Dielectric breakdown of cryogenic gases and liquids

Gerhold, J.

doi:10.1016/0011-2275(79)90030-4

Cited by 49 publications

(14 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The permittivity, conductivity, dielectric loss and breakdown strength under different conditions are known [7]. However, there has not been a research focuses specifically on the interruption performances of cryogenic fluids.…”

Section: Potential Dielectrics For Cryogenic Interruptionmentioning

confidence: 99%

“…Paschen's curves of cryogenic gases measured at (a) uniform field of parallel-plate electrodes [5,7] and (b) non-uniform field of coaxial electrodes [8,9] at room temperature Besides the dielectric strength, an ideal cryogenic interruption medium should have low boiling temperature, low viscosity, high thermal conductivity and high heat capacity. For cryogenic liquids, the enthalpy of vaporization should be high enough to prevent excessive gas formation.…”

Section: Potential Dielectrics For Cryogenic Interruptionmentioning

confidence: 99%

See 1 more Smart Citation

Future cryogenic switchgear technologies for superconducting power systems

Saluja

Damle

et al. 2017

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

View full text Add to dashboard Cite

Section: Potential Dielectrics For Cryogenic Interruptionmentioning

confidence: 99%

Section: Potential Dielectrics For Cryogenic Interruptionmentioning

confidence: 99%

Future cryogenic switchgear technologies for superconducting power systems

Saluja

Damle

et al. 2017

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

View full text Add to dashboard Cite

“…The electrical breakdown of liquid helium [22][23][24] and other cryogenic liquids [25,26] has been studied extensively by research groups interested in the dielectric properties of helium and other cryogenic liquids as insulators. In these studies, however, little attention was given to the mechanism of ionization.…”

Section: The Field Ionization Mechanism Of Chargingmentioning

confidence: 99%

Generation of charged droplets by field ionization of liquid helium

Tsao¹,

Lobo²,

Okumura³

et al. 1998

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Abstract. Positively charged helium droplets were produced by ionization of liquid helium in an electrostatic spraying experiment, in which fluid emerging from a thin glass capillary was ionized by applying a high voltage to a needle inside the capillary. At 2.2 K, fine droplets (<10 µm in diameter) were produced in pulsed sprays or showers with total currents as high as 0.4 µA at relatively low voltages (2-4 kV). Ionization was accompanied by a visible glow at the needle and glass tips. Droplet formation was suppressed at 3.5 K. In contrast, liquid nitrogen formed a well-defined Taylor cone with droplets having diameters comparable to the jet (≈100 µm) at much lower currents (3 nA) and higher voltages (9 kV), in agreement with previous results. The mechanism for charging in these liquids was proposed to be field ionization, identical to the processes leading to conduction in cryogenic insulating liquids observed by Gomer. The high currents resulting from field ionization in helium, together with the intrinsically low surface tension of helium I, led to charge densities that greatly exceeded the Rayleigh limit, thus preventing formation of a Taylor cone and resulting in Coulomb explosion of the liquid.

show abstract

“…Potential problems with liquid nitrogen insulated large gaps and voltages above few 100 kV are well known [1] . In addition, a temperature increase of the superconductor, e. g. in case of transition of the superconducting to the normal conducting state of a super conducting fault current limiter, may have a strong impact on the dielectric strength of liquid nitrogen in case of occurrence of gas bubbles.…”

Section: Introductionmentioning

confidence: 99%

AC breakdown voltage of liquid nitrogen depending on gas bubbles and pressure

Fink

Kim

Mueller

et al. 2014

2014 ICHVE International Conference on High Voltage Engineering and Application

View full text Add to dashboard Cite

Liquid nitrogen is often used within superconducting high voltage apparatus as pressurized coolant and for electrical insulation purposes. A temperature increase of the super conductor surface, e. g. up to about room temperature during a quench of a fault current limiter, may cause a decrease of the breakdown voltage within the apparatus by generation of nitrogen gas bubbles. A cryostat was equipped with a sphere to plane electrode arrangement for the examination of breakdown and withstand voltages of liquid nitrogen. The temperature of liquid nitrogen was kept at 78 K whereas the pressure values were adjusted to 0.1 MPa, 0.2 MPa and 0.3 MPa. Alternating voltage up to 230 kVrms was applied to the arrangement. Impact of bubble generation by heating impulses on the dielectric strength was not found for 0.3 MPa and it was found for 0.2 MPa only in case of low distances. This is different than the already known behavior at 0.1 MPa and boiling temperature.

show abstract

Dielectric breakdown of cryogenic gases and liquids

Cited by 49 publications

References 19 publications

Future cryogenic switchgear technologies for superconducting power systems

Future cryogenic switchgear technologies for superconducting power systems

Generation of charged droplets by field ionization of liquid helium

AC breakdown voltage of liquid nitrogen depending on gas bubbles and pressure

Contact Info

Product

Resources

About