유도전동기의 불평형 자기흡인력 해석 및 이를 고려한 회전자축계의 진동평가

Abstract

This paper presents the calculation of unbalanced magnetic pull (UMP) due to geometrical problem in induction motor and evaluation the stability of the motor system. Usually, the excessive noise and vibration occurred in induction motor by means of geometrical problem. The existence of abnormal assembling in rotor will produce air-gap permeance wave which is function of axial and circumferential coordinate. In this paper, the UMP is calculated using permeance and magneto motive force (MMF) and it is not only the case of parallel eccentricity but also static and dynamic misalignment. Based on the percentage of misalignment and eccentricity, the result shows that the UMP and magnetic pressure are increased according to the increasing of misalignment and eccentricity. The UMP is occurred not only in 2fL frequency component but also the others. In order to analyze the rotor system, the modal test is implemented. The analysis consists of two types: normal mode analysis and imbalance response analysis.