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E-Journal № 3(8) 2008

"PROBLEMS OF THE REGIONAL ENERGETICS"

CONTENTS

1 Increase of capacity and controlability of alternating current power transmission lines
Authors: Postolatii V.M, Bicova E.V.,Timashova L., Shakarian Iu.
  Abstract: The basic characteristics and economic parameters of electricity transmissions of new type - controlled self-compensating high-voltage lines (CSHVL) are stated. Advantages of the given type of electricity transmissions in comparison with traditional consist in the increased throughput and deep regulating in regime parameters and characteristics. These advantages are reached due to a new design, application of a complex of the equipment – phase shifting and compensating devices and the appropriate control systems. By the principles of work and regime parameters the given electricity transmissions concern to a category of controlled flexible systems of transfer of the electric power of an alternating current (Controlled Flexible Alternating Current Transmission Systems – CFACTS).
  Keywords: controlled transmission line, flexible electricity transmissions, capacity, natural capacity, phase shifting devices.
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2 Mathematical model of a resistive element made from a microwire of a high-voltage divider of a voltage
Authors: V.Berzan
  Abstract: It is proposed the mathematical model of a resistive element of a high-voltage voltage divider made from a microwire. The model is presented as a long line with longitudinal running capacity. There are formulated conditions of continuity for a current and voltage on borders of sections with various values of running parameters which are constant within the limits of this section. It is proposed the scheme in final differences and the analysis of its stability is executed as well. This scheme refers to a class of implicit schemes and for getting the numerical decision it is recommended to use a method of repeated iteration with multisequencing of procedures of the numerical calculation. It is offered the algorithms of repeated iteration on the assumption of that in points of discontinuity of the solution values of this solution are known.
  Keywords: high-voltage divider, microwire, mathematical model.
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3 THE EMERGENCY CONDITIONS IN A LOADED HALF-WAVE LINE
Authors: Rimsky V.X., Berzan V.P., Patsiuk V.I.
  Abstract: The emergency and postemergency states in the unloaded and loaded half-wave line without optional connections are investigated. It is found that the overvoltage ratio during the transition process induced by a short circuit (with the action time equal to 130 mc) or by a break in the circuit (with the action time equal to 60 mc) runs up to 6.
  Keywords: telegraph equations, half-wave and quarter-wave transmission lines.
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4 THE NO SINUSOIDAL VOLTAGES UNDER THE SINUSOIDAL CURRENT AT THE ENTRY OF THE OPEN–ENDED LINE WITH REAL LOSS
Authors: Patsiuk V.I.
  Abstract: The classical problems of the theoretical electrical engineering, such as open-ended (or short-circuited) line energization on alternating voltage (or current), are solved by means of Fourier series method. The conditions of creation of no sinusoidal steady-state regimes in the lines with nonzero loss are discovered.
  Keywords: The telegraph equations, no sinusoidal voltage and current, half-wave and quarter-wave transmission lines.
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5 The coordination of a power parametrical regulator with a transmission line
Authors: Kalinin L.P., Zaitsev D.A., Tirsu M.S.
  Abstract: There are considered the operating conditions of a power parametrical regulator controlled with the help of the power electronic converter, at installation of the device on the transmitting end of a line. Performance data of the device are submitted, allowing determining area of a mode existence, and also preliminary to estimate settlement power of the converter at various angular length of a line.
  Keywords: a power parametrical regulator, the power electronic converter, a transmission line, the phase-shifting transformer.
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6 CLASIFICATION OF METEOROLOGICAL SCENARIOS FOR USING IN PREDICTORS OF RESIDENTIAL AREA POWER CONSUMPION
Authors: Voronenko D. I.
  Abstract: The work is dedicated to identification and classification of meteorological scenarios for using them as additional input information in predictors of coherent consumption of electrical and thermal energy in residential area. Kohonen self-organized maps were used as mathematical apparatus for clusterization of weather data. Research results led to quality improvement of energy consumption forecasts.
  Keywords: energy consumption forecasting, meteorological scenarios, Kohonen maps.
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7 EVALUATION OF DYNAMIC CARACTERISTICS OF GAS COOLER OF THE CARBON DIOXIDE HEAT PUMP ÎN THE TRANSCRITICAL CYCLE
Authors: Sit M.L., Juravleov A.A., Sit B.M., Institute of Power Engineering of the Academy of Sciences of Moldova
  Abstract: Dynamic characteristics of heat pump gas cooler obtained by means of the solution of the dynamics equations in partial derivatives are examined. Control system of the heat pump used for the heating of the heating–system water, supplied from CHP to the district heating system is examined. Possibility of PID-controller with gain scheduling utilization with the coefficients changing depending on gas cooler mode of operation for temperature disturbances compensation of direct heating–system water is shown.
  Keywords: heat pumps, carbon dioxide, gas cooler, control systems.
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8 HEAT – AND MASS TRANSFER EQUIPMENT DEVELOPMENT FOR POWER SYSTEMS (PART 2)
Authors: Doroshenko A. V., Vasyutynsky S. Y.
  Abstract: The results of experimental investigations in film flow area in heat and mass exchangers are given. Values of critical number of Reynolds and average values of the liquid film thickness are adjusted. The special attention is given to the revelation of the optimal value the regular roughness of the surface, providing an intensification of heat and mass exchanging processes.It is possible to use the results which are obtained for designing heat – and mass exchangers in the refrigerate technique, air conditioning and generally, in power systems (alternative energetics).
  Keywords: heat – and mass transfer apparatus, film currents, alternative energetics.
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9 MOVING CAPACITOR DISCHARGE ON THE LONG TRANSMISSION LINE
Authors: Patsiuk V.I.
  Abstract: The class of nonstationary problems about the moving electric capacitor discharge on the long-distance transmission line is solved by means of characteristics method. The different velocities of the capacitor’s motion are considered.
  Keywords: cable equations, capacitor discharge, transmission line with losses.
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10 Power productivity of the ground surface
Authors: Gutu A.I., E. Radgbhandari
  Abstract: Here there is presented an attempt to estimate the efficiency degree when working with soil surface through the different methods of valorization incident solar radiation. Such technical methods are being analyzed as (solar collectors, photovoltaic cells, solar thermal power plants), power cultures field (bushes, wheat, sunflower, maize, rape, sorghum) as well as microalgae crops. Here is the description of advantages and disadvantages for each group in part out of these three. The technical methods are up to date from the efficiency utilization view-point of industrial area. Microalgae crops are similar to technical methods from this point of view.
  Keywords: solar radiation, power production, solar collectors, electricity generating installations, biofuels, microalgae.
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11 Complex biopower installation
Authors: M.Tirshu, N.Konstantinov, M.Uzun
  Abstract: It is presented the technological scheme of complex biopower installation for manufacture of the electric power, hot water and gas at use as raw material of manure, birds dung and firm organic waste products. The suggested technical solution provides practically 100 % use of energy of burnt gas due to the introduced feedback between power station and a bioreactor. Recommendations for the best use of installation in Republics Moldova are developed as well.
  Keywords: Biogas, biogas installation, biogas production, manure and firm organic waste products.
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12 High Voltage Resistive Divider Based on Cast Microwire in Glass Insulation on 6–24 kV Alternating Current of Commercial Frequency.
Authors: A. Juravleov, M. Sit, Colpacovich I., Cojocaru D., Cleimenov V.
  Abstract: It is presented the analysis and description of the construction of the high voltage resistive divider on the base of cast microwire in glass insulation on 6–24 kV alternating current of commercial frequency. It is presented the procedure of compensation of frequency error during the process of fabrication of divides and results of tests of the sample model of the divider as well.
  Keywords: High voltage dividers, high voltage measurement.
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13 Mathematical model “The electric line - wind farm”
Authors: V. Merenco
  Abstract: It is considered the problem of finding of the mathematical model of a circuit “electric line – wind farm” with the purpose of analysis of operating modes by a method of mathematical simulation. The mathematical model is based on a method of characteristics, takes into account heterogeneity of a circuit and allows realizing various modes and changes in structure of a circuit simple change of values of sizes set as the concentrated parameters.
  Keywords: electric line, wind farm, mathematical model, method of characteristics.
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