DKE German Commission for Electrical, Electronic & Information Technologies of DIN and VDE
DIN EN 61788-8
; VDE 0390-8:2011-06
Superconductivity - Part 8: AC loss measurements - Total AC loss measurement of round superconducting wires exposed to a transverse alternating magnetic field at liquid helium temperature by a pickup coil method (IEC 61788-8:2010); German version EN 61788-8:2010
Supraleitfähigkeit - Teil 8: Messung der Wechselstromverluste - Messung der Gesamtwechselstromverluste von runden Supraleiterdrähten in transversalen magnetischen Wechselfeldern mit Hilfe eines Pickupspulenverfahrens bei der Temperatur von flüssigem Helium (IEC 61788-8:2010); Deutsche Fassung EN 61788-8:2010
Overview
This part of IEC 61788 specifies the measurement method of total AC losses by the pickup coil method in Cu/Nb-Ti composite superconducting wires exposed to a transverse alternating magnetic field. The losses may contain hysteresis, coupling and eddy current losses. The standard method to measure only the hysteresis loss in DC or low-sweep-rate magnetic field is specified in IEC 61788-13. In metallic and oxide round superconducting wires expected to be mainly used for pulsed coil and AC coil applications, AC loss is generated by the application of time-varying magnetic field and/or current. The contribution of the magnetic field to the AC loss is predominant in usual electromagnetic configurations of the coil applications. For the superconducting wires exposed to a transverse alternating magnetic field, the present method can be generally used in measurements of the total AC loss in a wide range of frequency up to the commercial level, 50 Hz or 60 Hz, at liquid helium temperature. For the superconducting wires with fine filaments, the AC loss measured with the present method can be divided into the hysteresis loss in the individual filaments, the coupling loss among the filaments and the eddy current loss in the normal conducting parts. In cases where the wires do not have a thick outer normal conducting sheath, the main components are the hysteresis loss and the coupling loss by estimating the former part as an extrapolated level of the AC loss per cycle to zero frequency in the region of lower frequency. The coupling loss per cycle is proportional to the frequency. The responsible Committee is K 184 "Supraleiter" ("Superconductors") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.
