Analysis of Bridge Currents and UMP of an Induction Machine With Bridge Configured Winding Using Coupled Field and Circuit Modeling

Unbalanced magnetic pull (UMP) reduction is an important aspect of high-speed electrical machines and it can be reduced using a specialized winding scheme called bridge configured winding. A bridge configuration winding has two parallel paths in each phase. The mid points of these two parallel paths can be short-circuited to achieve passive control of the UMP or a power supply can be added in between these points to achieve active control of UMP. Moreover, it is important to understand the behavior of UMP in different eccentricity conditions for its active suppression. A finite-element modeling of a bridge configured induction machine has been developed to study the effects of different eccentricity conditions on UMP and bridge currents. A generalized circuit equation has been coupled with the field equation for the implementation of bridge configuration winding. All of the three kinds of eccentricity conditions have been simulated. In addition, two experimental setups have been developed to study the UMP-induced vibration and to study the effect of eccentricity on bridge currents.