Research On A Pair Of Poles Line-start Ferrite Permanent Magnet Synchronous Motor

In order to solve the contradiction between performance and cost of air compressors,a new type of line-start ferrite permanent magnet assisted reluctance synchronous motor(hereinafter referred to as line-start ferrite motor)is used as a high-performance,low-cost motor with a good application prospect.extensive attention.As a new type of permanent magnet motor,the manufacturing cost is lower,the cost performance is higher,the starting ability is stronger,and the synchronous speed is drawn into more stable,etc.,and it has good advantages in the air compressor system.This paper designs a multi-layer ferrite structure to replace NdFeB line-start permanent magnet synchronous motor.On the one hand,It can improve the performance of the motor;on the other hand,It can reduce the cost.But the a pair of poles line-start ferrite motor field waveform Distortion rate and bad air gap magnetic field make the design of a pair of poles line-start ferrite motor a difficult point.First,this paper summarizes the development and research status of a pair of poles line-start ferrite motor.There are some problems need to solve.Sush as line-start ferrite motor: determination of rotor slot number;design and optimization of rotor structure;Rotor magnetic field harmonic suppression;a pair of poles motor end winding length,harmonic difficult to suppress the problem.The slot and slot cooperation of line-start permanent magnet synchronous motor and the determination of the number of rotor slots are analyzed theoretically and by finite element simulation.The comparison of starting current,starting torque,force energy index,etc.Determines the permanent magnet synchronous motor of ferrite line-start Optimum slot fitting and comparison of three different rotor structures,comparing various indicators to determine the optimal electromagnetic solution.Then,based on the magnetic field theory,the mathematical expressions of the air gap length δ(θ)of the inhomogeneous air gap structure with different eccentricity are deduced for the disadvantages of large harmonic content of the rotor magnetic field and flat top of the air gap.Finally,Determines the optimal eccentricity,and simulates parameters such as torque capacity,force energy index,efficiency and power factor.For the conventional distributed winding structure of a pair of poles motor,the pitch of the winding pitch is 5/6 semi-circle,which results in redundant winding ends,and difficult harmonic suppression.Based on the basic theory of winding magnetic potential,this paper summarizes the design method of concentric sinusoidal windings for conventional induction motors,and analyzes and designs the different winding connection methods for double-layer concentric sine windings,single-layer concentric sine windings,and single-layer hybrid windings.Compared the performance parameters of motors under different winding structures.