Radial force and speed detection for improved magnetic suspension in bearingless motors

In this paper, radial forces and speeds are detected and used in negative feedback loops to enhance damping factors and response speed in bearingless induction motors. Radial forces and speeds are calculated from the detected radial force fluxes. Both radial force and torque generating fluxes are detected from search coil fluxes wound around stator teeth. The effectiveness on improving damping of radial positioning is shown both theoretically and experimentally.