IEEE Transactions on Electrical Insulation

This summarizes the important physical and electrical characteristics of these diverse and highly useful insulating materials. Factors of chemical structure which influence the resulting resin properties are discussed. The great variety of properties which can be achieved through variations in this one class of resins is emphasized. A range of applications of these resins is mentioned and illustra... View full abstract»

Voids produced in the impregnation process exist in mica insulation system of rotating machine coil. Distribution of those voids' size, gap spacing, and discharge area is estimated based on the experimental data on the repetition rate and the apparent charge of partial discharges of sample coils. The method is grounded on several assumptions such as Paschen's law for discharge inception voltage of... View full abstract»

Based on measurements, the strength of synthetic oil impregnated capacitor paper (Askarel) to dc and ac voltage 1.2/50-μs voltage surges and switching surges of various wavefront duration are discussed. The results of measurements are compared with the performance figures of mineral oil impregnated capacitor paper. The diminishing effect of the number of lightning and switching surges and ... View full abstract»

Two electrostatic detectors are designed to search for the presence of microparticles of dimensions greater than 10 μm, in an ultrahigh-vacuum test gap (≈7 mm), when a high dc voltage (> 100 kV) is applied across the gap. The experiments with both the detectors revealed that such microparticles are not generated in detectable numbers, within the vacuum gap, prior to breakdown. View full abstract»

An experimental investigation of the effect of a cuprous oxide coating upon the surface flashover of high-density alumina in vacuum is reported. It is shown that such coatings improve the impulse strength of the system and eliminate the conditioning effect observed in the case of uncoated specimens at dc and 60-Hz voltages. An explanation of the observed behavior is given in terms of a surface cha... View full abstract»

Underwater repeatered telephone cable systems are series powered by high-voltage dc. Each repeater and equalizer contains a power separation filter (PSF) for extracting the dc current from the center conductor of the coaxial cable while allowing signal transmission. Corona discharges occurring across the high-voltage components are coupled through reactive components to the repeater's terminals. E... View full abstract»