bluuebunny/crossref_metadata_2025 huggingface dataset:
High frequency electric discharge between jet and solid electrodes
Authors: Kuputdinova A I , Akhmadullina L I , Zheltukhin V S , Gaysin Al F , Gaysin F M , Gaysin Az F
Published: August 2020

The types and forms of combustion of electric discharges of high-frequency (HF) current with liquid and solid electrodes at atmospheric pressure are investigated. The discharge emission spectrum, plasma composition, electron concentration, and temperature of the heavy component are studied. Thermograms on the surface of liquid and solid electrodes during the combustion of the discharge are investigated.
Electrolyte-plasma product treatment
Authors: Akhmadullina L I , Gaisin Al F , Gaisin Az F , Kashapov N F , Zheltukhin V S
Published: August 2020

The low-temperature plasma of direct current electric discharges in the process of surface treatment of a product investigated. The types and forms of discharge burning investigated. The electric parameters of the discharge, oscillations of the current and voltage of the discharge, the power invested in the discharge investigated. The temperature distributions of the electrodes in the combustion zone of the discharge investigated. The composition of the discharge plasma, the electron concentration, and the rotational and vibrational temperatures of the heavy components are studied. The micro relief of the surface of the product studied before and after electrolyte-plasma treatment.
Features of formation of fullerene-containing soot during combustion gaseous and liquid hydrocarbons
Authors: Shakirov A S , Galeev I G , Ya Asadullin T
Published: August 2020

Features of obtaining fullerene-containing soot during combustion of gaseous and liquid hydrocarbons with the influence of an electric field on the flame are discussed. The characteristic voltage - current characteristics of the discharge created in the flame region and electron microscopic photographs of fullerene-containing soot were obtained.
Modification of semi-finished rabbit pelts by low-temperature plasma
Authors: Garifullina A R , Sysoev V A , Lutfullina G G , Tihonova V P , Kuznetsova O P , Nasirova R A , Astafeva A E
Published: August 2020

The influence of the effect of plasma processing and non-isocyanate urethanes on the skin of rabbit pelt has been investigated. Synergistic effect of modification resulting in the change of microstructure of high-molecular material and increasing chemical activity of collagen is established. In order to study the regularities of plasma effect on the skin of rabbit pelt the following indicators were determined: heat resistance temperature, relative moisture content (in mass), strength characteristics.
The problem of the structure of quasi-stationary electromagnetic field of an infinite solenoid induction loaded with a metal cylinder of constant conductance
Authors: Gerasimov A , Kirpichnikov A
Published: August 2020

An exact solution of the problem of distribution of the magnetic and electrical field intensities in space around the metal cylinder placed inside an infinite solenoid, with alternating current flowing through it, is obtained. The solution is derived for Maxwell equations, describing the cylindrically symmetric electromagnetic field outside the metal cylinder for complex values of the magnetic and electric components of the electromagnetic field. A comparison between the derived exact solution and an approximate one is drawn. Their asymptotic convergence is shown.
Structural and chemical changes of aramid fibers modified by low temperature plasma
Authors: Ibatullina A , Krasina I , Antonova M , Ilushina S , Isayeva E , Mingaliyev R , Parsanov A
Published: August 2020

The article considers changes in the properties of Rusar-S brand aramid fiber due to the treatment of low-pressure plasma of radiofrequency capacitive discharge. After modification, there was recorded the growth of hydrophilicity in the environment of inert and oxidizing gases. The paper discusses the results of IR spectroscopy of Rusar-S aramid fiber before and after plasma modification. An obtained data of research can explain the influencing mechanisms of RFC discharge plasma of a low-pressure on the properties of aramid fiber.
Effect of the variable gradient of sound speed on pulsating combustion of the solid fuel in Helmholtz resonator-type setup
Authors: Larionov V M , Iovleva O V , Malahov A O , Larionova I V
Published: August 2020

In previous works, a theoretical study of pulsating combustion of solid fuel in Helmholtz-resonator-type setup was carried out under the condition that the distribution of the sound speed in the combustion products is constant, i.e. independent of the amplitude of gas oscillations. In this work, it is assumed that the gradient of sound speed linearly depends on the amplitude of pressure fluctuations in the combustion chamber. It is shown that the frequency of oscillations calculated for variable gradient of the sound speed differs significantly from the frequency that corresponds to a constant gradient.
Distribution of electric potential during pulsating combustion of a propane-butane fuel mixture with air in a vortex combustion chamber
Authors: Malahov A O , Larionov V M , Fadeev S A , Sadikov K G , Khalilov A R
Published: August 2020

Currently, research on pulsating combustion regimes, in particular, control methods, remains relevant. Pulsating combustion mode has its own electric field created due to the ionization of the combustion products and is characterized by oscillatory processes of the combustion zone. In this work is to assess the effect of acoustic gas vibrations on the distribution of electric potential and its amplitude-frequency characteristics.
Pulsating combustion of propane-butane fuel mixture with air in a vortex combustion chamber
Authors: Malahov A O , Larionov V M , Iovleva O V , Gaianova T E , Gaponenko S A
Published: August 2020

In this paper pulsating combustion of a pre-mixed propane-butane fuel with air in a vortex combustion chamber is considered. In view of the insufficiency of information about the reasons of self-oscillations, it is necessary to determine the gas-dynamic, physical and chemical parameters that cause oscillations of the heat release rate in the vortex combustion chambers.
CFD-modeling of the pulsed combustion in vortex chamber
Authors: Khalilov A R , Larionov V M , Malahov A O , Nazarychev S A
Published: August 2020

The article is a review of existing mathematical methods used in modeling the combustion process of gaseous fuels in order to determine the most suitable model for pulsed combustion.
Modification of the surface of polyethylene by low-temperature plasma and liquid electrodes
Authors: Mardanov R R , Kayumov R R , Akhatov M F , Gazizova A I , Gaisin A F
Published: August 2020

In the framework of this work, experimental studies of the modification of the surface of polyethylene by low-temperature plasma and liquid electrodes at atmospheric pressure were carried out. For these purposes, a direct current experimental setup was used. The results of modifications in the parameter range are presented: voltage U = 400 … 800V, current I = 0.3 … 0.8A, jet length l = 50mm, electrolyte flow rate G = 6.2ml / s, jet diameter d = 3mm, NaCl concentration 26%. Estimates of the results are given.
A review of use of barrier discharge for modification of surface of polymers
Authors: Mardanov R R , Kayumov R R , Akhatov M F , Gaisin A F
Published: August 2020

In the framework of this work, a review of the use of a barrier discharge for modifying the surfaces of various polymer products is given. There are various examples of reducing, increasing the wettability angle of modified samples, deforming, smoothing their surface and changing their surface energies.
Study of electric spark coatings of nanocrystal structure
Authors: Sakhapov R L , Makhmutov M M , Sultanov V A
Published: August 2020

The article presents the results of studies of new electrospark coatings having an amorphous and nanocrystalline structure. The results of metallographic and X-ray diffraction studies are analyzed. The microhardness and thickness of the coatings were studied. For the formation of a nanostructure, a plasma spraying method is used, in which materials are formed upon separate solidification of particles, most often disk-shaped. When the thickness of the sprayed particles is up to 10 μm, they quench from the liquid state at a cooling rate of 108 K / s. Nonequilibrium structures in sprayed particles with a nanocrystalline and amorphous structure have high mechanical properties. However, the use of plasma spraying in some cases is not advisable, due to the relatively high cost of equipment and materials. Therefore, this article will present the results of studies on the creation of amorphous and nanocrystalline coatings using electrospark processing (ESP), which is a cheaper way to obtain them.
Nonequilibrium low temperature plasma in process of collagen containing polymer materials electrical properties modification
Authors: Makhotkina L Yu , Bil V , Khristoliubova V I
Published: August 2020

The process of treatment with nonequilibrium low temperature plasma allows to reduce collagen materials electric potential due to charges dissipating along leather surface. Under certain conditions the main reason for the generation and accumulation of static electricity is the high hydrophilicity of the material. Leather surface hydrophobization is achieved through water repellent application and bulk nonequilibrium low temperature plasma treatment. Despite material surface hydrophobization nonequilibrium low temperature plasma processing parameters for genuine collagen containing polymer materials hygroscopicity increasement are determined. Collagen containing polymer materials plasma treatment also increases its biological compatibility and antimicrobial properties, improves mechanical characteristics by changing the internal structure of the material.
Properties of Al2O3 coatings obtained by electric arc plasma method in “dynamic vacuum”
Authors: Mordynsky A V , Gadzhiev M Kh , Tyuftyaev A S , Gusev V M , Borodina T I
Published: August 2020

The results of studies of the influence of the electrophysical characteristics of a heterogeneous plasma flow on the properties of Al2O3 coatings (phase composition, adhesion, porosity) during plasma arc thermal spraying on a steel grade 20 in dynamic vacuum, in the pressure range from 7 to 50 kPa and at 100 kPa are presented. As well as the results for different plasma thermal spraying modes (power, consumption rate of plasma-forming gas and powder, pressure in the chamber). For the plasma torch design in this work, it was shown that Al2O3 particles are deposited most efficiently when their size is up to 100 μm, with an arc current of 300 A, flow rates for powder 0.1 g/s and for plasma-forming gas of up to 1 g/s in the pressure range (2.0-3.0) • 104 Pa.
Viscous fluid flow in a wide annular gap of two rotating coaxial cylinders
Authors: Morenko I V
Published: August 2020

The Couette-Taylor flow is considered in a wide gap between coaxial cylinders in the case when the outer cylinder is at rest and the inner one rotates at a constant speed. Unsteady motion of a viscous fluid is described by the system of Navier-Stokes equations. The problem is solved by the control volume method in the OpenFOAM software. Two stable states were obtained depending on the surface rotation speed: the cylindrical Couette flow and the Taylor vortex flow. The calculation results are compared with the known data of other authors. The dependence of the dimensionless shear rate on the Taylor number is obtained.
Study of the Surface Structure Variations of AK5M7 Alloy after Electro Spark Alloying and Annealing
Authors: Hasan I K , Fomin N E , Kyashkin V M
Published: August 2020

The current work presents the results of studding surface structure of the AK5M7 aluminum alloy hardened by the Electro Spark Alloying (ESA) technique with subsequent annealing. Analysis of crystallite size (CS) values, microdistortion of phase crystal lattices found on the surface, microhardness, and wear resistance allows concluding that, the degree of defectiveness of the surface structure plays a decisive role in its wear resistance.
Full compensation of reactive power in electric networks 0.4-10kV
Authors: Nazarychev S A , Akhmetshin A R , Gaponenko S O
Published: August 2020

The most important task in electric networks is to reduce energy losses. According to Network Company, in distribution electric networks with a voltage of 0.4-10 kV, they account for 62% of the total number of losses. One way to save energy is reactive power compensation. From Order of the Ministry of Energy of the Russian Federation dated June 23, 2015 No. 380 “On the Procedure for Calculation of the Ratio of Consumption of Active and Reactive Power for Individual Energy Receiving Devices (Groups of Energy Receiving Devices) of Electric Power Consumers” at a voltage of 0.4 kV, the reactive power coefficient should not exceed the value 0.35, and on the side of 10 kV - values of 0.4. In practice, in distribution electric networks, reactive power compensation devices are not installed in most cases, and the reactive power factor is 2-3 times higher than the standard values. Since compensating devices are expensive equipment, it is necessary to evaluate the feasibility of deep reactive power compensation, in the range of reactive power factor changes from its standard value to zero. The article discusses the economic and technical feasibility of deep reactive power compensation. The use of a generalized parameter of the electric network for determining the voltage at substations of distribution electric networks is proposed. The need for the coordinated use of reactive power compensation devices and booster transformers to ensure the quality of electricity is shown.
Combustion characteristics of mixtures of certain hydrocarbon fuels in air
Authors: Nazarychev S A , Larionov V M
Published: August 2020

A theoretical study of the combustion of hydrocarbon fuel mixtures in water heating unit was carried out. The effect of hydrogen impurities and propane-butane fuel on the optimal (α = 1) combustion of natural gas in air is established.
Threshold frequency of standing wave at hydrodynamic separation of particles
Authors: Gubaidullin D A , Osipov P P , Nasyrov R R
Published: August 2020

In this paper, the question of the separation of particles in a standing wave in closed resonator at first resonance frequency is considered. The threshold values of the frequency of the standing wave, as well as the densities and radii of the particle, which allow to separate the particles depending on their radius and density are studied.
To the question about mechanisms for the formation of dust fractal structures from an arc plasma
Authors: Smolanov N A
Published: August 2020

The paper presents the results obtained in the study of dusty particles of an arc discharge plasma (fractal aggregates). One of the possible reasons for the formation of fractal structures is the current layers. These are ion flows between adjacent cathode spots of an arc discharge. The magnetic field of the current sheet is an energy source, the dissipation of which leads to the creation of instability of the growth front. In this area, the formation of fractal-like aggregates (drift-dissipative instability) can occur.
Mathematical principles of modeling processes of heat and mass exchange in multiphase media
Authors: Sultanov V A , Makhmutov M M
Published: August 2020

The paper presents a method for studying the process of heat and mass transfer in multiphase media by the example of constructing mathematical models.
Influence of plasma modification on free surface energy of synthetic fibrous materials
Authors: Timoshina Y A , Voznesensky E F , Karnoukhov A E , Krasina I V , Rakhmatullina G R , Pankova E A , Shagivalieva R R
Published: August 2020

The results of experimental studies of the effect of plasma modification in various plasma-forming gases on the acid-alkaline properties and free surface energy of samples of synthetic fibrous materials are presented. The effect of changes in the free surface energy of fiber samples on their adhesion to an epoxy binder in a composite material is studied.
Numerical simulation of the propagation of a shock wave from a neutral and electrically charged dusty medium into a homogeneous gas
Authors: Tukmakov D A , Tukmakova N A
Published: August 2020

In this work, the expansion of a shock wave from a dusty medium into a pure gas is simulated. The carrier medium is described as a viscous compressible and heat-conducting gas. A mathematical model of the dusty medium dynamics allowed for force interaction. Also, the mathematical model took into account inter-component heat transfer. The aim of the work was to study the effect of the electric charge of the dispersed component on the parameters of a shock wave during the passage of a shock wave from an inhomogeneous medium to a homogeneous gas. Differences between processes in neutral and electrically charged dusty media were revealed.
Modification of Particulate Fillers in Low-Pressure Radio Frequency Gas Discharge
Authors: Khubatkhuzin A A , Sharifullin F S , Zheltukhin V S , Valeeva E E
Published: August 2020

The paper aims at investigating the effects of low-pressure radio-frequency plasma on properties of zeolites which may be used as fillers for producing composite materials.
The Influence of Supersonic Gas Stream on Spatial Structure of Glow Discharge
Authors: Timerkaev B A , Shamsutdinov R S
Published: August 2020

This work investigates into the properties of longitudinal glowing discharge in supersonic gas stream between central body and reducer. It has been established that the properties of discharge spatial localization, intensity of radiation, formation of near-electrode areas directly depend on arrangement of supersonic stream. This work analyzes the properties of gas stream in expanding area of supersonic nozzle, pressure recovery in reducer. It has been experimentally established that gas circulation at supersonic speed in the area of glowing discharge makes it possible to control the distribution of concentration of neutral particles in interelectrode space as well as localization of near-electrode zones and positive glow.
Features of Glow Discharge burning between a hollow cathode and a mesh anode
Authors: Yunusov R F , Garipov M M
Published: August 2020

The article is devoted to an experimental study of the features of the combustion of a glow discharge between a hollow copper cathode and a mesh anode in a longitudinal air flow. The cylindrical channel of the discharge chamber was formed by five glass sections separated by copper plates, which served as probes for measuring the plasma potential. Air flowed through the hollow cathode into a cylindrical channel. The anode was a metal grid of a copper plate 1.5 mm thick with holes uniformly located on it with a diameter of 1 mm. The distance between the hollow cathode and the mesh anode was 6.5 cm. Air pressure P, its velocity V, discharge current I and its voltage U varied respectively in the ranges: P = (6. 4 - 19) kPa, V = (0 - 10) m / s, I = (5-100) mA, U = (1. 0 – 2. 0) kV. The current-voltage characteristic had a negative differential resistance. By changing the ballast resistance, the forward and reverse branches of the current-voltage characteristic were removed. It was found that in the range of discharge currents I = (40-80) mA, these branches do not coincide, that is, hysteresis phenomena were observed. In the ascending branch of the current-voltage characteristic in the region of the current strength I = 80 mA, the discharge voltage increases sharply from U = 1. 2 kV to U = 1.6 kV. In this case, the discharge glow becomes more intense, wider and brighter, and the structure of light and dark zones along the discharge chamber also changes. Characteristic photos of the discharge are given. The formation of luminous and dark gaps inside the positive column of the discharge and their movement towards the anode was detected.
Calculation of portable properties of some real gas mixtures at high temperatures
Authors: Takseitov R R , Galimova R K , Yakupov Z Ya
Published: August 2020

A method for calculating the power parameters of a potential of the Lennard-Jones type for a number of individual gases, which can be products released during the ignition and combustion of a gas-vapor discharge with a liquid electrode, is presented. The information obtained makes it possible to calculate the viscosity and diffusion coefficients of individual gases and gas mixtures, which will make it possible to solve a range of problems when modeling processes in the processing technology of various materials (substances) by vapor-gas discharge plasma with a liquid electrode.
Reduction of Torque Ripple for Interior Permanent Magnet Motor with Fractional-Slot Concentrated-Windings
Authors: Le Wang , Dejun Yin
Published: August 2020

Fractional slot concentrated winding motors have advantages of compact structure, high efficiency and high power density, and are widely used in various fields. Due to the large torque fluctuation caused by improper design, it is necessary to pay attention to the torque ripple of the motor. This paper analyses the torque ripple of an 18-slot 12-pole motor, and provides a new method to reduce cogging torque and torque ripple torque through optimizing the harmonic magnetic field generated by permanent magnets. Finally, the validity of the method is verified by the FEM method.
A new short-circuit calculation method of power system with photovoltaic power sources
Authors: Chen Gang , Wu Jiafang , Xiao Yanhui , Hu Jiajia , Chen Yunchao , Zhou Niancheng
Published: August 2020

A large number of photovoltaic power sources connected to the grid will increase short-circuit current level of power system, and its fault transient process will change the fault characteristics of power grid. In this paper, the equivalent models of transient and steady state faults are obtained, by analysing the full current expression of photovoltaic power sources and its current characteristics in different fault stages. Based on the superposition theorem, the short-circuit current calculation method of power system with photovoltaic power sources is proposed. Finally, the effectiveness of the proposed method is verified by the analysis of actual power grid calculation examples, and the results can be used for power grid planning and relay protection setting.
An IGBT short-circuit protection method using variable VCE detection threshold
Authors: Li Yi-Wen
Published: August 2020

When mine fan is driven by power inverter, the high-power inverter maybe used to drive low-power motors, so the short-circuit protection threshold of the IGBT needs to be adjusted online. Firstly, the principle of DESAT function of IGBT driver chip is analyzed, then the detection threshold adjustment circuit is designed by using precision voltage reference and voltage comparator, and the method of real-time threshold adjustment by PWM wave with different duty ratio is designed. Experiments show that the IGBT overcurrent detection circuit can respond and act quickly and accurately, so that the IGBT can be protected in time and effectively under different overcurrent conditions.
Research on the Power Batteries for the Sutong GIL Special Transportation Vehicle
Authors: Yan Yao , Sun Lei , Xia Shunjun , Dai Dahai , Chen Jianghua
Published: August 2020

The GIL Special Transportation vehicle (GIL) is a special device to transport the GIL unit equipments for the GIL project. Due to the complicated environment and massiveness of Sutong tunnel, combined with the large weight of the GIL unit, the power system for the GIL transportation vehicle is crucial for the completing of GIL project. In this paper, we discuss the generally used power systems for the transpostation vehicles in terms of safty, reliability, capacity, and effectiveness, etc. By analyzing the power requirement of Sutong GIL special transportation vehicle according to the environment of the Sutong tunnel and the weight of GIL unit equipment, we choose the lithium iron phosphate power batteries for the Sutong GIL special Transportation Vehicle combining with the features of these power batteries, which helps the Sutong GIL project to finish within the schedule.
Research on Real-time Reliability of Relay Protection System in Intelligent Substation
Authors: Lu Xi-Ning , Wang Hong , Liu Hai-Tao , Xu Chen , Zhang Li-Wu , Jin Zhi-Song
Published: August 2020

Because the intelligent substation is composed of a variety of intelligent electronic components, various types of information data will be generated during its operation. With the continuous implementation and rapid development of smart grid construction, the application of smart substations in power systems is becoming more and more extensive, and the number and scope of use are gradually expanding. In the face of the substantial increase in the commissioning of smart substations, people are paying more attention to the reliability of relay protection devices in smart substations during use. Strengthening research on the relay protection system of intelligent substations and improving the reliability of the system are urgent problems that need to be solved. The digitization of data information of the whole station is a typical feature of intelligent substations, on this basis, distributed relay protection can be realized; At the same time, the system-level status information can be identified and evaluated. Because there are too many spatial states, the calculation is very complicated. To solve this problem, this paper proposes to calculate the reliability of the relay protection device by Markov method, and then calculate in system level by GO method. Combining the Markov algorithm model with the GO method, the reliability of the relay protection system is calculated and analyzed, enabling the on-site operation and maintenance personnel to grasp the basic status of the relay protection device and the system operation in real time, obtain real-time feedback information, and better relay protection work of smart substations.
The Influence of Natural Light on the Design of Electrical Lighting -Taking Liaohe Art Museum as an Example
Authors: Zhao Guohua
Published: August 2020

In the museum, electrical lighting is a very important part, which will affect the visitors’ feelings. This paper mainly studies the impact of natural light on the design of electrical lighting engineering. This experiment was conducted in Liaohe Art Museum. First of all, the lighting situation of each area of the museum was investigated to obtain objective data. Then 30 visitors were invited to conduct subjective survey experiments. The experiment selected two exhibition halls with different lighting methods, one of which only uses artificial lighting (Exhibition Hall 1), and the other uses a combination of natural light and artificial light (Exhibition Hall 3). It was found that people gave a better evaluation score to the exhibition hall combining natural light and artificial light. Therefore, in the museum, the rational use of natural light will bring better psychological feelings to visitors.
Research on the Size of Non-contact High-voltage Electroscope Based on Ansoft Simulation
Authors: Wang Wenlin , Zhang Peng , Shi Yingchun , He Peng , Yang Hongwei
Published: August 2020

Aiming at the time-consuming and labor-intensive problems of traditional electroscopes, a non-contact high-voltage electroscope was developed. This article uses the contact network as an example. First, the electric field simulation of the transmission line under Ansoft is performed. At the same time, the voltage and electric field strength changes under different conditions at 1m under the transmission line are analyzed to determine the test height of the high-voltage electroscope. A human substitution model is proposed, and the effect of humans on electric field distortion is analyzed. Secondly, the relationship between the induced voltage on the parallel plates and the distance test circuit of the parallel plates was deduced according to the principle of space capacitor voltage division, and the dimensions of each part of the high-voltage electroscope were initially determined to provide data references for subsequent electroscope designs.
Household Electricity Load Forecasting Based on Pearson Correlation Coefficient Clustering and Convolutional Neural Network
Authors: Xie Minghao , Chai Chengwei , Guo Heng , Wang Minghao
Published: August 2020

With the development and construction of country, the rapid growth of electricity consumption has caused the problem of undersupply of electricity. It has become a necessarily daily work to forecast the load of the electricity precisely. A new method, new clustering load forecasting method, is used to forecast residential electricity consumption. Distinguished from other methods with Euclidean distance as their evaluation index, however, the method in this paper is defined with the Pearson correlation coefficient. Furthermore, CNN is used in the experiment about residential load forecast. The result indicates that the new method offers more accurate forecasting data than the traditional methods.
Simulation of electric field on a polypropylene slice between high voltage electrodes
Authors: Liu Jieyu , Cheng Wenyu , He Jianning , Zhuang Qiming , Zhao Yan , Wang Donglai
Published: August 2020

The dielectric strength of insulating slice in the high voltage apparatus can be changed by doping the nano clay. In order to test the breakdown time of nano clay-doped polypropylene slices in different temperatures, an experiment has been carried out. In this article, the model of electric field simulation for the experiment is studied. Influences of the thickness and relative permittivity of polypropylene slice on electric field strength are considered. The simulated results can be used as reference for analysing the experimental phenomena of the breakdown of polypropylene slices.
Influence of Active/Reactive Power Control on Harmonics of Wind Unit Converters and Photovoltaic Inverters
Authors: Wang Shibo , Wang Nan , Cheng Yan , Wang Yanzhuo , Wang Shangbin , Yu Peng , Wang Yuejiao , Teng Wei , Sun Shumin
Published: August 2020

Wind units and photovoltaic inverters are the central generation devices of new energy power generation. Hence, the research on harmonic mechanisms and feature influencing factors of new energy power generation units is essential for its safe and stabile operation. This paper analyzes harmonic and inter-harmonic mechanisms of wind units/photovoltaic inverters and studies the influence of active and reactive power output of wind farms and photovoltaic plants on harmonic features of wind units/photovoltaic inverters. Simulation results and harmonic test data verify the theoretical analysis of harmonic mechanisms and influencing factors of photovoltaic inverters and directly-driven wind unit converters.
Analysis and Research on the fault disposal process of the electric energy metering devices
Authors: Wang Pingxin , Li Lin , Dai Yanjie , Zhang Zhi , Li Congcong , Du Yan , Dong Xianguang , Chen Zhiru , Zhu Hongxia , Yang Jie , Yu Chao , Xu Ziqian
Published: August 2020

With the wide application of electronic equipment, the electric energy metering device of site operation is often subject to various types of interference. Due to the complex operation environment, various kinds of fault problems often occur in the electric energy metering devices. However, the actual failure disposal methods were not unified and standardized, which often results in the waste of electric energy metering device assets. In view of the above problems, the faults disposal methods of the electric energy metering devices were studied, the work flow of standardized fault disposal of electric energy metering devices was sorted out and the disposal requirements of each link were identified, which provides a good foundation for standardizing the unified and efficient disposal of the failed electric energy metering devices, deepening the quality management of the whole life cycle of the electric energy metering devices, and realizing the effective reuse of the electric energy metering devices.
A Novel Variable Flux Reluctance Generator for Vehicles
Authors: Yang Tianyu , Zhang Guangming
Published: August 2020

The general vehicle generators are claw-pole synchronous generators, which have the problems such as complicated processing technology of claw poles, low reliability of brushes and low operating efficiency. In this paper, a novel variable flux reluctance generator (VFRG) for vehicles is introduced and it is different from common reluctance machines. It has field coils on each stator pole and forms sinusoidal flux-linkage at each phase’s winding. Compared with general vehicle generators, it has the advantages of simple structure, strong robustness and high efficiency. The structure and operating principle are illustrated at first. Then a VFRG vehicle generator of 28V output voltage for 24V power systems is designed and optimized, which has low cogging torque as well as sinusoidal back-EMF waveforms. In addition, the characteristics and voltage ripple are obtained by simulation. And the technical specifications meet the requirements for a vehicle generator to work in a wide speed range. The results validate the applicability and superiority of VFRG to be a novel generator for vehicles.
Summary of a Numeric Method for Calculating Heat Transfer in the Rotary Air Preheater
Authors: Chen Kai , Qin Yao , Liu Xinfei
Published: August 2020

Due to the introduction and implementation of new standards and new specifications, the structure of the heat transfer elements inside the air preheater has undergone relatively large changes. The thermal calculation method of the rotary air preheater is based on the Soviet 1973“Standard Method for Thermal Calculation of Boiler Units” It has been impossible to directly establish the heat transfer formula. According to the actual operating conditions of the rotary air preheater, the boundary conditions of the calculated heat transfer model can be obtained, including: the inlet temperature and inlet flow rate of the flue gas and air of the preheater; the heat transfer element of the regenerator is repeated Rotation, there are continuous conditions of the temperature of the heat storage element heat transfer element between the different air flow sub-bins. And a method for solving discrete equations is proposed.
Study on test and assessment of low voltage ride through characteristics of electrochemical energy storage system
Authors: Si Xuezhen , Rao Yufei , Xu Ben , Shi Tao
Published: August 2020

In this paper, it is focused on test and assessment of low voltage ride through characteristics of electrochemical energy storage system. Based on the national standard GB/T 36547-2018: technical rule for electrochemical energy storage system connected to power grid, this paper proposes a test and evaluation method for the low voltage ride through characteristics of EESS, and carries out a case analysis based on test data of experimental system to verify the feasibility and effectiveness of the method.
Implementation of Intelligent Distributed Feeder Automation for Distribution Network
Authors: Wu Linwei , Huang Yibiao , Li Rong , Xie Xicheng , Wang Yifan
Published: August 2020

With the increasing demand for power supply reliability in the society, the demand for the degree of feeder automation in the distribution network is also increasing, and the feeder automation function for the purpose of improving power supply reliability is gradually improving. The research and judgment strategy of fault section location, isolation and non-fault section power supply recovery based on the feeder automation function has become a research hotspot. This paper introduces the research and judgment strategy of fault information interaction based on communication network for fast location and isolation of fault section, and expounds the research and judgment strategy of intelligent distributed feeder automation of boundary switch and contact switch in main line and branch line of distribution network in detail.
Summary of Chinese Patents Regarding to Heat Pump
Authors: Chen Kai , Liu Xinfei , Qin Yao
Published: August 2020

The heat pump is an efficient energy-saving device that makes full use of low-grade heat energy. Heat can be transferred spontaneously from a high-temperature object to a low-temperature object, but it cannot spontaneously proceed in the opposite direction. The working principle of the heat pump is a mechanical device that forces heat to flow from a low-temperature object to a high-temperature object in a reverse cycle. It consumes only a small amount of reverse cycle energy and can obtain a large amount of heat supply, which can effectively use low-grade products that are difficult to apply. Finally, the purposes of saving energy are achieved. This article mainly relates to the patents of high-power heat pumps, compact heat pumps, and split heat pumps, this article discusses from three aspects: high power, split and compact heat pumps. In the hope that reflect the novelty, it mainly discusses the relevant patent documents in the past five years.
Study on the Electric Field Distribution Characteristics of the DC Arrester in the Case of Pollution
Authors: Wang Hui , Li Ze , Yao Weijia , Zang Yiming , Qian Yong , Sheng Gehao
Published: August 2020

The DC electric field has a strong adsorption effect on the polluted particles of the substation, so the surface of the DC surge arrester is more prone to fouling. The DC pole bus arrester of the UHV converter station will change the electric field on the external insulation surface and the electric field between the resistance valve and the insulation jacket due to its internal resistance sheet structure characteristics, so it will have a certain impact on the operation status of the arrester. In this paper, by constructing a simulation model of the pollution electric field on the surface of the UHV DC pole bus arrester, the distribution characteristics of the surface pollution in the DC field are studied, and the radial electric field characteristics of the umbrella skirt surface when the surge arrester is wetted and the local drying zone occurs are calculated. It will enhance the surface field strength and the internal radial field strength of the insulating jacket, but the value is small, and it will not cause surface corona and flashover and other discharge phenomena; but when the local dry zone appears on the surface, it will be on the outer insulating surface and the resistance valve A penetrating discharge with the insulating jacket will have a serious impact on the safe and stable operation of the arrester.
Modeling and Analysis of Industrial Power Load Based on Measured Data
Authors: Yan Zhang , Huajia Wang , Danwen Yu , Gaofeng Zhang , Weichao Li
Published: August 2020

With the rapid development of electronic technology, the construction of smart grids has been accelerated. Establishing an accurate load model is of great significance to the stability of distribution network system. Some large-capacity installations with more harmonics and impact, such as electric arc furnaces and wind farm are connected to the grid, which has a serious impact on the power quality of the distribution network. This paper adopts a method of industrial load modeling based on the fitting of measured data, selects electric arc furnace and aluminum rolling mill as typical industrial loads, establishes its model through fitting the measured data, which proves the reliability and accuracy of the load model.
Research on Single Tower Cost Prediction Technology of Transmission Line Engineering Based on 3D Design
Authors: Chen Wenhan , Qi Xuecheng , Fang Jingyu , Shao Jian , Chen Chao
Published: August 2020

Overhead transmission line project investment and construction is an important part of the daily investment activities of power grid companies. With the continuous advancement and implementation of my country’s power system reform, improving the efficiency and efficiency of investment in power grid projects has become the main way for grid companies to invest. The construction and development of overhead line projects is an important support for power grid companies to ensure the safe and stable supply of electricity. The construction cost control of large-scale overhead line projects faces many influencing factors. Factors such as terrain, geology, meteorology, and transportation conditions will cause large differences in cost and other realities. Therefore, strengthen the lean management of the construction cost determination of overhead line projects, rely on the development and application of three-dimensional design, strengthen the construction of a “tower-oriented” construction cost determination system, reasonably control project investment, and increase the level of power grid construction investment efficiency.
DSP Implementation of Neutron Radiation Detection Based on Kalman Filter
Authors: Teng Yuchao , Zheng Xiaohai , Wang Qi Long
Published: August 2020

Aiming at the situation of nuclear neutron pulse count distortion and low measurement accuracy, a digital processing chip and Kalman filter are designed to replace the traditional hardware filtering method. The system uses TMS320F28335 as the main control chip, and takes advantage of the DSP-specific digital signal processing chip. After using the extended Kalman filter to reduce the noise and filter the pulse neutron count, the experiment proves that the nuclear pulse neutron count measurement after the extended Kalman filter process is stable, and the measurement accuracy has been significantly improved. The overall structure and working principle of the system are introduced, and specific hardware and software design schemes are given.
Design of Electric Steering Wheel for Agricultural Machinery
Authors: Li Yueyang , Deng Wenzhi , Cheng Xiaofei , Song Weihai , Li Zhen , Zhang Xianchong
Published: August 2020

Aiming at the automatic steering control system of agricultural machinery, this paper puts forward the method of using S7-200 intelligent PLC of Siemens company as the core controller, which uses the high-speed pulse signal output by the controller to control the stepper motor to drive the rotation of the steering shaft, realizes the automatic steering through the control of the motor speed and steering, uses the encoder to detect the rotation angle of the steering shaft to realize the feedback control, and selects the touch screen to realize the user interaction scheme.
Research on dynamic simulation technology and fault characteristics of Pumped Storage Power Station
Authors: Jin Long , Yu Yue , Zhan Rongrong , Meng Jiangwen , Liu Longhao
Published: August 2020

The fault equivalent circuit model of the pumped storage unit is established, the key electrical parameters of the generator motor of the pumped storage power station are analyzed, and the short-circuit fault characteristics of the generator motor of the pumped storage power station are studied. Based on the typical connection mode of pumped storage power station, a dynamic model test platform including dynamic model pumped storage unit, excitation system, frequency conversion starting device and its control system is established. The dynamic model tests of metal or transition resistance short circuit fault, stator ground fault and stator turn to turn short circuit are carried out.
Comprehensive Experimental Research on Complex Electromagnetic Environment of Aircraft
Authors: Tian Guansuo , Zhou Jun , Li Xiaosong , Li Dawei
Published: August 2020

The battlefield environment that modern electronic information equipment faces during use is very complicated, which has become one of the main characteristics of the informationized battlefield. This article starts with the composition and characteristics of a complex electromagnetic environment, references relevant standards, introduces the definition and composition of a complex electromagnetic environment, and summarizes its characteristics. On this basis, this article introduces the general methods of complex electromagnetic environment tests, including digital simulation tests, semi-physical simulation tests, and full-physical simulation tests. Among them, in the full physical simulation test, an equivalent method is generally used to achieve it. At the same time, this article introduces test evaluation methods, including element-level evaluation and effectiveness-level evaluation. Combining engineering practice, this paper puts forward the difficulties of constructing a complex electromagnetic environment. It is an inevitable requirement for the development of weapons and equipment to carry out comprehensive experimental research on the complex electromagnetic environment of aircraft, and to be able to assess the combat capability of the product. It is also an objective requirement for the development trend of the information military.
Modeling and Optimization of Bus-bar Local Stray Inductors in Converter
Authors: Liu Y , Liao Q H , Yao J K
Published: August 2020

Taking a two level inverter laminated bus as the research object, a mathematical model of local stray inductance is established. The ANSYS Q3D finite element simulation software is used to extract the self-inductance and mutual inductance of local stray inductances in laminated bus-bars. The equivalent local stray inductance is calculated according to the stray inductance mathematical model. The size and generation factors of the local stray inductance of the bus-bar are analysed, and the bus-bar structure is improved. By reducing the local stray inductance between the bus capacitors to IGBT module, the operational status of the converter circuits of the power converter is effectively improved. A double pulse test circuit is built to extract the local stray inductance of the bus-bar before and after optimization. The experimental results show that the improved bus-bar stray inductance is obviously reduced, the correctness of the theoretical analysis is verified, and it is helpful to optimize the bus-bar structure.
Optical parametric oscillator based on electro-optically polarization mode conversion
Authors: Li Lujie , Liu Hang
Published: August 2020

The back conversion of optical parametric oscillator seriously restricts its application in spectral analysis, optical holography, lidar and so on. The optical parametric amplifier output energy is simulated theoretically, and it is confirmed that the back conversion can be compensated by reducing the input energy of parametric light. An optical parametric oscillator with electro-optically polarization mode converter in the resonant is proposed to change the polarization state of the parametric light and adjust the proportion involved in the oscillation. The polarization mode conversion of MgO:PPLN crystal is analyzed theoretically. The experiment of energy regulatory structure is carried out. When the applied voltage of electro-optically polarization mode converter is 157 V/mm, the maximum output power of 1.47 μm and 3.84 μm are 4.4 W and 3.7 W, with a ratio of 1.2. It is confirmed that such structure can suppress back conversion and adjust the output ratio.
Intrusion Object Detection on Transmission Corridors Based on Deep Learning
Authors: Mu Xiaochen , Zhou Xuekun , Li Changyong , He Wenjun , Wei Xin
Published: August 2020

With the construction and development of Chinese power grid, the scale of the power grid continues to expand, the transmission corridors environment is becoming more and more complex, the possibility of external damage caused by intrusion objects of the transmission line is constantly increasing, which seriously threatens the normal operation of the power grid and the reliability of power supply. In order to solve the above problems, it is particularly important to study a detection method that can replace manual identification. That method helps the field personnel to timely detect the intrusion objects within the monitoring scope of the transmission line, so as to improve the efficiency and accuracy of transmission channel inspection.