Analytical Modeling And Performance Analysis Of Dual-barrel Permanent Magnet Governor

Permanent magnet governor is a new type of speed control equipment.It has many advantages,such as soft start,.-easy installation,low maintenance,anti-overload,lowenvironmental configuration and so on.It has great application prospects in the field of speed control of general loads such as fans and pumps.Firstly,the change of air gap magnetic field of dual-barrel permanent magnet governor is analyzed,and then the distribution of induced current is obtained.Finally,the analytical model between structural parameters and transmission characteristics is established.The main research contents are as follows:(1)Based on the equivalent depth method,the air-gap magnetic field of the dual-barrel permanent magnet governor is analyzed,and the air-gap magnetic induction intensity model is established by using the idea of subsection.The results show that the air gap magnetic induction intensity can be increased by increasing the coupling area,reducing the air gap thickness,increasing the number of magnetic poles,reducing the axial length of permanent magnets,increasing the radial length and circumferential length within the allowable range.(2)Based on Maxwell's equations,a mathematical model of induction current of dual-barrel permanent magnet governor is established,and the structure parameters of the prototype are used to calculate an example.The results show that the more the number of poles,the smaller the thickness of air gap,the greater the relative speed and the thickness of permanent magnet,the stronger the induced current.(3)Based on the principle of electromagnetics,the transfer torque,eddy current loss and transfer efficiency of the dual-barrel permanent magnet governor are analyzed,and the structure parameters of the prototype are used to calculate the actual cases.The results show that,within the allowable range,increasing the coupling area,properly increasing the number of magnetic poles,increasing the radius of conductor,reducing the thickness of air gap,increasing the thickness of permanent magnet and increasing the conductivity of conductor can increase the transmission torque and eddy current loss of governor,but the heating becomes more serious.(4)The finite element analysis is used to verify the simulation results of analytical analysis.The results show that although there are some errors between the analytical results and the finite element analysis results,the errors are acceptable in the actual engineering calculation,and the calculation speed is faster.Therefore,it is feasible to use analytic method to assist the design and optimization of permanent magnet governor.