Low loss of a permanent magnet motor by applying local stress

We have been reported measured results for magnetic properties of a non-oriented electrical steel sheet under various magnetic flux and stress conditions and a new vector magnetic characteristic analysis technique in order to consider the stress effect on magnetic properties in the motor core. Next, we try to control the vector magnetic properties of non-oriented electrical steel sheets by applying the stress. In this paper, the effect of the stress on the vector magnetic properties of the non-oriented electrical steel sheet and permanent magnet motor is examined. At first, the effect of the stress of the caulking on the vector magnetic properties and residuals stress distribution are measured. Next, the assumed stress distribution is applied to the local part of a stator core, and the vector magnetic characteristic analysis is performed by using stress-complex E&S modeling. From these results, the loci of the magnetic field strength vector and the magnetic power loss decreased by applying the stress.