MOTOR-INTEGRATED MAGNETIC BEARING

摘要

A motor-integrated magnetic bearing includes a three-phase rectifier-less motor (28) having phase detectors (40A to 40C) for detecting the phase of a motor rotor (28a). The motor has: a calculation unit (38) for generating a coil current application timing signal for applying current to respective phase coils (28ba) of a motor stator (28b) according to outputs of the phase detectors (40A to 40C); and a power circuit (39) which applies current to the respective phase coils (28ba) of the motor stator (28b) according to the coil current application timing signal outputted from the calculation unit (38). The power circuit (39) has: a voltage variable unit (41) which controls a DC bus voltage as an inter-line voltage of the motor coils (28ba); and a power output unit (39B) which controls the motor coil inter-line voltage as an equivalent voltage based on a pulse width by the pulse modulation; so as to use both of the voltage variable control and the pulse width modulation.