Method of modeling twist pitch effect upon static current diffusion in lap joints between superconducting cables

The DC resistance of a lap joint between cabled superconductors can be accurately calculated using a finite element model of static current diffusion. Such models can become too complex to solve, however, if too many cable details, such as multiple filaments, multiple strands, solder, and twist are included. One of the most complicated details to model is the cable twist. In this paper, two methods are developed to include cable twist when predicting joint losses under steady-state conditions. Both methods are applied to a hypothetical lap joint configuration and comparison of the associated results indicates close agreement. These results also suggest that if cable twist is ignored, the resistance calculation will give a value that is too large.