Speaker
Description
In order to examine the applicability of superconducting technology to fields of industrial applications such as linear conveyor, transfer, and transport systems, we investigated AC loss characteristics of HTS sample coils under conditions assumed for use in power electronics devices. Since inverters are used in the drive circuit of power electronics devices in a linear transfer system and so on, the drive current contains harmonic components, and then it is expected that AC losses increase. In this study, we measured AC loss characteristics of the HTS sample coil by the nitrogen boil-off method under various conditions in which the amplitude and frequency of the harmonic current were changed. The HTS sample coils were wound by a Bi-2223 tape. The outer diameter of sample coil is about 60 mm, and the height is about 25 mm. As the results of the measurement, AC losses increased in proportion to the square of the harmonic current amplitude and increased in proportion to the square of the harmonic frequency. Based on the measured results, the factors of the increase of AC losses due to the harmonic current component were discussed.
