This master's thesis focuses on composite systems based on varnish combined with different filler ratios of micronized mica. The aim is to analyse impact of the filler on dielectric properties of the varnish, i.e. relative permittivity and loss factor as functions of frequency as well as charging and discharging currents as functions of time. Dielectric mixture formulas are applied on relative permittivity values. Calculated and measured values are compared.

This work deals with persepective environmentally friendly electroinsulating liquids. Important properties of currently used electroinsulating liquids are listed. Physical nature of viscosity of liquids and its temperature dependance are described and methods of its measuring are listed. Also temperature dependance of density is described from physical point of view. Measurement of density and of temperature dependance of viscosity of chosen vegetable and mineral oils was performed. On the basis of this measurement was calulated the activation energy of these samples. Two methods of dynamic viscosity measurement were used for some samples.

This work deals with issues of elecroinsulating varnish and composite materials. The general aim is to observe impact of fulfilment and size of particle against measured values.

This work deals with issues of dielectric composite materials. The general aim is to observe how the amout of nanofilling influence dielectric spectrum in dependence on relative humidity and temperature which is measured on prepared samples. For this purpose had been created variety of a samples of electroinsulating varnish with different percentage of filling with nanoparticles. Experimental material is epoxy resin NH91 LV filled by Al2O3 nanoparticles.

The bachelor thesis submitted deals with properties of electro-insulating lacquer hardenable by ultraviolent radiation and temperature. Within the theoretical part a summary of electro-insulating lacquers used in electrotechnics has been elaborated. Chemical changes that take place in this material group have been described during hardening process. A method of dielectric relaxation spectroscopy specifically focused on mathematic and physical description of polarisation and conductive mechanisms taking place in the structure of the given material has been closely studied. In the experimental part a workplace for hardening and long-term exposition of lacquered samples during simultaneous effect of various climatic elements has been designed and built. The selected electric and mechanical properties have been monitored on three sets of experimental samples prepared by means of different methodical procedures. The results gained have been mathematically evaluated and physically interpreted in term of methodical procedure of hardening and different temperature of measurement.

This diploma thesis deals with not-aged and thermally, electric and multistress aged slotted isolations dielectric properities experimental probing. Dutiny experiment is watched influence moisture on dielectric properties insulating materiále ISONOMŽNMN. Especially both two permitivity complex components are surveyed, in dependence on the frequency and the temperature changes during thermal, electric and multistress ageing. These characteristics are viewed in light of application the isolation in practice.