Analytical modeling of manufacturing tolerances for surface mounted permanent magnet synchronous machines

No production process of electrical machines is ideal. During the process, various stochastic manufacturing deviations can occur. Common tolerances are for example static or dynamic rotor eccentricities, asymmetric stator teeth if segmented sheets are used or - for electrical machines with permanent magnets (PMs) - a variable magnetic behavior caused by material or due to the magnetization process. Manufacturing tolerances can affect the acoustic emission of an electrical machine significantly. To estimate the influence of tolerances in an early design stage of an electrical machine, an analytical approach based on conformal mapping (CM) is presented here to model manufacturing tolerances for surface mounted permanent magnet synchronous machines (PMSMs) and calculate the tolerances´ impact on radial force densities in an acceptable computational time.