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Design And Optimization Of Less-Rare-Earth Hybrid Permanent Magnet Brushless Motor

Posted on:2019-01-16Degree:MasterType:Thesis
Country:ChinaCandidate:X WangFull Text:PDF
GTID:2382330566972225Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
With the rapid development of the automotive industry,the oil consumption of automobiles is increasing,which accounts for more than half of the world's oil output.In the future,mankind will suffer the challenge of severe shortage of petroleum resources.At the same time,the emissions that exhausted by automobiles will also cause bad effects on the environment.Therefore,the development of energy-efficient,environmental,safe and reliable new energy electric vehicles(EVs)has attracted more and more attention.Nowadays,many automobile companies have done a lot of researches in this field.As the key of EVs,the performance of traction motor plays an important role in the whole performances of EVs.Therefore,the design and research of traction motor have been widely concerned by scholars.The rare-earth permanent magnet brushless motor(such as Nd Fe B)possesses many advantages,including high torque density,low loss,high efficiency,simple structure and reliable operation,which becomes a desirable choice of traction motors.However,with the rising price and unstable supply of rare-earth permanent magnet,the further large-scaled application of the rare-earth PMBM has partly limited.Thus,it has been a hot issue on how to reduce consumption of rare-earth in PMBMs and keep the motor electromagnetic performances competitive at the same time.According to the background of rare-earth resource crisis and performance requirements of traction motor,this paper designs and optimizes of a less-rare-earth hybrid permanent magnet brushless motor(H-PMBM).O n the one hand,the proposed motor reduces the consumption of rare-earth materials and permanent magnet(PM)cost.On the other hand,less-rare-earth H-PMBM can meet the requirements of the torque density,speed range and anti-demagnetization capability.This paper is divided into several parts:Firstly,the current development of the EVs and the general situation of rare-earth materials are introduced in this paper.Based on this research background,the necessity and urgency of the developing non-rare-earth PMBM and less-rare-earth PMBM are analyzed.Since non-rare-earth PMBMs(such as F-PMBMs)often suffer from the shortcoming of irreversible demagnetization phenomenon,narrow speed range and relatively low torque density,this paper selects less-rare-earth H-PMBM as design object.Secondly,since the great property difference of two PM materials in less-rare-earth H-PMBM,the operating points of the rare-earth PM materials and ferrite PM materials may affect each other.Hence,this paper will analyze two kinds of PM dimensions in details during the design process.In order to achieve the PM size preliminarily,the equivalent magnetic circuit method of the proposed motor is given and analyzed in theory.Then,considering the output torque requirements and cost constraints of the traction motor,the torque output capability,PM cost and PM operating points are chosen as the optimization objectives,which can further determine the dimensions of PMs.Moreover,in order to fairly estimate the electromagnetic performances of the less-rare-earth H-PMBM,the non-rare-earth F-PMBL motor with the same overall dimensions is also analyzed as a refere nced motor,including d-axis and q-axis inductance,speed range and anti-demagnetization capability.As the simulation results show that the H-PMBM can meet the output torque requirements and possess better flux-weakening ability and enhanced demagnetization withstand capability.Finally,the prototype motors of the two motors are manufactured and experimental platforms are set up.The partial experimental results of no-load characteristics have been finished,which can verify the reliability and validity of the proposed motor.
Keywords/Search Tags:less-rare-earth, permanent magnet brushless motor, hybrid permanent magnet, speed range, anti-demagnetization ability
PDF Full Text Request
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