Influence of Stator/Rotor Torque Ratio on Torque Performance in External-Rotor Dual-Armature Flux-Switching PM Machines

External-rotor dual-armature flux-switching PM (ER-DA-FSPM) machines have high torque density and decent fault tolerance, making them promising candidates for in-wheel machine applications in electric vehicles. The torque output and optimal design parameters of ER-DA-FSPM machines are affected by th...

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Main Authors: Zijie Zuo, Yidong Du, Lei Yu
Format: Article
Language:English
Published: MDPI AG 2024-08-01
Series:Machines
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Online Access:https://www.mdpi.com/2075-1702/12/9/588
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author Zijie Zuo
Yidong Du
Lei Yu
author_facet Zijie Zuo
Yidong Du
Lei Yu
author_sort Zijie Zuo
collection DOAJ
description External-rotor dual-armature flux-switching PM (ER-DA-FSPM) machines have high torque density and decent fault tolerance, making them promising candidates for in-wheel machine applications in electric vehicles. The torque output and optimal design parameters of ER-DA-FSPM machines are affected by the stator/rotor torque ratio, which is the focus of this paper. Firstly, this paper analyzes airgap flux density harmonics of ER-DA-FSPM to provide a clear insight into the torque-generation mechanism. Then, this paper investigates the influence of torque ratio on average torque under the same copper loss. It is found that the average torque decreases with torque ratio increasing due to the reduction of the positive torque component generated by the sixth airgap field harmonics and the rise in the negative torque component from the eighth harmonics. Moreover, this paper also provides the optimal parameter recommendation to guide the machine design. The split ratio should increase, and the arc of PMs should decrease for a larger torque ratio, whilst the other parameters are hardly influenced. Next, this paper makes a comparison among the ER-DA-FSPM machine, external rotor flux-switching PM (ER-FSPM) machine, and surface-mounted PM (ER-SPM) machines. It shows that the ER-DA-FSPM machine, with the torque ratio being 2, can lead to a much larger total torque. In addition, in the event of rotor winding failure, which is more possible due to the existence of slip rings than stator winding failure, the stator can still provide an average torque larger than that of ER-SPM machine and 92.0% that of the ER-FSPM machine, respectively. Finally, the theoretical analysis is verified by the experiments.
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spelling doaj-art-1f3bfb433e5b49789a778ee6b21f71f32025-08-20T01:55:38ZengMDPI AGMachines2075-17022024-08-0112958810.3390/machines12090588Influence of Stator/Rotor Torque Ratio on Torque Performance in External-Rotor Dual-Armature Flux-Switching PM MachinesZijie Zuo0Yidong Du1Lei Yu2School of Mechanical and Electrical Engineering, Soochow University, Suzhou 215000, ChinaSchool of Mechanical and Electrical Engineering, Soochow University, Suzhou 215000, ChinaSchool of Mechanical and Electrical Engineering, Soochow University, Suzhou 215000, ChinaExternal-rotor dual-armature flux-switching PM (ER-DA-FSPM) machines have high torque density and decent fault tolerance, making them promising candidates for in-wheel machine applications in electric vehicles. The torque output and optimal design parameters of ER-DA-FSPM machines are affected by the stator/rotor torque ratio, which is the focus of this paper. Firstly, this paper analyzes airgap flux density harmonics of ER-DA-FSPM to provide a clear insight into the torque-generation mechanism. Then, this paper investigates the influence of torque ratio on average torque under the same copper loss. It is found that the average torque decreases with torque ratio increasing due to the reduction of the positive torque component generated by the sixth airgap field harmonics and the rise in the negative torque component from the eighth harmonics. Moreover, this paper also provides the optimal parameter recommendation to guide the machine design. The split ratio should increase, and the arc of PMs should decrease for a larger torque ratio, whilst the other parameters are hardly influenced. Next, this paper makes a comparison among the ER-DA-FSPM machine, external rotor flux-switching PM (ER-FSPM) machine, and surface-mounted PM (ER-SPM) machines. It shows that the ER-DA-FSPM machine, with the torque ratio being 2, can lead to a much larger total torque. In addition, in the event of rotor winding failure, which is more possible due to the existence of slip rings than stator winding failure, the stator can still provide an average torque larger than that of ER-SPM machine and 92.0% that of the ER-FSPM machine, respectively. Finally, the theoretical analysis is verified by the experiments.https://www.mdpi.com/2075-1702/12/9/588dimensional parametersharmonic analysissequential optimizationtorque ratio
spellingShingle Zijie Zuo
Yidong Du
Lei Yu
Influence of Stator/Rotor Torque Ratio on Torque Performance in External-Rotor Dual-Armature Flux-Switching PM Machines
Machines
dimensional parameters
harmonic analysis
sequential optimization
torque ratio
title Influence of Stator/Rotor Torque Ratio on Torque Performance in External-Rotor Dual-Armature Flux-Switching PM Machines
title_full Influence of Stator/Rotor Torque Ratio on Torque Performance in External-Rotor Dual-Armature Flux-Switching PM Machines
title_fullStr Influence of Stator/Rotor Torque Ratio on Torque Performance in External-Rotor Dual-Armature Flux-Switching PM Machines
title_full_unstemmed Influence of Stator/Rotor Torque Ratio on Torque Performance in External-Rotor Dual-Armature Flux-Switching PM Machines
title_short Influence of Stator/Rotor Torque Ratio on Torque Performance in External-Rotor Dual-Armature Flux-Switching PM Machines
title_sort influence of stator rotor torque ratio on torque performance in external rotor dual armature flux switching pm machines
topic dimensional parameters
harmonic analysis
sequential optimization
torque ratio
url https://www.mdpi.com/2075-1702/12/9/588
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AT yidongdu influenceofstatorrotortorqueratioontorqueperformanceinexternalrotordualarmaturefluxswitchingpmmachines
AT leiyu influenceofstatorrotortorqueratioontorqueperformanceinexternalrotordualarmaturefluxswitchingpmmachines