Investigation of inductance variation with rotor eccentricity for permanent magnet motors

Recently, the motor eccentricity problem, which can cause vibrations and noise, has become increasingly important due to the growing demand for improved quality of life and work environment. Because the eccentricity problem causes an imbalance of electromagnetic forces, most of the previous research has focused on the analysis of this concern. However, motor eccentricity can also influence the operating point and incremental inductance variation which could unbalance the current and break the winding. Therefore, this paper investigates the characteristics of inductance and operating point of motor teeth with different rotor eccentricity percentages using a permanent magnet motor. Moreover, the relationship between the incremental inductance variation and eccentricity percentages is derived by the equivalent magnetic circuit method in this paper.