DIELECTRIC STRENGTH ENHANCEMENT IN LIQUID-INSULATED HIGH-VOLTAGE PULSED DEVICES
E.I. Pal'chikov1,2
1Lavrentyev Institute of Hydrodynamics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
Keywords: solid insulation, liquid insulation, electrical breakdown at the interface, polarization charge, ionic charge
Abstract
To improve the insulating properties of the solid-liquid dielectric interface and to reduce the risk of surface discharges, partial discharges in the liquid dielectric, and dendrite growth in the solid dielectric, it is proposed to minimize polarization and ionic charges at the solid-liquid dielectric interface. For this purpose, nonpolar solid dielectrics with the same permittivity ε as the liquid dielectric are used. Polypropylene and polyethylene, both with ε = 2.3, are suitable for transformer oil with ε = 2.3. Polypropylene has relatively high mechanical strength and is easy to machine, while polyethylene is flexible and deforms without cracking, making it suitable for wire sheaths. This approach makes it possible to increase the dielectric strength of high-voltage pulsed devices, improve insulation reliability, and reduce device dimensions.
|
