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Showing papers by "Jacob Østergaard published in 1999"


Journal ArticleDOI
TL;DR: In this article, a 4-layer three meter long prototype superconducting cable conductor with self and mutual inductances of the layers is studied theoretically. And the current distribution between the super-conducting layers is monitored as a function of transport current.
Abstract: One important issue in the design and optimization of a superconducting cable conductor is the control of the current distribution between single tapes and layers. This presentation is based on a number of experiments performed on a 4-layer three meter long prototype superconducting cable conductor. The self and mutual inductances of the layers are studied theoretically. The current distribution between the superconducting layers is monitored as a function of transport current. The results are compared with the expected current distribution given by the authors' equivalent electrical circuit model. The AC losses are measured as a function of transport current and a given current distribution and compared with the monoblock model. Recommendations for design of future cable conductor prototypes are given.

89 citations


Journal ArticleDOI
TL;DR: The planned large groups of off-shore windmills in Denmark generating up to 400 MVA or more will be an obvious case for the application of superconducting AC or DC cables.
Abstract: In Denmark a growing concern for environmental protection has lead to wishes that the number of overhead lines is reduced as much as possible and that the energy supply should be shifted to renewable energy sources, e.g. windmills. Superconducting cables represent an interesting alternative to conventional cables, as they have other characteristics than conventional cables and will be able to transmit two or more times the current. Superconducting cables are especially interesting as a target for replacing overhead lines. Superconducting cables in the overall network are of interest in cases such as transmission of energy into cities and through areas of special beauty. The planned large groups of off-shore windmills in Denmark generating up to 400 MVA or more will be an obvious case for the application of superconducting AC or DC cables. These opportunities can be combined with other new technologies such as high voltage DC (HVDC) based on isolated gate bipolar transistors (IGBTs). The network needed in a system with a substantial wind power generation has to be quite stiff in order to handle energy fluctuations. Such a network may be possible, e.g., using superconducting cables.

14 citations