Effect of Magnet Mass Distribution on Balancing Quality of the High-Speed Permanent Magnet Turbo Generator

Abstract

The main objective of this paper is to study the importance of rotor assembly procedure on balancing behavior of a high-speed rotor. The rotor consists of series of magnets in the electric motor section is considered as a case study. This study employs 3D beam elements based on the Timoshenko beam theory to model the model the dynamic behavior of the rotor. One of the solutions for accurate balancing is the minimization of unbalance force due to the assembly of parts with the prior balancing of those parts. In this case, although magnets had a unique design, by reason of manufacturing tolerances they have a different mass that can vary around 1.5$\%$ from their nominal mass, that can be considered as the subject of the importance of magnet arrangement. Based on the mass histogram of the real magnets, several sets of magnet masses are randomly generated. In the scope of the study, two critical speeds are covered by the speed range of analysis. The result emphasizes the need for making the arrangement prior assembly. The model is partially validated by experimental results.