The cooling system of high-temperature superconductivity (HTS) applications has become the most important issue in this field nowadays. Some HTS applications are mostly developed as systems that have an established place in our society. However, cooling systems are not developed for the HTS applications and are still in the experimental stage. Cooling systems should be developed as systems which can be used in the commercial world. In this paper, cooling systems, refrigerators and pumps were described and the available and the required cooling systems were shown.
As energy storage equipment for electric power systems, superconducting magnetic energy storage (SMES) systems have good characteristics such as high efficiency, quick response and no deterioration under repeated operations. Since 1991, a national project by the Agency for National Resources and Energy Japan has been carried out to develop an SMES system for power control in a power system. Moreover, SMES has been developed as a bridge for instantaneous voltage dips since 2003. In this issue, cooling systems and cryocoolers for SMES are introduced.