الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The high voltage electrical porcelain insulator plays an important role
in the electrical power system. Outdoor porcelain insulators are exposed to
various mechanical, electrical, and thermal stresses that cause the
degradation of the insulating material used in the electrical power systems.
Consequently, enhancing the dielectric properties of porcelain insulators
becomes the main issue of many recent kinds of research to withstand
higher voltage levels. The effect of different addition of nanoparticles on
the electrical and physical properties of porcelain insulators sintered at
different temperatures is investigate in the present study.
Kaolin, feldspar, and quartz (in the form of silica sand) were used as
economical Egyptian raw materials to prepare porcelain insulator samples.
Different additions of nanoparticles (Alumina, Silica, and Zirconia) were
used with different concentrations (silica 0–15 wt.%, alumina 0–15 wt.%,
and zirconia 2-8 wt.%) to neat porcelain samples to illustrate their effects on its electrical and physical properties. The different samples were treated at a different sintering temperature (from 1100 oC to 1400 oC). The Morphology and microstructure of selected samples were investigated using
a Scanning electron microscope (SEM). The phase composition was
identified using X-ray diffraction (XRD), to evaluate the thermal, structural, and microstructural changes with increasing the concentration of silica (0– 15 wt.%), alumina (0–15 wt.%), and zirconia (2-8 wt.%). The dielectric properties were evaluated by measuring the AC breakdown strength, the
relative permittivity (εr), and dielectric loss (tan δ) at a wide range of frequencies and room temperature. A Finite Element Method is used to
evaluate the voltage and electric field distribution in and around the samples
at the breakdown voltage. The results revealed that the physical and dielectric properties of porcelain samples are enhanced with increasing the
sintering temperature. The results obtained revealed that the porcelain samples admixed with 10 wt.% silica nanoparticles (S2) and sintered at 1300 oC present the maximum density (3.57 g/cm3 ), minimum water absorption 0.0173%), and
minimal porosity values (0.043%). The obtained results for alumina
nanoparticles indicate that samples sintered at 1300ºC give the best
electrical and physical properties. Also, the porcelain samples admixed with
5 wt.% NA (A1) and sintered at 1300oC showed the maximum density
3.255 g/cm3 ), minimum water absorption (0.218%), and minimum porosity (0.099 %) values. For zirconia nanoparticle addition, the results obtained revealed that the samples sintered at 1300ºC give the best electrical and physical properties. Nanocomposite samples admixed with 4 wt.% zirconia nanoparticles (Z2) and sintered at 1300 oC presented the maximum density (3.678 g/cm3
), minimum water absorption (0.031%), and minimum porosity (0.049%) values. The results obtained indicated that porcelain samples admixed by 10 %NS (S2), 5% NA (A1), and 4 % NZ (Z2) showed the best insulating properties when sintered at 1300 0C and this confirms the electrotechnical porcelain production feasibility.