Transport Current Loss Against Distorted Current With Even-Order Harmonics in an HTS Tape Conductor

We have previously investigated the characteristics of a transport current loss against a distorted current with an odd-order harmonic in a Bi2223 tape conductor. In the distorted current with odd-order harmonics, the transport current loss could be estimated using the amplitudes of the major and minor hysteresis loops independent of the phase lag between the fundamental and the harmonics. However, the positive peak value of the distorted current with a phase lag between the fundamental and even-order harmonics is different from the negative peak value. Therefore, we investigated an estimation method of the transport current loss in the distorted current with even-order harmonics. We found that, independent of the phase lag between the fundamental and the harmonics, the transport current loss could be estimated as the sum of the hysteresis losses due to the major and minor hysteresis loops. In addition, the hysteresis losses could be estimated by regarding half of the difference between the maximum and minimum values of each hysteresis loop as the amplitude of the distorted current. This estimation method can be applied to the distorted current with high-order harmonics in a power converter and electric machinery.