This paper describes the conductor eddy current loss that occurs in a permanent magnet type synchronous motor with a distributed winding stator using a rectangular copper wire designed for mild hybrid system applicati...This paper describes the conductor eddy current loss that occurs in a permanent magnet type synchronous motor with a distributed winding stator using a rectangular copper wire designed for mild hybrid system applications for small vehicles.Compared with the conventional round wire inserter method,the space factor can be improved and the coil-end length can be shortened by applying a so-called hairpin windings using a pre-formed into hairpin shape of bar conductor,and as a result,DC current resistance of the armature winding can be reduced.However,since the conductor cross-sectional area tends to increases,the conductor eddy current loss generated by the space harmonics linkage becomes too large to ignore.In order to study the reduction of the conductor eddy current loss,it is important to visualize the spatial leakage flux distribution which causes loss and finely analyze how the magnetic path is formed.Therefore,analysis of the conductor eddy current loss distribution generated in the bar-wound conductor is performed using the CAE model that faithfully reproduces the coil-end shape of the actual machine.Furthermore,it was qualitatively clarified what ratio of conductor eddy current loss at various driving points.Finally,the results of preliminary study on reduction of conductor eddy current loss are reported.展开更多
In-wheel direct-drive is the most efficient driving mode for electric vehicles,and it is the trend for applications in the future.In this paper,a novel variable-flux outer-rotor permanent magnet synchronous motor with...In-wheel direct-drive is the most efficient driving mode for electric vehicles,and it is the trend for applications in the future.In this paper,a novel variable-flux outer-rotor permanent magnet synchronous motor with a hybrid magnetic structure design is developed.Due to the hybrid magnetic pole with Nd-Fe-B and Al-Ni-Co permanent magnet(PM),the air-gap flux can be adjusted by changing the magnetization states of Al-Ni-Co PM,which is beneficial to realize a wide range of speeds and loads from the electromagnetic structure design.Firstly,basic structure features of the motor and the flux-adjusting principle are introduced.The design and calculation method of the PM dimensions is derived based on magnetic circuit analysis.Then the Preisach hysteresis model of Al-Ni-Co PM is described and is adopted to analyze the motor performance with the coupling of the time step finite element method(FEM),and the magnetization are investigated.Finally,the operational performance of the proposed motor is obtained by simulation,which verifies the design.展开更多
In this paper, a novel split-winding doubly salient permanentmagnet (DSPM) motor is proposed and the theoretical and experimental studies on the magnetic field, static characteristics and control strategy of this moto...In this paper, a novel split-winding doubly salient permanentmagnet (DSPM) motor is proposed and the theoretical and experimental studies on the magnetic field, static characteristics and control strategy of this motor are carried out. The steady-state and dynamic models are presented and the output power equation is derived. The feasibility of extending the operation range of the DSPM motor by using split-windings is proved. The finite element method is used to analyze the magnetic field, in which the leakage flux outside the stator circumference is taken into account. Based on the operation principle and the static characteristics of the motor, the control strategy and scheme are developed and implemented in a microcomputer-based controller. According to the features of the 4-phase 8/6-pole DSPM motor, a half-bridge power converter without neutral is adopted to reduce the number of power devices and to eliminate the problem of voltage unbalance in the split capacitors. The experimental results on the prototype machine not only verify the theoretical analysis, but also show that the proposed DSPM motor drive possesses good steady-state and dynamic performances, offering high efficiency over wide power range, and that the split-winding topology can effectively extend the operation range of the DSPM motor.展开更多
文摘This paper describes the conductor eddy current loss that occurs in a permanent magnet type synchronous motor with a distributed winding stator using a rectangular copper wire designed for mild hybrid system applications for small vehicles.Compared with the conventional round wire inserter method,the space factor can be improved and the coil-end length can be shortened by applying a so-called hairpin windings using a pre-formed into hairpin shape of bar conductor,and as a result,DC current resistance of the armature winding can be reduced.However,since the conductor cross-sectional area tends to increases,the conductor eddy current loss generated by the space harmonics linkage becomes too large to ignore.In order to study the reduction of the conductor eddy current loss,it is important to visualize the spatial leakage flux distribution which causes loss and finely analyze how the magnetic path is formed.Therefore,analysis of the conductor eddy current loss distribution generated in the bar-wound conductor is performed using the CAE model that faithfully reproduces the coil-end shape of the actual machine.Furthermore,it was qualitatively clarified what ratio of conductor eddy current loss at various driving points.Finally,the results of preliminary study on reduction of conductor eddy current loss are reported.
基金Supported by the National Natural Science Foundation of China under Grant 51407064。
文摘In-wheel direct-drive is the most efficient driving mode for electric vehicles,and it is the trend for applications in the future.In this paper,a novel variable-flux outer-rotor permanent magnet synchronous motor with a hybrid magnetic structure design is developed.Due to the hybrid magnetic pole with Nd-Fe-B and Al-Ni-Co permanent magnet(PM),the air-gap flux can be adjusted by changing the magnetization states of Al-Ni-Co PM,which is beneficial to realize a wide range of speeds and loads from the electromagnetic structure design.Firstly,basic structure features of the motor and the flux-adjusting principle are introduced.The design and calculation method of the PM dimensions is derived based on magnetic circuit analysis.Then the Preisach hysteresis model of Al-Ni-Co PM is described and is adopted to analyze the motor performance with the coupling of the time step finite element method(FEM),and the magnetization are investigated.Finally,the operational performance of the proposed motor is obtained by simulation,which verifies the design.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 59507001) .
文摘In this paper, a novel split-winding doubly salient permanentmagnet (DSPM) motor is proposed and the theoretical and experimental studies on the magnetic field, static characteristics and control strategy of this motor are carried out. The steady-state and dynamic models are presented and the output power equation is derived. The feasibility of extending the operation range of the DSPM motor by using split-windings is proved. The finite element method is used to analyze the magnetic field, in which the leakage flux outside the stator circumference is taken into account. Based on the operation principle and the static characteristics of the motor, the control strategy and scheme are developed and implemented in a microcomputer-based controller. According to the features of the 4-phase 8/6-pole DSPM motor, a half-bridge power converter without neutral is adopted to reduce the number of power devices and to eliminate the problem of voltage unbalance in the split capacitors. The experimental results on the prototype machine not only verify the theoretical analysis, but also show that the proposed DSPM motor drive possesses good steady-state and dynamic performances, offering high efficiency over wide power range, and that the split-winding topology can effectively extend the operation range of the DSPM motor.
