  AC losses in High Temperature Superconductor tapes (HTS) are an important
design parameter for large scale power applications. The electrical method is
often used for losses measurements on SC tapes and, when the results are to be
compared to computed estimations, simple theoretical models like the Norris
Brandt are typically used. Electromagnetic dynamic effects are not usually
taken into account by the simpler models, but their presence may corrupt the
measured data. In this paper, a preliminary study on a conventional copper bar
sample has been done to evaluate the effect of the skin currents on the
specimen losses measures obtained from the electrical method. The measurement
procedure has afterward been applied to a SC YBCO tape (Superpower SCS4050AP),
obtaining circuit configuration dependent results. Because the SC losses must
obviously be measurement circuit independent, a systematic error due to the
skin currents must be playing a role. The skin current induced error is always
there and, in order to apply the electrical method for losses estimation, the
only possibility is its minimization. The best choice for the measurement
circuit to be adopted, in order to minimize the skin current undesired
contribution, will finally be proposed.
