Electrical machines with eccentrically positioned rotor experience strong unbalanced magnetic pull directed towards the narrowest air gap. This unbalanced force increases the rotor eccentricity and degrades machine performance. This work aims to demonstrate the passive control of unbalanced magnetic pull (UMP) under different eccentricity conditions of permanent magnet synchronou s machine (PMSM) equipped with specialised stator winding.
A two-dimensional finite element model of bridge configured PMSM is presented to investigate the force compensating strategy under different eccentricities of PMSM. A coupled field and circuit equation is derived and solved using time stepping finite element method.
The force components under rotor eccentricity are compared with Bridge ON and Bridge OFF conditions. Connecting the bridge points enables redistributed currents among coil groups, significantly reducing the UMP caused by the rotor eccentricity.
Accurate computation and reduction of electromagnetic force are required for controlling the electromagnetic vibration. The findings show that passive control of UMP can be achieved, supporting better design and enhanced performance of PMSM.
