Analysis of Transient Magnetic Force on End-Winding in the Inverter-Fed Induction Machine

The increasing harmonics caused by inverter supply have an adverse impact on the end-winding vibration of the induction machine in accelerating failure and adding noise. Therefore, this paper puts forward an approach for end-winding magnetic force calculation in the inverter-fed induction machine. The 2D field–circuit–motion coupling analysis is used to calculate the stator currents in an induction machine, which are taken as loads in 3D transient magnetic analysis to obtain magnetic force on the end-windings. A three-phase squirrel-cage induction machine was designed and an experiment was carried out on the test motor to validate the proposed model. The simulated stator current, magnetic flux density and magnetic force agree well with both the theoretical analysis and measured results. Finally, a 3-D transient structural simulation was performed to further analyze the end-winding vibration. However, there is some difference of end-winding vibration acceleration between the simulation and experiment in harmonic components. The above deviation is probably attributed to the structure simplification of the induction machine. Thus, the developed simulation model can calculate the magnetic force on end-winding with reasonable accuracy, but it is advisable to perform an experimental study to fully analyze the vibration characteristics of end-winding.