Design And Analysis Of A Consequent-pole Segmented Dual-stator Permanent Magnet Machine

Due to the serious global warming,energy depletion and environmental pollution,the conventional energy consumption modes of the main transportations should be changed.Consequently,new energy vehicles(NEVs)have gradually became a research hotspot in related industries at this stage.As an important part of NEVs,electric vehicles(EVs)have the advantages of high power density,high efficiency,environmental protection and low cost.Based on the superiorities mentioned above,it can be seen that EVs have a strong competitive ability and a wide application range in the automotive industry.In this dissertation,a new consequent-pole segmented dual-stator permanent magnet(CPSDSPM)machine is proposed,which is applied in EVs.First,the operation mechanism of the proposed CPSDSPM machine is analyzed in detail.Next,based on the finite element method(FEM),the electromagnetic characteristics of CPSDSPM machine are analyzed to validate the correctness of the theoretical analyses.The operation characteristics of the CPSDSPM machine under different working conditions are summarized.Then,based on the simulating results of the FEM,the corresponding mathematical models are established.After that,the design method of the proposed machine is given.Furthermore,the optimization methods of the CPSDSPM machine are illustrated.Finally,a CPSDSPM prototype is manufactured in this study.The torque-boost ability,the overload capacity and the collaborating capability of the proposed machine can be validated by the experimental test.The main research contents and the innovations of this dissertation are summarized as shown below:1.The status and trend of EVs are introduced in this dissertation.The research statuses of double-stator machines are introduced.Furthermore,these machines are classified and discussed based on their structural characteristics.2.In this dissertation,a new CPSDSPM machine is proposed,and the operating principle of this machine is analyzed by the analytic method.First,the asymmetry of the magnetic circuit of the heteropolar consequent-ploe(CP)permanent magnet(PM)machine is elaborated by the magnetomotive force(MMF)model and the permeance model.Next,based on the magnetic flux method,the main electromagnetic characteristics of the proposed machine are discussed in detail.Hence,the structural features of the CPSDSPM machine are revealed.Then,according to the perspective of energy conversion,the air-gap flux distribution of the proposed CPSDSPM machine is concluded.Therefore,the cause of the asymmetry of the flux path can be obtained.After that,the characteristics of torque ripples of the CPSDSPM machine are studied.In addition,the segmented stator of the proposed machine is introduced in detail,and the working mechanism of the segmented stator is analyzed.3.The electromagnetic characteristics of the CPSDSPM machine are analyzed by the FEM.Furthermore,the main causes of the torque ripple and the magnetic field asymmetry are studied,which can be used to verify the proposed theoretical analysis of the CPSDSPM machine.4.The mathematical models in the stator reference frame and the rotor reference frame are established,which are helpful to the further research of the working operation and the control strategy.First,according to the theoretical research and the simulation result,the approximate expressions of the flux linkage,the no-load back-electromotive force(back-EMF)and the inductance can be obtained.Hence,the complete mathematical models of the proposed machine can be obtained.Then,an adjustment coefficient of flux linkage is proposed to describe the electromagnetic coupling phenomenon in the CPSDSPM machine.It’s helpful to improve the theoretical system of the proposed machine.5.The design principles and the optimization method of the CPSDSPM machine are proposed.First,the design objectives and the design steps are given.Next,the phase number and the slot/pole combination of this proposed machine are studied.Then,based on the dimension equations of the CPSDSPM machine,the initial design dimensions of the CPSDSPM machine are obtained.Then,the main dimension parameters are analyzed by the FEM,respectively.After that,the initial design dimensions of the CPSDSPM machine are optimized.The calculation results of this proposed optimization method are verified by the FEM.At last,the final design parameters of the CPSDSPM machine are obtained.6.A CPSDSPM prototype is manufactured and its test platforms are built.The main electromagnetic properties of the proposed machine are measured and compared with the simulation results.In addition,the overload capacity,the torque-boost ability and the collaborating capability of the proposed machine are also validated.