Research And Design Of Permanent Magnet Speed Regulating Device And Its Water-Cooling System

As a new type of transmission,the permanent magnet speed regulating device has many advantages such as no harmonic,less friction loss,separable active,smooth operation and high security compared with the traditional mechanical transmission mode,which has broad prospects for development.In this thesis,the magnetic circuit and the components of permanent magnet speed regulating system are designed,and the correctness of the design is verified by finite element simulation of the magnetic field.The basic principle of increasing the flux distribution in the device and reducing the flux density in the air is observed.The variation trend of the permanent magnet speed governor is analyzed and the optimization parameters of each part are selected.Secondly,the mathematical model of torque and eddy current of permanent magnet speed-governing device is established by separate variable method.Through the analysis and comparison of the finite element simulation data,the rationality of the mathematical analytic formula is verified.Based on the analysis of eddy current field,it is found that permanent magnet speed control device has higher heating power.In order to ensure long-term stable operation of the device,it is necessary to install heat dissipation system.A lot of heat will accumulate inside the device as the thermal effect of eddy current,and the traditional air-cooling method cannot meet its cooling requirements,so the water cooling system which has high convective heat transfer coefficient and high cooling efficiency is the best choice for permanent magnet cooling device.According to the heat dissipation characteristics of permanent magnet speed control system,the corresponding water cooling system is designed.Through the deep analysis the loss,heat and temperature calculation and other issues of the copper side,the cooling tank structure program of the copper side is designed.Corresponding cooling system is also designed for the cooling of the side of the permanent magnet,and the permanent magnet coolant key performance indicators are analyzed,including the demonized water resistivity,dissolved oxygen content and so on.At the same time the program that makes the cooling unit perennial stable under different climatic conditions is designed.Finally,in order to improve the speed control system of the permanent magnet speed governor,a double DC torque motor is adopted as the servo motor to speed up the response speed of the control system.At the same time,multi-closed-loop control method is adopted.And the ADRC controller is introduced to detect the disturbances of the sensors and compensate them,so as to improve the control accuracy.The results of simulation of the effects of the immunity control strategy are obtained from Simulink platform,which shows that the introduction of ADRC controller in the speed loop of the control system can make the response time of the control system shorter and can quickly eliminate disturbance then make it return to steady state.