Analysis of Dynamic Unbalanced Magnetic Pull in Induction Motor With Dynamic Eccentricity During Starting Period

In practical motors, static eccentricity and dynamic eccentricity (DE) (mixed eccentricity) appear rarely with the developed manufacturing techniques nowadays. Curved eccentricity takes up most of the eccentricity. However, the motor is dynamic eccentric in axial cross section when in curved eccentricity. Eccentricity is bound to cause unbalanced magnetic pull (UMP), whereas the study of dynamic UMP under DE in this paper has rarely been mentioned before. According to relevant past papers, UMP is deemed to be invariable numerically. Dynamic UMP is put forward formally for the first time. In addition, UMP during the starting period is a function with time, relatively larger than the steady-state UMP according to the calculation in this paper, namely, UMP during starting period is of greater significance in motor deflection calculation than that during the steady state. The finite-element software is used to analyze the dynamic UMP accurately.