Development of Stator Windings for Fully Superconducting Motor With $\hbox{MgB}_{2}$ Wires

Komori, Kazuhiro; Uchida, Yuushi; Nakamura, Taketsune; Kobayashi, Hiroaki; Wakuda, T.; Tanaka, Kazuhide

doi:10.1109/tasc.2013.2240033

Cited by 20 publications

(10 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We see that for partly decoupled filaments, (8), the relationship coincides with (3) as expected (keeping the assumption ω 2 τ 2 << 1 in mind). For fully coupled filaments, (8), the losses are independent of ω and B a , whereas they are inversely proportional to L 2 (while the coupling current is constant, the resistance in the loop decreases linearly with L and the losses are expressed per unit length).…”

supporting

confidence: 84%

“…For fully coupled filaments, (8), the losses are independent of ω and B a , whereas they are inversely proportional to L 2 (while the coupling current is constant, the resistance in the loop decreases linearly with L and the losses are expressed per unit length). It should be noted that we in (8) have made the approximation that the coupling current becomes I c /2 throughout the period as soon as its peak value is I c /2.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Coupling currents and hysteresis losses in MgB₂superconductors

Magnusson¹,

Lindau²,

Taxt³

et al. 2014

Supercond. Sci. Technol.

View full text Add to dashboard Cite

MgB 2 multi-filamentary superconductors are widely considered for use in dc applications. To expand the possible application range to ac apparatuses, the development of a low ac loss wire is needed. This development involves several steps, and a solid understanding of the loss mechanisms is important to optimize that process as well as for evaluating dc wires exposed to current or magnetic field ripple. In this study we discuss the coupling currents and their influence on hysteresis loss as well as on coupling current loss. We give a phenomenological explanation of the origin and behaviour of the coupling currents and describe the loss patterns for hysteresis loss and coupling current loss separately. Finally, we interpret measured AC losses in an MgB 2 wire cut into different lengths representing different twist pitches. Under certain circumstances short sample lengths are shown to give inaccurate measurement results. On the other hand, short sample lengths of non-twisted wires can be used to estimate the twist pitch necessary to electromagnetically decouple the superconducting filaments.

show abstract

supporting

confidence: 84%

mentioning

confidence: 99%

Coupling currents and hysteresis losses in MgB₂superconductors

Magnusson¹,

Lindau²,

Taxt³

et al. 2014

Supercond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…The continuous improvement of the properties of high temperature superconducting materials creates more opportunities for high power superconducting motors [1]. Compared with the conventional machines of same power, high temperature superconducting (HTS) motors have the advantages of small volume, light weight, high power density and being less expensive to operate because of their high current density, ironless design, high magnetic field, and high operating temperature [2][3][4][5][6][7]. The potentially significant size, weight, cost and efficiency benefits of superconducting machines, which are especially important factors in these applications such as electric propulsion in ships, Figure 1 shows the squirrel cage rotor exploded diagram of the proposed HTS induction motor, which is composed of cast aluminum bars, cast aluminum end rings, balance rings, silicon steel core and shaft.…”

Section: Introductionmentioning

confidence: 99%

A Superconducting Induction Motor with a High Temperature Superconducting Armature: Electromagnetic Theory, Design and Analysis

et al. 2018

View full text Add to dashboard Cite

Large electric superconducting machines are being sought to solve emissions challenges in aircraft and provide a solution to >12 MW wind turbine electricity generation. Superconducting motors with only high temperature superconducting (HTS) armatures can offer advantages of high reliability, high power density, and high efficiency compared with conventional superconducting motors. In this paper, a novel HTS squirrel-cage induction motor is proposed for high speed operation, which adopts the structure of HTS windings with a certain inclination angle in the stator slots. Due to the limitation of curvature radius of superconducting tapes, the pitch of HTS windings can be only set to 1 and adopt the short pitch arrangement structure, which such design details of the HTS motor would ensure the superconducting coils can undertake larger current and reduce AC losses. In order to keep the HTS windings in superconducting state and larger current density, a special fixed cryogenic cooling system below 70 K with the method of gas extraction and decompression, which is made of aramid fiber, has been fabricated and the whole structure of the stator is placed in liquid nitrogen. According to the motor control principles and electromagnetic field theory, the electrical performances of the novel designed stator-HTS motor, which driven by the variable-voltage variable-frequency (VVVF) inverter, are analyzed including the flux density distributions, the torque, the induced electromotive force, losses and efficiency by using the finite element method. Finally, the components of HTS squirrel-cage induction motor have been manufactured according to the designed parameters. Next step, the motor will be assembled and tested.Energies 2018, 11, 792 2 of 15 all-electric aircraft propulsion, electric vehicles and wind generators, etc., will change the development direction of the electrical machinery industry [8][9][10][11][12][13][14].However, most superconducting machines adopt superconducting material as the rotor poles for the field to supply high air-gap magnetic flux density, consequently the HTS motor has high power density and has been studied by many researchers and institutions, but this structure brings some problems such as cooling, maintenance, mechanical speed and manufacture cost, etc., and this technology is also complex [15][16][17][18]. In addition, because the superconducting magnets face an air gap with a high flux density at all times, the magnetic flux density in the superconducting coils is also high. This will affect the critical current of the superconducting tapes, so the operation temperature of superconducting magnets must decrease to 20-30 K to eliminate this influence. Therefore, the costs of cooling increase.We have focused on the HTS induction motor [19][20][21][22], in which the superconducting material is only applied to the stator part. The HTS induction motors avoid the key problems of the rotor dynamic seal and the rotor mechanical strength compared with the conventional superconducting motor under the ...

show abstract

“…In rotating machines, a racetrack coil configuration is used due to its electromagnetic and geometric advantages [4,14,18,19]. To employ such superconducting coils in practical applications, however, extensive experimental validation is required to attain high coil performance.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of a solid nitrogen impregnated MgB₂ racetrack coil

Patel

Qiu

Mustapić

et al. 2018

Supercond. Sci. Technol.

View full text Add to dashboard Cite

To develop powerful wind turbine generators using superconducting technology, highperformance superconducting racetrack coils are essential. Herein, we report an evaluation of a multifilamentary magnesium diboride (MgB2) conductor-based racetrack coil cooled and impregnated simultaneously by solid nitrogen (SN2). The coil was wound on a copper former with 13 mm winding width, an inner diameter of 124 mm at the curvature, and 130 mm length of the straight section. An in situ processed S-glass-insulated 36-filament MgB2 wire was wound on the former in two layers with

show abstract

Development of Stator Windings for Fully Superconducting Motor With $\hbox{MgB}_{2}$ Wires

Cited by 20 publications

References 11 publications

Coupling currents and hysteresis losses in MgB₂superconductors

Coupling currents and hysteresis losses in MgB₂superconductors

A Superconducting Induction Motor with a High Temperature Superconducting Armature: Electromagnetic Theory, Design and Analysis

Evaluation of a solid nitrogen impregnated MgB₂ racetrack coil

Contact Info

Product

Resources

About

Development of Stator Windings for Fully Superconducting Motor With $\hbox{MgB}_{2}$ Wires

Cited by 20 publications

References 11 publications

Coupling currents and hysteresis losses in MgB2superconductors

Coupling currents and hysteresis losses in MgB2superconductors

A Superconducting Induction Motor with a High Temperature Superconducting Armature: Electromagnetic Theory, Design and Analysis

Evaluation of a solid nitrogen impregnated MgB2 racetrack coil

Contact Info

Product

Resources

About

Coupling currents and hysteresis losses in MgB₂superconductors

Coupling currents and hysteresis losses in MgB₂superconductors

Evaluation of a solid nitrogen impregnated MgB₂ racetrack coil