A Lumped-Parameter Off-Axis-Capable Dynamic Switched Reluctance Machine Model Including Unbalanced Radial Forces

A detailed procedure for reducing a switched reluctance machine (SRM) design to a dynamic lumped-parameter model accounting for all important magnetic interactions is given. Although the rotor is assumed mass-balanced, its center is allowed to move with respect to the stator center, which introduces unbalanced radial electromagnetic forces (URFs). The developed model is then integrated with dynamic power converter, controller, and mechanical system models to facilitate integrated-system studies for understanding the impacts of rotor off-axis dynamics. Detailed simulation results are given to highlight the utility of the model, and the undesirable negative stiffness characteristics of the SRM caused by the URFs are described and examined.