Statistic properties of a sensorless control method for a three phase permanent magnet biased radial active magnetic bearing

In this paper a sensorless control method for position control of a radial active magnetic bearing is investigated. This novel bearing concept consists of a three phase design utilized by a three phase voltage source inverter. Additionally the stator coils themselves are used for position sensing by electrical current and voltage signals. Especially statistic properties of position estimation during static and sensorless position controlling are discussed. The control architecture of the complete system is presented. Measurement results of the magnetic bearing prototype are used for verification of the theoretical expectations.