Thermal Design of a Cryogenics Cooling System for a 10 MW-Class High-Temperature Superconducting Rotating Machine

A cooling system is an essential part of high-temperature superconducting (HTS) rotating machine manufacturing. Moreover, thermal behavior is a crucial parameter of the cooling system that shows unique characteristics of superconductivity below a specific temperature to maintain a superconducting state. Therefore, many experiments have been performed to investigate new reliable cryogenic cooling systems for a large-scale HTS rotating machine. The motivation for the study is our recent development of the cryogenic cooling system using thermal trigger switches; it effectively minimizes non-operational downtime of the HTS machine in cases of power supply or cryocooler failure. This paper focuses on two main targets. First, the thermal design of the cooling system for the 10 MW-class HTS rotating machine is enhanced. Second, the performance of the cooling system is observed for various cryogens to investigate the feasibility of using solid cryogen.