Relation of joining parameters of stator core production and iron loss

The demand for environmentally friendly and sustainable mobility leads to the increasing spread of electric vehicles. An important part of the electric drive is the stator. This is made up of many laminated steel sheets. The production quality of such a laminated stator core is effected by the essential process steps of cutting, joining and winding. The causes of potential losses can arise in each of these phases. At high frequencies, the eddy current losses dominate the iron losses and thus also the major part of the total losses. Different manufacturing technologies for joining the laminations are often compared in literature to highlight differences. Within the scope of this publication, different joining technologies are compared with respect to the hysteresis and eddy current losses influenced by them. For this purpose, differently manufactured ring core samples with multiple production parameters are examined. In particular the increase of the iron losses caused by the local and global generation of conductive paths in the sheet metal package is the focus of interest here. Subsequently, the losses resulting from baked resin and welding joining technology are determined and compared by means of measurements. We present industry relevant results by considering the specific hysteresis and eddy current losses according to DIN DIN EN 60404-6. The experiments are carried out varying different process parameters like welding seams, welding energy, feed speed and pressure, baking time and temperature with regard to diameters of ring core samples.