Konrad Kierczyński

An analysis of AC conductivity in moist oil-impregnated insulation pressboard

The paper presents research results of testing AC conductivity in a moist oilimpregnated electric insulation pressboard, depending on the moisture content level and temperature of the samples. A new method has been elaborated for converting experimentally obtained dependences from frequency-domain spectroscopy (FDS) to the reference temperature of 293 K (20 /dpl deg/C). Activation energy values have been determined for the conduction and relaxation time. It has been found the conductivity is realized by electron tunnelling between potential well formed by water molecules contained in the structure of moist cellulose.

Magnetic Anisotropy in Bicomponent Self-Assembled Ni and Ni-Pd Nanowires Studied by Magnetic Resonance Spectroscopy

Self-ordered arrays of Ni, Ni(50)Pd(50), and Ni(78)Pd(22) nanowires were synthesized by simultaneous electrochemical deposition of Ni and Pd components into porous templates of anodic aluminum oxide using alternating current. This paper is focused on the interplay of structure and chemical composition of Ni and Ni-Pd bicomponent nanowires arrays and the peculiarities of its magnetic anisotropy.

Analysis of AC conductivity in wet oil impregnated insulating paper

In paragraph are presented the results of research based on the AC conductivity of the wet oil-impregnated insulating paper, depending on the moisture content and temperature of the samples. This is a new experimental method, which converts the results from the FDS to the reference temperature of 293.15 K (20 ° C). Takes account of the activation energy for conduction and relaxation time.

The influence of moisture on the activation energy of the conductivity of paper-oil insulation of power transformers

In the paper presents the influence of moisture content and electric field intensity on the activation energy of the conductivity DC electrical pressboard impregnated with insulating oil in the measuring temperature range of from 20 °C to 80 °C and the electric field intensity range from 10 kV/m to 1000 kV/m. With Arrhenius plots for each of the moisture content and for all seven of the electric field intensity was determined coefficients of determination R2, which are very close to one. This proves the high accuracy of approximation linear experimental results on the Arrhenius plots and highly accurate measurements of conductivity, accurate stabilization and measurements temperature. It was found that the moisture content of range from 1.15% to 6.5% wt. and the electric field intensity does not affect (in the margin of error) on the activation energy value of the DC conductivity, which is (1.0338 ± 0.02000) eV.

The influence of temperature on the AC conductivity of a composite pressboard-synthetic ester-water nanoparticles

This paper presents the results of the AC conductivity of electrical pressboard production company Weidman with a water content from 0,6% to 7% by weight, impregnated with MIDEL 7131 synthetic ester. Frequency and temperature dependencies of the AC conductivity were determined. The Arrhenius plots were developed for the whole range of measurement frequencies, from which the activation energies of the AC conductivity were determined. It was found that changes in AC conductivity can be described by means of two activation energies. Each of these activation energies decreases with the increase of the measurement frequency. This may mean, in our view, that these differences are due to changes the environment occurring water nanoparticles. Some of the nanoparticles be are located in the environment cellulose material, while the other part - in the environment the MIDEL 7131 ester.

The influence of electric field intensity on the activation energy of the DC conductivity the electrical pressboard of impregnated with synthetic ester

In the paper presents the influence of electric field intensity on the activation energy of the DC conductivity the electrical pressboard impregnated with synthetic ester in the measuring temperature range of from 20°C to 80°C and the electric field intensity range from 10 kV/m to 1000 kV/m. With Arrhenius plots for pressboard sample about the moisture content 6% wt. and for all of the electric field intensity was determined coefficients of determination R2, which are very close to one. This proves the high accuracy of approximation linear experimental results on the Arrhenius plots and highly accurate measurements of conductivity. It was found that for pressboard sample about the moisture content of 6% wt. impregnated with synthetic ester and the electric field intensity does not affect (in the margin of error) on the activation energy value of the DC conductivity, which is (0.59075±0.01202) eV.

The influence of strong electric fields on the DC conductivity of the composite cellulose, insulating oil, and water nanoparticles

The paper presents investigated the dependencies of DC conductivity electrical pressboard impregnated insolating oil of moisture content and electric field strength. The studies were conducted for measuring temperature in the range of 20 °C to 80 °C and the electric field intensity in the range of 10 kV/m to 1000 kV/m. With approximate waveforms in double logarithmic coordinates conductivity depending on the intensity of the electric field exponential function determined coefficients of determination R2. The value of this ratio is close to unity, which provides high accuracy measurements of conductivity and the exact stability and temperature measurements. It was found that changes in the electric field intensity will decrease the activation energy of conductivity of about 0.01 eV, thus increasing the DC conductivity of about 1.5 times.

Właściwości elektryczne nanokompozytów (FeCoZr) x (Al2O3) (100-x) wytworzonych rozpylaniem wiązką argonu i tlenu jako układy kondensatorowe

The paper presents the results of measurements which determine the electrical properties of nanocomposites (FeCoZr)x(Al2O3)(100-x) which were produced using the ion-sputtering. In the research samples, which were made as capacitor measurement system, were used to reduce the impact of resistance of the sample. Temperature and frequency dependence on capacity, conductance, loss angle and phase angle were determined. Measurements were performed using alternating current at a frequency range from 42 Hz to 1 MHz at temperatures range from 77 K to 373 K.

Moisture level content analysis in oil impregnated pressboard used in power transformers

The article presents the results of research based on the DC electrical conductivity of wet paper depending on the moisture content and temperature of the samples. The change of moisture content does not change the activation energy of conductivity. The conductivity is performed by the hopping mechanism between the nearest possible holes which are formed in the material with nanodrops of water by the plotting of theoretical dependence that accurately describes the dependence of the conductivity of the water content and temperature. Medium size of nanodrops was about 1.5 nm, and the composition contains about 220 molecules of water.