Influence of Asymmetrical Stator Axes on the Performance and Multi-Physical Field of Canned Permanent Magnet Machine for Vacuum Dry Pump With Vector Converter Supply.

Limitation in manufacturing tolerances and assembly imperfections are the source of asymmetrical stator axes (ASA) defect, in particular, in a vacuum dry pumps (VDP) where the canned permanent magnet machines (CPMMs) are with fractional slot concentrated winding (FSCW). The performance and multi-physical field of CPMM in the vacuum environment is vulnerable to ASA. This work provides comprehensive research on the influence of ASA on the performance and multi-physical field of CPMM for VDP. This article establishes a mathematical model and Park transformation of a 1.6kW 6-pole/9-slot CPMM under the ASA condition. With the universality of ASA and not so strictly symmetrical stator axes as commonly expected, the experimental results demonstrated the significant impacts of ASA on the drive performance and multi-physical field, especially the inductance characteristics, the symmetry degree of stator current and flux linkage, rotor electromagnetic force and stator electromagnetic vibration of CPMM. The obtained conclusions can act as a significant reference for robust design and analysis of electric machines and drives. [ABSTRACT FROM AUTHOR]