Estimation for the performance of superconducting DC transmission lines with cryogenics improvements

Recent energy saving and environmental protection highly demand the development of new technology such as superconducting applications. At Chubu University, we have developed direct current (DC) superconducting 20 m transmission lines as a working trial system for the actual applications. Our parameter is promising for long distance transmission with low pump power. On the other hand, superconducting DC distribution is also useful in green internet technology such as the energy saving in the internet data center. However, such short length superconducting applications require special thermal designs because the heat leak into the system is comparably larger than the energy reduction in superconducting cables. From the viewpoint of cryogenics, high performance current lead is in high demand such as the Peltier current lead (PCL). With the improvements of current leads, we can reduce the heat leak to reach the very low loss systems required for the small superconducting application systems as the cost-effective ones. (C) 2010 Elsevier B.V. All rights reserved.