Reduction of Iron Loss on Laminated Ultrathin Electrical Steel Sheet Cores by Secondary Current Heating Method

Abstract

　This paper presents the newly proposed heating method names as “Secondary Current Heating Method” to reduce the iron loss on laminated electrical steel sheet cores for high efficiency electrical motors. It is well known that the magnetic properties of electrical steel sheets, which are used for electrical motor cores, are deteriorated by the residual stress during manufacturing the electrical motors, and then the iron loss of the laminated electrical steel sheet cores of the electrical motors increases inevitably. The newly proposed Secondary Current Heating Method can improve the magnetic properties on laminated electrical steel sheet cores and reduce the iron loss of them in the very short time in comparison with conventional methods. In this paper, the electromagnetic and heating characteristics of the specimens by proposed method were confirmed, and then it was applied into the laminated ultrathin electrical steel sheet cores for high speed motors to reduce iron loss.