Transport Current Loss Characteristics of HTS Tape With Odd-Order Harmonic Current

We investigated the characteristics of transport current loss against distorted current with odd-order harmonic component using a Bi2223 short sample conductor. We measured the transport current loss against the distorted current with the 3rd, 5th, or 7th harmonic as a function of the amplitude of each harmonic current. The transport current loss per cycle of fundamental frequency against the distorted current was independent of the fundamental frequency and was compared with the sum of transport current losses against the sinusoidal current with the amplitude of each harmonic current component obtained by Fourier analysis. Fair agreement was obtained in the distorted current with the 3rd harmonic, while a big difference was observed in the distorted current with the 5th or 7th harmonic. Independent of harmonic order, the transport current loss against the distorted current was almost the same as the sum of the transport current losses against the sinusoidal current with the amplitude of the distorted current corresponding to a major hysteresis loop and the amplitude of the small rise and fall of the distorted current corresponding to a minor hysteresis loop that can be directly estimated from the distorted current waveform.