases featuring high capacitive compensation levels.

  • 131. Ugalde Loo, Carlos Ernesto
    et al.
    Liceaga-Castro, Eduardo
    Acha, Enrique
    Vanfretti, Luigi
    Rennselaer Polytech Institute, Troy, NY, USA.
    Synchronous Generators Modeling and Control Using the Framework of Individual Channel Analysis and Design: Part 12007In: International Journal of Emerging Electric Power Systems, ISSN 2194-5756, E-ISSN 1553-779X, Vol. 8, no 5Article in journal (Refereed)
    Abstract [en]

    In this paper a comprehensive dynamical assessment of a high order synchronous generator plant is carried out using the Individual Channel Analysis and Design (ICAD) framework – a multivariable control engineering tool that allows robustness and system performance evaluations.

    The great benefits of ICAD are elucidated and contrasted to those provided by the long-time honored block diagram representations. Several models used for the small signal stability analysis of synchronous generators are evaluated under the framework of ICAD.

    The study, which builds on pioneering work, reveals the great advantages of carrying out control system analysis and design with higher order generator models. Moreover, careful analysis of the ICAD’s Multivariable Structure Function (MSF) helps to explain, formally, why some operating conditions of the control system are more critical than others. Furthermore, correct interpretations of MSFs are amenable to robust and stable control system designs. Two kinds of studies are considered in the paper; one assesses operation under various power factor conditions and the other under a varying tie-line reactance. The control system design and stability and structural robustness assessment of the system are presented in the second part of this paper. Moreover, results obtained under the ICAD framework are compared with those arising from conventional controllers.

  • 132. Uhlén, Kjetil
    et al.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    de Oliveira, Marcio
    Leirbukt, Albert
    Aarstrand, Vemund Halmo
    Gjerde, Jan O.
    Wide-Area Power Oscillation Damper Implementation and Testing in the Norwegian Transmission Network2012In: 2012 IEEE Power and Energy Society General Meeting: Invited Paper, Panel Session: Synchrophasor Measurement Applications in Power Industry to Enhance Power System Reliability, New York: IEEE , 2012, p. 6344837-Conference paper (Refereed)
    Abstract [en]

    This article reports the results from the implementation and testing of a Wide-Area Power Oscillation Damper (WAPOD) controlling a 180 Mvar TCR Static Var Compensator (SVC) installed in the Hasle substation of Norwegian 420 kV transmission grid. The WAPOD uses voltage phase angle signals from two distant locations in the Norwegian grid as inputs to the damping controller. The damping controller modulates the voltage reference set point used by the SVC’s voltage controller, thereby creating a damping effect. The WAPOD is an extension to the existing Power Oscillation Damping (POD) controller that uses local measurements. A switch-over logic allows for the use of no damping control, local damping control or wide-area control.

    Field tests were performed during November 2011, and involved the disconnection and re-connection of a 420 kV transmission line. The performance of the WAPOD is compared to that of state-of-the-art local Phasor POD, and when no damping control is enabled. The testing results show that the WAPOD performed satisfactorily and according to the design expectations. These results show that the potential flexibility of the WAPOD to choose, among the different PMU signals, those that have the good observability of inter-area modes can be an advantage to the use of local feedback signals for damping control, as it is current practice today. Further testing of this WAPOD with other PMU signals from locations with stronger observability will be helpful to illustrate the advantage of this flexibility.

  • 133.
    Ur-Rehman Malik, Naveed
    et al.
    KTH, School of Electrical Engineering (EES), Electrical Energy Conversion.
    Almas, Muhammad Shoaib
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Challenges of Real-Time Parameter Estimationof a DFIG using Synchrophasors2015In: Environment and Electrical Engineering (EEEIC), 2015 IEEE 15th International Conference on, IEEE conference proceedings, 2015, p. 1939-1944Conference paper (Refereed)
    Abstract [en]

    This paper explores the challenges faced duringthe utilization of synchrophasors received from PMUs in orderto estimate the parameters of a DFIG in a real-time. PMUsare installed at the stator and rotor terminals of an 11-KVADFIG, in order to provide high resolution synchrophasor dataat a reporting rate of 50 msgs/sec. These synchrophasors areprocessed in real-time using an embedded controller in order tomeasure and estimate the internal parameters of the generator,i.e., magnetization and leakage inductances. Closed-loop variablespeed drive, active power and reactive power controls areimplemented for the DFIG. This paper discusses the laboratorysetup, control and parameter estimation experiments carried outon the DFIG. The testing process, challenges faced, and overallexperimental findings are also presented.

  • 134.
    Vahdati, Pouya Mahdavipour
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Kazemi, Ahad
    Amini, M. Hadi
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Hopf Bifurcation Control of Power System Nonlinear Dynamics via a Dynamic State Feedback Controller-Part I: Theory and Modeling2017In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 32, no 4, p. 3217-3228Article in journal (Refereed)
    Abstract [en]

    This two-part paper introduces a dynamic state feedback control law that guarantees the elimination of Hopf bifurcations (HB) before reaching the saddle-node bifurcations (SNB). Part I is devoted to the mathematical representation of the detailed system dynamics, investigation of HB and SNB theorems, and state feedback controller design. For purposes of dynamical analysis, the stable equilibria of the system is obtained. Then the control system is designed with the objective of preventing the voltage collapse before the SNB, such that the structural stability of the system is preserved in the stationary branch of the solutions. The controller aims to relocate Hopf bifurcations to the stationary branch of solutions located after SNB, eliminating the HB from normal operating region of the system. In order to evaluate the performance of the proposed controller, bifurcation analysis has been performed in Part II using single-machine and multi-machine test systems.

  • 135.
    Vahdati, Pouya Mahdavipour
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Vanfretti, Luigi
    Rensselaer Polytech Inst, ECSE, Troy, NY USA..
    Amini, M. Hadi
    Carnegie Mellon Univ, ECE, Pittsburgh, PA 15213 USA..
    Kazemi, Ahad
    Iran Univ Sci & Technol, Ctr Excellence Power Syst Automat & Operat, Tehran, Iran..
    Hopf Bifurcation Control of Power Systems Nonlinear Dynamics Via a Dynamic State Feedback Controller - Part II: Performance Evaluation2018In: 2018 IEEE POWER & ENERGY SOCIETY GENERAL MEETING (PESGM), IEEE , 2018Conference paper (Refereed)
  • 136.
    Vahdati, Pouya Mahdavipour
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Amini, M. Hadi
    Kazemi, Ahad
    Hopf Bifurcation Control of Power Systems Nonlinear Dynamics Via a Dynamic State Feedback Controller-Part II: Performance Evaluation2017In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 32, no 4, p. 3229-3236Article in journal (Refereed)
    Abstract [en]

    This is the second part of a two-part paper presenting a dynamic state feedback control law that guarantees the elimination of Hopf bifurcations before the occurrence of a saddle-node bifurcation. In Part I, the mathematical representation of the system's dynamics, Hopf, and Saddle-Node bifurcation theorems, and the state feedback controller design were presented. In this part, to illustrate the system analysis methodology, control design, and to carry out performance evaluation of the controller, both single-machine and multimachine power systems are analyzed. To highlight the effect of saturation phenomena, bifurcation analyses are performed before and after detailed modeling of synchronous generator saturation, for the single-machine power system case. The multimachine case is used to illustrate the scalability and applicability of the method to generic power networks.

  • 137. Vanfretti, L.
    et al.
    Chow, J. H.
    Sarawgi, S.
    Fardanesh, B.
    A Phasor-Data-Based State Estimator Incorporating Phase Bias Correction2011In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 26, p. 111-119Article in journal (Refereed)
    Abstract [en]

    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.

  • 138.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Estimation of Electromechanical Modes in Power Systems using Synchronized Phasor Measurements and Applications for Control of Inter-Area Oscillations2013Report (Other academic)
  • 139.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Experiences on Power System Model Identification using Modelica and FMI Technologies2014In: 8th MODPROD Workshop on Model-Based Product Development / [ed] Peter Fritzon, Linköping, 2014Conference paper (Refereed)
  • 140.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Mathematical Models and Software Tools for Simulation of Transmission Lines Transients2004In: Congreso de Estudiantes de Centroamérica y Panamá (CONESCAPAN XXIII), IEEE Section 9, September 2004, Guatemala, 2004Conference paper (Refereed)
    Abstract [es]

    Este documento trata la modelación de líneas de transmisión para el estado dinámico con la finalidad de obtener modelos matemáticos que representen con exactitud el comportamiento de estos elementos durante los fenómenos transitorios. La elaboración de estos modelos, por su naturaleza, involucra el uso de métodos matemáticos especializados que están fuera de la experiencia consciente del profesional de la ingeniería y deben ser estudiados.

    Estos modelos, son en esencia no lineales (debido a la dependencia de la frecuencia de las líneas de transmisión), por lo que hacen uso de herramientas computacionales para poder resolverlos, así como para obtener los parámetros relacionados con los mismos. Finalmente, la simulación de los fenómenos transitorios, casi en su totalidad, es llevada a cabo por medio de simulación de los fenómenos transitorios por maniobra en la línea de transmisión Brillantes-Esperanza utilizando MATLAB©/SIMULINK© y el ATP/EMTP.

  • 141.
    Vanfretti, Luigi
    Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY, United States.
    Notions for PMU-based power system model reduction: of large power systems2010Book (Other (popular science, discussion, etc.))
    Abstract [en]

    Model reduction of large scale power systems is currently carried out by coherency-based methods which start from a large data set of network model parameters. This monograph summarizes the most basic notions that will enable model reduction of large power systems using only phasor measurement unit (PMU) data. The monograph starts by reviewing the general aspects of network model-based reduction methods and describing the corresponding network aggregation techniques. For the measurement-based model reduction methods, observations are made about the voltage and frequency oscillation amplitude from the physical characteristics and from the time-domain simulations. These observations are illustrated with time-domain simulations of radial power systems with different network, machine, and exciter models. Reduced-order models of radial systems are obtained with simplified algorithms and are compared to the ones obtained by aggregation techniques. A numerical algorithm for parameter extrapolation is also outlined.

  • 142.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Phasor-Only State Estimation: Synchronized Phasor Measurements: Fundamentals and applications, Tutorial2010Conference paper (Refereed)
  • 143.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    SmarTS-LAB: a Smart Transmission Grids Laboratory at KTH2010Report (Other academic)
    Abstract [en]

    In this document we propose the development of a Smart Transmission Grids Laboratory named (SmarTS-Lab - Smart Transmission Systems-Laboratory) to be developed jointly by KTH-EPS and KTH-ICS. This laboratory has the aim of serving as a test-bench where research enabling the future ?Smart Grids? at the transmission level will be performed. To this aim, the SmarTS-Lab will be designed as a completely configurable system which will allow testing and development of power system operations methods and techniques; control methods, strategies, and algorithms; advanced protective system coordination with system controls; communication network paradigms and computer system architecture paradigms; information and communication technology design specifications - all under a completely controlled environment. This approach will allow the assessment of research ideas by subjecting them to a ?near-real-world? power network (emulated by a highly accurate real-time simulator) and allowing gradual testing of the performance of our research ideas under near ?real-world? conditions imposed by ?actual? communication networks and computer system architectures. It is important to emphasize that this approach will bring to our research area a methodology that is not standard in similar research groups ? a completely controlled environment where we can reproduce experiments. Therefore, this will allow for a very rigorous and careful assessment of new methods and techniques and to determine applications requirements for ICT; in addition to incorporating practical limitations, which are close to those present in the field. Recently, the European Institute of Technology (EIT) assigned KTH as a Smart Grids center. Within the EIT cooperation the proposed SmarTS-Lab will provide a suitable launching platform to develop innovative technologies for Smart Transmission Grids. Once established, the SmarTS-Lab can be used to develop innovative software/hardware solutions that can be used by transmission system operators worldwide. KTH?s long-standing collaboration with ABB and Vattenfall will provide an opportunity to establish the potential of the developed solutions within this EIT collaboration. This laboratory will also serve the larger research and education goals of the EPS and ICS departments at KTH. At EPS it will serve for on-going PhD and Master thesis projects, while it may also be used to perform illustrations for some courses. At ICS it will serve as a canvas where different paradigms of communication methods and computer system architectures for real-time operation of power systems can be demonstrated. This document provides background information and justifications to develop such simulator by KTH EPS and ICS.

  • 144. Vanfretti, Luigi
    State Space and Simulation of Simple Physical Systems with MATLAB2004In: Magazine of the Mathematics Department, Universidad de San Carlos de Guatemala, p. 21-30Article in journal (Refereed)
    Abstract [es]

    Este documento hace una introducción a la modelación de una sistema físico sencillo utilizando el método de la variable de estado y sus implementación para simulación en MATLAB, con el objetivo de introducirnos a la utilización de este paquete para el estudio de sistemas.

    En este documento modelaremos matemáticamente un sistema físico sencillo, un sistema mecánico, para luego utilizar MATLAB en la simulación de las respuestas de este sistema ante la aplicación de un escalón unitario.

  • 145.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Unambiguous Power System Modeling and Simulation using Modelica Tools2013Conference paper (Refereed)
  • 146.
    Vanfretti, Luigi
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Aarstrand, Vemund H.
    Statnett SF.
    Almas, Muhammad Shoaib
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Peric, Vedran S.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Gjerde, Jan Ove
    Statnett SF.
    A Software Development Toolkit for Real-Time Synchrophasor Applications2013In: 2013 IEEE Grenoble Conference PowerTech, POWERTECH 2013, 2013Conference paper (Refereed)
    Abstract [en]

    This article presents a software development toolkit for Wide Area Monitoring Systems. By using this development toolkit, a researcher is able to manipulate synchrophasor data in the LabView environment, which enables fast software prototyping and testing. This toolkit makes full scale testing in real-time easier for researchers, liberating them of complex and time consuming synchrophasor data handling. The toolkit exploits the IEEE C37.118.2 – 2011 protocol making it independent of any specific equipment and their manufacturers. An application of the development kit is demonstrated in a laboratory environment with a specially designed experimental setup composed of a real-time digital simulator and four phasor measurement units (PMUs).

  • 147.
    Vanfretti, Luigi
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Adib Murad, M. Ahsan
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Gómez, Francisco José
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    León, Gladys
    Grupo AIA.
    Machado, Silvia
    Grupo AIA.
    Heyberger, Jean-Baptiste
    RTE France.
    Petitrenaud, Sebastien
    RTE France.
    Towards automated power system model transformation for multi-TSO phasor time domain simulations using Modelica2017In: IEEE PES Innovative Smart Grid Technologies Conference Europe, IEEE, 2017, Vol. F126485, article id 7856341Conference paper (Refereed)
    Abstract [en]

    Transmission system operators in Europe describe their dynamic power system models using different simulation tools, and due to the de-facto modeling philosophy used, these descriptions are ambiguous between tools. In addition the current CIM standard for dynamic model exchange does not guarantee consistency when exchanging models. This poses a challenge to perform pan-European dynamic security assessment. This paper presents a method for transforming power system model descriptions typically used by TSOs into a consistent and unambiguous equation based modeling language. As a result, this method allows performing simulations in multiple tools supporting the standardized Modelica language. The transformation method is validated by steady state and dynamic simulations and comparing simulation outputs between a reference tool (PSS/E or Eurostag) and a Modelica tool. It is shown that the Modelica language can be used as a common language to provide unambiguous model descriptions consistent with those tools typically used by TSOs, without loss of information and maintaining simulation fidelity.

  • 148.
    Vanfretti, Luigi
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Aliyu, Usman
    Chow, Joe H.
    Modelling of a System Collapse in the Nigerian National Power System using Frequency Disturbance Recorder Data2012In: 9th International Conference on Power System Operations adn Planning (ICPSOP) 2012, 2012, p. 1-6Conference paper (Refereed)
    Abstract [en]

    This paper exploits the availability of frequency disturbance recorder (FDR) measurements and knowledge of the underlying operational data from the Nigerian National Power System to develop a model capable of reproducing the most important characteristics of one of the many collapses in the Nigerian grid during the last recent years.

    The collapse investigated in this paper was captured on December 2nd , 2006, with an FDR unit installed at Abubakar Tafawa Balewa University (ATBU). Using operational information from the National Control Center (NCC) at Osogbo, three models representing the Nigerian power system were developed to capture the most relevant dynamics of the grid during the cascading failure. These models include both detailed representations of the different network components, as well as average frequency dynamics only.

    Comprehensive simulation results show how the models are capable of representing the most important features of the collapse of the system, and hence, their continuous improvement through model validation may allow their use in the development of load shedding mechanisms which are needed for mitigating cascading failures in the Nigerian system.

  • 149.
    Vanfretti, Luigi
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Aliyu, Usman
    Chow, Joe H.
    Momoh, James A.
    System frequency monitoring in the Nigerian power system2009In: 2009 IEEE POWER & ENERGY SOCIETY GENERAL MEETING, VOLS 1-8, IEEE , 2009, p. 2301-2306Conference paper (Refereed)
    Abstract [en]

    Frequency is one of the most important measures of the state of a power system, especially for structurally weak and rapidly growing power systems. Thus, frequency monitoring is a desirable practice to ensure reliability and provide data for analysis. This paper reports the joint work between Abubakar Tafawa Balewa University (ATBU) and Rensselaer Polytechnic Institute (RPI) to study frequency dynamics of a relative small power system. We describe the frequency disturbance recorder (FDR) implementation experience at ATBU, Bauchi, Nigeria, and present analysis on the digital recordings obtained by the FDR. A proposal for a university-based frequency monitoring network for the Nigerian power system is also presented. Such monitoring system will allow further investigations on the Nigerian system and ultimately enhance the understanding of the dynamics and control of structurally weak and rapidly growing power systems found in many developing countries.

  • 150.
    Vanfretti, Luigi
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems. Statnett.
    Al-Khatib, Iyad
    Almas, Muhammad Shoaib
    KTH, School of Electrical Engineering (EES), Electric Power Systems.