Sum-flux Rotor Position Sensor with Self-balancing Magnetic Bearing Concept

Rotor position sensing is a key feature for successful operation for magnetic bearings. A position sensing concept based on the induction principle, embedded in a symmetrical multi-phase system may provide many interesting features. The knowledge of the electrical system’s phase angle, combined with a conductive sensing coil as the only additional physical component, the principle allows detecting the radial rotor offset and can be used for providing self-balancing magnetic bearing functionality. The paper is aimed at clearly demonstrating the concept and is not meant as an actual magnetic bearing design.