Research On Levitation Support Of Permanent Magnet Synchronous Motor For Driving Vacuum Dry Pump

In the field of industrial production applications,some products cannot be produced without the support of a vacuum environment,such as chemical,semiconductor,biological and pharmaceutical,medical appliances and other fields.As vacuum technology continues to advance,the performance of vacuum dry pumps is becoming more and more recognised and accepted by the industry,and their applications are becoming more widespread,but work continues to improve them.At present,the vacuum dry pump field exists in the drive motor due to long working hours caused by rotor overheating,and the vacuum environment,thermal convection,thermal radiation heat dissipation effect is not good,coupled with the traditional mechanical bearing friction overheating,vacuum dry pump cavity heat dissipation environment is very severe,rotor shaft heat through the heat conduction heat dissipation to the bearing,resulting in mechanical bearing heat expansion holding problem,in view of this,this subject using magnetic levitation bearing In view of this,this topic uses magnetic levitation bearing technology as a solution to replace conventional bearings.Compared to mechanical bearings,magnetic bearings are more technically demanding and make the whole dry pump system more complex,but at the same time have the advantage of creating a certain amount of open space so that there is no mechanical contact between the rotor section and the housing,no need to design a lubrication system,and the mechanical vibration and noise of the motor is mitigated.The article begins with the design of a 3k W permanent magnet synchronous motor to meet the drive requirements of a vacuum dry pump,with all performance parameters(e.g.motor efficiency,starting torque multiplier,maximum torque multiplier,no-load air gap magnetic density,etc.)designed to meet the standards.Then,on the basis of the designed drive motor,a temperature field simulation was carried out,focusing on the heat distribution in the rotor part and the mechanical bearing part,and the temperature field analysis results of the mechanical bearing were used to deduce the mechanical bearing holding mechanism,so as to pave the way for the introduction of magnetic bearing technology.The design of the magnetic bearing is then combined with the parameters of the designed drive motor.In this section the five key components of the magnetic bearing system are first introduced: controller,rotor,stator(electromagnet),sensor and power amplifier.The working principle of the magnetic bearing is then introduced,a mathematical model of the single-degree-of-freedom system and the radial four-degree-of-freedom magnetic levitation bearing is established,and on this basis a Simulink simulation model of the magnetic levitation rotor-motor control is set up,and an improved fuzzy PID control method is proposed on the basis of fuzzy PID control,which makes the call of the three adjustment parameters of the PID controller more flexible and precise,making the The simulation model response is faster and more accurate,which significantly improves the system’s anti-disturbance and stability maintenance capability.The control effect will be verified by simulation in Matlab software for the Simulink simulation model of maglev rotor-motor to prove the effectiveness of the method for the control of maglev rotor-motor system,and also provide some reference value for the stability control of other closed-loop systems.