Investigation of the impact of production processes on iron losses of laminated stator cores for electric machines

Abstract

To further improve the power density of modern electric drive technologies many motor designers decide to increase the rotational speed of the motor up to several tens of thousands revolutions per minute. Along with these high frequencies of the fundamental wave of the flux density inside the laminated stator cores, the electromagnetic strain of the core and the importance of the iron losses are increasing. Due to this, the high amount of different mechanisms, responsible for these iron losses, need to be identified and associated to the appropriate production process. For this reason, a suitable and inline-capable electromagnetic measuring method is used to determine the iron losses for real motor stator core geometries and to separate the impact of different production steps. In this paper, the large number of manufacturing methods for stator cores is presented and the iron losses are assigned to the corresponding production step in an overall consideration. The cause of the measured losses are identified and described. The mentioned measuring adapter can also be used to monitor a specific assembly line with regard to separation and joining quality to represent an innovative and economic possibility of quality assurance.