Cogging torque reduction by optimal design of PM synchronous generator for wind turbines

Öztürk, Nihat; Dalcalı, Adem; Çelik, Emre; Sakar, Selçuk

doi:10.1016/j.ijhydene.2017.02.093

Cited by 23 publications

(14 citation statements)

References 12 publications

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“…Indeed, PM machines are preferred for their low speed and variable speed applications. Since the parameters such as efficiency and power coefficient are independent of rotation speed in the performance of PM machine, the machines can suit for low cycle applications [10][11][12][13]. In addition to its advantages, one of the major disadvantages of PM machines is the generation of cogging torque.…”

Section: Introductionmentioning

confidence: 99%

Cogging Torque Minimization Using Skewed and Separated Magnet Geometries

et al. 2020

Self Cite

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Çalışmada, 2,5 kW gücünde 14 kutuplu, 84 oluklu sabit mıknatıslı senkron generatörün (SMSG) analitik tasarımı, analizi ve optimizasyonu gerçekleştirilmiştir. Bu tasarıma ait verim, tork, vuruntu torku ve manyetik akı yoğunluğu gibi performans özelikleri değerlendirilmiştir. Ardından mıknatıs geometrisinin vuruntu torkuna etkisini incelemek amacıyla ilgili generatörün 3 boyutlu modeli çıkartılmıştır. Bu bağlamda bölünmüş ve kaykı/çarpıklık (skew) verilmiş mıknatıs yapılarının etkileri araştırılmıştır. İlk tasarımda mıknatıs tek parça modellenmiş ve vuruntu torkunun etkin değeri 436,75 mNm olarak bulunmuştur. İkinci tasarımda mıknatıs yüzeyi boyunca belli ölçüde çarpık bir yarık açılmış ve bu işlem vuruntu torkunu 434,58 mNm değerine düşürmüştür. Diğer tasarımda, birinci tasarımdaki mıknatıs iki parçaya bölünmüş ve bölünen mıknatıslar çarpık şekilde tekrar birleştirilmişlerdir. Böylece vuruntu torkunun değeri 159,60 mNm olarak bulunmuştur. Son olarak, son modeldeki mıknatıs geometrisine belli ölçülerde iki tane yarık açılarak vuruntu torku 89,95 mNm'e kadar düşürülmüştür. Elde edilen sonuçlardan, son tasarımın, ilk tasarıma kıyasla vuruntu torku değerinde %80'e varan bir iyileşme sağladığı sonucuna varılmıştır.

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Section: Introductionmentioning

confidence: 99%

Cogging Torque Minimization Using Skewed and Separated Magnet Geometries

et al. 2020

Self Cite

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“…PMSGs combine high efficiency with low maintenance and a high power density [1], factors that make them extremely attractive for use in renewable energy applications are, such as wind [2], wave power [3], and tidal power [4], or electrical mobility applications [5] and, in general, in uses where they must act as a motor or generator. Furthermore, in renewable energy applications, PMSGs allow direct-drive configurations, making the use of a gearbox unnecessary or reducing the number of gearbox stages, which decreases the overall generator volume and improves its efficiency [6].…”

Section: Introductionmentioning

confidence: 99%

“…There are several methods to reduce cogging torque in the PMSG design phase. The most used is skewing, which consists of preventing the stator teeth and the magnets from becoming aligned by either turning the stator teeth [6,12] or the rotor's permanent magnets [1,2,13]. The required skew angle to largely cancel out the effect of the interactions between the PMs and the slots depends on how many slots and poles the machine has.…”

Section: Introductionmentioning

confidence: 99%

Cogging Torque Reduction Based on a New Pre-Slot Technique for a Small Wind Generator

García-Gracia

Romero

Ciudad³

et al. 2018

Energies

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Cogging torque is a pulsating, parasitic, and undesired torque ripple intrinsic of the design of a permanent magnet synchronous generator (PMSG), which should be minimized due to its adverse effects: vibration and noise. In addition, as aerodynamic power is low during start-up at low wind speeds in small wind energy systems, the cogging torque must be as low as possible to achieve a low cut-in speed. A novel mitigation technique using compound pre-slotting, based on a combination of magnetic and non-magnetic materials, is investigated. The finite element technique is used to calculate the cogging torque of a real PMSG design for a small wind turbine, with and without using compound pre-slotting. The results show that cogging torque can be reduced by a factor of 48% with this technique, while avoiding the main drawback of the conventional closed slot technique: the reduction of induced voltage due to leakage flux between stator teeth. Furthermore, through a combination of pre-slotting and other cogging torque optimization techniques, cogging torque can be reduced by 84% for a given design.

show abstract

“…PMSGs combine high efficiency with low maintenance and a high power density [1], factors that make them extremely attractive for use in renewable energy applications, such as wind [2], wave power [3] and tidal power [4], or electrical mobility applications [5] and, in general, in uses where they must act as a motor or generator. Furthermore, in renewable energy applications, PMSGs allow direct-drive configurations, making the use of gearbox unnecessary or reducing the number of gearbox stages, which decreases the overall generator volume and improves its efficiency [6].…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cogging Torque Reduction Based on a New Pre-Slot Technique for a Small Wind Generator

García-Gracia¹,

Romero²,

Ciudad³

et al. 2018

Preprint

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Cogging torque is a pulsating, parasitic and undesired torque ripple intrinsic of the design of a permanent magnet synchronous generator (PMSG), which should be minimized due to its adverse effects: vibration and noise. In addition, as aerodynamic power is low during start-up at low wind speeds in small wind energy systems, the cogging torque must be as low as possible to achieve a low cut-in speed. A novel mitigation technique using compound pre-slotting, based on a combination of magnetic and non-magnetic materials, is investigated. The finite element technique is used to calculate the cogging torque of a real PMSG design for a small wind turbine, with and without using compound pre-slotting. The results show that cogging torque can be reduced by a factor of 48% with this technique, while avoiding the main drawback of the conventional pre-slotting technique: the reduction of induced voltage due to leakage flux between stator teeth. Furthermore, through a combination of pre-slotting and other cogging torque optimization techniques, 84%, cogging torque can be eliminated for a given design.

show abstract

Cogging torque reduction by optimal design of PM synchronous generator for wind turbines

Cited by 23 publications

References 12 publications

Cogging Torque Minimization Using Skewed and Separated Magnet Geometries

Cogging Torque Minimization Using Skewed and Separated Magnet Geometries

Cogging Torque Reduction Based on a New Pre-Slot Technique for a Small Wind Generator

Cogging Torque Reduction Based on a New Pre-Slot Technique for a Small Wind Generator

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