Design And Optimization Of Permanent Magnet Synchronous Motor With Parallel Shaft Dual-Rotor

Parallel counter-drive equipment such as twin-screw pumps and counter-roll mills are widely used in related manufacturing fields.Traditional parallel mechanical equipment uses a single motor to drive the driving shaft and the driven shaft to achieve synchronous rotation,or uses two motors to drive two shafts.However,these two schemes bring a series of problems such as large equipment volume,difficult maintenance and large investment.Based on this,a permanent magnet synchronous motor with parallel shaft dual-rotor is designed for the driving system of twin-screw pump.Based on the design of conventional single-rotor permanent magnet synchronous motor,the general principle of stator magnetic field division is determined,and the calculation method of air gap size in parallel connection area is given.Based on this,the main structural parameters of permanent magnet synchronous motor with parallel shaft dual-rotor are determined,the finite element simulation model of permanent magnet synchronous motor with parallel shaft dual-rotor is established,the no-load and load characteristics of the motor are analyzed,the influence of air gap size in parallel connection area on motor output electromagnetic torque and torque pulsation is studied,and the basic electromagnetic performance of permanent magnet synchronous motor with parallel shaft dual-rotor is verified.Combined with the preliminary analysis of permanent magnet synchronous motor with parallel shaft dual-rotor,according to the magnetic field distribution characteristics of permanent magnet synchronous motor with parallel shaft dual-rotor,the equivalent magnetic conductance of each part is calculated with the conventional equivalent magnetic conductance calculation model.Considering the special structure of the parallel connection area and the size of the parallel connection area,this area is reasonably divided and the calculation formula of equivalent magnetic conductance of each part of this area is deduced.On the basis of reasonable equivalence of windings and permanent magnets,the equivalent magnetic network model of permanent magnet synchronous motor with parallel shaft dual-rotor is established,and the equivalent magnetic network matrix is formed.The equivalent magnetic network matrix of permanent magnet synchronous motor with parallel shaft dual-rotor is solved by iterative method,and the rationality of the equivalent magnetic network method is verified by finite element method.Aiming at the outstanding problem of large torque ripple of permanent magnet synchronous motor with parallel shaft dual-rotor,several motor parameters such as the length and width of air gap in parallel connection area are selected as optimization variables,and several motor performance parameters such as cogging torque and torque ripple are taken as optimization objectives.Taguchi method and genetic algorithm are used for optimization calculation and analysis.By comparing the performance parameters of the motor before and after optimization,the optimization effect of two different algorithms on torque ripple in permanent magnet synchronous motor parallel shaft dual-rotor is verified.