Coupling Analysis And Calculation Of Magnetic Field And Temperature Field Of Permanent Magnet Driver

Loads of fans and pumps account for a large proportion of total energy consumption of the motor.Traditional systems usually use valves or damper to control the speed and it will cause a great waste of energy.Adjustable-speed permanent magnet coupling could achieve non-contact transmission between motor and loads perfectly.It could not only realize adjustable-speed performance,but also have the advantage of vibration isolation,misalignment permit,soft start and stop and so on.This paper studies the design characteristics and performance of PMD as follows:First of all,the permanent magnet driver is modeled by the equivalent magnetic circuit method.During this modeling process,fully considering the magnetic saturation,material properties and a variety of simulation parameters,the formula of the output torque and the eddy current formula of the copper disk are obtained by using the formula.Secondly,the choice of materials and the distribution of permanent magnet are analyzed,designing a 500kW permanent magnet driver model.Achieve the three-dimensional finite element simulation and performance test of the designed high power permanent magnet driver.And the three-dimensional magnetic field was analyzed by the software of Ansys Maxwell,including static and dynamic analysis.The magnetic field distribution of the permanent magnet driver,the magnetic field distribution of the copper disk,the eddy current distribution of the copper disk,the output torque after stabilization,the eddy current loss of the copper disk are simulated.The performance of the designed 500kW permanent magnet driver is then analyzed,study the relationship between torque and slip speed,the relationship between air gap size and torque,the relationship between axial force and slip speed,and the relationship between eddy current loss and slip speed.Thirdly,simulate the prototype’s temperature distribution at rated load and maximum load in the software Ansys Workbench.Consequently,the highest temperature appears in the copper disc,and permanent magnetic material’s temperature is much smaller than allowed value so demagnetization won’t happen.The effects of the slip,the length of the air gap and the number of magnetic poles on the temperature of the permanent magnet driver are analyzed Combining prototype’s practical operating situation,check the deformation of.permanent magnet disc which is most prone to deformation through the analysis of the stress field.The results show that maximum deformation value is less than the minimum air gap length,and the stress meets material’s permissible stress.So the prototype can operate stably for a long time.Finally,the influence of the cooling fins on the temperature of permanent magnet driver was analyzed,simulation results show,the heat dissipation effect of the cooling fin on the permanent magnet drive is remarkable.Conduct a detailed thermal analysis to the fin heat sinks which are used widely and discuss the influence of structural parameters to the heat sinks’ cooling performance in the conditions of natural convection.A reasonable size of the cooling fin structure is conducive to improving the cooling performance,reduce weight and cost.