Abb Research Ltd.

Abb Ab

Christer T&ouml;rnkvist

Anna Kornfeldt

Mikael Bergkvist

Johan Felix

Per Nordberg

Thorsten Sch&uuml;tte

Disclosed is a dielectric gelling composition, exhibiting a thermo-reversible liquid-gel transition at a transition temperature, T , wherein the gel comprises an oil and a combined gelator system having molecules of a polymer compound together with fine dielectric particles with a particle size in the nanomneter, 6 nm, range, preferably a particle size within the range from 0.001 to 1000 nm, the use of this dielectric gelling composition in an electric device comprising one or more conductors, a casing or enclosure and an insulation system comprising the dielectric gelling composition. An electric DC-cable having a conductor and an electrical insulation comprising a solid part with a porous, fibrous and/or laminated structure impregnated with the dielectric gelling composition and a method for production of such DC-cable wherein the combined gelator is prepared prior to impregnation are also disclosed.

DIELECTRIC GELLING COMPOSITION, THE USE OF SUCH DIELECTRIC GELLING COMPOSITION, AN INSULATED ELECTRIC DC-CABLE COMPRISING SUCH GELLING COMPOSITION, AND A METHOD FOR MANUFACTURING AN INSULATED ELECTRIC DC-CABLE COMPRISING SUCH GELLING COMPOSITION

A method for space-charge measurement in a coaxial cable comprising an inner conductor (,), a cable screen (,) and an electric insulation (,) between the inner conductor and the cable screen, wherein the cable screen is removed on both sides of a measurement region, an electric voltage pulse is generated by an electric pulse generator (,) and is applied over part of the insulation (,) of the cable within the measurement range, an acoustic signal, in the presence of space charges in the cable insulation, is generated by the voltage pulse in cooperation with the space charges and a possible acoustic signal is recorded by a sound-recording device (,). A grounded annular outer electrode (,) is applied around the measurement region, the sound-recording device is arranged in direct contact with the annular outer electrode, the voltage pulse is applied to the cable screen on both sides of the measurement region and is connected, via the impedance of the cable, to the inner conductor of the cable.

Method and a device for space-charge measurement in cables using a pulsed electroacoustic method

Growing community of inventors

Västerås, Sweden

Christer Törnkvist

Growing community of inventors

Västerås, Sweden

Christer T&ouml;rnkvist

Christer Törnkvist