Electromagnetic evaluation and quantification of welding processes for the packaging of electrical steel sheets, DFG project number: 432930813
Despite the high influence of the packaging process on electrical machines, it is currently not considered in the electromagnetic simulations of electrical machines. The aim of the project is to achieve an in-depth electromagnetic assessment evaluation and quantification of all effects of welding processes. In contrast to gluing and interlocking, welding, as a packaging process for electrical sheet stacks, has great improvement potential because of the process variants and parameters that can be varied over a wide range.
Understanding the material changes during the welding process, in particular the effect of the internal stresses, the grain size change and the resulting eddy current paths, through welding points or through the weld seam, helps to a targeted improvement of the efficiency of the electrical machines. Targeted electromagnetic property improvements can be achieved through the use of stochastically distributed welding points instead of conventional weld seams. This improvement reduces the eddy current losses, because it reduces the development of global eddy current paths over the entire cross section, thereby contributing to an increased efficiency. Subsequently application-specific welding strategies to minimize the total losses are to be derived. Through the evaluation and quantification of the influences of the residual stresses, eddy current paths and grain size changes through welding, a targeted improvement of the magnetic properties can be achieved by adopting the derived welding strategy.