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In this paper, a new topology of concentric magnetic gears is proposed and implemented. The key of the new topology is to bury permanent magnets (PMs) of the outer rotor into the iron core in a new way so that the mechanical integrity can be improved, and the PM material can be saved while the torque density is maintained. The proposed gear is designed with the speed reduction ratio of 7.33 and optimized by using the three-dimensional finite element method (3D-FEM). The key of the 3D-FEM is to employ scalar magnetic potential to reduce the required memory and time for data manipulation and computation. After prototyping, the measured maximum static torque well agrees with the calculated one, hence verifying the proposed design and analysis. [ABSTRACT FROM AUTHOR]

This paper proposes a cost-effective approach to design permanent magnet brushless dc motors for electric vehicles. The key is to shape the pole arc in such a way that the air gap length is at a maximum at the leading edge of each rotor pole arc and at a minimum at the trailing edge of the same pole arc, hence resulting in an asymmetric air gap. Thus, for a specified rotational direction, the distortion of air gap flux density and hence the torque ripple can be significantly suppressed. Also, with the use of advanced conduction angle control, the motor can achieve a wide speed range. The proposed motor drive is designed and implemented for a low-voltage battery-powered electric motorcycle. [ABSTRACT FROM AUTHOR]

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]

A new permanent-magnet (PM) hybrid brushless (PMHB) machine is proposed and implemented as the integrated starter–generator (ISG) for hybrid electric vehicles (HEVs). It has the advantages of higher torque density than other PMHB machines and much wider speed range than other PM brushless machines. The key is to tune its dc-field winding current in such a way that three major modes of ISG system operation for HEVs, namely, engine cranking, battery charging, and torque boosting, can be achieved effectively. The finite-element method is employed to simulate its steady-state and dynamic performances. Finally, a 2-kW prototype is constructed and tested to experimentally verify the simulation results and the validity of the proposed ISG system. [ABSTRACT FROM PUBLISHER]

This paper quantitatively compares two coaxial magnetic gears (CMGs) with different topologies, namely, the CMG installed with radially magnetized permanent magnets (CMGRM) and the CMG installed with Halbach magnetized permanent magnets (CMGHM). By using the 3D finite element method, the end-effect and the performances of both CMGs are investigated. Analysis results show that the CMGHM can offer higher pull-out torque, lower torque ripple and lower iron losses than the CMGRM. Experimental results are also given for verification. [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]

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]