Control Technology For Bearingless Permanent Magnet Synchronous Motor

A bearingless permanent magnet synchronous motor(PMSM) is a high performance motor adopting bearingless technique,can provide both torque and radial suspension forces.Compared with traditional permanent magnet motors,a bearingless permanent magnet motor has a serial of advantages,such as no friction,no need of lubrication,no pollution,high-speed and high-precision.It will be widely used in field of biologic engineering,aeronautics and astronautics, semiconductor manufacturing industries,and so on.Supported by National Natural Science Foundation of China and National Hi-Tech Research and Development Plan of China,in this dissertation author devotes to sensorless control technology and digital control system research of the bearingless permanent magnet-type synchronous motor(BPMSM),including setting up a novel sliding mode observer,simulating the speed-sensorless control strategy using sliding mode observer and developing software of digital control.Firstly,the research background of bearingless motors are summarized,the main characteristics of bearingless motors are introduced,research status and development trend of bearingless motors are generalized.Secondly,the magnetic forces in the motor have been analyzed and the basic theories of BPMSM have been discussed in detail.The relationship between radial force and radial force windings current has been deduced.The mathematical model of BPMSM is established.A speed-sensorless control strategy using sliding mode observer has been presented in the dissertation.By analyzing the model of BPMSM,a novel sliding mode observer is set up to estimate the shaft position.Finally,the experiment platform of BPMSM's control system is constructed,and the hardware and software of digital control system are debugged.The experiment waves are showed,which prove that digital control system can achieve the stable operation of the BPMSM.