IEC 61788-14 pdf download

IEC 61788-14 pdf download Superconductivity – Part 14: Superconducting power devices – General requirements for characteristic tests of current leads designed for powering superconducting devices
1 Scope
This part of IEC 61 788 provides general requirements for characteristic tests of conventional as well as superconducting current leads to be used for powering superconducting equipment.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60050-81 5:2000, International Electrotechnical Vocabulary (IEV) – Part 815:Superconductivity
IEC 60071 -1 , Insulation coordination – Part 1: Definitions, principles and rules
IEC 601 37, Insulated bushings for alternating voltages above 1 000 V
3 Terms and definitions
For the purposes of this document, the terms and definitions contained in IEC 60050-81 5:2000 as well as the following terms and definitions apply:
3.1
current lead
power lead
conductor to introduce electric current into a device with an insulation and a cooling channel especially when leading from room temperature to cryogenic temperature
[IEV 81 5-06-47]
3.2
normal conducting current lead
conventional current lead
current lead made only of a normal conducting section
3.3
superconducting current lead
current lead containing a superconducting section
NOTE A superconducting current lead consists of a normal conducting section from room temperature to intermediate temperature and a superconducting section from intermediate temperature to cryogenic temperature. In this standard,the superconducting section is mostly made by a high temperature superconductor (HTS).
3.4
non-gas cooled type current lead
current lead cooled by conduction cooling method
3.5
gas-cooled type current lead
current lead cooled by a cooling gas
NOTE In some cases, the gas cooling is made between cooling via gas flow inside the leads and (additional) convection cooling on the outside surface.
3.6
self-cooled current lead
vapour enthalpy cooled current lead
current lead capably cooled by an evaporated gas generated by heat load from current leads into cryogen
3.7
heat leakage
non-current heat leakage
heat conducted from higher temperature portion into lower temperature portion of the current lead at zero current operation without any Joule heating
3.8
heat load
total heat induced into a cryogenic system through the current leads under current-carrying operation
3.9
rated current heat load
heat load at a rated current operation
4 Principles
The powering of superconducting equipment is made via components that provide the electrical link between the room temperature environment and the cryogenic temperature of the powered equipment. These components are called current leads. Since they operate in a gradient of temperature and they transport current into the cryogenic environment, they are one of the major sources of a heat leakage into the cryostat.