Domain refinement technique for very thin silicon steel sheets

在日本，电力变压器的电能损耗为每年1.5*10^&lt；10&kWh。为了降低功率损耗，有必要获得一种新的电力变压器铁心材料。本研究的目的是开发低损耗的新型取向硅钢片，通过在薄晶取向硅钢片表面开槽来检测磁通细化效果，动态磁通观察，澄清磁通运动与涡流损耗之间的关系，估算磁通细化样品的损耗。我们发现，静磁能通过在表面开槽来使磁畴宽度变窄。阐明了磁畴壁运动产生涡流损耗的机理。得到的32MU m厚样品在50 Hz、1.7T下的损耗极低，仅为0.21W/kg，是传统取向硅钢片损耗的1/5，成功地获得了降低变压器损耗的新材料。此外，还提出了一种新的磁通细化机制，阐明了磁通运动与涡流损耗之间的关系。

Electric energy loss at power transformers is 1.5*10^<10>kWh/year in Japan. To reduce the power loss, it is necessary to obtain a new material for the power transformer core. The purpose of this research work is to develop new grain oriented silicon steel sheets with very low loss.We did examination of effects for domain refining by grooving on the surface of the thin grain oriented silicon steel sheets, dynamic domain observation, clarifying relation between domain movement and eddy current losses, estimation of the loss of domain refined samples. We found the magneto-static energy make the domain width narrow by grooving the surface. The mechanism of generating the eddy current loss by domain wall movement were clarified. The loss value of a 32mu m thickness sample obtained by this work is extremely low as 0.21W/kg at 50Hz, 1.7T.This value is 1/5 compare with the loss of the conventional grain oriented silicon steel sheets.In conclusion, this work succeed to obtain the new material for reducing the electric power loss at the transformers. In addition, new mechanism for domain refinement are developed and the relation of domain movement and the eddy current loss were clarified.