Dielectric properties of cryogenic gas mixtures for superconducting power applications

Cheetham, Peter; Park, C; Kim, C H; Graber, Lukas; Pamidi, Sastry

doi:10.1088/1757-899x/278/1/012040

Cited by 21 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, it is possible to achieve higher electrical strength by increasing the percentage of moles of the mixed H2 or by creating a ternary combination of 88 mol% helium, 4 mol% hydrogen, and 8 mol% nitrogen. Compared to GHe, the breakdown voltage was increased by up to 300% using a ternary combination 39 . When a short circuit occurs in a superconducting device , a large electric field is created.…”

Section: Iiib Liquid and Gaseous Insulationmentioning

confidence: 99%

Insulation Materials and Systems for Superconducting Powertrain Devices in Future Cryo-Electrified Aircraft: Part I—Material Challenges and Specifications, and Device-Level Application

Yazdani-Asrami

Seyyedbarzegar

Zhang

et al. 2022

IEEE Electr. Insul. Mag.

View full text Add to dashboard Cite

Superconducting technology for aerospace application is enabled by emerging development around hydrogen cooled electrically powered aircraft, aiming at zero-emission aviation. Superconductors, typically in the form of tape or wire in a composite architecture, can not only carry current density which is over 100 times that of copper and aluminium, but are also characterized by much lower losses. This property of superconductors makes them good candidates for the fabrication of superconducting devices of high specific power density, i.e. lower size and lighter weight, which is critical for aerospace applications. Superconductors, like any other conductors, require standard insulation to function safely and reliably in the electrical apparatus of aircraft, especially due to the special architecture, operating temperature, and operating condition of superconducting apparatus at high altitude. Extra attention should be drawn to choose proper insulating materials for such applications. In this paper, the challenges and considerations for choosing insulating materials for superconducting devices in cryo-electrified aircraft are reviewed and discussed.

show abstract

Section: Iiib Liquid and Gaseous Insulationmentioning

confidence: 99%

Insulation Materials and Systems for Superconducting Powertrain Devices in Future Cryo-Electrified Aircraft: Part I—Material Challenges and Specifications, and Device-Level Application

Yazdani-Asrami

Seyyedbarzegar

Zhang

et al. 2022

IEEE Electr. Insul. Mag.

View full text Add to dashboard Cite

show abstract

“…Higher operating pressure will also increase the dielectric strength of the cryogens and reduce the bubble formation if subcooled [30]. This is important as we have established that the dielectric strength of a gaseous cryogen is directly related to the density of the cryogen [31]- [33]. Furthermore, bubble formation reduces the dielectric strength of the cryogen and the partial discharge inception voltage.…”

Section: Lh2mentioning

confidence: 99%

“…The dielectric strength and dielectric constant of LNG at 110 K and 1 bar are 27 kV/mm and 7.4, respectively. Both the cryogenic fuels can be used as a coolant and dielectric medium [31], [34]. Safety concerns related to the combustibility of the fuels in direct contact with electrical equipment need to be addressed.…”

Section: Lh2mentioning

confidence: 99%

Electric Aircraft Fueled by Liquid Hydrogen and Liquefied Natural Gas

Telikapalli

Swain

Cheetham

et al. 2022

IOP Conf. Ser.: Mater. Sci. Eng.

View full text Add to dashboard Cite

The paper is a review of the opportunities and challenges of cryogenic power devices of electric aircraft, and the ongoing research and development efforts of the government agencies and the industry. Liquid Hydrogen (LH2) and Liquefied Natural Gas (LNG) are compared to support high temperature superconducting (HTS) and normal metal devices, respectively. The power devices were assumed to operate at the normal boiling point of the fuel used. The efficiencies of the electrical devices are estimated based on state-of-the-art technology. The mass flow rates and total fuel requirements for both the cryogenic fuels required to maintain the operating temperatures of the devices were simulated using thermal network models. A twin-aisle, 300 passenger aircraft with a 5.5 h flight duration was used for the models. The results show that the required masses of LH2 and LNG are 744 kg and 13,638 kg, respectively for the cooling requirement. The corresponding volumes of LH2 and LNG required are 9,760 and 30,300 L, respectively. In both cases, the estimated mass of the fuel needed for the aircraft is more than what is needed to maintain the cryogenic environment of the power devices. It was concluded that an electric aircraft with LNG cooled normal metal devices is feasible. However, an aircraft with HTS devices and cooled with LH2 is more attractive if the ongoing R&D efforts on HTS devices and LH2 infrastructure are successful. The emission reductions would be substantially higher with LH2, particularly when H2 is produced using renewable energy sources.

show abstract

“…In addition, the thermal contraction of a typical polymer insulation material that occurs due to the intense temperature gradients of the superconductor cool down cycle is significant, potentially leading to mechanical failure and high-voltage electrical shorts at cryogenic temperatures. 6,7 Therefore, the need has increased for highperformance polymer dielectric materials with enhanced mechanical properties suited to the extreme operating environments required by superconductors. [8][9][10] Liquid nitrogen (LN 2 )-cooled HTS tapes and cable assemblies traditionally utilize lapped polymer tape dielectric layers of thermally stable materials such as Kapton™ polyimide or polypropylene laminated paper (PPLP).…”

Section: Introductionmentioning

confidence: 99%

Mechanics of dielectric polyamide/SiO₂ nanocomposite coatings for cryogenic service in superconductor systems

Mahon

Pagliocca

Harnack

et al. 2022

J of Applied Polymer Sci

View full text Add to dashboard Cite

The implementation of high‐temperature superconducting (HTS) power transmission has the potential to revolutionize the efficiency of electrical grids and help unlock a fully electric transportation infrastructure. Realizing the benefits of HTS systems has been impeded by a lack of available dielectric insulation materials that can (1) withstand the extreme cryogenic operating environment of superconductors and (2) demonstrate low temperature processing that is compatible with existing superconductor manufacturing methods. In this study, a silicon dioxide reinforced polyamide (PA/SiO2) nanocomposite with exceptional thermal stability has been developed as a solid dielectric coating solution. Thermomechanical characterization of the fabricated nanocomposite is conducted to explore multi‐scale material property relationships relevant to the sought applications. The multifunctionality of the processed nanocomposite is demonstrated by an improved thermomechanical performance for cryogenic conditions and low temperature processing without decrements in certain mechanical properties. Additional experiments to investigate the nanoparticle‐polymer interfacial mechanics are discussed. Results obtained herein present a viable option to solve the material challenges impeding wider implementation of HTS power transmission.

show abstract

Dielectric properties of cryogenic gas mixtures for superconducting power applications

Cited by 21 publications

References 12 publications

Insulation Materials and Systems for Superconducting Powertrain Devices in Future Cryo-Electrified Aircraft: Part I—Material Challenges and Specifications, and Device-Level Application

Insulation Materials and Systems for Superconducting Powertrain Devices in Future Cryo-Electrified Aircraft: Part I—Material Challenges and Specifications, and Device-Level Application

Electric Aircraft Fueled by Liquid Hydrogen and Liquefied Natural Gas

Mechanics of dielectric polyamide/SiO₂ nanocomposite coatings for cryogenic service in superconductor systems

Contact Info

Product

Resources

About

Dielectric properties of cryogenic gas mixtures for superconducting power applications

Cited by 21 publications

References 12 publications

Insulation Materials and Systems for Superconducting Powertrain Devices in Future Cryo-Electrified Aircraft: Part I—Material Challenges and Specifications, and Device-Level Application

Insulation Materials and Systems for Superconducting Powertrain Devices in Future Cryo-Electrified Aircraft: Part I—Material Challenges and Specifications, and Device-Level Application

Electric Aircraft Fueled by Liquid Hydrogen and Liquefied Natural Gas

Mechanics of dielectric polyamide/SiO2 nanocomposite coatings for cryogenic service in superconductor systems

Contact Info

Product

Resources

About

Mechanics of dielectric polyamide/SiO₂ nanocomposite coatings for cryogenic service in superconductor systems