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Kucheriava I.M.,NASU Institute of Electrodynamics
Technical Electrodynamics | Year: 2017

The electric field distribution in the vicinity of stress cone of high-voltage XLPE insulated cable termination (110 kV) is studied by computer modeling. The dependence of cable insulation conductivity on electric intensity and the different cone positions relative to the cutting ends of the cable outer semiconducting layer and copper wire shield are taken into account. The stress control cone is considered both in the form of only cone reflector and as a complete stress cone with insulation body. The peculiarities of field distribution depending on the cone shape and surface roughness are analyzed. The attained results are of interest for designing and improvement of up-to-date high- and extra- high-voltage cable terminations.

Kucheriava I.M.,NASU Institute of Electrodynamics
Technical Electrodynamics | Year: 2016

The distributions of electric field, electric force and mechanical stress in the polyethylene insulation of power cable that contains separate branch of a water tree are studied by computer modeling. Two models of water tree branch which include a string of water-filled spherical microcavities connected by cylindrical channels with equal radius and with radius decreasing along the length of the branch are examined. It is shown that the action of electric force and electromechanical stresses at the ends of thinner tree channels can cause their destruction and then growth of water trees in polyethylene insulation.

Shcherba M.A.,NASU Institute of Electrodynamics
Technical Electrodynamics | Year: 2016

The analysis of the local amplification of law-frequency electric field (EF) in nonlinear polyethylene (PE) insulation with water trees (WT), which have thickening of spheroids type and cylindrical areas with different conductivity has been made. The influence of specific non-linear electrical conductivity of PE insulation, as well as its amplitude- and frequency-dependent dielectric permittivity on the EF distribution and such multi-physical degradation mechanisms of insulation as tensed volumes, total current density and electromechanical pressures at different trees conductivity has been determined. © Shcherba M.A.,2016.

Podoltsev O.D.,NASU Institute of Electrodynamics | Shcherba M.A.,NASU Institute of Electrodynamics
Technical Electrodynamics | Year: 2016

The mathematical model and the analysis of inhomogeneous electric field and total current density distribution in micro-volumes of crosslinked polyethylene (XLPE) insulation on ultrahigh voltage near water micro-inclusions extracted along the field have been made. The analysis was made considering a nonlinear conductivity dependence on the electric field. The multi-physical character of possible degradation processes ofsolid polymer insulation of ultra high voltage cables in the appearance of conducting ellipsoidal inclusions and branched water dendrites has been specified. The studies were made with taking into account the calculation results of electric field macro-inhomogeneity distribution along the cross-section of XLPE insulation of ultra high voltage cables.

Gyzhko Y.,NASU Institute of Electrodynamics
Acta Technica CSAV (Ceskoslovensk Akademie Ved) | Year: 2010

Analysis and processing of vibration signals measured on moving parts of electrical machines using a diagnostic information-measuring system based on the Bluetooth wireless standard for transmission of measured data from moving parts of electrical machine is discussed. © 2010 Institute of Thermomechanics AS CR.

Goncharenko I.S.,NASU Institute of Electrodynamics
2016 2nd International Conference on Intelligent Energy and Power Systems, IEPS 2016 - Conference Proceedings | Year: 2016

Constant growth of distributed generation (DG) in power systems has not only positive changes. Incorrect placement of DG can worsen steady-state parameters of a power grid, for example, power losses. The specific method of optimal DG placement and capacity, that has been developed previously, was improved. Now method determines the effect of installed DG on the power grid operation considering type and capacity of DG units, climatic pattern of installation region and different power grid steady-states. Method improvements have been tested on IEEE 14-bus test system using Monte-Carlo method. The results of simulation tests show viability of the updated method. © 2016 IEEE.

Shcherba A.A.,NASU Institute of Electrodynamics | Suprunovska N.I.,NASU Institute of Electrodynamics
Technical Electrodynamics | Year: 2014

It is performed the structure-parametric synthesis of the two-circuit and three-circuit electrical circuits with capacitive energy storage (CES) in the thyristor discharge pulse former (DPF) for supply of technological load, which electrical resistance depends on CES charge voltage and changes from one discharge to another stochastically. The discharge pulse former under consideration is realized both positive back coupling of charge voltage of reservoir capacitor from residual voltage its previous discharge and a negative one. Objective function of synthesis was a increasing of average pulse power in the load, and optimization criterions were the capacitor charge voltage, efficiency factor of discharge circuit and use energy factor of reservoir capacitor. The optimal parameters of elements of two-circuit and three-circuit capacitive energy storage circuits at which the maximum average pulse power in the load is attained are defined. The power and dynamic restrictions on objective function and circuit element parameters were taken into account.

Zakharchenko S.N.,NASU Institute of Electrodynamics
Technical Electrodynamics | Year: 2012

Results of research of dependence of equivalent electric resistance of a layer of metal granules from time and from a current proceeding in a layer on example Al are given. Characteristics of areas of dependence of resistance from time are described. The critical analysis of the functions approximating nonlinear dependence of resistance from a current by means of three known and one original criteria is carried out. It is shown that in the best way given dependence is described by hyperbolic function of the first degree on which basis the equivalent circuit of electric resistance of the granulated current-carrying medium is offered.

Golubev V.V.,NASU Institute of Electrodynamics
Technical Electrodynamics | Year: 2012

The design procedure and is offered to optimization of the target LC-filter of the converter of a AC voltage with a pulse regulator, active loading and high-frequency pulse-width regulation, simple engineering formulas for calculation of optimum parameters of the filter are received.

Bragynets I.O.,NASU Institute of Electrodynamics
Technical Electrodynamics | Year: 2013

The possibility of reducing the influence of low-frequency noise in the laser phase-frequency rangefinders, which leads to a short-term instability of converting links of the device has been reviewe. This is achieved through the use of filtering the output signal of the phase-frequency system, the frequency which is proportional to the measured distance. The electronic simulation of converting processes in such system was carried out for which the output signal models in analog and discrete form were received. The results of the simulation allow to choose optimal parameters for a high pass filter according to the allowable value of the error arising from the transition processes in it. By numerical simulations assessment of the random error of the device due to the influence of broadband noise has been carried out. The simulation results are presented as a function of the random error from the signal/noise ratio for the selected filter time constant. References 7, tables 2, figure 1.

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