Examination of Eddy Current in Laminated Core without Insulation

摘要

In the laminated core of transformer, motor, etc., each electrical steel sheet is usually insulated in order to reduce the eddy current loss. It is reported that the insulation is not necessary in such laminated core in some condition. But, the report about the quantitative and systematic examination of the relationship between the insulation and eddy current is few. In this paper, the eddy current losses of core made of SPCC (colded rolled steel sheets) of different widths with and without insulation under various conditions are analyzed. It is shown that the increase of eddy current is affected by the ratio of the resistance of steel and the contact resistance.