Magnetic bearing device and fluid machine system using same

A magnetic bearing device, comprising:

• a magnetic bearing including a plurality of electromagnets configured to apply electromagnetic force to a shaft connected to a rotary electric machine;
• a displacement sensor configured to output an output signal in accordance with a displacement of the shaft;
• and
• a controller configured to control the electromagnets, wherein
• the controller compensates for a change in levels of the output signal, the change occurring in accordance with a change in ambient temperature around the displacement sensor, based on one or more reference values correlating with the change in levels of the output signal, the one or more reference values being detected for use in controlling the rotary electric machine, a fluid machine system including the rotary electric machine, or an apparatus including the fluid machine system, and
• the controller controls the electromagnets based on the compensated output signal for the change in levels of the output signal.