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Power Technology and Engineering
Journal Prestige (SJR): 0.204
Number of Followers: 3  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1570-145X - ISSN (Online) 1570-1468
Published by Springer-Verlag Homepage  [2626 journals]
  • Process Equipment of the Zaramag HPP-1
    • Abstract: The layout of the process equipment that ensures the reliable and safe operation of the Zaramag HPP-1 on the Ardon river is briefly described. The Zaramag HPP-1 is unique in that it has the highest head in Russia, the most powerful Pelton turbines, and the longest diversion tunnel.
      PubDate: 2020-07-29
       
  • A Statistical Overview of Fault Location Methods and Problems in
           Calculating and Locating Faults in 110 kV (and Higher) Power Transmission
           Lines
    • Abstract: To locate faults in 110 kV (and higher) power transmission lines, distant methods based on one-sided and two-sided measurements of emergency parameters are used. Statistical data are an actual indicator of the accuracy of these methods, using which the probability characteristics can be plotted. The accuracy of the one-sided method depends on the fault resistance. Using software to determine the fault location based on one-sided measurements does not improve substantially the accuracy compared with indicating devices, emergency event recorders, and microprocessor relay protection. However, software based on two-sided measurements is more effective. To reduce procedure errors, it is necessary to use a single inspection zone independent of the line length.
      PubDate: 2020-07-29
       
  • Filtering the Frequency-Directional Spectrum of the Waves of a Navigation
           Channel
    • Abstract: The refractive effect of the reflection of waves from a channel has made it possible to propose a model of refractive filtering of the frequency-directed wave spectrum by the navigation channel. If the frequency-directed spectrum is known on the way to the channel, then when traversing the channel some frequency components of the waves are reflected from the channel. Thus, part of the wave energy is reflected from the channel; that is, the part of the energy of the initial wave does not reach the second embankment shoulder, which results in a decrease of wave altitude in the region beyond the channel.
      PubDate: 2020-07-29
       
  • Numerical Modeling of Moisture Separation Processes in the PGV-1000m Steam
           Generator
    • Abstract: A description is presented of the ANSYS Fluent-19.1 finite-element software program for a rigorous mathematical model to study the processes of separating steam moisture that occurs in the steam space of the PGV-1000M steam generator. Calculations of the pressure distribution in the steam space, velocity fields of the generated steam, trajectories of steam flow and the condensed moisture, and distribution of the concentration of moisture in the steam space were done, and conclusions were drawn based on analysis of the obtained results and a suggestions for a methodology for further study of the issue.
      PubDate: 2020-07-29
       
  • On Filtration through a Cofferdam with a Screen
    • Abstract: A critical analysis of an analytic and numerical calculation of filtration through a cofferdam with imperfect (submerged) screen is presented. Computational dependences that present a high level of reliability (2 – 5%) for use in determining the characteristics of seepage in a cofferdam without a screen are presented, including the suction lift, discharge of water into suction zones and backwater of channel downstream, and the contour of the depression curve where there is water present in the channel downstream versus where there is no water present.
      PubDate: 2020-07-29
       
  • A Model of Snowpack Formation and Snowmelt Model for the Volga-Kama
           Cascade Watershed
    • Abstract: A mathematical model has been developed of snowpack formation and snowmelt for the watershed of the Volga-Kama cascade, intended for calculation of the distribution of water resources in snow in the catchment area overall and the volumes of stored water for each water storage basin of a cascade. The model was implemented in the form of a computer program, and as needed makes it possible to perform daily calculations. Experience in using the program in 2017 – 2019 showed its high effectiveness and good correspondence with the data of snow-measurement surveys.
      PubDate: 2020-07-29
       
  • Zaramag HPP-1 on the River Ardon in the Republic of North Ossetia —
           Alania: Preoperational Program of Hydraulic Structure Safety Tests and its
           Implementation
    • Abstract: Zaramag HPP-1 is an extremely challenging project, unique in its design and in head. Prior to start-up, the hydraulic structures are subjected to a multistage testing program at different heads. The first test results are presented in this paper.
      PubDate: 2020-07-29
       
  • Analysis of Different Types of Power Circuits and Algorithms for
           Excitation Control of TVV-500 Turbogenerators of Nuclear Power Plants in
           Normal and Emergency Operating Regimes
    • Abstract: Computer simulation tools are used for the analysis of competing designs of excitation systems of the high-power turbogenerators of nuclear power plants. Different variants in normal and emergency regimes are compared relative to field blanking time and the resulting overvoltages. It is shown that the particular variant of the power circuit has little effect on the length of time it takes to achieve complete de-excitation of the turbogenerators. Problems related to the power transitions of the field winding of a turbogenerator from the working to the standby excitation system and back are identified. The technology underlying automatic transition from a standby to a working excitation system is demonstrated.
      PubDate: 2020-07-29
       
  • Development and Pilot Operation of a Three-Phase Fully Optical Measuring
           Voltage Transformer of 220 kV with Digital Output
    • Abstract: An electronic three-phase fully fiber-optic measuring voltage transformer (FOVT) of accuracy class 0.2 for a nominal voltage of 220 kV with a digital output for operation at power system facilities, including electrical substations, is described. The operation principle of the device is based on the use of a longitudinal linear electro-optical effect (Pockels effect) for measuring AC voltage. The fiber-optic measurement scheme based on low-coherent interferometry is connected via a fiber cable to an optical high-voltage primary converter (HVPC) with an electro-optical crystal placed in it; there are no additional voltage dividers inside. The digital signal processing unit (DPU) contains optical and electronic circuits for generating, detecting, and processing an electro-optical signal. FOVT has a digital interface that complies with the IEC 61950-9-2 LE standard, and can be used as a component for the Digital Substation and Smart Power Grid technologies. The design features of the HVPC and the DPU are described and the results of the metrological characteristics of FOVT-220, based on the data obtained during the certification and pilot operation at the 220 kV electrical substation, are presented.
      PubDate: 2020-07-29
       
  • Modeling a Berth with a Moored Ship under Wind Wave Loads
    • Abstract: The algorithm and results of calculating the impact of the moored ship under the wind, current and wave loads on the berth are presented. The methodology is presented on the case study of calculating the mooring system of a massive floating object in the Kola Bay, for which numerical modeling and forecasting of hydrometeorological factors have been carried out. The calculations are performed using the SCAD complex with a simplified modeling of mooring lines. In the conclusions, the regulatory methodology for finding the loads from weather factors on the ship is analyzed; problems of using regulatory documents are formulated.
      PubDate: 2020-07-29
       
  • Quality Control of Cementation Operations Performed in Country Massif in a
           Test Section by Seismic Well Logging
    • Abstract: The process of monitoring the effectiveness of consolidation cementation of the country massif of the Rogun hydroelectric power plant’s generator hall by means of seismic well logging along with selection of a test section in the aleurolite zone and the configuration of drilled cementation and test wells are considered. Results of processing and interpretation of the results of processing and interpretation of the results of geophysical studies are presented.
      PubDate: 2020-07-29
       
  • Development of Improved Methods for Calculating Steady States of Power
           Systems Taking Into Account the Temperature Dependence of the Resistances
           of the Overhead Transmission Lines
    • Abstract: The problem of calculating the steady state of an electric power system taking into account the temperature dependence of the resistances in the overhead transmission lines is considered. Two alternative algorithms are proposed. One solves an augmented system of equations by Newton’s method, while the other calculates the resistances separately within the iteration process of solving the equations of the electric state of the power system. The results of a numerical experiment are presented. They validate the algorithms and show a significant increase in the accuracy of determining state variables such as current, voltage, and power loss. The convergence of the algorithms is analyzed compared to each other and to Newton’s method used disregarding the temperature dependence of the resistances.
      PubDate: 2020-07-29
       
  • Mathematical Modeling of Combined Thermal Protection of a Deep-Groove
           Asynchronous Motor
    • Abstract: A mathematical model is developed for a deep-grove asynchronous motor with combined thermal protection. In the model measurement data on the instantaneous currents and voltages of the stator are used to determine the heating temperatures of the windings of the stator and rotor via two channels: in the first of these, by comparing the initial and instantaneous resistances of the direct sequence resistance of the stator and rotor and in the second, in terms of a thermal model based on the calculated instantaneous power losses in the stator and rotor. A contactless method of measuring the slip, based on including the frequency dependences of the resistances of the rotor owing to the skin effect is developed and used in the protection algorithm. To prevent overheating of the windings of an asynchronous motor when nonsynchronous regimes develop, in the protection algorithm the instantaneous values of the phase currents and voltages are used to determine the moduli of the voltages, currents, and resistances of the reverse sequence, which are compared with the permissible values. The workability of the proposed algorithm for combined thermal protection is confirmed by the results of a mathematical model of the direct startup regime and operation with different loads and power supply asymmetries for a 630 kW deep-groove asynchronous motor with a 6 kVstator voltage.
      PubDate: 2020-07-29
       
  • Seepage Through a Homogeneous Earth-Fill Dam with a Cut-Off Wall on a
           Permeable Foundation
    • Abstract: A behavior of the seepage flow through a uniform earth-fill dam constructed on a limited-depth permeable foundation and provided with a cut-off wall has been studied, and effective counter-seepage arrangements within the dam foundation were developed. The studies were conducted by using an electro-hydrodynamic analogy (EHDA) method for various cut-off wall design schemes, including impervious diaphragms, inverted filters, etc. Based on the obtained experimental data, advantages and disadvantages of various counter-seepage schemes were established, and engineering recommendations were developed to increase the seepage safety and performance reliability of earth-fill dams with cut-off walls formed on permeable foundations.
      PubDate: 2020-07-29
       
  • Hydraulic Calculations of Flow Parameters on the Weir Krieger –
           Ofitserov
    • Abstract: Krieger – Ofitserov analysis of coordinate of discharge surface and Krieger coordinates of free surface of nappe-shaped crest flow is presented. The defects of the proposed coordinates are detected, and calculated dependences are proposed to construct discharge and flow surfaces for calculating the flow parameters, including the inertial forces emerging in the flow on the curved surface.
      PubDate: 2020-07-29
       
  • Development of a Method for Online Monitoring and Diagnostics of Turbine
           Generators for Increased Reliability and Service Life
    • Abstract: Issues in the practical application of continuous monitoring tools for assessing the technical condition and identifying defects of turbine generators are considered. In order to ensure an effective monitoring solution, it is necessary to take a specific approach to individual installations. Particular attention should be paid to the generator “trouble spots,” i.e., important structural elements prone to defects. Using specific examples from diagnostic examination practice, the most typical problems affecting the structural elements of various turbine generators are discussed. The current state of regulatory and technical documentation is analyzed. Inadequacies affecting some existing documents in terms of supporting the needs of operating personnel for solving contemporary problems of online monitoring and diagnostics of turbine generators are noted.
      PubDate: 2020-07-29
       
  • Ensuring the Balance of Electric Energy Production and Consumption in the
           German Energy System in Days with the Maximum Generation of Plants Using
           Res
    • Abstract: In accordance with the energy strategy, the share of renewable energy sources (RES) in Germany’s electric energy consumption is expected to increase up to 35% by 2020, 50% by 2030, 65% by 2040 and 80% by 2050. An increase in RES share in the energy system will affect the operating modes of all types of power plants. The structure of generating capacities should ensure the maintenance of electrical modes taking into account the daily and seasonal unevenness of electricity consumption. Currently, the balance of production and consumption in the German energy system in the days with the maximum generation of renewable energy plants is ensured by the export of electricity.
      PubDate: 2020-07-29
       
  • Technology of Constructing an Impervious Diaphragm in the Lower Bureya
           Earth-Fill Dam
    • Abstract: The design and construction of an impervious diaphragm as a “wall in trench” from secant bored piles in an earth-fill dam are described. It is for the first time in Russia that such a diaphragm was made as an independent project rather than a repair measure. The design of clay-cement concrete to fill the boreholes of the “wall in trench” is described. The technology and features of drilling and grouting and the equipment and appliances used are described. It is concluded that the task has been successfully completed and that the experience can be used in the future.
      PubDate: 2020-07-29
       
  • Results of Experimental Studies on the use of PPP Technology for Global
           Navigation Satellite Systems of Monitoring of Sayano-Shushenskaya HPP
    • Abstract: Annual measurements from two stations of the satellite monitoring system of the Sayano-Shushenskaya HPP are considered. This data was processed using the absolute PPP method and the relative method in the BERNESE software product. The RMS between the two solutions was 2.0 – 3.5 mm for the horizontal coordinates and 6.3 – 7.5 mm for the height. Using the PPP method, it was established that the annual variation of the earth’s crustal sediments in the area of the HPP due to the effect of atmospheric loads is 31.3 mm, and the annual variation due to the influence of the water reservoir is 9.7 mm. PPP technology can be used to monitor the horizontal position of hydropower structures on a compressible base. Using the PPP method, geodynamic studies of differences in the sediments of the earth’s crust caused by the water reservoir influence at the locations of base stations and monitoring stations can also be performed.
      PubDate: 2020-07-29
       
  • Assessment of Temperature Effect on the Stress-Strain Behavior of a
           Concrete Gravity Dam
    • Abstract: The paper discusses the effect of temperature on the stress-strain behavior on a concrete gravity dam built on a rocky foundation during the operational period. A numerical simulation was used to obtain the temperature conditions of the structure during the operational period. The thermal stresses of the structure were calculated. Based on the study results, the assessment of the extent of thermal factors impact during the operational period was performed, and the conclusions were made concerning the operability and safety of the structure under the basic load combination. The most dangerous operation period for the “dam-foundation” system was determined.
      PubDate: 2020-07-29
       
 
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