Estimation Method of AC Losses in HTS Tape Against a Distorted Current and/or a Distorted Magnetic Field With Harmonic Components

We have investigated an estimation method of transport current loss in Bi2223 tape exposed to distorted current with odd-order and/or even-order harmonic components. In HTS coil such as DC reactor having distorted current with harmonic components, however, HTS tape is exposed to not only the distorted current but also the distorted magnetic field generated by the distorted current. Therefore, we investigated the estimation method of AC loss in HTS tape and coil simultaneously exposed to the distorted current and the distorted magnetic field with harmonic components. Magnetization loss in Bi2223 tape exposed to the distorted magnetic field could be calculated by estimating the amplitudes of magnetic field in major and each minor hysteresis loops using magnetic field waveform and then calculating the sum of hysteresis losses using Brandt's formula. AC loss in HTS coil exposed to the distorted current could be estimated by the following method: 1) evaluate AC loss as functions of the amplitudes of sinusoidal current and magnetic field experimentally or analytically; 2) calculate magnetic field distribution within the HTS coil and then estimate the amplitudes of magnetic field in the major and each minor hysteresis loops in each location within the HTS coil; and 3) estimate AC loss in each location using the amplitudes of current and magnetic field and then calculate the sum of AC loss.