25 research outputs found
The temperature dependence of the dielectric strength of transformer oil and pressboard insulation at HVDC polarity reversal stress
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Zur Ontologie und Subjektivit\ue4t der Zeit
No full textDie Frage nach dem Ph\ue4nomen \u201eZeit\u201c ist nicht ohne das mensch-liche Begreifen als sich-selbst-erfahrendes Bewusstsein und den Horizont der sich unabl\ue4ssig \ue4ndernden Naturwirklichkeit m\uf6glich. Die Frage nach der Zeit ist sehr komplex und deswe-gen ist sicher ratsam sie aus verschiedenen Gesichtspunkten zu behandeln. Zum Beispiel aus der Perspektive der Literatur und Philosophie der Antike. Oder aus den tiefen psychologi-schen Analysen von Augustinus. Immanuel Kant nahm auch die Zeitfrage in den Horizont seinem erkenntnistheoretischen System hinein und will sie mit seinem Wage zu wissenbeantworten. Es ist auch von Interesse auf die Typologie biblischer Motive und Strukturen \ufcber die Zeit acht zu geben. Den irritierenden R\ue4tselcharakter der Zeit bringt Augustinus in seinen Confessiones auf pr\ue4gnante Weise zum Ausdruck: \u201cWas ist also Zeit? Wenn nie-mand mich fragt, so wei
f ich \u301s; will ich \u301s einem Fragenden erkl\ue4ren, so wei
f ich \u301s nicht\u201c. Wie ein nicht weichender Schatten begleitet die Zeit den Menschen. Versucht er aber sie zu bestimmen, so entzieht sie sich ihm wie ein grosses Geheimnis \u2013 allm\ue4chtig und wesenlo
Cable systems in multi purpose or shared structures
No full textWith the increase in demand and the challenges posed by the design and installation of high voltage (HV) and extra high voltage (EHV) cables in congested right of ways, structures such as tunnels and bridges for multipurpose use are becoming an attractive option. Cigre’s working group B1.08 met in various parts of the world and developed engineering guidelines on Cable Systems in Multi Purpose or Shared Structures during 2006-9. This working group had electrical cable engineers from Australia, Austria, Canada, France, Italy, Japan, Korea, Netherlands, Singapore, Spain, Sweden, and the United Kingdom, and a civil engineer from the United States.
With the increase in demand and the challenges posed by the design and installation of high voltage (HV) and extra high voltage (EHV) cables in dense urban and other congested right of ways, structures such as tunnels and bridges for multipurpose use are becoming an attractive option. They offer reduced overall costs, environmental advantages and less disruption to the community during installation, maintenance and replacement of cables and other services. In the Cigre’ WG B1-08.9.3, the reader can follow Sections 1 to 5 and review the examples described in Section 8 to decide if a shared structure is appropriate. If the decision is to use a shared structure, Sections 6 and 7 offer expert guidance on various technical and administrative issues, forming a wonderful reference document on the design and implementation of such a system. Section 8 indeed is a review of the international experience of HV cables in multipurpose or shared structures, offering prior established experienced in this field. Future trends are summarized in Section 9. Section 10 offers a list of 60 references. A comprehensive appendix presents the results of TF B1-14, which surveyed through comprehensive questionnaires on the global use of cables and structures. The same issue for Gas Insulated Lines (GIL) has been reviewed by JWG B3/B1.09 in the TB 351 "Application of Long High Capacity Gas Insulated Lines in Structures."
Scope of Work
Due to the complexity of cabling in general, this study group elected to mainly deal with cable systems of 50 kV and above in multipurpose and shared structures where it felt that future investments are most likely to be made. There is no limitation to applying these principles, however, to cables of lower voltages
Italy-Austria GIL in the new planned railway galleries Fortezza-Innsbruck under Brenner Pass
No full textThe paper deals with the possibility of installing a double-circuit Gas Insulated transmission Line (GIL) in the pilot tunnel of the new planned railway galleries Fortezza-Innsbruck. The high GIL power ratings with very low power losses would allow a strong and highly efficient energy exchange particularly useful for the future European Market and could represent a new fundamental step in reconstructing the European interconnection network. Two separate railway tunnels (Φ ≈ 9,6 m) will run under the Brenner Pass from Fortezza (Italy) to Innsbruck (Austria) but will be preceded by the construction of a continuous pilot tunnel (Φ ≈ 4,3 m) useful for work logistics and chiefly for detection of the rock stratigraphy. Once the whole work will be over, the pilot tunnel will be used as a service gallery (drainage of water) where a double-circuit GIL can be efficiently installed. The paper gives the main characteristics of planned galleries, several details on the transmission line and its performance, the electro-magnetic field impact considering the proximity effects and the earthing arrangement in order to zero the touch-voltages in case of phase-to-enclosure short-circuit. The chief features of GIL solution are the lowest transmission power losses and the absence of shunt reactive compensation for this line length (appr. 65 km) but mostly the safety of personnel in case of short-circuit and the possibility of usual re-closure cycles for operation continuity. This paper gives an overview of other analysis: GIL no-load regime, electromagnetic interferences between railway and GIL system, pilot tunnel ventilation and GIL thermal regime. In order to achieve satisfying power flows, the new link requires both Italian/Austrian regional grids (380 kV÷110 kV) to be restructured and rationalised. This research is supported by European Community in the framework of TEN-ENERGY programme for analysing both, technical and environmental issues of integrating 380 kV Gas Insulated transmission Line and Rail Transport in tunnel between Italy and Austria entitled "Studies for a new 380 kV transmission line between Italy and Austria through the Brenner pass: Integration of Electricity and Rail Transport in Tunnel". The project leader is TERNA (Italian TSO) whereas the associated beneficiaries are the University of Padova and TIWAG-Netz AG (Tyrol TSO) with support of Graz University of Technology
