Method and system for detecting bend in rotating shaft of magnetic bearing

A system for detecting bending in a rotating shaft of a magnetic bearing, characterized by comprising at least one first displacement sensor disposed on one side of the rotating shaft, at least one second displacement sensor disposed on an opposite side of the rotating shaft, and a processor electrically connected with the first displacement sensor and the second displacement sensor;

• the first displacement sensor is configured to measure a relative displacement between the rotating shaft and the first displacement sensor;
• the second displacement sensor is configured to measure a relative displacement between the rotating shaft and the second displacement sensor;
• the processor comprises a calculating unit, a first judging unit and a second judging unit;
• the calculating unit is configured to calculate center positions of the rotating shaft stopping at different positions during rotation of the rotating shaft;
• the first judging unit is configured to judge whether the rotating shaft is bent or not according to a curve of changed center positions, output a first test result of qualification if the rotating shaft is not bent, and send an instruction to the second judging unit if the rotating shaft is bent;
• the second judging unit is configured to after receiving the instruction, output a second test result of qualification of the rotating shaft if a difference between a maximum value and a minimum value of the center positions is less than a threshold value, and output a test result of disqualification of the rotating shaft if the difference is greater than or equal to the threshold value.