Study on the eddy current losses and thermal characteristic of a conduction-cooled HTS energy storage magnet

Abstract

During the dynamic response of conduction-cooled high temperature superconductor (HTS) energy storage magnet, the AC loss of the magnet and the eddy current losses of the cold-conducting plates are generated. These two losses seriously threaten the thermal stability of the magnet, especially eddy current losses when the cold-conducting plates are not slit. Therefore, it is important to find a simple and effective way to model and reduce eddy current losses of cold-conducting plates for the sake of thermal stability. In this paper, both an effective 3D model to evaluate eddy current losses of cold-conducting plates and an efficient reduction scheme are proposed. The results prove that the eddy current loss of single cold-conducting plate is reduced by 99.9%, but the existence of longitudinal slit greatly affects its heat transfer efficiency. The epoxy impregnation method is further proposed to alleviate this influence availably, and the validity of homogenization method in the thermal analysis of magnets is verified.