Strand Joint Losses in Superconductors Employing Monolithic High Purity Aluminum Stabilizers
Computer simulations of ohmic joint heating in the Superconducting Magnetic Energy Storage — Engineering Test Model (SMES-ETM) conductor have been conducted at the Westinghouse Science & Technology Center as part of the Ebasco SMES team effort. The presence of soldered-butt type strand joints in high field regions of the SMES coil causes superconductor strand current to divert through finite lengths of the surrounding aluminum stabilizer. Localized zones of steady-state heat generation result from this current transfer phenomenon. In this work, a three-dimensional finite element model of the SMES ETM conductor joint geometry is developed to approximate the steady-state distributions of current and joule heating associated with each joint. The numerical results indicate that providing an axial separation between joints in adjacent strands substantially reduces conductor losses.
KeywordsFinite Element Model Heat Generation Current Diffusion High Purity Aluminum Current Transfer
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