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Measurement uncertainty in diagnostics of insulating materials
Kamenická, Zuzana ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work deals with measurement capacity and dissipation factor of capacitor with real dielectric in frequency range 20 Hz to 30 MHz. Liquid and solid dielectrics are measured by LCR instruments and by test fixtures, both from company Agilent. Relative permittivity and loss number are calculated for different instruments settings. The general aim is to specify the influence of parameters as frequency, voltage, integration time and thickness of material on the uncertainties of primary and secondary quantities for measurement.
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Influence of nanoparticles on the properties of electroinsulating materials
Sedláček, Michal ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work deals with influence nanoparticles, as fillers of polymer, to electrical properties dielectric composite materials. Addition of just a few weight percent of nonofillers has profound impact on the physical, chemical, mechanical and electrical properties orf polymer. Simultaneously is focused on production and diagnostics by the relaxation spectroscopy and measure internal resistance. Examination material is epoxy resin TSA 220S filled Al2O3 and SiO2 nanoparticles.
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Automated workplace for the direct current measurements
Plocr, Radek ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
The present thesis attempts at an overview of DC methods used for diagnosing electrical isolation systems. It investigates the problem of small currents and how to measure them. Part of the thesis deals with building a workstation designed for long-term monitoring of absorbing characteristics of dielectric materials and it also presents a layout of a workstation used for measuring recovery voltage. Both workplaces are computer-automated using the VEE Pro application provided by Hewlett-Packard. Tests were performed on both workstations and the obtained results were processed in a test report as specified under ČSN IEC 93. During the experiment, every effort was made to ensure and monitor the atmospheric conditions of the measuring process.
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Analysis of composite system with different filler ratio
Mydlář, Marek ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
This master’s thesis applies dielectric relaxation spectroscopy to analyse impact of climatic changes on dielectric properties of composite material samples (TSA 220S varnish combined with 60.030 mica). Experiments aim to analyse effect of mica composite mass ratio (0, 4, 8 and 16 % of mica), relative humidity (0, 33, 55, 65, 75 and 95 %) and temperature (23, 30, 40 and 50 C) on complex permitivity as a function of frequency.
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Multistress ageing analysis of the electroinsulating materials
Jeřábek, Michal ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
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.
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Modification of electroinsulating varnish with ground mica
Drápal, Aleš ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
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.
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The use DC electrical method in diagnostics of insulating materials
Volf, Michal ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
In this work describe to the Dielectric relaxation spectroscopy for the evaluation of the actual status of insulation systém. The used methods of quantifying the dielectric response in time domain are polarization-depolarization current and recovery voltage measurement and in frequency domain the loss factor and the complex capacitance measurement. Influence of thermal ageing and temperature dependences of charge and dischage currents are observed.
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