Selection of Excitation Operating Points of 10 MW HTS Exciting Double Stator Direct-Drive Wind Generators Having Single and Double Polarity Inner Stator

Cheng, Ming; Ning, Xinfu; Zhu, Xinkai; Wang, Yubin

doi:10.2339/politeknik.605750

Cited by 7 publications

(3 citation statements)

References 28 publications

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“…Equally, the power density of the HTS-FSM was found to be 49% better than the PM-FSM. Equally, in the quest for better electromagnetic performance as well as cost and weight effectiveness, two variants (single-and double-polarity) of a high-power, double-stator, direct-drive HTS offshore-classed wind generator was analysed in [107]. While both machines produced similar average torque waveforms (11 MNm), the double-polarity variant provided better cost and materials savings (about $33,200).…”

Section: Wound-field Flux Switching Machine (Wf-fsm)mentioning

confidence: 99%

Non-Conventional, Non-Permanent Magnet Wind Generator Candidates

Udosen

Kalengo

Akuru

et al. 2022

Wind

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Global industrialization, population explosion and the advent of a technology-enabled society have placed dire constraints on energy resources. Furthermore, evident climatic concerns have placed boundaries on deployable energy options, compounding an already regrettable situation. It becomes apparent for modern renewable energy technologies, including wind generators, to possess qualities of robustness, high efficiency, and cost effectiveness. To this end, direct-drive permanent magnet (PM) wind generators, which eliminate the need for gearboxes and improve wind turbine drivetrain reliability, are trending. Though rare-earth PM-based wind generators possess the highly sought qualities of high-power density and high efficiency for direct-drive wind systems, the limited supply chain and expensive pricing of the vital raw materials, as well as existent demagnetization risks, make them unsustainable. This paper is used to provide an overview on alternative and viable non-conventional wind generators based on the so-called non-PM (wound-field) stator-mounted flux modulation machines, with prospects for competing with PM machine variants currently being used in the niche direct-drive wind power generation industry.

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Section: Wound-field Flux Switching Machine (Wf-fsm)mentioning

confidence: 99%

Non-Conventional, Non-Permanent Magnet Wind Generator Candidates

Udosen

Kalengo

Akuru

et al. 2022

Wind

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“…There are three main kinds of superconducting flux modulation machines: flux switching machines [21][22][23][24], double-rotor machines [25], and double-stator machines [18][19][20][26][27][28][29], as shown in figure 1. Despite their difference in design, they are similar in structure and principle to fit the pole-pair number of the counter-stator windings through field modulation.…”

Section: Operating Principlementioning

confidence: 99%

Investigation of AC loss of superconducting field coils in a double-stator superconducting flux modulation generator by using T-A formulation based finite element method

Liu

Cheng

et al. 2021

Supercond. Sci. Technol.

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In order to reliably make use of superconductors in wind generators, a double-stator superconducting flux modulation generator is proposed here to avoid rotation of field coils and armature windings. The superconducting field coils are located in the inner stator while the armature windings are placed in the outer stator. In this way, the stationary-rotatory couplings of current and cryogenic coolants for superconducting field coils and/or armature windings are removed. Because of the modulation effect of the reluctance rotor between the two stators and the armature reaction field, moving AC magnetic fields are acted on superconducting coils in the inner stator. These moving AC magnetic fields are called magnetic field harmonics in the flux modulation generators. The frequencies of these harmonics are multiples of rotor mechanical frequency. Compared to synchronous superconducting generators, the amplitudes of the harmonics are higher. Even though methods to reduce the amplitudes of harmonics have been studied, the level of the AC loss in the superconducting field coils is still unknown. In this paper, numerical simulations based on the T–A formulation are used to estimate the AC loss of the superconducting field coils in a 10 MW double-stator superconducting flux modulation generator. It is found that by choosing a suitable working temperature, the AC loss of the superconducting field coils without any harmonic reduction methods is not very high, but eddy current loss of copper thermal shield inside the cryostat is significantly higher.

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“…Wind platforms become more economically attractive if the unit capacity of the wind turbine can be increased to 5–20 MW, but without the use of superconducting materials, the large weight of the wind generator becomes a limiting factor. Projects have been developed with various materials with both low- (Wang et al , 2016) and high-temperature superconductivity (HTS) (Keysan and Mueller, 2015; Marino et al , 2016; Cheng et al , 2018; Liu et al , 2017a, 2017b; Cheng et al , 2020; Zhang et al , 2019), as well as projects of fully superconducting generators (Kalsi, 2013; Hoang et al , 2018) or generators with only a superconducting exiting system (Liu et al , 2017a, 2017b; Liu et al , 2015; Jeong et al , 2017) and projects with different stator and rotor topologies (Guan et al , 2017; Kovalev et al , 2017; Bauer, 2018). The world’s leading firms are engaged in the search for the optimal solution, and an overview of the latest achievements in this area is given in Antipov et al (2020).…”

Section: Introductionmentioning

confidence: 99%

Novel model of rotor design to increase the air gap flux of superconducting generator

Antipov

Иванова²,

Grozov³

2022

COMPEL

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Purpose The purpose of this study is to investigate a novel rotor design model to improve the technical performance of a superconducting synchronous generator. Design/methodology/approach Superconducting synchronous generators with a modular rotating cryostat for a single coil of the superconducting winding instead of an old-style single cryostat in which all rotor components are cold are briefly discussed. Subsequently, a new method of cryostat arrangement in the magnetic system of a rotor is considered. Different options were compared for the cryostat placement. The advantages of the novel rotor design model are noted. Findings In the novel rotor design model, the leakage coefficient of the excitation winding decreases, and the air gap magnetic flux increases, which will save on a superconductor material. Research limitations/implications For the purposes of this investigation, a finite element study of flux distribution in the cross section of a superconducting synchronous generator with a 10 MW rating at 10 rpm was conducted, and the magnetic fluxes and air gap flux densities were obtained for different modes. For direct-drive superconducting synchronous generators with distributed winding and different pole numbers, the calculations of magnetic fluxes were carried out by calculating the magnetic conductivities. Originality/value A new method of the cryostat arrangement in the magnetic system of a rotor has been classified as an invention and was protected by a patent. This paper is directly applicable to the field of superconducting synchronous generators.

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Selection of Excitation Operating Points of 10 MW HTS Exciting Double Stator Direct-Drive Wind Generators Having Single and Double Polarity Inner Stator

Cited by 7 publications

References 28 publications

Non-Conventional, Non-Permanent Magnet Wind Generator Candidates

Non-Conventional, Non-Permanent Magnet Wind Generator Candidates

Investigation of AC loss of superconducting field coils in a double-stator superconducting flux modulation generator by using T-A formulation based finite element method

Novel model of rotor design to increase the air gap flux of superconducting generator

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