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  • 1.
    Al Karim, Miftah
    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.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Synchrophasor-based data mining for power system fault analysis2012In: Innovative Smart Grid Technologies (ISGT Europe), 2012 3rd IEEE PES International Conference and Exhibition on, IEEE , 2012, p. 6465843-Conference paper (Refereed)
    Abstract [en]

    Phasor measurement units can provide high resolution and synchronized power system data, which can be effectively utilized for the implementation of data mining techniques. Data mining, based on pattern recognition algorithms can be of significant help for power system analysis, as high definition data is often complex to comprehend. In this paper three pattern recognition algorithms are applied to perform the data mining tasks. The deployment is carried out firstly for fault data classification, secondly for checking which faults are occurring more frequently and thirdly for identifying the root cause of a fault by clustering the parameters behind each scenario. For such purposes three algorithms are chosen, k-Nearest Neighbor, Naïve Bayes and the k-means Clustering.

  • 2. Al-Hammouri, A.T.
    et al.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Chenine, Moustafa
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Honeth, Nicholas
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Leelaruji, Rujiroj
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Virtualization of synchronized phasor measurement units within real-time simulators for smart grid applications2012In: Power and Energy Society General Meeting, 2012 IEEE, IEEE , 2012, p. 6344949-Conference paper (Refereed)
    Abstract [en]

    Synchronized phasor measurement units (PMUs) provide GPS-time tagged high-sampling rate positive-sequence voltage and current phasors. When placed in high-voltage substations in power networks, PMUs can provide real-time information that is necessary for the development of Smart Transmission Grid software applications for improving power system monitoring, control and protection. The development of these applications, particularly for use within control centers for on-line purposes, is limited by the availability of and access to real-time PMU data and other information. One attractive approach for application development is the use of real-time simulators to which PMUs can be interfaced as hardware-in-the-loop (HIL) devices to harvest PMU data. However, this approach has technical and economical limitations, which can be tackled by the virtualization of PMU devices. This article describes the development of an entirely software-based synchronized phasor measurement unit for use within real-time simulators that will allow the emulation of a large number of real-life PMUs, which in turn can be used for creating new phasor-based applications.

  • 3.
    Armendariz, Mikel
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Babazadeh, Davood
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Brodén, Daniel
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Strategies to improve the voltage quality in active low-voltage distribution networks using DSO's assets2017In: IET Generation, Transmission & Distribution, ISSN 1751-8687, E-ISSN 1751-8695, Vol. 11, no 1, p. 73-81Article in journal (Refereed)
    Abstract [en]

    This study addresses the problem of voltage variations in active low-voltage distribution networks caused by distributed photovoltaic (PV) generation. Three strategies based on model predictive control (MPC) are introduced to flatten the voltage profile in a cost-optimal way. The compared strategies are the business as usual approach that manipulates a controllable on-load tap changer at the primary substation, the problematic feeder control strategy (CS) that adds an additional degree of freedom by controlling the critical secondary substations (SSs), and finally the compensation strategy, which controls the primary substation and compensates the non-critical SSs. A sensitivity analysis on the CSs has been conducted comparing the voltage variation reduction and the asset utilization with regard to the accuracy of the prediction models and the forecasted disturbance data. The results show that better (and more costly) characterisation of these parameters only provide a marginal improvement in the reduction of the voltage variations due to the restriction caused by the heavy tap change penalisation. Moreover, the tested case-study shows that the problematic feeder CS outperforms the compensation strategy in terms of larger voltage variation reduction for similar asset utilisation.

  • 4.
    Armendariz, Mikel
    et al.
    KTH, School of Electrical Engineering (EES), Electric power and energy systems.
    Babazadeh, Davood
    KTH, School of Electrical Engineering (EES), Electric power and energy systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric power and energy systems.
    Barchiesi, Michele
    Department of Electrical, Electronic and Inf. Engineering University of Bologna.
    A Method to Place Meters in Active Low Voltage Distribution Networks using BPSO Algorithm2016Conference paper (Refereed)
    Abstract [en]

    This paper proposes a method to be used by a DSOto optimally place sensors at MV/LV substation and some lowvoltage cable distribution cabinets. This method aims to improvethe estimation of the grid states at low voltage distributionnetworks. This method formulates a multi-objective optimizationproblem to determine the optimal meter placementconfiguration. This formulation minimizes the low voltage stateestimation error and the cost associated to a particular meterdeployment configuration. The method uses Binary ParticleSwarm Optimization (BPSO) to solve the optimization problemand it has been tested on a network based on the Cigré LVbenchmark grid. The simulation results show that the methodcan be applied to both situations where smart metermeasurements are available and situations where they are not. Inthe latter situation the measurements are replaced by pseudomeasurements,which represent meter readings by using smartmeter historical data and prediction models.

  • 5.
    Armendariz, Mikel
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Brodén, Daniel
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Honeth, Nicholas
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    A Method to Identify Exposed Nodes in Low Voltage Distribution Grids with High PV Penetration2015In: IEEE Power and Energy Society General Meeting 2015, Denver, CO. July 26-30, 2015. / [ed] IEEE, IEEE Press, 2015Conference paper (Refereed)
    Abstract [en]

    The impact of introducing distributed energyresources at the low voltage side of the distribution grid iscurrently raising new challenges for utilities. In particular, thehigh penetration of photovoltaic panels (PVs) in radial grids isincreasing the active power losses in the branches and thevoltage level at some of the nodes. Principally nodes next to PVarray installations. This paper presents a methodology based ondesign of experiments (DOE) to detect such exposed nodes andbranches, together with the identification of the main scenariosthat cause such problems, characterized by: season, type of day,solar radiation and outdoor temperature levels. Themethodology is simulated on a LV network based on the Cigrebenchmark Grid with real utility data. The exposed nodes areclassified for each feeder from most to least problematic andshowed (as expected) sensitivity to seasonality (summertime),characterized by high solar radiation and outdoor temperatures.

  • 6.
    Armendariz, Mikel
    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.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Al-Hammouri, Ahmad
    Jordan University of Science and Technology.
    A co-simulation platform for medium/low voltage monitoring and control applications2014In: 2014 IEEE PES Innovative Smart Grid Technologies Conference, ISGT 2014, IEEE conference proceedings, 2014, p. 6816369-Conference paper (Refereed)
    Abstract [en]

    The increasing demand for electricity and the penetration of renewable energy resources into the electrical grid are triggering the electric power system to undergo changes and complex modifications at high, medium and low voltage levels. There are large and complex projects such as Smart Grid Gotland to deploy solutions to address such challenges. However, there are several scenarios that could be more practical to be first studied via simulations. As such, the purpose of this paper is to propose and develop a co-simulation platform that allows performing real-time monitoring and control tests and simulations for MV/LV grids. This platform combines both electrical, and information and communication technology (ICT) infrastructure simulations. It consists of a real-time power system simulator (Opal-RT) connected to a communication network simulator (OPNET) through an automatic meter reading interface that is based on commercial off-the-shelf (COTS) and low cost devices such as Raspberry Pi and Arduino boards. The platform allows the analysis of realistic MV/LV grids and communication networks, and will facilitate the simulation and comparison of low voltage control strategies for real-time test scenarios that could be more complicated to test otherwise in real-life due to cost and complexity aspects , i.e., high power losses on the low voltage grid.

  • 7.
    Armendariz, Mikel
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Johansson, Christian
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Yunta Huete, Angel
    Unión Fenosa Distribución.
    García Lobo, Miguel
    Gas Natural Fenosa Engineering.
    A Method to Design Optimal Communication Architectures in Advanced Metering Infrastructures2017In: IET Generation, Transmission & Distribution, ISSN 1751-8687, E-ISSN 1751-8695, Vol. 11, no 2, p. 339-346Article in journal (Refereed)
    Abstract [en]

    This paper proposes a method to determine the optimal communication architecture in advance metering infrastructures (AMI). The method starts by indicating suitable groups of meters that share similar characteristics such as distance to the secondary substation and mutual proximity. Then it connects each group of meters to the AMI-Head End through a communication architecture formed by wireless and Power Line Communication (PLC) technologies. The optimality criterion takes into account the Capital Expenditures (CAPEX), Operational Expenditures (OPEX) and the Quality of Service (QoS) in the communication architecture. The method is tested on a LV network based on real utility data provided by EU FP7 DISCERN project partners. These tests show that the method is consistent with planning foresight and can be useful to assist in the AMI communication architecture designing process.

  • 8.
    Armendariz, Mikel
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems. KTH - Royal Institute of Technology.
    Rodrigo, Gonzalez
    KTH, School of Electrical Engineering (EES). KTH - Royal Institute of Technology.
    Korman, Matus
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems. KTH - Royal Institute of Technology.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems. KTH - Royal Institute of Technology.
    Method for Reliability Analysis of Distribution Grid Communications Using PRMs-Monte Carlo Methods2017Conference paper (Refereed)
    Abstract [en]

    This paper presents a method to perform reliability analysis of communication systems for distribution grids. The method uses probabilistic relational models to indicate the probabilistic dependencies between the components that form the communication system and it is implemented by Monte Carlo methods. This method can be used for performing reliability predictions of simulated communication systems and for evaluating the reliability of real systems. The paper contains a case study in which the proposed method is applied to evaluate the reliability of the communication systems that are required for monitoring the network components at low voltage levels using the smart metering infrastructure. This case study is taken fromthe EU FP7 DISCERN project. Finally, the results are presented in a quantitative way, showing the individual reliability of each component and the combined reliability of the entire system.

  • 9.
    Armendariz, Mikel
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Saleem, Arshad
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Brugeron, Mathieu
    Grenoble INP.
    Facilitating Distribution Grid Network Simulation Through Automated Common Information Model Data Conversion2015In: IEEE PowerTech Conference 2015, Eindhoven (Netherlands), 29 June - 2 July 2015 / [ed] IEEE, IEEE , 2015Conference paper (Refereed)
    Abstract [en]

    In R&D projects as well as in development work,simulations of grid configurations and control methods are acommon tool for assessing different technical options. At thesame time, these simulations are often limited by difficulties indata exchange, simply due to the fact that systems are notcompatible and data format in operational systems is not alignedwith data in simulation and analysis tools. To this extent a toolhas been developed that allows large scale import of real-worldgrid data using CIM XML to state of the art simulation toolsbased on MATLAB. The tool is used in a large FP7 projectinvolving leading European DSOs.

  • 10.
    Babazadeh, Davood
    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.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Survey on the Factors Required in Design of Communication Architecture for Future DC grids2013In: IFAC Proceedings Volumes (IFAC-PapersOnline), 2013, p. 58-63Conference paper (Refereed)
    Abstract [en]

    This paper aims first to survey various aspects of DC grids from grid topologies to TSOs structure which has been carried out in several studies, and second try to highlight the factors to be considered in the design of the universal communication architecture for DC grid control and protection purposes. The result of the survey will be used as the first step to introduce the possible communication solutions such as network and data transfer protocols in order to ensure the reliable data delivery in operation of multi-national DC grids.

  • 11.
    Babazadeh, Davood
    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.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Real-Time Smart Grid Application Testing using OPNET SITL2012Conference paper (Refereed)
    Abstract [en]

    Phasor -based Wide Area Monitoring and Control (WAMC) system promise to improve the monitoring of power grid across large geographic areas and accordingly controlling grid in more efficient and intelligent ways. In order to have confidence on the correctness, performance and reliability of applications used in WAMC system in real world scenarios, pseudo-real test beds where the requirements for the applications and their supporting Information and Communication Technology (ICT) can be quantified and analyzed. In this paper, a WAMC system testing platform is proposed to facilitate the real-time simulation of dynamic power grid, the ICT infrastructure that overlays the grid and WAMC applications. The proposed platform consists of OPNET as a powerful communication network simulator connected to real-time power system simulator on one side through virtualized Phasor Measurement Unit device, and linked to end point stations such as Phasor Data Concentrator or application on the other side through OPNET’s real-simulation gateway. A set of proof of concept scenarios using this framework is presented.

  • 12.
    Babazadeh, Davood
    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.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Al-Hammouri, Ahmad
    Department of Network Engineering and Security, Jordan University of Science and Technology.
    A Platform for Wide Area Monitoring and Control System ICT Analysis and Development2013In: 2013 IEEE Grenoble Conference PowerTech, POWERTECH 2013, IEEE , 2013Conference paper (Refereed)
    Abstract [en]

    PMU-based Wide Area Monitoring and Control(WAMC) system is introduced to improve the monitoring ofpower grid across large geographic areas and control the gridusing more efficient and smart applications. The performance ofWAMC applications in real power system scenarios and impactof their supporting Information and Communication Technology(ICT) on the data quality can be quantified and analyzed bypseudo-real co-simulation test beds. The purpose of this study isto propose and develop a WAMC testing platform to facilitate thereal-time simulation of dynamic power grid, the ICTinfrastructure that overlays the grid and WAMS applications.The platform consists of OPNET, a powerful communicationnetwork emulator, connected to a real-time power systemsimulator through virtualized PMU device. The end pointstations such as Phasor Data Concentrator or PMU-basedapplications are also linked to the platform through OPNET’sreal-simulation gateway called SITL (System-In-The-Loop). Toassess the performance of the platform architecture, a case studyhas been performed with five PMUs which collect the data from apower model and deliver to PMU-based mode-estimationapplication over a typical communication network. In this study,the results explicitly intend to quantify the effect of networkprotocols on data delay.

  • 13.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Farhad, Freizadeh
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Distributed Ancillary Service Support for Independent AC-Areas through HVDC Grid2015In: 2015 IEEE EINDHOVEN POWERTECH, IEEE conference proceedings, 2015Conference paper (Refereed)
    Abstract [en]

    This work aims to study different ancillary servicessuch as frequency support, rotor angle stability and voltagestability that can be provided to independent AC areas throughMulti-Terminal HVDC grid. An agent-based control scheme hasbeen suggested to support the frequency of the imbalanced ACarea using other intact areas during a disturbance. The frequencysupport is carried out through some agents/controller, wherethe objective of the agents is to reach a common value fora given state, i.e. frequency, using the local and neighbouringinformation. In this scheme, the concept of Adaptive Graph (AG)has been introduced to the consensus problem to deal with thelimitation of original scheme in considering the rated capacityof HVDC converters. In this case, the frequency consensus canbe reached to a new stable value by removing one or severalconverters from the communication graph when reaching ratedactive power capacity. In order to test the proposed scheme,a model of 7-terminal dc-grid and corresponding AC areas isdeveloped in real time simulator OPAL-RT. The results showthat the adaptive graph scheme improves the reliability of thesystem during distributed frequency support.

  • 14.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Hohn, Fabian
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Wu, Yiming
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Distributed Two-stage Network Topology Processor for HVDC Grid Operation2017In: 2017 IEEE Manchester PowerTech, Powertech 2017, IEEE, 2017, article id 7980841Conference paper (Refereed)
    Abstract [en]

    This paper presents the results of an analysis of distributed two-stage coordination of network topology processor for HVDC grids. In the first stage of the two-stage processor, the substation topology is analyzed locally using an automated graph-based algorithm. Thereafter, a distributed algorithm is proposed to used the neighboring information to realize the grid connectivity. For distributed islanding detection, the connectivity problem is formulated as a set of linear equations and solved iteratively using successive-over-relaxation method. The performance of the proposed methods versus conventional one-stage method has been tested in an islanding scenario for a 5-terminal HVDC grid.

  • 15.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Electric power and energy systems.
    Muthukrishnan, Arvind
    KTH, School of Electrical Engineering (EES).
    Mitra, Pinaki
    HVDC, ABB Sweden, Ludvika.
    Larsson, Tomas
    HVDC, ABB Sweden, Ludvika.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric power and energy systems.
    Real-Time Estimation of AC-Grid Short Circuit Capacity for HVDC Control Application2016In: IET Generation, Transmission & Distribution, ISSN 1751-8687, E-ISSN 1751-8695Article in journal (Refereed)
    Abstract [en]

    Being able to estimate the AC grid strength using Short Circuit Capacity (SCC) fromthe perspective of a connected HVDC station allows adjustment of converter control parameters orto select the converter’s operational control mode. The short circuit capacity can be calculated byestimation of the grid’s impedance and its equivalent voltage. This paper presents the operationaland practical challenges in real-time implementation of the grid estimation algorithms especiallyfor HVDC applications. This paper shows that the Recursive Least Square (RLS) algorithm can bevery efficiently used for the real-time estimation of SCC. This technique forms a regression prob-lem using algebraic complex equations with an objective to minimize the error between estimatedand measured parameters. The algorithm has been reformulated and simplified to make it non-complex without the use of matrices, in order to facilitate further implementation on an industrialreal-time controller. The performance of the real-time implementation has been evaluated usinga HIL platform. A sensitivity analysis has been also carriedout to study the impact of differentparameters and operational conditions on the performance of the estimation algorithm. Finally, theactual application of real-time SCC estimation for the HVDCsystems has been demonstrated.

  • 16.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Muthukrishnan, Arvind
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Mitra, Pinaki
    HVDC, ABB Sweden, Ludvika.
    Larsson, Tomas
    HVDC, ABB Sweden, Ludvika.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Selection of DC Voltage Controlling Station in an HVDC Grid2016In: Electric power systems research, ISSN 0378-7796, E-ISSN 1873-2046, Vol. 144, p. 224-232Article in journal (Refereed)
    Abstract [en]

    This paper proposes a real-time quantitative evaluation of HVDC converters’ in an HVDC grid to select the suitable DC slack converter. This real-time evaluation considers the strength of connecting AC grid and the converter's on-line capacity margin as selection metrics. The strength of AC grid is evaluated in real-time by the estimation of grid short circuit capacity using recursive lease square algorithm. Given these selection metrics, the credibility of HVDC stations in controlling the DC voltage can be offered to the system operator in real-time for further operational decisions. This paper also studies the practical aspect of the estimation algorithm regarding selection of the operating points. As major contribution, it suggests to intelligently use a naturally occurring droop response in HVDC grids as a second operating point in the estimation algorithm to calculate the short circuit capacity. The method has been tested through set of scenarios using a real-time co-simulation platform. This platform includes real-time power system simulator to model AC/DC grid, industrial HVDC controllers and corresponding ICT systems. The results show that the proper selection of DC slack station can improve the AC system response and DC voltage drops during disturbances.

  • 17.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Electric power and energy systems.
    Muthukrishnan, Arvind
    KTH, School of Electrical Engineering (EES), Electric power and energy systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric power and energy systems.
    Mitra, Pinaki
    HVDC, ABB Sweden, Ludvika.
    Larsson, Tomas
    HVDC, ABB Sweden, Ludvika.
    Short Circuit Capacity Estimation for HVDC Control Application2016In: Power Systems Computation Conference (PSCC), 2016, IEEE conference proceedings, 2016Conference paper (Refereed)
    Abstract [en]

    This paper studies various operational aspects ofrecursive least square algorithm as a potential solution for theestimation of short circuit capacity in HVDC application. Inthis work, low computational requirement, minor operationalcomplication and acceptable accuracy of the estimated gridparameters have been considered as the performance metricsfor the selection of the suitable estimation algorithm. The chosenalgorithm forms a regression problem using at least two algebraiccomplex equations based on two different operating points. Theappropriate selection of the second operating point which fulfillsthe minimum required accuracy and convergence rate is of greatimportance, particularly in the practical implementation. Thispaper proposes and analyzes several choices of providing thesecond operating point for the estimation algorithm adopted toHVDC application. Furthermore, a sensitivity analysis has beencarried out to assess the impact of different parameters andoperational conditions such as execution time on the performanceof the estimation algorithm for the HVDC control purposes.

  • 18.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nazari, Mohammad
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Fidai, Muhammad Hassan
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Chenine, Moustafa
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Ghandhari, Mehrdad
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Implementation of agent-based power flow coordination in AC/DC grids using co-simulation platform2014In: 2014 IEEE International Conference on Smart Grid Communications, SmartGridComm 2014, 2014, p. 188-193Conference paper (Refereed)
    Abstract [en]

    This paper presents work on the coordination of power sharing contribution of converters in an overlaid HVDC grid using a Multi-Agent System (MAS) approach. This approach is further implemented in a real-time co-simulation platform in order to study the proposed control scheme including the supporting information and communication Technology (ICT) systems. The platform consists of OPNET, a communication network simulator, connected to a real-time power system simulator through virtualized and real devices. Furthermore, the impact of different supporting system parameters such as bit-error rate has been studied using this real-time co-simulation platform.

  • 19.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Agent-based Control of VSC-HVDC Transmission Grid: A Cyber Physical System Perspective2014In: MSCPES 2014, 2014Conference paper (Refereed)
    Abstract [en]

    This paper proposes a control scheme to coordinatethe DC voltage of converters in a HVDC grid using a Multi-agentSystem concept. Such interactions between agents, converters,and communication units are approached from a Cyber-PhysicalSystem (CPS) perspective. The Multi-agent based control schemetries to update the DC voltage set-points of the converters basedon local and neighboring information. The information exchangebetween the agents and communication delay tolerance of thecontrol scheme is studied by means of graph theory. The multiagentcontrol scheme has been implemented for a seven-terminalHVDC grid in a real time simulator and the impact ofcommunication delay on this distributed control approach hasbeen studied and is presented in the result.

  • 20.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Distributed Security-Constrained Secondary Control of HVDC grids in the Presence of Wind UncertaintyIn: Sustainable Energy, Grids and Networks, ISSN 0284-4354, E-ISSN 2352-4677Article in journal (Refereed)
    Abstract [en]

    This paper proposes a distributed coordination of converters in an HVDC grid in order to provide close-to-real-time optimal DCvoltage and power profiles in the presence of wind uncertainty. This coordination is a part of HVDC grid secondary control actionthat carries out after the automatic primary control response by DC voltage droop controlling converters. It aims to optimize thegrid operation by finding the new DC power and voltage set-points that minimize the operational costs due to wind fluctuations andprediction error. Furthermore, the N-1 secure operation of HVDC grid is considered in this distributed coordination by adding a setof security constraints that tightens the upper and lower bounds of the problem variables. The coordination problem is formulatedas a convex optimization problem and therefore a modified version of alternating direction method of multipliers is adopted to solvethe problem in distributed manner. The performance of distributed coordination has been tested by a set of scenarios. The resultsimply that the distributed coordination is eligible in terms of time and complexity to be considered as either the main option forsecondary coordination or a complementary back-up solution for the central coordination.

  • 21.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Multi-Stage Network Processor for an Independent and Integrated HVDC grid Supervisory Control Architecture2015Conference paper (Other academic)
    Abstract [en]

    Increasing the integration of renewable energy resources has introduced new requirements to the structure of electric power transmission grids. In addition to distributed renewable production, electric power exchange between neighboring countries also leads to development of transmission grids. Since AC grid solution is limited by legislative issues and long distance transmission capacity, High Voltage Direct Current (HVDC) technology with its different benefits compared to AC such as lower power losses, controllability and visual impact is being considered as appropriate alternative solution. Different aspects of HVDC technology from technical and economic challenges regarding the selection of proper HVDC grid topology to detailed control schemes are addressed extensively in the literature. Regarding the control of HVDC grids, the concept of centralized DC slack converter has been presented with the task to control the DC voltage level of the grid within the defined value and keep DC power flow in the grid balanced in real-time. Beside the centralized DC slack concept, a distributed DC slack concept called DC voltage droop is proposed and investigated. Similar to primary frequency control in AC grid, the controller uses the local DC voltage deviation as indication of power mismatch and tune the power production based on this local signal. An alternative agentbased control scheme has been also proposed to coordinate the power sharing in HVDC grids. On top of this fast control design, a supervisory controller is needed to guarantee the optimal operation of the HVDC grid in normal or abnormal states. This supervisory controller can be integrated to available AC Supervisory Control and Data Acquisition (SCADA) in the case of HVDC grid embedded in a single AC area. When it comes to HVDC grid connecting different AC areas, an “independent HVDC SCADA” can be defined which coordinates with connecting AC areas’ SCADA or it again can be integrated to one of the AC Area’s SCADA system called “integrated HVDC SCADA”. Regardless of system operation architecture, in order to monitor and operate the HVDC grid, supervisory control needs to be equipped with state estimation including the topology processor. Topology processor uses the real-time circuit breaker status within the substation to determine the system level topology. In the case of HVDC grid, the importance of such topology processor is bolder when it comes to detection of different islands. The islanding case should be recognized as real-time as possible in order to assign the DC slack bus, if not available in the island. In the literature, different algorithms and challenges have been investigated for topology analysis in the context of AC grid. This includes presentation artificial intelligence methods (e.g. artificial neural network) or integration of Phasor Measurement Unit (PMU) information in the process. Considering the future attentions toward overlay or interconnecting HVDC grid, the similar detailed methodology for HVDC grid with particular challenges seems to be vital. This work presents a multi-stage network processor as part of independent supervisory control in HVDC grid connecting or overlaying AC areas which can be extended to integrated supervisory control architecture. The proposed approach consists of two levels: 1) process of AC or DC substation topology locally and 2) the secondary process at HVDC grid central supervisory controller. At the substation level, the local topology processor determines the branch/bus model of the substation including the possible standalone HVDC converter using breaker status in the form of support matrix which is the combination of substation matrix and standing alone matrix. Substation Matrix holds information regarding this simplified substation model and the lines connected to it and number of logical buses/vertexes per substation. Standing alone matrix is created when the converter in the substation is not connected to DC grid and just standing alone. This can be useful for operator for starting the SVC functionality of the VSC stations. The same analysis is performed on all the substations locally and then the support matrices are sent to the network processor at SCADA level. At central level, the processor creates the general adjacent matrix based on the support matrix of the substations for whole HVDC grid to form the admittance matrix (Y). For the islanding analysis, the corresponding Laplacian Matrix is built from the adjacent matrix and clustering method is used to analysis the corresponding Eigen vectors of the Laplacian matrix. Besides, an extended version of current algorithm has been studied and presented for the integrated HVDC supervisory control architecture in which one AC area is responsible for the operation of HVDC grid.

  • 22.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Tonti, Alessio
    Dept. of Electrical, Electronic and Information Engineering University of Bologna , Italy.
    Armendariz, Mikel
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Borghetti, Alberto
    Dept. of Electrical, Electronic and Information Engineering University of Bologna , Italy.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nucci, Carlo Alberto
    Dept. of Electrical, Electronic and Information Engineering University of Bologna , Italy.
    Two-stage Network Processor for an Independent HVDC Grid Supervisory Control2016Conference paper (Refereed)
    Abstract [en]

    This paper proposes a two-stage network processorfor the supervisory control of multi-terminal HVDC grid thatconnects different AC areas. The proposed network processorprocesses the DC substation topology locally in the first stageand analyzes the HVDC grid connectivity at the supervisorycontroller. The processor uses the k-means clustering methodto detect the islands in HVDC grid and prepares requiredinformation to carry out the converter control mode assignation.The performance of the method has been tested for an isladingscenario in a 7-terminal HVDC grid using a real-time cosimulationplatform. The output of network processor helps thecontrol application at the supervisory level to make decisionsbased on the control modes of the available converters in theislands. This two-stage architecture has been compared with thecentralized architecture in terms of computational complexity.

  • 23.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Van Hertem, Dirk
    ELECTA Research Group, KU Leuven, 3001 Leuven-Heverlee, Belgium.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Study of Centralized and Distributed Coordination of Power Injection in Multi-TSO HVDC Grid with Large Off-shore Wind Integration2016In: Electric power systems research, ISSN 0378-7796, E-ISSN 1873-2046, Vol. 136, p. 281-288Article in journal (Refereed)
    Abstract [en]

    This paper studies centralized and distributed schemes for the coordinationof power injection in an HVDC grid connected to large wind generation.This coordination of power injection aims to keep the power balanced withinthe HVDC grid especially during large wind disturbances. Furthermore, thecoordination tries to follow the converters’ schedules set by the connectingAC-TSOs every 15−minutes. This schedule comes from an overall combinedAC/DC economic dispatch calculation with lower resolution compared to thiscoordination. In this paper, the coordination of power injection has been formulatedas a non-linear constrained optimization problem for the centralizedarchitecture. Next, the centralized optimization problem is decomposed tosub-problems using the Auxiliary Problem Principle (APP) method for thedistributed architecture. This distributed optimization problem is solved byexchanging the required information between the AC TSOs. These two differentapproaches have been evaluated for a 5-terminal HVDC grid. Furthermore,a sensitivity analysis has been carried out to find the optimal updatingrate of power injection set-points. The result shows that the more frequentupdating of power injection coordination in the centralized architecture improvesthe generation reserves in each AC area.

  • 24.
    Babazadeh, Davood
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Van Hertem, Dirk
    Esat-Electa, KU Leuven.
    Rabbat, Michael
    Department of Electrical and Computer Engineering, McGill University,.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Coordination of Power Injection in HVDC Grids with Multi-TSOs and Large Wind Penetration2015In: ACDC 2015, 2015Conference paper (Refereed)
    Abstract [en]

    This paper proposes different architectures for the coordinationof power injection in interconnected hybrid AC/DC gridswith Multi-TSO. The power dispatch problem is first formulatedfor the HVDC grid with the aim of keeping the balancein real time and try to follow the 15-min schedules introducedby AC TSOs considering the ongoing changes in the HVDCgrid. Next, the Auxiliary Problem Principle (APP) method isproposed to decompose the dispatch problem and distributedbetween connected AC operators who control the local converters.Two different approaches are tested and the sensitivityof the OPF updating rate has been evaluated for a 5-areaHVDC grid with the wind production.

  • 25. Baccino, F.
    et al.
    Massucco, S.
    Sandels, Claes
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Domestic heat load aggregation strategies for wind following in electric distribution systems2013In: 2013 IEEE Power and Energy Society General Meeting (PES), IEEE , 2013, p. 6672610-Conference paper (Refereed)
    Abstract [en]

    This paper investigates the operation of a domestic heat load aggregator on the Swedish island of Gotland. In the considered business case the aim of the aggregator is to minimize the losses on the HVDC connection with the mainland matching local wind generation and load. A network model is implemented and static power flow simulations are performed to evaluate the aggregator profit and the effects of its actions on the network behavior. Various aggregator strategies are simulated in different wind penetration scenarios, several indices are calculated to compare the different cases on a quantitative base.

  • 26.
    Baccino, Francesco
    et al.
    University of Genova – Italy.
    Massucco, Stefano
    University of Genova – Italy.
    Sandels, Claes
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Technical analysis of an aggregator's operation for the Gotland power system2013In: 22nd International Conference and Exhibition on Electricity Distribution (CIRED 2013), 2013, p. 1017-Conference paper (Refereed)
    Abstract [en]

    The large scale deployment of distributed generation from renewable energy sources may undermine the network safe operation and may require network reinforcements. In order to avoid or postpone the infrastructural investments it is possible to exploit other resources. In this paper the operation of a load aggregator is simulated on the Swedish island of Gotland in different wind penetration condition to test two different business models, one oriented to the price following and the other oriented to the wind following. The adopted methodology is described and the results presented and commented.

  • 27.
    Björkman, Gunnar
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Sommestad, Teodor
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Ekstedt, Mathias
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Information system architectures in electrical distribution utilities2010In: Proceedings of the 9th Nordic Electricity Distribution and Asset Management Conference, 2010Conference paper (Refereed)
    Abstract [en]

    Computerized control systems have been used in many years to supervise and control power distribution. These systems, which often are referred to as SCADA (Supervisory Control And Data Acquisition) systems, have in recent been more and more interconnected to other systems in recent years. In modern utilities various kinds of data are exchanged between the distribution management systems and the administrative systems located in the office network. For example are operational statistics, trouble reports and switch orders often communicated between the office systems and the systems inside the control center. This paper desccribes a survey over state-of-practice architectures in electrical distribution utilities. A set of system-services have been identified together with the interfaces that typically exists between these services. How these services are located within different zones within utilities is also identified. The set services, the data flows, and the location of these has been reviewed and validated by vendors of SCADA systems in the electric utility industry.

  • 28.
    Bottura, Riccardo
    et al.
    Department of Electrical, Electronic and Information Engineering (DEI), University of Bologna.
    Babazadeh, Davood
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Zhu, Kun
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Borghetti, Alberto
    Department of Electrical, Electronic and Information Engineering (DEI), University of Bologna.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nucci, Carlo Alberto
    Department of Electrical, Electronic and Information Engineering (DEI), University of Bologna.
    SITL and HLA Co-simulation Platforms: Tools for Analysis of the Integrated ICT and Electric Power System2013In: 2013 IEEE EUROCON, 2013Conference paper (Refereed)
    Abstract [en]

    Due to the necessity of developing analysis tools inthe integrated ICT and power system domain, this paperdescribes and compares the architecture and configuration oftwo different co-simulation approaches called SITL and HLACo-simulation platforms. We provide several details on theirimplementation and present their features by means of theresults obtained for two test cases. The paper aims at clarifyingthe type of analysis that can be effectively carried out by usingthe two different platforms. Both platforms make use of thecommunication network simulator OPNET (Optimum NetworkPerformance). One of the two platforms operates in real time, inorder to perform system-in-the-loop (SITL) simulations. Theother platform is based on the interface between OPNET and thepower network simulation environment EMTP (ElectromagneticTransient Program). The interface is based on the application ofthe High-Level Architecture (HLA) standard.

  • 29.
    Brodén, Daniel
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Armendariz, Mikel
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems. KTH, Superseded Departments (pre-2005), Electrical Systems. KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Anticipating Overrides of Schedulable Space Heating Systems in Detached Houses for Demand ResponseIn: Article in journal (Other academic)
    Abstract [en]

    In this paper we propose and evaluate two cases of a model predictive scheduling approach to anticipate overrides of schedulable electric space heating systems in detached houses. We assume a demand-response set-up where the space heating systems of a population of heterogeneous detached houses are scheduled over a finite horizon with the objective of having their aggregated space heating load follow a desired load profile. We envision that the desired load profile provides hourly to sub-hourly ancillary services to electricity market actors and define schedule overrides as the interruption of demand response following a violation of the indoor temperature comfort in a house. We use a model to represent the indoor temperature change in detached houses on minute resolution which considers, among other variables, weather- and individual behavioral-related heat gains and losses in the building. The model predictive scheduling approach is evaluated on a use-case consisting of a balance responsible player looking to minimize its daily expected power imbalances on the intraday market. The scheduling is performed on 100 detached houses participating in demand-response for two predictive cases and a non-predictive case for comparison. The predictive cases differ in the level of information known about thebuilding attributes of the population. Simulations are performed for 90 consecutive days corresponding to a Swedish winter period where results indicate power imbalance reductions of up to 30% and notable differences between predictive cases.

  • 30.
    Brodén, Daniel
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Paridari, Kaveh
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems. KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems. KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    MATLAB Applications to Generate Synthetic Electricity Load Profiles of Office Buildings and Detached Houses2017Conference paper (Refereed)
    Abstract [en]

    In this paper we present two MATLAB applications that generates synthetic electricity load profiles for office buildings and detached houses down to 1-minute resolution. The applications have been developed using App Designer — a MATLAB environment for application development. The applications are based on consumer load models for office buildings and detached houses published in previous research work. The aim of this paper is to present an overview of the application functionalities, code design, assumptions and limitations, and examples of their potential use in power system education and research. To the author’s knowledge these are the first applications which allow generating synthetic load profiles for office buildings and houses in practical and intuitive manner where building attributes can be easily configured.

  • 31.
    Brodén, Daniel
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Sandels, Claes
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Assessment of Congestion Management Potential in Distribution Networks using Demand-Response and Battery Energy Storage2015In: Innovative Smart Grid Technologies Conference (ISGT), 2015 IEEE Power & Energy Society, IEEE conference proceedings, 2015Conference paper (Refereed)
    Abstract [en]

    The integration of large shares of renewable energy sources in distribution grids runs the risk of outpacing the capacity of the network. Thus, high investment costs are expected at distribution system level to expand the existing grid to manage, among other challenges, anticipated congestion. This paper involves a study of the technical feasibility of using an ancillary service toolbox including day- and hour-ahead demand-response and battery energy storage as an alternative to grid expansion. The ancillary service toolbox is applied on radial distribution grids having large shares of renewable generation, controllable loads and power export capability to the overlaying power grid. The toolbox is simulated for a real use case presenting results on required demand-response participants and operation of flexibility resources for different congestion scenarios. The study concludes that the ancillary service solution is technically feasible for the use case, which may imply network investment deferral for distribution system operators.

  • 32.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Al Khatib, Iyad
    Ivanovski, Jordan
    Maden, Volkan
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    PMU traffic shaping in IP-based wide area communication2010In: 2010 5th International Conference on Critical Infrastructure, CRIS 2010 - Proceedings, IEEE conference proceedings, 2010, p. 1-6Conference paper (Refereed)
    Abstract [en]

    Phasor based Wide Area Monitoring and Control (WAMC) Systems are becoming a reality with increased research, development and deployments. Many potential control applications based on these systems are being proposed and researched. Such applications are either local applications using data from one or a few Phasor Measurement Units (PMUs) or centralized utilizing data from several PMUs. An aspect of these systems, which is less well researched, is the WAMC system dependence on high performance communication. This paper presents results of research on the use of Internet Protocol (IP) networks for both PMU and Remote Terminal Unit (RTU)/Intelligent Electronic Devices (IED) data for monitoring purposes. The paper examines performance aspects of the IP network Infrastructures when utilized by both: continuous PMU data streams and critical IED/RTU data. A set of simulation models characterizing a network of a Nordic Transmission System Operator were built to perform the analysis. The paper considers Quality of Service (QoS) strategies and the resulting delays and data loss that would be experienced.

  • 33.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Karam, Elias
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Modeling and Simulation of Wide Area Monitoring and Control Systems in IP-based Networks2009In: 2009 IEEE POWER & ENERGY SOCIETY GENERAL MEETING, VOLS 1-8, New York, USA: IEEE , 2009, p. 2514-2521Conference paper (Refereed)
    Abstract [en]

    Phasor based Wide Area Monitoring and Control Systems (WAMC) is becoming a reality with increased international research and development. Many aspects of these systems are being addressed and researched. These systems depend largely on high performance communication architecture. This paper addresses the analysis of PMU systems and communication architectures by utilizing simulation tools to implement and analyze models. Specifically, focusing on the transmission of Phasor samples to the Phasor Data Concentrator (PDC) and control signals from the WAMC systems back to substations devices. This done by implementing shared and dedicated communication network scenarios to analyze delays. This is the first step to analyzing the performance and scalability of the IT infrastructure to support PMU-based Systems.

  • 34.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Investigation of communication delays and data incompleteness in multi-PMU wide area monitoring and control systems2009In: 2009 International Conference on Electric Power and Energy Conversion Systems, EPECS 2009, 2009, p. 144-149Conference paper (Refereed)
    Abstract [en]

    Phasor based Wide Area Monitoring and Control Systems (WAMC) are becoming a reality with increased international research and development. Many potential control applications based on these systems are being proposed and researched. An aspect which is less well investigated is the WAMC system's dependence on high performance communication systems. This paper presents the results of simulations performed in order to determine the characteristics of communication delays incurred in WAMC systems using multiple PMUs distributed over a large geographic area. Such systems normally include one or several Phasor Data Concentrator (PDC) that collect and sort the data from the PMUs. Two specific parameters, completeness and currency of the PMU data has been studied as part of the simulations. The results indicate that configuration of central nodes such as the PDC needs to be optimized based on the intended WAMC application being supported.

  • 35.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Modeling and Simulation of Wide Area Communication for Centralized PMU-based Applications2011In: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 26, no 3, p. 1372-1380Article in journal (Refereed)
    Abstract [en]

    Phasor-based wide-area monitoring and control (WAMC) systems are becoming a reality with increased research, development, and deployments. Many potential control applications based on these systems are being proposed and researched. These applications are either local applications using data from one or a few phasor measurement units (PMUs) or centralized utilizing data from several PMUs. An aspect of these systems, which is less well researched, is the WAMC system's dependence on high-performance communication systems. This paper presents the results of research performed in order to determine the requirements of transmission system operators on the performance of WAMC systems in general as well as the characteristics of communication delays incurred in centralized systems that utilize multiple PMUs distributed over a large geographic area. This paper presents a summary of requirements from transmission system operators with regards to a specific set of applications and simulations of communication networks with a special focus on centralized applications. The results of the simulations indicate that the configuration of central nodes in centralized WAMC systems needs to be optimized based on the intended WAMC application.

  • 36.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Performance considerations in Wide Area Monitoring and Control Systems2010In: 43rd International Conference on Large High Voltage Electric Systems 2010, CIGRE 2010, 2010, p. 1-8Conference paper (Refereed)
    Abstract [en]

    Phasor based Wide Area Monitoring and Control (WAMC) Systems are becoming a reality with increased research, development and deployments. Many potential control applications based on these systems are being proposed and researched. Such applications are either local applications using data from one or a few PMUs or centralized utilizing data from several PMUs. An aspect of these systems which is less well researched is the WAMC system's dependence on high performance communication systems. To understand the performance and scalability requirements for such systems, a survey on communications and technical requirements for applications based on Phasor Measurement Units (PMU) has been performed. The survey was carried out in the Nordic Region with participants from Transmission System Operators (TSOs) and researchers. The survey focused on documenting the state of art that TSOs and researchers are in, as well as, their plans and visions for the future. This includes planned PMU deployments and prioritization of PMU based applications, a brief summary of this survey is described in this paper. Furthermore, the paper also summaries work in which WAMC communication networks were modeled and simulated. Two basic paradigms were captured in these models: Shared communication and dedicated communication. In the shared communication the WAMC system operated on wide area network that is also utilized for other devices such as RTUs, as well as other possible network uses. In the dedicated model it was assumed that the network was only used for PMU data. 4 scenarios were implemented and simulated. These scenarios represented parameters such as bandwidth capacity or channel capacity variation as well as variations in overall network traffic. Various End to End (ETE) Delay values were collected. A further study focused on analyzing the impact of the PDC configurations on the overall End to End (ETE) delay and measurement quality specifically in terms of measurement data loss or completeness. These studies were done by varying the delays of PMU traffic in the network as well as the amount of time that the PDC would wait for measurements belonging to a specific timestamp arrived from all PMUs in the network. In the paper, a set of parameters that impact the overall performance, including transmission delays as well as delays depending on system architecture and use of PDC within WAMC systems are outlined. These parameters were modeled and simulated and the results compared to the finding from the PMU application survey conducted earlier.

  • 37.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Performance Considerations in Wide Area Monitoring and Control Systems2010In: Water and Energy International, ISSN 0974-4711, Vol. 67, no 7Article in journal (Refereed)
  • 38.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Johnson, Pontus
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Factors in assessing performance of wide area communication networks for distributed control of power systems2007In: 2007 IEEE LAUSANNE POWERTECH, VOLS 1-5, NEW YORK: IEEE , 2007, p. 1682-1687Conference paper (Refereed)
    Abstract [en]

    This position paper presents research that is being started on the subject of modeling and evaluating performance and related system quality concerns in design of information and communication technology platforms used for power system operation and control. The focus of the project is on how the performance and other quality aspects of such networks interact with modern power control system technologies such as for instance Wide Area Monitoring and Control (WAMC) systems. Specifically the paper presents an evaluation and modeling approach based on a set of theoretically grounded factors important for assessing performance of wide area control systems. These assessment factors are used to define the modeling semantics necessary for enhanced models of the information and communication technology platforms. The factors are further represented in Influence Diagrams, enabling analysis of their inter-dependence with for instance Bayesian analysis. This approach has the potential of offering decision support for design of high performance information and communication technology platforms, while at the same time considering other system qualities. The paper presents an overview of the suggested approach, complemented with influence diagrams describing the inter-dependence of performance factors. The paper also provides an example of application of the approach to a simple control system architecture.

  • 39.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Ullberg, Johan
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Wu, Yiming
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Ericsson, Göran
    Swedish National Grid (Svenska Kraftnät), Sundbyberg, Sweden.
    A Framework for Wide-Area Monitoring and Control Systems Interoperability and Cybersecurity Analysis2014In: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 29, no 2, p. 633-641Article in journal (Refereed)
    Abstract [en]

    Wide-area monitoring and control (WAMC) systems are the next-generation operational-management systems for electric power systems. The main purpose of such systems is to provide high resolution real-time situational awareness in order to improve the operation of the power system by detecting and responding to fast evolving phenomenon in power systems. From an information and communication technology (ICT) perspective, the nonfunctional qualities of these systems are increasingly becoming important and there is a need to evaluate and analyze the factors that impact these nonfunctional qualities. Enterprise architecture methods, which capture properties of ICT systems in architecture models and use these models as a basis for analysis and decision making, are a promising approach to meet these challenges. This paper presents a quantitative architecture analysis method for the study of WAMC ICT architectures focusing primarily on the inter-operability and cybersecurity aspects.

  • 40.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Bengtsson, Sebastian
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Implementation of an experimental wide-area monitoring platform for development of synchronized phasor measurement applications2011In: Power and Energy Society General Meeting, 2011 IEEE, IEEE , 2011, p. 1-8Conference paper (Refereed)
    Abstract [en]

    Synchrophasor-based Wide-Area Monitoring and Control Systems (WAMC) are becoming a reality with increased international research and development. Several monitoring and control applications based on these systems have been proposed, and although with a relative small adoption, they are currently supporting the operations of some large transmission system operators. It is expected that the continued research and development of phasor data applications will enable the miracle of #x201C;Smart Grids #x201D; at the transmission level. The authors have realized that this can be achieved in timely fashion only if a research and development platform is developed to simultaneously address issues regarding information and communication infrastructures, and phasor data applications. This paper discusses the preliminary development, and deployment of an experimental wide-area monitoring and control platform in which several basic applications have been implemented, and that in the future will allow for the implementation and testing of envisioned applications. At its current stage, the platform allows both online monitoring and off-line analysis. In the future, it will be the cornerstone to a wider platform enabling research on phasor data applications that intrinsically account for ICT aspects.

  • 41.
    Chenine, Moustafa
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Zhu, Kun
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Survey on Priorities and Communication Requirements for PMU-based Applications in the Nordic Region2009In: 2009 IEEE Bucharest PowerTech: Innovative Ideas Toward the Electrical Grid of the Future, IEEE , 2009, p. 1183-1190Conference paper (Refereed)
    Abstract [en]

    Phasor based Wide Area Monitoring and Control Systems (WAMC) promise to offer more accurate and timely data on the state of the power system, thus, increasing the possibilities to manage the system at a more efficient and responsive level and apply wide area control and protection schemes. This paper presents results of a survey on communications and technical requirements for applications based on Phasor Measurement Units (PMU). The survey was carried out in the Nordic Region with participants from Transmission System Operators (TSOs) and researchers. The survey focused on documenting the stage of research and development among TSOs and researchers in the Nordic Region, as well as, their plans and visions for the future. This includes planned PMU deployments and prioritization of PMU based applications. Furthermore, a significant part of the survey was an elicitation of communication requirements for applications based on PMU data. In the paper, an examination of the time requirements for these applications in terms of delays and samples per second and comparison similar published specifications is provided.

  • 42.
    Ekstedt, Mathias
    et al.
    KTH, Superseded Departments, Electrical Systems.
    Johnson, Pontus
    KTH, Superseded Departments, Electrical Systems.
    Lindström, Åsa
    KTH, Superseded Departments, Electrical Systems.
    Johansson, Erik
    KTH, Superseded Departments, Electrical Systems.
    Nordström, Lars
    KTH, Superseded Departments, Electrical Systems.
    Management of Enterprise Software System Architectures: Focusing on Information Economy and Model Consistency2003In: Proceedings of the 3rd Conference on Software Engineering Research and Practice in Sweden, 2003Conference paper (Refereed)
  • 43.
    Elfstadius, Martin
    et al.
    Linköpings Universitet.
    Gecer, Daniel
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Axehill, Daniel
    Linköpings Universitet.
    Method to detect and measure potential market power on electricity markets using the concept of monopolistic energy2009In: 2009 IEEE/PES Power Systems Conference and Exposition, PSCE 2009, Seattle, WA, 2009Conference paper (Other academic)
    Abstract [en]

    The existence of market power is a serious concern in modern electric energy markets. Systems and processes that monitor the trading is needed and much research and many proposals on how to deal with the problem have been introduced over the past couple of years. A challenge to all such methods is execution speed, since the identification of market power needs to be done in real-time as market prices are settled. To overcome this challenge the methods need to be simple, involving limited computational effort. This paper presents a simple method with the potential of overcoming the challenge of execution speed. The method is based on the idea of determining the participants with the ability to make considerable increases in price raises without losing all market shares. Such determination can be made in advance during day ahead trading to identify critical areas. During realtime settlement, the method can then be used in a second iteration to study the identified critical areas. In the paper we propose a way to calculate the remaining market shares after a large price raise and refer to these as Monopolistic Energy Levels. These calculated levels of energy, that are deliverable by a single certain participant or by a certain group of participants, are caused by the active congestions in the network. The method detects the quantity of these energy levels and their respective locations in the network. This is a prospective method when used with a prediction of the following days demand. The paper presents the background and development of the proposed method. The use of AC and DC power flow as means to determine the monopolistic energy levels are analyzed and discussed. The paper is concluded with examples of application of the method to a simple multi area power system.

  • 44.
    Eriksson, Markus
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Armendariz, Mikel
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Vasilenko, Oleg
    Ericsson Innovations Russia.
    Saleem, Arshad
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Multiagent-Based Distribution AutomationSolution for Self-Healing Grids2015In: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948, Vol. 62, no 4, p. 2620-2628Article in journal (Refereed)
    Abstract [en]

    A multiagent-based distribution automationsolution is proposed to be used in the distribution of selfhealinggrids to solve the service restoration part of theFault Location, Isolation and Service Restoration (FLISR)task. The solution reduces the grid topology to an undirectedweighted graph and executes a distributed implementationof Prim’s minimum spanning tree algorithm tosolve the problem. The solution is compliant with state-ofthe-art standards within smart grids, including but not limitedto IEC61850. To test the performance of the algorithm,a testbed is assembled consisting of a physical dc gridmodel and several Arduino microcontrollers and RaspberryPi computers. The test results show that the proposedalgorithm can handle complex FLISR scenarios.

  • 45. Esterl, Tara
    et al.
    Kaser, Stefanie
    Stifter, Matthias
    Austrian Institute of Technology.
    Kamphuis, René
    Toegepast Natuurwetenschappelijk Onderzoek.
    Galus, Matthias
    Renting, Marijn
    Rijneveld, Arnoud
    Targosz, Roman
    Widergren, Steve
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Brodén, Daniel
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Galsworthy, Stephen
    Valuation Analysis of Residential Demand Side Flexibility: Analysis of business cases and existing valuation frameworks2016Report (Other (popular science, discussion, etc.))
  • 46.
    Fidai, Muhammad Hassan
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Babazadeh, Davood
    KTH, School of Electrical Engineering (EES).
    Hanning, Jonathan
    DC Grids Simulation Center, ABB .
    Larsson, Tomas
    DC Grids Simulation Center, ABB .
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Real-time Implementation of Optimal Power Flow Calculator for HVDC Grids2015Conference paper (Refereed)
    Abstract [en]

    The aim of the paper is to present the centralized architecture for power balancing management in an HVDC, High Voltage Direct Current, grid connecting different AC areas with high penetration of variable energy resources. Such a centralized high level DC Supervisory Control (DCSC) that functions in slower time scale compared to outer level controller has been evaluated in a real time co-simulation test-bed. The test platform includes OPAL-RT’s eMEGAsim real time simulator to model the power system, the ABB’s industrial HVDC controller (MACH), real time communication simulator OPNET to model the communication network and finally the DCSC application which is implemented on a Linux machine. The DCSC consists of a network topology manager to identify the grid configuration and employs an Optimal Power Flow (OPF) calculator based on interior point optimization method to determine the set-point values for all HVDC stations in a grid. The OPF calculator takes into account the DC voltage, converter and DC line constraints. The performance of the DC supervisory control has been tested for various test cases for a 7-terminal HVDC grid. Test cases include I) Variable power generation from wind farms, II) Station disconnection and III) DC grid islanding. Besides, the proper sampling rate has been chosen and justified to show the benefit of frequent updating of set-point compared to letting the DC droop control scheme take over the mismatch in the system. The results of different test cases show that a DCSC can improve the power extraction from wind farms by updating the set-points following any change in the system. Using a 3.2 GHz machine, it approximately takes 15 ms for the DCSC to converge to a proper solution and send the updated set-points.

  • 47.
    Fidai, Muhammad Hassan
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Babazadeh, Davood
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Muthukrishnan, Arvind
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Supervisory Control for VSC-HVDC Grid Interconnecting AC Systems2015Conference paper (Refereed)
    Abstract [en]

    The aim of the paper is to introduce an independentsupervisory architecture for optimal control of power flow inHVDC grids. Such an independent DC supervisory control isable to manage the optimal operation of connecting VSCs incooperation with other AC SCADA systems. Identifying the gridtopology, DC supervisory control employs an optimal power flow(OPF) calculator based on interior point optimization method todetermine the setpoint values for all HVDC stations in a grid.The performance of such an independent supervisory control hasbeen studied through various test case scenarios using a real-timeco-simulation platform.

  • 48.
    Gammelgård, Magnus
    et al.
    KTH, Superseded Departments, Electrical Systems.
    Nordström, Lars
    KTH, Superseded Departments, Electrical Systems.
    Effect of New Regulatory Frameworks on Utilities’ Investment in Asset Management.2004In: Proceedings of the International Conference on Maintenance Systems, 2004Conference paper (Refereed)
  • 49.
    Gammelgård, Magnus
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Närman, Per
    KTH, School of Electrical Engineering (EES).
    Ekstedt, Mathias
    Nordström, Lars
    KTH, School of Electrical Engineering (EES).
    Business Value Evaluation of IT Systems: Developing a Functional Reference Mode2006In: Proceedings of the the Fourth Conference on Systems Engineering, 2006Conference paper (Refereed)
    Abstract [en]

    In this paper an approach to develop and refine a functional reference model for IT-systems is presented. Such reference models form a fundament on which to evaluate the business value of IT systems. The approach involves scrutinizing the functional reference model with respect to correctness, completeness, granularity and measurability. In the particular case of this study, the functional reference model represents systems functionality needed to support asset management processes in industries such as electric energy production and distribution. It is based on the IEC 61968 standard and its Interface Reference Model, IRM, which has been refined in the process described in the paper. The refinement included a comprehensive field study, interviewing experts in the field of asset management at a large European energy company, as well as vendors of asset management systems.A general method for evaluating IT investment scenarios is outlined in the paper and the refined functional reference model is an important component in this method. Creation of this IT evaluation method is an ongoing research project, where the functional reference model forms a central part. The purpose of the IT investment evaluation method is to give decision makers a tool to evaluate potential investment scenarios with respect to the value the investment would generate to the business. The first part of the method consists of evaluating the technical quality of the system scenarios. Technical quality is divided into functional and non-functional attributes, where the functional reference model is used for the functional assessment. The second part of method consists of establishing the business value based on the evaluation of the technical qualities. This paper thus focuses on the first part, and in particular the development of the functional reference model which is a central piece in the IT investment evaluation method.

  • 50.
    Gustafsson, Pia
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Johnson, Pontus
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Enterprise architecture: A framework supporting organizational performance analysis2009In: IET Conference Publications: Issue 550 CP, 2009, Prague, 2009, no 550 CPConference paper (Refereed)
    Abstract [en]

    Enterprise Architecture is a model-based approach to business-oriented IT management. To promote good IT decision making, an enterprise architecture framework needs to explicate what kind of analyses it supports. It is desirable to create enterprise architecture models based on metamodels that support well-defined analyses. In this paper we use enterprise models to analyze the performance of the maintenance organization. A set of performance indicators from the area is presented in the shape of an extended influence diagram. An example illustrates that the theory-based metamodel does support organizational performance analysis.

1234 1 - 50 of 174
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