A Unified Model for Radial Flux Bearingless Motors with Short-Circuited Suspension Windings

This work investigates bearingless motors configured to function as radial electrodynamic bearings (EDBs), focusing on the feasibility and effectiveness of different stator winding configurations and bearingless motors (BMs). A theoretical framework based on short-circuiting the suspension winding is developed to calculate shaft forces during eccentricity. This model integrates all possible radial flux bearingless motor configurations with p<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> = p ± 1 or p<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</inf> = 1 suspension pole-pairs in a unified manner that incorporates their electromechanical properties. The paper uses this model to analyze stability, investigate the systems’ performance potential, and inform design decisions. It is shown that each configuration (BM type, winding type, pole-pair combination) offers distinct features and shortcomings when evaluated as an EDB that should be considered in the design process.