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\n\n \n \n \n \n \n Modelling the System Dynamics of Islanding Asynchronous Generators.\n \n \n \n\n\n \n Edvardsen, H. M.; and Winkler, D.\n\n\n \n\n\n\n In Tummescheit, H.; and Årzén, K., editor(s),
Proceedings of the 10th International Modelica Conference, pages 543–548, Lund, Sweden, March 2014. Linköping University Electronic Press, Linköpings universitet\n
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@inproceedings{modelica2014,\n title = {Modelling the System Dynamics of Islanding Asynchronous Generators},\n booktitle = {Proceedings of the 10th {{International Modelica Conference}}},\n author = {Edvardsen, H{\\aa}kon Molland and Winkler, Dietmar},\n editor = {Tummescheit, Hubertus and {\\AA}rz{\\'e}n, Karl-Erik},\n year = {2014},\n month = mar,\n pages = {543--548},\n publisher = {Link{\\"o}ping University Electronic Press, Link{\\"o}pings universitet},\n address = {Lund, Sweden},\n doi = {http://www.ep.liu.se/ecp_article/index.en.aspx?issue=108;article=010},\n abstract = {Asynchronous generators are often used for small hydro power stations with an installed power capacity of under 1MW. The reason for this is their robustness and low cost. In order do be able to produce active electrical power with an asynchronous generator once needs to provide enough excitation by means of reactive power provided by either the electrical grid or additional capacitors. But in asynchronous generators we can also find the phenomenon of self-excitation which allows the asynchronous generator to operate as a standalone unit. Investigation of the self-excitation process shows that significant over-voltages can occur if a generator with sufficient capacitors is suddenly disconnected from the utility grid. The precondition for a successive voltage build-up is that the generator is left with enough capacitive power and a low load after the disconnection. The L{\\o}nnestad radial in Seljord, Norway, is a distribution radial with both asynchronous and synchronous generators connected. In order to investigate the system dynamics in the radial after it is disconnected from the rest of the 22kV distribution grid, the radial was modelled and simulated using Modelica as modelling language.},\n keywords = {asynchronous generators,electric power library,islanding,Modelica,self-excitation},\n annotation = {ISSN (print):1650-3686 ISSN (online):1650-3740},\n file = {/home/dietmarw/FoU/Publications/zotero/storage/JB2GR5EI/ecp14096101.pdf}\n}\n\n
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\n Asynchronous generators are often used for small hydro power stations with an installed power capacity of under 1MW. The reason for this is their robustness and low cost. In order do be able to produce active electrical power with an asynchronous generator once needs to provide enough excitation by means of reactive power provided by either the electrical grid or additional capacitors. But in asynchronous generators we can also find the phenomenon of self-excitation which allows the asynchronous generator to operate as a standalone unit. Investigation of the self-excitation process shows that significant over-voltages can occur if a generator with sufficient capacitors is suddenly disconnected from the utility grid. The precondition for a successive voltage build-up is that the generator is left with enough capacitive power and a low load after the disconnection. The Lønnestad radial in Seljord, Norway, is a distribution radial with both asynchronous and synchronous generators connected. In order to investigate the system dynamics in the radial after it is disconnected from the rest of the 22kV distribution grid, the radial was modelled and simulated using Modelica as modelling language.\n
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\n\n \n \n \n \n \n Power System Stability Using Modelica.\n \n \n \n\n\n \n Øyvang, T.; Winkler, D.; Lie, B.; and Hegglid, J. G.\n\n\n \n\n\n\n In
Proceedings of 'The 55th Scandinavian Conference on Simulation and Modeling (SIMS 2014)', of
Linköping Electronic Conference Proceedings, pages 120–127, Aalborg, Denmark, October 2014. Linköping University Electronic Press\n
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@inproceedings{Oyvang2014,\n title = {Power System Stability Using {{Modelica}}},\n booktitle = {Proceedings of '{{The}} 55th {{Scandinavian Conference}} on {{Simulation}} and {{Modeling}} ({{SIMS}} 2014)'},\n author = {{\\O}yvang, Thomas and Winkler, Dietmar and Lie, Bernt and Hegglid, John Gunne},\n year = {2014},\n month = oct,\n series = {Link{\\"o}ping {{Electronic Conference Proceedings}}},\n pages = {120--127},\n publisher = {Link{\\"o}ping University Electronic Press},\n address = {Aalborg, Denmark},\n doi = {10.3384/ecp14108010},\n abstract = {This paper is concerned with power system modeling using the Modelica language in comparison to a traditional simulation tool. Though most common power system simulation tools are computationally efficient and reasonably user-friendly, they have a closed architecture. Thus, there is motivation to use an open-source modeling language to describe electric networks, such as Modelica. A well-established benchmark for power system studies was analyzed. Regarding the voltage as a function of time, a reasonable agreement was found between the simulation results of the used simulation tools for long-term voltage stability. However, a comparison of faster electromechanical mechanisms, such as rotor angle stability, demands more detailed models in the Modelica tool.},\n copyright = {All rights reserved},\n file = {/home/dietmarw/FoU/Publications/zotero/storage/EGPE5PPW/ecp14108010.pdf}\n}\n\n
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\n This paper is concerned with power system modeling using the Modelica language in comparison to a traditional simulation tool. Though most common power system simulation tools are computationally efficient and reasonably user-friendly, they have a closed architecture. Thus, there is motivation to use an open-source modeling language to describe electric networks, such as Modelica. A well-established benchmark for power system studies was analyzed. Regarding the voltage as a function of time, a reasonable agreement was found between the simulation results of the used simulation tools for long-term voltage stability. However, a comparison of faster electromechanical mechanisms, such as rotor angle stability, demands more detailed models in the Modelica tool.\n
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\n\n \n \n \n \n \n Impact - A Modelica Package Manager.\n \n \n \n\n\n \n Tiller, M.; and Winkler, D.\n\n\n \n\n\n\n In Tummescheit, H.; and Årzén, K., editor(s),
Proceedings of the 10th International Modelica Conference, pages 543–548, Lund, Sweden, March 2014. Linköping University Electronic Press, Linköpings universitet\n
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@inproceedings{Tiller2014,\n title = {Impact - {{A Modelica Package Manager}}},\n booktitle = {Proceedings of the 10th {{International Modelica Conference}}},\n author = {Tiller, Michael and Winkler, Dietmar},\n editor = {Tummescheit, Hubertus and {\\AA}rz{\\'e}n, Karl-Erik},\n year = {2014},\n month = mar,\n pages = {543--548},\n publisher = {Link{\\"o}ping University Electronic Press, Link{\\"o}pings universitet},\n address = {Lund, Sweden},\n doi = {10.3384/ecp14096543},\n abstract = {To manage complexity, modern programming languages use organizational units to group code related by some common purpose. Depending on the programming language, these units might be called libraries, packages or modules. But they all attempt to encapsulate functionality to promote modular code and reusability. For the remainder of this paper, we will simply refer to these organizational units as packages (as they are called in Modelica). Also common to many modern programming languages are tools to manage these packages. These tools are generally called package managers and they allow developers to quickly ``fetch'' any packages they may need for a given project. The main functions of package managers are to allow developers to search, install, update and uninstall packages with a simple command-line or graphical interface. In the Java world, the most common package manager is maven. For Python, tools like easy\\_install and pip are used for managing packages. For clientside web development, bower is used. For serverside JavaScript, the tool of choice is npm. For compiled languages, these package managers often include some additional build functionality as well. This paper introduces impact, a package manager for Modelica. Using impact, Modelica users and developers can quickly search for, install and update Modelica libraries. In this paper, we will discuss the functionality provided by impact. In addition, we will discuss how the functionality was implemented. As part of this we will discuss the importance of collaborative platforms, like GitHub in our case, for providing a means for collecting, curating and distributing packages within a community of developers. The impact package manager is provided to the Modelica community as a free, open-source tool. Furthermore, the protocols involved are all documented and we encourage tool vendors to integrate them into their own tools so they can provide the same searching, updating and installation capabilities that the command-line tool provides.},\n keywords = {dependency management,GitHub,Modelica,package manager,Python},\n annotation = {ISSN (print):1650-3686 ISSN (online):1650-3740},\n file = {/home/dietmarw/FoU/Publications/zotero/storage/CQ49M2QB/ecp14096057.pdf}\n}\n\n
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\n To manage complexity, modern programming languages use organizational units to group code related by some common purpose. Depending on the programming language, these units might be called libraries, packages or modules. But they all attempt to encapsulate functionality to promote modular code and reusability. For the remainder of this paper, we will simply refer to these organizational units as packages (as they are called in Modelica). Also common to many modern programming languages are tools to manage these packages. These tools are generally called package managers and they allow developers to quickly ``fetch'' any packages they may need for a given project. The main functions of package managers are to allow developers to search, install, update and uninstall packages with a simple command-line or graphical interface. In the Java world, the most common package manager is maven. For Python, tools like easy_install and pip are used for managing packages. For clientside web development, bower is used. For serverside JavaScript, the tool of choice is npm. For compiled languages, these package managers often include some additional build functionality as well. This paper introduces impact, a package manager for Modelica. Using impact, Modelica users and developers can quickly search for, install and update Modelica libraries. In this paper, we will discuss the functionality provided by impact. In addition, we will discuss how the functionality was implemented. As part of this we will discuss the importance of collaborative platforms, like GitHub in our case, for providing a means for collecting, curating and distributing packages within a community of developers. The impact package manager is provided to the Modelica community as a free, open-source tool. Furthermore, the protocols involved are all documented and we encourage tool vendors to integrate them into their own tools so they can provide the same searching, updating and installation capabilities that the command-line tool provides.\n
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