Updating of stator coil FE models using FEMtools

Dynamics of 3 different pieces of stator windings was studied as part of the FCEP research program. The goal of the study was to find an effective way to simulate the dynamics of stator windings accurately using finite element method (FEM) and to find out the unknown material parameters of the materials used in stator windings. The results of the simulations were verified using results of experimental modal analyses performed as part of the study. The material parameter values used in the simulations were updated manually to match the measurement results. The goal of this study was to improve the accuracy of the material parameter values defined in the previous study by automated model updating using FEMtools software. The model updating processes of the first two studied pieces of coil showed that the material parameter values defined in the previous study were accurate in general. The correlation criteria (average absolute difference between the measured and calculated natural frequencies) could be improved only by less than 0.1 %. Considering the third piece of coil, the correlation criteria was already relatively low (2.9 %) before the model updating process, but there was one mode shape pair with a difference of 14.6 % in the natural frequencies. As result of the model updating process, the greatest difference in the natural frequencies of a mode shape pair was reduced to 6.1 % and the correlation criteria was improved to 2.05 %.