Characterization of Commercial MgB<sub>2</sub>Conductors for Magnet Application in SMES

Leys, P.; Klaeser, M.; Ruf, C.; Schneider, T.

doi:10.1109/tasc.2016.2539260

Cited by 11 publications

(6 citation statements)

References 13 publications

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“…Those studies showed that as function of temperature, T, the threshold Bth(T) increases up to T~10 K, above which the instability stops nucleating [5][6][7]. This increases the interest for implementing MgB2 devices using liquid hydrogen as coolant [11][12][13]. In the present work we show that MgB2 films exposed to sufficiently rapid field variations can indeed result in nucleation and full development of thermomagnetic avalanches even above liquid hydrogen temperature.…”

supporting

confidence: 62%

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Dendritic flux instability in MgB₂films above liquid hydrogen temperature

Baruch-El

Baziljevich

Johansen

et al. 2017

Supercond. Sci. Technol.

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Magnetic flux instability limits potential applications of superconductors such as MgB2 in practical devices. Previous studies in MgB2 films exposed to magnetic fields revealed the occurrence of dendritic flux avalanches at temperatures below T~10 K. In the present work it is shown that films of MgB2 exposed to a fast-ramped magnetic field display a dendritic flux instability at elevated temperatures, up to 23 K. Such instability can therefore cause malfunctioning of practical devices based on MgB2 films even when operating at liquid hydrogen temperature.MgB2 is a promising material for superconducting applications such as electricity transmission cables, high-field magnets, energy storage devices, high power applications, and sensors [1][2][3]. Various characteristics ensure considerable attractiveness of this material, including its low cost, good mechanical properties, high critical current density, and relatively high critical temperature, Tc ~ 39 K. Nevertheless, dendritic flux avalanches resulting from the onset of a thermomagnetic instability in MgB2 [4][5][6][7][8], strongly challenges the use of this material in practical applications. Avalanche events can critically impact the performance of the device by causing sudden changes in the material resistance and current flow. Clearly, thermomagnetic instability is not an intrinsic characteristic of the MgB2 material. For instance, while most MgB2 films display the instability, some exclusive ultrapure MgB2 films did not exhibit dendritic avalanches [9,10]. In addition, external parameters such as the magnetic field and the sample temperature may affect the stability. Therefore, all these factors should be considered in applying MgB2 films in practical devices.

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supporting

confidence: 62%

“…There is at present a significant interest in devices based on MgB 2 used in an environment cooled by liquid hydrogen at 20 K [11][12][13]. This interest has motivated investigation of the stability limits in transient situations.…”

mentioning

confidence: 99%

Dendritic flux instability in MgB₂films above liquid hydrogen temperature

Baruch-El

Baziljevich

Johansen

et al. 2017

Supercond. Sci. Technol.

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“…Recent attention is focussed on optimising wire properties to achieve critical current density, J c , at higher magnetic fields than conventional low temperature superconductors to maximise industrial applications [9][10][11][12]. Exemplar applications for which MgB 2 wire quality is an important criterion include low field magnets for imaging [13] and energy storage [14], high energy physics [6] and fusion reactors [15,16].…”

Section: Introductionmentioning

confidence: 99%

Low temperature decomposition of metal borohydride drives autogenous synthesis of MgB₂

Shahbazi¹,

Alarco²,

Talbot³

2017

Supercond. Sci. Technol.

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We describe a low temperature, autogenous pressure method to synthesise mm-scale MgB2 aggregates with highly connected grains. The decomposition of metal borohydrides such as NaBH4 and KBH4 at low temperature (i.e. < 150 °C) in the presence of Mg provides reactive boron species at pressure and subsequent formation of MgB2 in high yield. Optimum synthesis conditions include heating to 250 °C for > 30 min then a ramp to 450 °C < Tmax < 500 °C and 1.4 MPa < Pmax < 2.2 MPa. Reactions with KBH4 release reactive boron species at higher temperature (∼130 °C) than reactions with NaBH4 (∼80 °C–100 °C). Alkali metal solubility in MgB2 is at ∼ppm levels. The onset superconducting transition temperature, Tc, for MgB2 produced by these syntheses ranges between 38.3 and 38.5 K. Magnetic measurements of MgB2 aggregates show a grain connectivity comparable to powders produced at higher temperature (> 800 °C) and suggests that this synthesis approach may be effective for ex situ wire production.

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“… The magnesium superconductor ( M g B 2 , T c =39 K ), is a medium‐temperature superconductor which is presented in 2001. The physical properties of the mentioned conductor for SMES usage can be found in Leys et al Some methods such as actual winding direct measurement, electromagnetic model direct measurement, and mathematical model building could be considered for measurements . A known model is based on the representation of single turns, and magnetic mutual couplings considering all other turns.…”

Section: Smes Coilmentioning

confidence: 99%

Superconductor magnetic energy storage system usage for distributed generation: Active/reactive power and voltage controller design in connected and disconnected cases

Sharouni

Hedayati

2018

Int Trans Electr Energ Syst

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Summary A novel model for superconductor magnetic energy storage (SMES) system as distributed generation system is proposed in this paper. Three‐level–bidirectional current fed chopper and 3‐level diode clamp inverter are used, and a novel switching strategy is proposed for control. Two cases are defined as the connected mode and islanded mode from the power grid that the SMES operation is considered and studied for both cases, for local load supplying and active/reactive power control. However, voltage controller in the islanded case and power controller in the connected case are designed. Proposed model and its associated control approaches have been verified through simulations by MATLAB/Simulink.

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Characterization of Commercial MgB₂Conductors for Magnet Application in SMES

Cited by 11 publications

References 13 publications

Dendritic flux instability in MgB₂films above liquid hydrogen temperature

Dendritic flux instability in MgB₂films above liquid hydrogen temperature

Low temperature decomposition of metal borohydride drives autogenous synthesis of MgB₂

Superconductor magnetic energy storage system usage for distributed generation: Active/reactive power and voltage controller design in connected and disconnected cases

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Characterization of Commercial MgB2Conductors for Magnet Application in SMES

Cited by 11 publications

References 13 publications

Dendritic flux instability in MgB2films above liquid hydrogen temperature

Dendritic flux instability in MgB2films above liquid hydrogen temperature

Low temperature decomposition of metal borohydride drives autogenous synthesis of MgB2

Superconductor magnetic energy storage system usage for distributed generation: Active/reactive power and voltage controller design in connected and disconnected cases

Contact Info

Product

Resources

About

Characterization of Commercial MgB₂Conductors for Magnet Application in SMES

Dendritic flux instability in MgB₂films above liquid hydrogen temperature

Dendritic flux instability in MgB₂films above liquid hydrogen temperature

Low temperature decomposition of metal borohydride drives autogenous synthesis of MgB₂