bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Reactive Power Compensation Planning for N-1 Line Outage Based on Line Fault Betweenness
Authors: Ye Bichao , Nie Jin , Chen Han 
Published: November 2019

Abstract
An inappropriate compensation capacity can cause oscillation or even collapse of the grid. This paper focus on the RPP problem considering single line outage in the grid. Firstly, the line fault betweenness (LFB) is proposed to identify the preoutage and post-outage impact on vulnerable lines. Then, considering the cost and power quality of the grid, a multi-objective optimization is adopted to analysis the result of compensation planning and solved by the multi-objective genetic algorithm and F1-scores. Finally, the IEEE-39 test system is employed to illustrate the important lines with LFB ranking and the decision of reactive power compensation planning. The compensation result reveals the improvement on power factor of generators and load voltage offset reduction.
Neural Network Model of Wind Farm Based on DFIGs
Authors: Guo Bingtao , Xie Baochang , Liang Zhan , Cai Xu 
Published: November 2019

Abstract
Due to the complexity of wind farms for power flow calculation in power system, it is difficult to accurately describe equivalent models in accordance with traditional methods such as weighted average parameters. However, the merit of neural network (NN) is able to mimic nonlinear and complicated function with multiple inputs and multiple outputs (MIMO). The back-propagation (BP) NN is adopted to substitute the wind farm based on doubly-fed induction generators (DFIG) in this paper. To do this, a simple BP model is established to be equivalent to single DFIG. The training data of the NN is obtained by simulation of actual DFIG, in which the wind speed, voltages of DFIGs, optimal power captured strategy are used as inputs and the active and reactive power are as outputs. Furthermore, a multilayer BP model is built and trained to mimic the wind farm based on DFIGs using simulation results of the actual 34 DFIGs, 102 MW electrical network with statistical wind speed and rotor-side voltage. The simulation results show that the BP NN can be used to model the wind farm, simplify the power flow calculation in the power system and be of high accuracy.
Research on Characteristics of Grounding Electrode of HVDC Transmission
Authors: Wang Bozhong , Peng Mai , Li Wenni , Li Peng , Jiang Yizhou , Xie Yaoxuan , Zou Yingxiang , Wang Qing 
Published: November 2019

Abstract
Abstract The grounding electrode is an important part of HVDC transmission system, especially in monopole operation. Based on the actual operation of the grounding electrode of Guanyin Pavilion in the ±500kV Goose-commutation station in Huizhou, Guangdong, this paper analyses in detail the specific influencing factors of the grounding electrode on the surrounding environment, underground metal pipelines and AC grid. Daily maintenance work considering current distribution, temperature, humidity and step voltage is also proposed to strengthen the understanding and attention of operation and maintenance personnel to the grounding electrode.
Research on Parallel Operation Characteristics and Current Sharing Method of High Power IGBT
Authors: Yong Tang , Bo Wang , Qiu Jie Lin 
Published: November 2019

Abstract
With the development of power electronics technology, the capacity of power conversion devices is getting larger and larger, and the current level requirements for high-power IGBT are also getting higher and higher. A single device often cannot meet the requirements, and multiple IGBT need to be used in parallel. When IGBT is connected in parallel, due to the differences in device parameters, external circuit parameters and heat dissipation conditions, the current distribution is easily unbalanced, resulting in device performance waste or even damage. Therefore, the current sharing problem is the core problem to be solved in parallel connection of IGBT. In order to solve the problems such as difficulty in analyzing a single factor for coupling of various influencing factors, difficult control of temperature and high cost of circuit, this paper adopts Saber software simulation method to analyze the influence of various internal and external factors on IGBT’s dynamic and static current sharing, thus obtaining the relationship between these factors and corresponding countermeasures, and obtaining an effective IGBT parallel current sharing scheme. Finally, the correctness and effectiveness of this scheme are verified by experiments.
A Power Transformer Fault Diagnosis Method Based on Hierarchical Classification and Ensemble Learning
Authors: Su L , Cui Y , Yu Z , Chen L , Xu P , Hou H , Sheng G 
Published: November 2019

Abstract
Since conventional machine learning methods often result in low diagnostic accuracy and non-negligible recognition difference among fault types with imbalanced class distribution among transformer fault types, a multi-level hierarchical power transformer fault diagnostic model is proposed based on hierarchical classification and ensemble learning, where classifiers are hierarchically constructed for level-by-level diagnosis according to the imbalance extent on each level. The Level I neural network classifier extracts 3 generalized feature labels of normal, discharge fault and thermal fault for feature fusion with original data input, to guide classification among 9 detailed operation status under DL/T 722-2014 standard. The Level II classifier adopts EasyEnsemble, generating balanced training subsets by undersampling majority classes and training sub-classifiers in parallel for parameter synthesis in ultimate classifier, to balance information between major fault types and minor ones. Experimental result shows that: compared to traditional methods, our proposed method improves the generalization ability on minority class faults and the overall accuracy by 7%.
Research on the Application Value of Wireless Mesh Network in Power Equipment of the UPIOT
Authors: Song S M , Yao W J 
Published: November 2019

Abstract
In this paper, an advanced wireless network called WMN was researched for the construction of UPIOT, especially from the perspective of power equipment. By introducing the fundamentals and analyzing the advantages of WMN, it proved that the WMN should have great application value in the communication system in Power Equipment of the UPIOT. By comparing ZigBee mesh and BLE mesh, it indicated that the WMN can be built by different technologies in relative application scenarios. By proposing a design of architecture with the application of WMN, it provided an innovative idea to construct the Power Equipment of the UPIOT and some theoretical supports for the subsequent research of the Ubiquitous Power Internet of Things.
Research on SaaS Layer Application Architecture for DCCP Considering Ubiquitous Internet of Things
Authors: Liu Hongjun , Guan Ti , Geng Yujie , Ma Qiang , Tian Dawei , Liu Yong , Lin Lin , Li Sheng 
Published: November 2019

Abstract
In 2019, State Grid Corporation of China officially proposed the overall planning of building SG-eIoT(State Grid-electric Internet of Things). DCCP(Dispatching and Control Cloud Platform) is an essential foundation and critical part of SG-eIoT, it aims at achieving cross-departmental resource sharing through resource virtualization, data standardization, and application orientation, so as to break a new way to improve operation level of power system, and operation efficiency of State Grid. At present, infrastructure layer and public service layer of DCCP have been formed, but with some inadequacies in application layer architecture. In consideration of practical operation of State Grid, this paper proposes an application architecture what is not only in line with operation specifications, but also convenient for unified management. This design helps to wipe off obstacles for data communication among different applications, and realize SG-eIoT. In addition, competition mechanism is introduced in application architecture to enhance practicability of applications.
Integrated Energy Service Platform Under the Umbrella of Ubiquitous Power Internet of Things
Authors: Siwu Li , Linzhi Xie , Xiaodi Ma , Xiaobing Zhou , Yulin Yan , Chan Pan 
Published: November 2019

Abstract
Integrated energy service is the trend and direction for grid companies to participate in the energy market competition and seek their own transformation. The construction and improvement of Ubiquitous power Internet of things is the basis for grid enterprises to gain advantages in the competition of integrated energy services. In the past, the literature usually focused on technical explanations and application scenarios. This paper first constructed a comprehensive Ubiquitous power Internet of Things ecosystem and further explored the role of the integrated energy service platform.
Numerical study of the methane-air combustion in the direct-flow burner of the boiler 300 MW TGMP-314 boiler
Authors: Fomenko N E , Jovicic Vojislav , Prokhorov V B , Fomenko M V 
Published: November 2019

Abstract
This paper presents the results of the numerical simulation of the methane-air combustion in the direct-flow burner. The construction of the burner was proposed by the Department of Thermal power plants MPEI for organization the staged combustion. the burners are designed for installation on boiler 300 MW TGMP-314 at thermal power plane in Moscow. The simulation of five modes of operation of the burner depending on the boiler load was carried out using modern packages of computational fluid dynamics ANSYS. The goal of this work is to investigate effects of replacement of existing vortex burners in previously described facilities with the direct-flow burners with organization of the new combustion process. As results after the simulation, the parameters of the numerical values of the turbulence parameters and the mass fractions of various substances for the gas-air flow in the boiler inlet plane was obtain. On the basis of the obtained results analysis of the proposed design of the burner was made. Numerical values of the parameters of the gas-air flow in the plane of the inlet to the boiler will be used later as input data for the numerical simulation of the boiler furnace.
Development M-shaped profile for A-USC steam boiler
Authors: Volkov E P , Chernov S L , Fomenko N E 
Published: November 2019

Abstract
Department of Thermal Power Plants of MPEI proposed the concept of a boiler of 1000 MW for steam generation advanced ultra-supercritical parameters M-shaped profile. In this boiler it is proposed to make an invert boiler furnace. Output main and secondary steam header are proposed to be placed under inclined boiler passes as close as possible to the cylinders of the steam turbine. The feasibility of using advanced ultra-supercritical parameters is associated with the possibility of increasing the efficiency of the power unit by 4.2%. The paper describes the location of the designed s heat exchangers, the movement of water and steam, flue gases along the path of the boiler. Also given are the results of calculations of the proposed layout of the boiler, as the temperature of the working medium and flue gases at the inlet and outlet to the surface, the flue gas temperature at the inlet and outlet to the surface, the numerical values of the heat loss of the boiler, affecting the efficiency of the boiler. The calculated boiler efficiency is 93.07%. The description of the proposed fuel combustion scheme, which is a system of vertical-horizontal tangential torches, is also given.
Investigation of unsteady heat transfer in a porous medium of a discontinuous heater
Authors: Koroleva A P , Frantsuzov M S 
Published: November 2019

Abstract
This paper presents the results of determining the features of heat transfer on the example of a discontinuous heat exchanger with ball filling, used to generate a high-enthalpy flow. In the first part, we developed a one-dimensional mathematical model (an improved model of Schumann) unsteady heat transfer in a porous medium taking into account heat wall heater cooperage. An analytical solution is found in the quadratures of the system of partial differential equations. The second part of the paper is devoted to numerical modeling. The influence of empirical coefficients on heat transfer was revealed. The results of numerical simulation were compared with the results of one-dimensional mathematical model. As a result of the computational study, the correspondence and differences in thermal and hydrodynamic processes using one-dimensional differential models and numerical modeling are established. A significant influence of empirical coefficients on the qualitative and quantitative nature of the temperature distribution of the gas and the solid matrix over time was revealed. The correspondence of results between two approaches is established: the solution of differential equations and numerical modeling. On the basis of the analysis the applicability of mathematical models of different levels for solving a certain class of problems is established.
Plasma flow from vacuum surface flashover initiated by 70-kV 20-ns pulses
Authors: Punanov I F , Emlin R V , Morozov P A 
Published: November 2019

Abstract
In this work we study plasma beams generated by vacuum surface flashover discharge. We measured ionic current, velocity of ions at values of discharge current 2.8 kA and 5.5 kA for polymethylmethacrylate (PMMA), polytetrafluorethylene (PTFE) and polyethylene (PE). The aim of the work is to compare parameters of particle flows at different values of discharge current and unchanged voltage. We used generators with coaxial and disk-shaped glycerol-filled pulse-forming lines. Maximum voltage is 70 kV; voltage pulse duration is 20 ns; width of a current pulse first half wave is 30 ns. Average velocity of the ions for all materials is within the range ∼ 100−150 km/s and doesn’t change significantly as the current increases from 2.8 kA to 5.5 kA. Ion current of the beam increase approximately linearly at higher discharge current. We estimate the density of electrons in plasma as a function of distance from the discharge. The applicability of this type of discharge for creating plasma for neutralizing high-power ion beams in inertial confinement fusion facilities is discussed.
The effect of microwave discharge on subsonic gas flow with different power characteristics
Authors: Vinogradov V A , Komratov D V , Yu Chirkov A 
Published: November 2019

Abstract
The results of the study of the effect on the subsonic flow in the transition microwave diffuser for controlling the boundary layer and restructuring the flow are presented. The effect of various ways of installing antennas in the channel and the power in the discharge from the minimum to the maximum in a pulse-continuous generation mode is shown. Impact assessment was carried out according to the total pressure in the outlet section of the channel.
Research of wetting on micro- and nano-scale coating
Authors: Kiselev A S , Kuzma-Kichta Y A 
Published: November 2019

Abstract
Surfaces with porous coatings are used to improve heat transfer during boiling and transportation of liquid to the drained areas [1]. Effectiveness of coatings will depend on their wetting. The aim of the work is to study the characteristics of wetting. Wetting angle and capillary rise liquid height are measured for surfaces with micro arc oxidation coating, microporous sintered coating and coated with aluminum oxide nanoparticles (Al2O3) in work.
Reactor graphite processing in low-temperature gas-discharge plasma
Authors: Shavaleev M R , Barbin N M , Terentyev D I , Dal’kov M P , Alexeev S G 
Published: November 2019

Abstract
Graphite elements of nuclear power plants accumulate in time a small amount of uranium, radionuclide conversion elements, as well as fission products, which creates additional difficulties in the utilization of graphite masonry. We proposed a new method of processing, based on high-temperature separation in a nitrogen atmosphere. The processing consists in heating the radioactive graphite in an inert nitrogen atmosphere to a temperature of 2873 K, which creates the necessary conditions for the separation of radionuclides from carbon.
Use of methane-hydrogen mixtures for energy accumulation
Authors: Dunikov D O , Blinov D V 
Published: November 2019

Abstract
Hydrogen-methane mixtures draw attention due to an idea of injection of hydrogen into natural gas network, thus lowering the need of huge investing in development of hydrogen infrastructure. Extraction of hydrogen from dilute mixtures with natural gas differs from traditional separations, since hydrogen concentration is low. Due to selective absorption of hydrogen from the feed, epy metal hydrides purification achieves high values of separation efficiency. We have experimentally demonstrated successful separation of the hydrogen (10%) – methane (90%) mixture at inlet pressure 9.5 bar by the LaNi4.8Mn0.3Fe0.1 intermetallic compound in one step with roundtrip (absorption/desorption) hydrogen recovery 74% and absorption hydrogen recovery 76%.
Formation of inelastic scattered background photoelectrons, X-ray photoelectron spectroscopy from multilayer inhomogeneous surface
Authors: Lubenchenko A V , Ivanov D A , Lubenchenko O I , Ivanova I V 
Published: November 2019

Abstract
In this work, a new method of background subtraction in XPS is suggested considering multiple inelastic scattering in a multilayer inhomogeneous target. The method is based on solution of the problem of multiple inelastic photoelectron scattering in a multilayer plane-parallel target. For a overlayer/substrate system, formulae for subtraction of background generated by multiple inelastic photoelectron scattering are found. It is shown that backgroundы of a spectral line of photoelectrons emitted from the overlayer and emitted from the substrate and inelastically scattered in the overlayer differ significantly.
Experimental and numerical study of heat and hydraulic characteristics of low head natural circulation loops with single-phase flow of working liquid
Authors: Sukomel L A , Kaban’kov O N , Ankudinov V B 
Published: November 2019

Abstract
A 2D numerical simulation of velocity and temperature fields for laminar low flow regimes have been carried out for laboratory experimental natural circulation loop with vertical electrically heated circular tube as flow up section. Calculations have been done for the case of full-length heating of flow up section at constant heat flux density on the heated wall. The variant of loop design with negligibly small hydraulic losses due to local drag reduction and friction on down comer compared with hydraulic losses due to friction in flow up tube has been considered. Laminar flow regime as the regime of most complex friction factor behaviour in buoyancy driven flows was the subject of the analysis. On the basis of calculated velocity and temperature fields in heated zone the longitudinal change of friction factor and heat transfer coefficients have been determined. In general, according to 2D numerical simulation the wall shear stresses are mainly affected by the change of wall velocity gradient due to practically continuous velocity profiles deformation along the whole heated zone. The form of velocity profiles and the extent of their deformation in its turn depend upon the wall heat flux density and the hydraulic diameter. It is shown that in single-phase natural circulation loop where fluid flow is governed exclusively by buoyancy forces wall shear stresses change along the heated zone in a complex way and friction factor for use in 1D calculations can not be described by simple correlations in the form of ξ = a/Reb. In all calculated regimes including the lowest considered wall heat flux density the Nusselt numbers exceeds that for stabilized forced flow with constant thermophysical properties. After decreasing with the distance from the inlet to the heated section Nusselt numbers achieve minimum values and then start to increase.
Analysis of XPS and REELS spectra of beryllium
Authors: Afanas’ev V P , Gryazev A S , Kaplya P S , Yu Ridzel O , Rybakova A V 
Published: November 2019

Abstract
The differential inverse inelastic mean free paths (DIIMFP) of beryllium were derived from energy spectra acquired using X-ray photoelectron spectroscopy and electron energy loss spectroscopy techniques by means of the fitting of calculated spectra to experimental data. The calculation of the energy spectra is performed employing the partial intensity approach (PIA). The EELS and XPS spectra were acquired in different laboratories using different Be samples. The comparison of the obtained DIIMFPs with literature data is presented.
Feature Extraction Using Discriminant Graph Laplacian Principal Component Analysis with Application to Biomedical Datasets
Authors: Aminu Muhammad , Ahmad Noor Atinah 
Published: November 2019

Abstract
In this paper, we propose a manifold learning method called discriminant graph Laplacian principal component analysis (DGLPCA) for feature extraction. The proposed method projects high dimensional data into a lower dimensional subspace while preserving much of the intrinsic structure of the data. Moreover, DGLPCA integrates maximum margin criterion into its objection function to improve class separability in the lower dimensional space. The effectiveness of the proposed method is demonstrated on two publicly available biomedical datasets taken from UCI machine learning repository. The results show that our proposed method provides more discriminative power compared to other similar approaches.
Automated Intelligent Diagnostic Procedure for Chronic Leukemia
Authors: Pooi Chan Lok , Mashor Mohd Yusoff , Adollah Robiyanti , Hassan Rosline 
Published: November 2019

Abstract
Due to growing statistics and the important role of early diagnosis for chronic Leukemia, an automated intelligent diagnostic procedure for chronic Leukemia is needed. This paper presents an automated procedure for this diagnostic system which consisted of four main stages; namely Image Segmentation, Feature Extraction, Feature Selection and Classification. Colour Thresholding and Gradient Edge Detection were applied to segment the nucleus of white blood cells from the image. A total of 548 cells nuclei were extracted from 100 images and used to develop and validate the proposed procedure. Three feature selection algorithms and three classifiers were analyzed and evaluated in order to obtain a reliable and robust automated diagnostic procedure. Based on the results, the ReliefF algorithm was selected and applied for feature selection, the method yields the best accuracy of 98.1% for testing accuracy. Besides, the selected classifier was Multilayer Perceptron (MLP) network trained by Levenberg Marquardt (LM) algorithm.