Magnetization Loss Estimation of HTS Solenoid Coils Wound With CORC

CORC is one of the candidates of the HTS cable for high field magnets. We have been interested in applying CORC to HTS power transformers that require not only large currents but also very low AC losses. Striation and twisting are the solutions for reducing AC losses. We suggested an estimation method for a rough calculation of magnetization losses in a striated CORC coil. First, we measured and calculated the magnetization losses of short samples of straight CC tapes and CORC. Before considering the striation effect, we analyzed the characteristics of slit HTS tapes. In order to emulate the slitting of an HTS tape, we prepared three kinds of HTS tapes with different widths: 2, 4, and 6 mm. Slitting will certainly create the effect of reducing the magnetization loss, but the effect is not directly dependent on the number of the slits nor the applied field magnitude. We measured and compared the magnetization losses of a wide HTS tape to those of narrow HTS tapes. And the narrow tapes were arranged in parallel and measured, so the net width was same as the width of the wide tape. Finally, we applied the measured data of the magnetization loss of several samples to the calculation of the losses of solenoid coils wound with CORC in order to take into account the loss reduction effect of slit HTS tapes.