Calculation and Analysis of Unbalanced Magnetic Pull Caused by Rotor Eccentricity Based on No-Load Characteristics

The unbalanced magnetic pull force is mainly caused by the asymmetry of the magnetic field. The analytical solution calculation of unbalanced magnetic pull force under saturation and load conditions is very complex, and numerical solution methods are generally used for calculation. This article takes a certain type of hydroelectric unit as an example and uses different calculation formulas based on the no-load characteristics to calculate the unbalanced magnetic pull force, providing a theoretical basis for dealing with the poor stability of the unit caused by unbalanced magnetic pull force in engineering sites. From the analysis, it can be seen that the empirical formula method, numerical analysis method, and discrete solution method are used to calculate the unbalanced magnetic pull force of the generator, and the calculation results of centrifugal force formed by the rotor counterweight on site are compared. The discrete solution method has the highest accuracy and the most accurate calculation results, which can provide a good basis for practical engineering applications.