| The world's major industrial countries are striving for the development of a new generation of clean acquiring equipment.The oil-free scroll vacuum dry pump is a new type of mechanical pump with directly discharging medium.It has the advantages of simple structure,small loss of gas flow,high efficiency,smooth operation,low vibration,low noise and high reliability,and it can meet the clean and oil-free ideal vacuum environment demanded by the scientific community and industry.So it has been widely used and developed in recent years.The performance of scroll vacuum dry pump closely relate to the quality of the product in industrial production and the accuracy of the scientific experimental results,and the performance of the drive motor directly affects the performance of the vortex vacuum dry pump.Switched reluctance motor is a new type of special motor,which has many advantages such as simple structure,sturdiness and durability,large starting torque and high efficiency.Switched reluctance motor drive system has a higher cost performance and combines the advantages of DC motor and AC motor speed control system.The rotor of the scroll vacuum dry pump drive motor is in the environment of high vacuum,the rotor is difficult to dissipate heat,but the SRM rotor has only a small amount of iron loss and little heat,so switched reluctance motor is very suitable to be used as drive motor for scroll vacuum dry pump to reduce the temperature rise of the rotor,improves the life of bearing on the shaft and system stability.First of all,this paper introduces the structure,working principle and characteristics of scroll vacuum dry pump and switched reluctance motor,and a linear mathematical model for the switched reluctance motor is established to analyze the operating characteristics of switched reluctance motor.Secondly,the electromagnetic scheme of switched reluctance motor is designed according to the performance index of 4L scroll vacuum dry pump,and then the switched reluctance motor is analyzed by the finite element method.The analysis results could verify the feasibility of the designed motor.Thirdly,the models of the switched reluctance motor speed control system based on the current chopping control and angle position control is established,and use MATLAB/Simulinkto carry on simulations.The simulation results effectively reflect the working mechanism and speed control effects of the switched reluctance motor.Finally,the loss of each part of the switched reluctance motor is taken as the thermal load of the three-dimensional temperature field simulation.The temperature distribution of the switched reluctance motor under the rated state is calculated and obtained.By Comparing with the temperature rise of asynchronous motor and permanent magnet synchronous motor,we can draw the conclusion that switched reluctance motor with scroll vacuum pump has a big leg-up,which is conductive to the operation of scroll vacuum pump. |
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