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Torque characteristics in a large permanent magnet synchronous generator with stator radial ventilating air ducts

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Abstract

In this study, we investigated the torque characteristics of large low-speed direct-drive permanent magnet synchronous generators with stator radial ventilating air ducts for offshore wind power applications. Magnet shape optimization was used first to improve the torque characteristics using two-dimensional finite element analysis (FEA) in a permanent magnet synchronous generator with a common stator. The rotor step skewing technique was then employed to suppress the impacts of mechanical tolerances and defects, which further improved the torque quality of the machine. Comprehensive three-dimensional FEA was used to evaluate accurately the overall effects of stator radial ventilating air ducts and rotor step skewing on torque features. The influences of the radial ventilating ducts in the stator on torque characteristics, such as torque pulsation and average torque in the machine with and without rotor step skewing techniques, were comprehensively investigated using three-dimensional FEA. The results showed that stator radial ventilating air ducts could not only reduce the average torque but also increase the torque ripple in the machine. Furthermore, the torque ripple of the machine under certain load conditions may even be increased by rotor step skewing despite a reduction in cogging torque.

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Authors and Affiliations

  1. College of Electrical Engineering, Zhejiang University, Hangzhou, 310027, China

    He Hao, Dong-min Miao, Meng-jia Jin & Jian-xin Shen

  2. Power Engineering Centre, Cranfield University, Cranfield, MK43 0AL, UK

    Wei-zhong Fei

Authors
  1. He Hao
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  2. Wei-zhong Fei
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  3. Dong-min Miao
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  4. Meng-jia Jin
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  5. Jian-xin Shen
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Corresponding author

Correspondence to Wei-zhong Fei.

Additional information

Project supported by the National Natural Science Foundation of China (No. 51377140) and the National Basic Research Program (973) of China (No. 2013CB035604)

ORCID: He HAO, http://orcid.org/0000-0001-6376-9106

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Hao, H., Fei, Wz., Miao, Dm. et al. Torque characteristics in a large permanent magnet synchronous generator with stator radial ventilating air ducts. Frontiers Inf Technol Electronic Eng 17, 814–824 (2016). https://doi.org/10.1631/FITEE.1500238

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  • DOI: https://doi.org/10.1631/FITEE.1500238

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