Search

A new speed range extension method for the simplex wave winding permanent-magnet (PM) brushless DC machine is proposed in this paper. The machine is with PM excitation, electric commutation, and close-connected winding identical to the brushed DC machine (see Zhu , “A new simplex wave winding permanent-magnet brushless DC machine,” IEEE Transactions on Magnetics, vol. 47, no. 1, pp. 252–259, Jan. 2011). By properly controlling the status of power electronic switches, the number of coils being connected into the equivalent circuit can be reduced, and thus the speed range will be extended. For the prototype of 10-pole and 11-slot machine, besides operating with all the 11 coils, the machine can be controlled with only 8 or 6 coils operating for wider speed range. The experiments verify the new speed range extension method for simplex wave winding PM brushless DC machine. [ABSTRACT FROM PUBLISHER]

A new simplex wave winding permanent-magnet (PM) brushless DC machine is proposed in this paper. Besides PM excitation and electric commutation, the machine has close-connected winding identical to the brushed DC machine. By properly controlling the power electronic switch status, the current direction of coils under N or S pole is unchanged. Thus, the new machine's operation principle is exactly as same as the brushed DC machine. Furthermore, as the adoption of PM and electric commutation, the new machine can be designed with larger pole number and lower slot number per pole, which respectively leads to less iron yoke and shorter end winding. Therefore, the proposed new machine not only keeps the characteristics of a brushed DC machine, but also improves the efficiency and power density. A 200 W, 10-pole, and 11-slot new machine is designed, prototyped, and tested to verify the analysis. [ABSTRACT FROM AUTHOR]

This paper presents a new permanent-magnet (PM) brushless machine for wind power generation. This machine adopts an outer-rotor topology, aiming at capturing wind power directly. In order to achieve high power density, a high-speed PM brushless generator is artfully integrated with a coaxial magnetic gear. The design details, with emphasis on the special constraints of wind power generation, are elaborated. By using the time- stepping finite element method, the static characteristics as well as no-load and on-load operations are simulated. A prototype is also built for experimentation. Both simulation and experimental results are given to verify the validity of the proposed machine. Finally, a quantitative comparison is made to justify that the proposed machine is of smaller size, lighter weight, and lower cost than its counterparts. [ABSTRACT FROM AUTHOR]

This paper quantitatively compares two emerging stator-permanent-magnet (PM) machines, namely, the doubly salient PM and the PM hybrid brushless types. Both of them are attractive for electric vehicles and wind power generation. For comparison, both machines adopt the outer-rotor 36/24-pole topology and are designed based on the same peripheral dimensions. By using the circuit-field-torque time-stepping finite element analysis (CFT-TS-FEM), both steady-state and transient performances of the two machines are critically compared. [ABSTRACT FROM AUTHOR]

In this paper, a new double-stator cup-rotor permanent-magnet brushless DC (PMBDC) machine is proposed and analyzed. Since the machine structure is so unique while its operating principle is so distinct, a numerical field approach, namely the circuit-field-torque grid-model time-stepping finite-element method (CFT-GM-TS-FEM), is newly developed to analyze the steady-state and dynamic characteristics of the machine. Particularly, the analysis of eddy-current loss in both the PMs and iron core of the machine is conducted. Experimental results are given for verification. [ABSTRACT FROM AUTHOR]

This paper proposes a novel in-wheel motor, which artfully integrates a magnetic gear into a permanent-magnet brushless (PMBL) DC motor so that they can share a common PM rotor, hence offering both high efficiency and high power density. Moreover, the low-speed requirement for direct driving and the high-speed requirement for compact motor design can be achieved simultaneously. A 2-kW 600/4400-rpm magnetic-geared outer-rotor PMBL DC motor is designed and analyzed, which is particularly suitable for battery-powered electric motorcycles. [ABSTRACT FROM AUTHOR]

In this paper, a new double-stator cup-rotor permanent-magnet machine is proposed and implemented for wind power generation. The design of unique double-stator configuration can improve the power density for easy installation, while the control of its winding connections can provide a constant output voltage over a wide range of wind speeds. The circuit-field-torque coupled time-stepping finite element method is utilized to analyze the proposed machine. Both analysis and experimental results are given to confirm the validity of the proposed machine. [ABSTRACT FROM AUTHOR]

This paper presents a new outer-rotor stator-doubly-fed doubly-salient permanent-magnet (SDF-DSPM) machine, which can be used as the integrated starter-generator for modern automobiles and mild hybrid electric vehicles. The key of the proposed machine is to incorporate both dc field windings and PMs in the inner stator, hence, offering a compact arrangement of hybrid field excitations. While armature windings are located in salient poles of the outer stator, the outer rotor is simply composed of salient poles without windings or PMs. In addition, an air bridge is purposely created in shunt with each PM in the inner stator, hence, providing an amplification effect for flux regulation. With this idea, the air-gap flux can be strengthened or weakened with a small dc field current so that the electromagnetic torque and induced electromotive force (EMF) can be effectively regulated. The newly designed SDF-DSPM machine is analyzed by using both the magnetic circuit model and finite element method, and assessed by performance simulation. [ABSTRACT FROM AUTHOR]

A hybrid approach, namely the finite element-analytical method (FEAM), is newly proposed and implemented for electromagnetic field analysis of electric machines with free rotation. The key is to derive a new analytical expression of the airgap field which can naturally couple with the finite element fields of both the stator and rotor. The proposed FEAM is exemplified by using two practical machines. The accuracy and validity are verified by comparing with both the finite element method and experimental results. [ABSTRACT FROM AUTHOR]