Research On Active Magnetic Bearing Rotor System With Redundant Sensor

With the development of magnetic levitation technology，the requirement for system reliabilityis higher and higher. In Active Magnetic Bearing (AMB) system, displacement sensor is installedclose to rotor and often affected by vibration of the rotor with high rotation speed and viaration of airtemperature. Owing to the abominable working surroundings, displacement sensor goes wrong easily.In order to improve the reliability of AMB system, redundancy design of sensor is an effectivemethod.In this paper, five degrees of freedom simulation model of AMB flexible rotor system wasestablished by using ADAMS, ANSYS and MATLAB software. The system co-simulation combinedwith incomplete differential PID and fuzzy PID control strategy was carried out. Dynamiccharacteristics of the system with location viaration of displacement sensor in the condition of staticsuspension and high-speed rotation of the rotor were analyzed. In addition, digital controller based onTMS320F28335DSP and algorithm programs of incomplete differential PID and fuzzy PID weredeveloped. Systems of sensor fault diagnosis based on BP neural network and signal differencecomparison were established separately, and the corresponding programs were also developed. Finally,test device of AMB system with redundant sensor was set up. Sensor failure in the condition of staticsuspension and high-speed rotation of the rotor was simulated by cutting off sensor signal lineartificially, and dynamic characteristics of the system in the condition of the sensor failure werestudied.The results show that, when displacement sensor breaks down, the controller can diagnose thefault sensor accurately and start processing program in time, and the system can still run safely. Onthe other hand, dynamic characteristics of the system with fuzzy PID controller are better than thesystem with incomplete differential PID controller designed in this paper.