B. Xia - Academia.edu (original) (raw)
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Papers by B. Xia
IEEE Transactions on Industry Applications, 2000
This paper investigates the cogging torque and torque ripple features of a permanent magnet flux ... more This paper investigates the cogging torque and torque ripple features of a permanent magnet flux switching (PMFS) integrated-starter-generator (ISG). The effects of the rotor pole arc width on cogging torque, torque ripple and output torque are first established using finite element analysis (FEA). Three torque ripple reduction techniques based on the optimization of three different rotor pole configurationsuniform, step skewed and axial pairing, are then proposed. The torque characteristics of each rotor configuration at varying load currents and phase angles are studied in detail. A prototype machine with a common stator and the three optimized rotor configurations are built for experimental validation. Both the FEA results and the experimental tests show that the step skewed and axial pairing techniques can alleviate the cogging torque significantly but the latter is less effective than the former in reducing the overall torque ripple. Index Terms-Axial pairing, back EMF, cogging torque, finite element analysis, phase angle, reluctance torque, step skew, torque ripple.
IEEE Transactions on Industrial Electronics
This paper presents a comprehensive analysis and comparison of air-cored axial flux permanent mag... more This paper presents a comprehensive analysis and comparison of air-cored axial flux permanent magnet (AFPM) machines with different types of coil configurations. Although coil factor is particularly more sensitive to coil band width and coil pitch in air-cored machines than conventional slotted machines, remarkably no comprehensive analytical equations exist. Here new formulae are derived to compare the coil factor of two common concentrated-coil stator winding types. Then respective coil factors for the winding types are used to
determine the torque characteristics, and from that the optimized coil configurations. Three -dimensional (3D) FEA
models are built to verify the analytical models. Furthermore,
overlapping and wave windings are investigated and compared
with the concentrated-coil types. Finally, a prototype machine is designed and built for experimental validations. The results
show that the concentrated-coil type with constant coil-pitch is
superior to all other coil types under study.
IEEE Transactions on Industrial Electronics
This paper presents a comprehensive analysis and comparison of air-cored axial flux permanent mag... more This paper presents a comprehensive analysis and comparison of air-cored axial flux permanent magnet (AFPM) machines with different types of coil configurations. Although coil factor is particularly more sensitive to coil band width and coil pitch in air-cored machines than conventional slotted machines, remarkably no comprehensive analytical equations exist. Here new formulae are derived to compare the coil factor of two common concentrated-coil stator winding types. Then respective coil factors for the winding types are used to determine the torque characteristics, and from that the optimized coil configurations. Three -dimensional (3D) FEA models are built to verify the analytical models. Furthermore, overlapping and wave windings are investigated and compared with the concentrated-coil types. Finally, a prototype machine is designed and built for experimental validations. The results show that the concentrated-coil type with constant coil-pitch is superior to all other coil type...
IEEE Transactions on Industry Applications, 2000
This paper investigates the cogging torque and torque ripple features of a permanent magnet flux ... more This paper investigates the cogging torque and torque ripple features of a permanent magnet flux switching (PMFS) integrated-starter-generator (ISG). The effects of the rotor pole arc width on cogging torque, torque ripple and output torque are first established using finite element analysis (FEA). Three torque ripple reduction techniques based on the optimization of three different rotor pole configurationsuniform, step skewed and axial pairing, are then proposed. The torque characteristics of each rotor configuration at varying load currents and phase angles are studied in detail. A prototype machine with a common stator and the three optimized rotor configurations are built for experimental validation. Both the FEA results and the experimental tests show that the step skewed and axial pairing techniques can alleviate the cogging torque significantly but the latter is less effective than the former in reducing the overall torque ripple. Index Terms-Axial pairing, back EMF, cogging torque, finite element analysis, phase angle, reluctance torque, step skew, torque ripple.
IEEE Transactions on Industrial Electronics
This paper presents a comprehensive analysis and comparison of air-cored axial flux permanent mag... more This paper presents a comprehensive analysis and comparison of air-cored axial flux permanent magnet (AFPM) machines with different types of coil configurations. Although coil factor is particularly more sensitive to coil band width and coil pitch in air-cored machines than conventional slotted machines, remarkably no comprehensive analytical equations exist. Here new formulae are derived to compare the coil factor of two common concentrated-coil stator winding types. Then respective coil factors for the winding types are used to
determine the torque characteristics, and from that the optimized coil configurations. Three -dimensional (3D) FEA
models are built to verify the analytical models. Furthermore,
overlapping and wave windings are investigated and compared
with the concentrated-coil types. Finally, a prototype machine is designed and built for experimental validations. The results
show that the concentrated-coil type with constant coil-pitch is
superior to all other coil types under study.
IEEE Transactions on Industrial Electronics
This paper presents a comprehensive analysis and comparison of air-cored axial flux permanent mag... more This paper presents a comprehensive analysis and comparison of air-cored axial flux permanent magnet (AFPM) machines with different types of coil configurations. Although coil factor is particularly more sensitive to coil band width and coil pitch in air-cored machines than conventional slotted machines, remarkably no comprehensive analytical equations exist. Here new formulae are derived to compare the coil factor of two common concentrated-coil stator winding types. Then respective coil factors for the winding types are used to determine the torque characteristics, and from that the optimized coil configurations. Three -dimensional (3D) FEA models are built to verify the analytical models. Furthermore, overlapping and wave windings are investigated and compared with the concentrated-coil types. Finally, a prototype machine is designed and built for experimental validations. The results show that the concentrated-coil type with constant coil-pitch is superior to all other coil type...