Study of AC Loss and Temperature Distribution of a BSCCO Coil Cooled in Liquid Nitrogen or Using a Cryocooler

Abstract

The prediction of critical current of the HTS coil is necessary in the HTS coil applications. This paper focuses on the AC loss and the temperature distribution of a BSCCO coil, based on the electro-thermal coupling of the AC loss and the environment, with an emphasis on the cooling boundary. The major concern of this paper is the balance between the AC loss and the cooling efficiency of the environment. This paper first provides a 2-D axisymmetric model based on the resistivity-adaption algorithm method and heat conduction equations. Then, the BSCCO coil with different thermal contact conditions and cooling methods are discussed. A 52-turn Bi2223/Ag double-pancake coil is tested. The measurement of surface temperature is compared with the model result, showing good consistency. The critical current decreasing with the increasing frequency was observed. In the cryocooler cooled situation, the coil stability might be achieved with a more economic cryocooler through operating at a lower temperature.