Active magnetic bearing e.g. radial-type active magnetic bearing, with self-position detection for electrical motor, has control device including position estimating unit to estimate position of ferromagnetic body forming rotor

摘要

The bearing (10) has a ferromagnetic body (16) forming a rotor held without contact between two stator electromagnets (12A, 12B). The electromagnets include respective excitation coils (26A, 26B) supplied with a current from a switching amplifier (18). A control device (22) controls an input signal to the amplifier based on the position of the body relative to magnetic circuits (24A, 24B) of the electromagnets. The control device includes a position estimating unit (30) to estimate the position of the body, and circuits (28A, 28B) to estimate inductance between the electromagnets and the body. An independent claim is also included for a method for controlling an input signal of an active magnetic bearing.