Sensitivity Analysis of Manufacturing Tolerances in Permanent Magnet Synchronous Machines With Stator Segmentation

In this article the sensitivity of manufacturing tolerances on the output of a permanent magnet synchronous machine with stator segmentation is studied. To reduce the simulation effort, a transition of the stator segment air gaps to replacement geometry was applied and the relevant parameters are discussed, whereas the uncertainty of geometric and material parameters is modeled with a normal distribution. Furthermore, tolerance chains are expressed through the convolution of independent probability distributions. For the Design of Experiments Sobol sequences are utilized. To further decrease the number of design parameters an approach is presented to reduce redundant parameters to individual design parameters. For the sensitivity analysis the torque and torque ripple serve as quality objectives. In addition, an approach is revealed to use the variance of the radial forces as quality objective without considering mechanical FE simulations. For manufacturing tolerances a linear regression is satisfying to describe the main effects on the quality objectives. Repetitive machine parameters, e.g. the remanences, have less influence on the machine's output than particular parameters such as the housing radius or static eccentricity. The influences of stator segmentation are negligibly small, whereas the housing radius has the highest sensitivity on the machine's output.