Superconducting traction transformer

An ongoing project to develop HTS traction transformers for the Chinese Fuxing high-speed train is demonstrating that the high-power density can be reached using high-temperature superconductors (HTS). The findings are spectacular: the existing 6.5 MVA traction transformers can be replaced with drop-in superconducting transformers, achieving targets of less than 3 tons transformer system weight and 99.5 % efficiency compared to 6 tons and 95 % in the existing devices. The key to achieving these impressive figures is minimizing the AC loss of the HTS windings. New high-performance wire, high current HTS Roebel conductor, high aspect-ratio windings, and flux diverters placed at the winding ends all contribute to reducing the electrical loss to less than 2 kW