| 1. |
- Andreasson, Martin, 1987-, et al.
(författare)
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Distributed Primary Frequency Control through Multi-Terminal HVDC Transmission Systems
- 2015
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Ingår i: American Control Conference (ACC), 2015. - : IEEE conference proceedings. - 9781479986859 ; , s. 5029-5034
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Konferensbidrag (refereegranskat)abstract
- This paper presents a decentralized controller for sharing primary AC frequency control reserves through a multi-terminal HVDC grid. By using passivity arguments, the proposed controller is shown to stabilize the closed-loop system consisting of the interconnected AC and HVDC grids, given any positive controller gains. The static control errors resulting from the proportional controller are quantified and bounded by analyzing the equilibrium of the closed-loop system. The proposed controller is applied to a test grid consisting of three asynchronous AC areas interconnected by an HVDC grid, and its effectiveness is validated through simulation.
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| 2. |
- Andreasson, Martin, 1987-, et al.
(författare)
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Distributed Secondary Frequency Control through MTDC Transmission Systems
- 2015
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Ingår i: Decision and Control (CDC), 2015 IEEE 54th Annual Conference on. - : IEEE conference proceedings. - 9781479978847 ; , s. 2627-2634
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present distributed controllers for sharing primary and secondary frequency control reserves for asynchronous AC transmission systems, which are connected through a multi-terminal HVDC grid. By using passivity arguments, the equilibria of the closed-loop system are shown to be globally asymptotically stable. We quantify the static errors of the voltages and frequencies, and give upper bounds for these errors. It is also shown that the controllers have the property of power sharing, i.e., primary and secondary frequency control reserves are shared fairly amongst the AC systems. The proposed controllers are applied to a high-order dynamic model of of a power system consisting of asynchronous AC grids connected through a 6-terminal HVDC grid.
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| 4. |
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Entrepreneurship, social capital and governance : Directions for the sustainable development and competitiveness of regions
- 2012. - 1
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- This book highlights the role of entrepreneurship, social capital and governance for regional economic development. In recent decades, many researchers have claimed that entrepreneurship is the most critical factor in sustaining regional economic growth. However, most entrepreneurship research is undertaken without considering the fundamental importance of the regional context. Other research has emphasized the role of social capital but there are substantial problems in empirically relating measures of social capital to regional economic development. © Charlie Karlsson, Börje Johansson and Roger R. Stough 2012. All rights reserved.
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| 5. |
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| 6. |
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| 7. |
- Johansson, Börje, et al.
(författare)
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Entrepreneurship and Development - local processes and global patterns
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The general motivation for this paper is the current interest in globalization as a phenomenon that strongly affects the conditions of local economic development. Our purpose is to contribute to some of the current development aspects, in particular those that foster the evolution of entrepreneurs in local-global processes. We present four eras of globalization, in recent decades and which have been described as different aspects of globalization are not new at all. In conclusion, we stress that those global patterns of change that are observed, and reported in the media and by social scientists are the result of innumerable local processes driven by economic, political and social entrepreneurs in localities, regions, and nations all around the globe.
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| 8. |
- Johansson, Börje, et al.
(författare)
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Entrepreneurship and Innovation in Functional Regions
- 2008
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this paper is to discuss the role of entrepreneurship and innovations foreconomic development in functional regions and in doing that highlighting the differentconditions offered for entrepreneurship and innovations in functional regions of various sizes.In conclusion, the conditions for entrepreneurship and innovations vary substantially betweenfunctional regions, since the necessary knowledge resources tend to be local and to cluster incertain regions and not others. Functional regions with a high capacity to generate new ideas,create knowledge, organizational learning and innovations are characterized as learningregions. Large functional regions offer a large market potential and a superior accessibility toknowledge and knowledge resources and they will further develop their creative capabilitiesdue to an accumulation of innovative and entrepreneurial knowledge.
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| 9. |
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| 10. |
- Johnson, Magnus, et al.
(författare)
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Mechanisms of the CO2 Insertion into (PCP) Palladium Allyl and Methyl sigma-Bonds. A Kinetic and Computational Study
- 2010
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Ingår i: Organometallics. - : American Chemical Society (ACS). - 0276-7333 .- 1520-6041. ; 29:16, s. 3521-3529
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Tidskriftsartikel (refereegranskat)abstract
- The reaction of the sigma-bonded (PCP)Pd-Me complex (PCP = 2,6-bis[(di-tert-butylphosphino)methyl]phenyl) with CO2 is first-order in palladium and first-order in CO, with a rate constant k(s) = 8.9 +/- 0.8 M-1 s(-1) at 353 K. Activation parameters are Delta H double dagger = 73 7 kJ/mol and Delta S double dagger = 118 +/- 19 J/K mol. Based on this and theoretical calculations we propose an S(E)2 mechanism where the coordinated methyl group attacks a completely noncoordinated carbon dioxide molecule in a bimolecular reaction. The PCPPd-crotyl complex was synthesized in an 65:35 E:Z mixture, and it was shown to react with CO, to give the complex PCPPd-O(CO)CH(CH3)CHCH2 as a single isomer, where the former gamma-carbon has been carboxylated. Theoretical calculations again suggest an S(E)2 mechanism with a noncoordinated carbon dioxide reacting with the terminal carbon on the allyl group, forming an eta(2)-bonded olefin complex as an intermediate. The rearrangement of this intermediate to the O-bonded product is concluded to be rate determining. The crystal structure of PCPPd-O(CO)C(CH3)(2)CHCH2 is reported and as well as the solubility of carbon dioxide in benzene-d(6) at different pressures and temperatures.
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