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1
Lee, Gunbok, Jeong-Yeon Kim, Gildong Kim e Jae Hee Kim. "Surface-Integrated Electric Field Sensor for the Detection of High-Voltage Power Lines". Sensors 21, n. 24 (13 dicembre 2021): 8327. http://dx.doi.org/10.3390/s21248327.
Abstract (sommario):
When a drone is used for inspection of facilities, there are often cases in which high-voltage power lines interfere, resulting in the drone being caught or falling. To prevent this type of incident, drones must be capable of detecting high-voltage power lines. Typically, a strong electric field is formed around the high-voltage lines. To detect the electric fields around high-voltage lines, this study proposes an electric field sensor that may be integrated within the body of a drone. In a laboratory environment, a voltage of 25 kV was applied to an overhead line, and the induced voltage in the proposed sensor was measured at various electric field intensities. Over an electric field range of 0.5 to 10.1 kV/m, a voltage of 0 to 0.77 V was measured with each proposed sensor. In addition, the electric field and the voltage induced in the sensor were measured in a real-world railway environment with overhead lines. Under these conditions, the proposed sensor has the compensated value of 4.5 when the measured electric field was 4.05 kV/m. Therefore, the proposed sensor may be applied in drones to measure large electric fields and to detect the presence of high-voltage lines in its vicinity.
2
Daus, Yulia V., Nikolai N. Romaniuk, Valery A. Eviev, Igor V. Yudaev e Amina N. Badrudinova. "Study of variants of pre-sowing preparation of melon seeds in high voltage electric fields". BIO Web of Conferences 103 (2024): 00064. http://dx.doi.org/10.1051/bioconf/202410300064.
Abstract (sommario):
The research was conducted to study the influence of electrophysical effects on melon seeds and their development, as well as to identify the most effective variant of pre-sowing stimulation and treatment mode. As an agro-technological task, we evaluated the possibility of realising the development potential inherent in the seeds of melon plants, which could be realised using electrical stimulation, with minimal negative impact on the ecology of the environment. To study the effect of high voltage electric fields (DC, AC, pulse) on gourd seeds before sowing, a specially assembled setup was used. Treatment of pumpkin seeds in the electric field of constant high voltage showed that on the 3rd day there were 100% of germinated seeds, in the electric field of variable high voltage – 50%, in the electric field of pulsed high voltage – 30%, pumpkin seedling in the treatment in the electric field of constant high voltage was longer in 9.0 and 3.6 times than in the control and other treatments; treatment of watermelon seeds in the electric field of constant high voltage showed that on the 3rd day there were 70 % of germinated seeds, in the electric field of variable high voltage – 20 %, in the electric field of pulse high voltage – 40 %; watermelon germ at treatment of seeds in the electric field of constant high voltage was longer in 1,5…2,0 times than in the control and other treatments.2.0 times longer than in other treatments. High effect on the destruction of pathogenic microorganisms was observed when seeds were treated in the electric field of pulsed high voltage – the number of pathogenic microorganisms on the seed coat of watermelon and pumpkin was 4.25 and 4.1 times lower compared to the control; when treated in the electric field of constant high voltage, their number was also 3.0 times less, but the treatment of seeds in the electric field of alternating high voltage recorded an increase in pathogenic microflora in 2.0 and 1.2 times. The highest yields of watermelon and pumpkin were obtained with pre-sowing seed treatment in the electric field of constant high voltage – by 25.5 and 37.8 %; in the field of alternating voltage – by 15.7 and 27.0 %; in the field of pulse voltage – by 9.8 and 5.4 %.
3
Li, Li, Qi Li, Shuxin Xu, Rui Liu, Manling Dong, Si Ying, Jieyuan Tian, Wanpeng Xin, Manu Haddad e Xingliang Jiang. "Electric Field Improvement for High-Voltage Bushings". Polymers 15, n. 1 (22 dicembre 2022): 40. http://dx.doi.org/10.3390/polym15010040.
Abstract (sommario):
Resin-impregnated paper (RIP) bushing has gained significant interest due to its extended application in Extra High Voltage (EHV) and Ultra High Voltage (UHV) electricity transmission systems. However, the design criterion of its overall structure, the geometry parameters of the condenser layers, and stress release devices, etc., are still not fully understood. This article proposes a unique electric field optimization technique to integrate both the analytical and the numerical methods. The charge simulation method (CSM) is employed to create the overall equipotential surface, within which the finite element analysis (FEA) is adapted to study the localized field enhancement effects, taking into consideration the multi-physics coupled fields. A case study is performed on an actual UHV bushing. The results are compared to the traditional methods, to demonstrate the benefit of the hybrid method.
4
Ashraf Balametov, Ashraf Balametov, e Tarana Isaeva Tarana Isaeva. "SOFTWARE FOR MONITORING AC CORONA EFFECTS OF OVERHEAD LINES". PAHTEI-Procedings of Azerbaijan High Technical Educational Institutions 20, n. 09 (14 settembre 2022): 04–14. http://dx.doi.org/10.36962/pahtei20092022-04.
Abstract (sommario):
The issues of environmental impact of high-voltage transmission lines are becoming relevant in connection with the development of electrical networks of high voltage 110, 220, 330 kV, extra-high voltage (EHV) 500-750 kV and ultra-high voltage 1150 kV. The harmful effect of electric and magnetic fields on living organisms and, first of all, on humans, manifests itself only at very high voltages in the wires of the overhead line (OH) phases, and is dangerous when working under voltage. The direct influence of the electromagnetic field of lines on a person is associated with an effect on the cardiovascular, central nervous systems and other organs. The harmful effects of a person's stay in a strong electric field depend on the strength of the field and on the duration of its exposure. Software has been developed for modeling electromagnetic compatibility, characteristics of power losses to the corona from the voltage impact on the environment. The results of simulation of corona losses are presented on the example of a 500 kV overhead line, electric field voltage and active energy losses due to radio interference. Keywords: environmental impact, overhead power lines, electric field strength, corona losses, radio interference, acoustic noise, electromagnetic compatibility
5
Kulkarni, G. A., e W. Z. Gandhare. "Prediction of Electromagnetic Fields around High Voltage Transmission Lines". Acta Technica Jaurinensis 10, n. 1 (6 marzo 2017): 50. http://dx.doi.org/10.14513/actatechjaur.v10.n1.414.
Abstract (sommario):
The electric and magnetic fields are present around the High Voltage Transmisssion Lines (HVTL) and reported to affect health of the workers working on these hotlines. The key parameter reportedly responsible for detrimental health effects, are internal induced fields in body. Induction of internal fields in different organs is heavily dependent on the external fields. Prediction of hazardous levels of external fields before measurement or in situations difficult for direct measurement will lead to identify the restrictive situations and working conditions for hotline workers. This work propose a method to model electric and magnetic field for different climbing routes using hybrid technique, formed by combining support vector machine (SVM) and neural network (NN) and also electric field and magnetic field values are predicted using NN for increase in tower height. The result shows the performance of proposed method for prediction of electric field and magnetic field for increase in tower height.
6
Gao, You Hua, Guo Wei Liu, Yan Bin Li e You Feng Gao. "Study on Electric Field Characteristics of Converter Transformer on Valve Side Winding". Applied Mechanics and Materials 130-134 (ottobre 2011): 1413–17. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.1413.
Abstract (sommario):
Numerical calculation model with compound insulation of transient electric field is given. The insulation is more prominent due to complication for voltage applied on valve side winding of the converter transformer. So the simplied structure for electric calculation on the valve side winding of the converter transformer is established. The electric field distribution characteristics on the valve side winding of the converter transformer is analyzed and electric fields in different resistivity and permittivity are calculated under AC high voltage, DC high voltage, AC superimposed DC voltage, polarity reversal voltage. The maximum electric field intensity is calculated and analyzed under kinds of high voltage. Some important influence factors for electric field distribution are also discussed in this paper.
7
Yu, Mengting, Jingang Wang, Jun Ma, Hu Peng e Lan Xiong. "Research on Non-contact Voltage Transducer for High-Voltage Transmission Lines Based on Inverse Problem of Electric Field". International Journal of Emerging Electric Power Systems 15, n. 2 (1 aprile 2014): 101–9. http://dx.doi.org/10.1515/ijeeps-2012-0060.
Abstract (sommario):
Abstract A new method to measure the voltage in a grid has been proposed based on the studies of a novel electronic voltage transducer for the high-voltage power transmission equipment using the charge induction principle and electromagnetic computing method. The voltage measuring method has been improved, the real-time electric field position and orientation near the high-voltage transmission lines has been measured and the real-time voltage has been calculated by computing the electric field inverse problem. According to the electric field simulation with test data, the data compensation and calibration calculation were carried out. With the rapid engineering method on computing voltage, a non-contact electronic voltage transducer has been developed. First, we did the confirmatory test of the electric field detection and designed the preliminary model of the sensor. By the contrast test of voltage detection, the sensor was able to realize the voltage detection, but the precision was not high enough. Next, the measuring mechanism of the voltage transducer was analyzed taking account of strong interference from electromagnetic field, electric field distortion, changes in temperature and humidity, and impact between adjacent electric fields and conductor galloping. The measuring accuracy was satisfied by data compensation.
8
He, Xiaoke, Yushuai Ruan e Weishu Wang. "Three-Dimensional Transient Electric Field Characteristics of High Pressure Electrode Boilers". Electronics 13, n. 9 (23 aprile 2024): 1615. http://dx.doi.org/10.3390/electronics13091615.
Abstract (sommario):
An uneven electric field during the operation of an electrode boiler will lead to the emergence of a high field strength area and low field strength area in the furnace, which will endanger the safe and reliable operation and heating efficiency of the electrode boiler. A numerical study of three-dimensional transient electric field distribution characteristics in a 10 kV high-voltage electrode boiler was carried out. The distribution characteristics of the global electric field of the electrode boiler under the nominal voltage of 10 kV were studied, and the distribution law of the electric field of the electrode boiler under poor power quality, such as different bus voltage and three-phase voltage imbalance, was explored. The results show that the electric field distribution characteristics of the three-phase transient are more obvious in the section closer to the electrode disc, and the electric field distribution is the most uniform in the section that is 1.4 m away from the furnace water. In the case of poor power quality, such as different bus voltage and three-phase voltage imbalance, the points of the maximum electric field intensity of the four surfaces change periodically with time, and the greater the bus voltage fluctuation, the more severe the impact on the transient electric field. The three-phase voltage imbalance will shift the peak value of the electric field intensity. The decrease or offset of electric field intensity in the electrode boiler caused by poor power quality will directly affect its heating efficiency. The electric field simulation results have a specific reference value for improving the internal electric field distribution and on-site operation and maintenance of the electrode boiler.
9
Deng, Shilong, Zhiwei Gao, Jing Xu, Guoqing Wang, Yu Bai e Changjiang Ding. "The Thawing Characteristic of Frozen Tofu under High-Voltage Alternating Electric Field". Journal of Food Quality 2017 (2017): 1–6. http://dx.doi.org/10.1155/2017/3914074.
Abstract (sommario):
To systematically and comprehensively investigate the high voltage alternating electric field (HVAEF) thawing processing, we investigated the high-voltage electric field thawing characteristic of the frozen tofu at different voltages for alternating current (AC). The thawing time, thawing loss of frozen tofu, and specific energy consumption (SEC) of HVEF system were measured. Seven different mathematical models were then compared to simulate thawing time curves based on root mean square error, reduced mean square of deviation, and modeling efficiency. The results showed that the thawing rate of frozen tofu was notably greater in the high-voltage electric field system when compared to control. Both Linear and Quadratic models were the best mathematical models. Therefore, this work presents a facile and effective strategy for experimentally and theoretically determining the HVAEF thawing properties of frozen tofu.
10
Syasko, V. A., S. S. Golubev e A. S. Musikhin. "THE IMPROVEMENT OF THE HIGH VOLTAGE TESTING METHOD". Kontrol'. Diagnostika, n. 258 (dicembre 2019): 4–14. http://dx.doi.org/10.14489/td.2019.12.pp.004-014.
Abstract (sommario):
The high voltage spark testing method of protective dielectric coatings is applied in almost all manufacture areas and is governed by ISO, ASTM etc. However, all of it doesn’t pay proper attention to high voltage forming (DC or AC) and its polarity relative to electrode, influence of environment and electric field inhomogeneity. In that paper a detailed analysis of air gap breakdown forming processes was given. A dependence of electric field strength on an interelectrode gap length was given for homogeneous and highly inhomogeneous electric fields. It was shown a breakdown voltage of air gaps in highly inhomogeneous field is greatly less than in homogeneous field. Also, it is described the breakdown voltage of air gaps with positive polarity is less then with negative polarity. The possibility coatings testing with a minimum thickness up to 50 m while reducing the testing voltage without reducing the reliability of the results is shown.
11
Solovey, Ivan. "RESEARCH OF INFLUENCE OF HIGH-FREQUENCY ELECTRICAL FIELD ON SOWING QUALITY OF CEREAL SEEDS". ENGINEERING, ENERGY, TRANSPORT AIC, n. 3(106) (29 novembre 2019): 95–99. http://dx.doi.org/10.37128/2520-6168-2019-3-12.
Abstract (sommario):
A study on the effect of high-frequency electric field on cereal seeds to increase seed germination and plant growth is presented. The study was conducted in the treatment of winter wheat seeds. High-voltage electric fields are one of the promising means of influencing crop seeds. One of the areas of use of high frequency high voltage electric fields is pre-sowing seed treatment, storage and processing. Experimental studies were conducted in the laboratory on a specially designed installation using a high-frequency high-voltage source. Processing doses have been established which make it practical to use a high-frequency, high-voltage electric field in electrotechnical winter wheat seed systems. Positive influence of high-frequency electric field on increase of sowing qualities and yielding properties of seeds is established. The optimal mode for determining the winter wheat field is the micro field, the mode is 16.8 kJ per 1 kg energy, the hour is 4 seconds, and the laboratory laboratory is 20% similar.
12
Ding, Changjiang, Jiabao Ni, Zhiqing Song, Zhiwei Gao, Shilong Deng, Jing Xu, Guoqing Wang e Yu Bai. "High-Voltage Electric Field-Assisted Thawing of Frozen Tofu: Effect of Process Parameters and Electrode Configuration". Journal of Food Quality 2018 (16 luglio 2018): 1–8. http://dx.doi.org/10.1155/2018/5191075.
Abstract (sommario):
Applying high-voltage electric field (HVEF) to some food materials has been shown to increase the thawing rate. To investigate the effect of process parameters and electrode configuration in high-voltage electric field system, we took the frozen tofu as the research object and investigated the influence of the different voltages, electrode configuration, and electrode distances on thawing process. The thawing time, center temperatures, and loss rate of samples were measured. The results showed that the thawing time of frozen tofu decreases with the increase of voltage and the thawing time has a great relevance with configuration and distance of electrodes. The electric parameters have a major effect on thawing loss and thawing time when center temperatures of frozen tofu are from −2°C to 0°C. This work provides clues and experimental basis for the further application of high-voltage electric field thawing technology.
13
Kucheriava, I. M. "NUMERICAL STUDY OF ELECTRIC FIELD DISTRIBUTION IN HIGH-VOLTAGE CABLE TERMINATION WITH STRESS CONTROL CONE". Tekhnichna Elektrodynamika 2017, n. 1 (15 gennaio 2017): 17–22. http://dx.doi.org/10.15407/techned2017.01.017.
14
Gao, You Hua, Guo Wei Liu, Xiao Ming Liu e Zeng Feng Lai. "Calculation and Analysis of Electrical Field in Valve Side Winding of Converter Transformer". Advanced Materials Research 383-390 (novembre 2011): 4865–70. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.4865.
Abstract (sommario):
The numerical calculation model with compound insulation of transient electrical field is established. The types of voltage applied on the valve side winding of the converter transformer are complicated and the insulation is more prominent. So the simplied calculation model of the valve side winding of the converter transformer is established. The distribution characteristics of electrical field of the valve side winding of the converter transformer is analyzed and electric field in different electrical conductivity and permittivity are calculated under AC high voltage, DC high voltage, AC superimposed DC voltage, polarity reversal voltage. Under all kinds of high voltages, the maximum electric field strength is calculated and analyzed. Some important influence factors for electrical field distribution are also discussed in this paper.
15
Dastgheib, A. M., Z. Buntat e S. M. Zafar Iqbal. "Effect of High Voltage Electric Field on Pineapple". Advanced Science Letters 19, n. 9 (1 settembre 2013): 2523–27. http://dx.doi.org/10.1166/asl.2013.4976.
16
Luo, Xi, Mengqi Yin, Ce Xu e Guanrong Tang. "Simulation Study on Safe Distance between Crane Boom and High-Voltage Line Based on Electric Field Intensity". Journal of Physics: Conference Series 2493, n. 1 (1 maggio 2023): 012020. http://dx.doi.org/10.1088/1742-6596/2493/1/012020.
Abstract (sommario):
Abstract Aiming at the safety accident caused by the close distance between the crane arm and the high-voltage line when the crane is working near the high-voltage transmission line, this paper proposes a simulation model of the electric field intensity distribution of the high-voltage transmission line. First, through the simplification and equivalent treatment of the high-voltage line, the simulation modeling, and analysis of the electric field around the high-voltage line are carried out. Then, the theory of solving the electric field intensity of any point around the high-voltage line based on the charge simulation method is deduced, and the conclusion that the electric field intensity at the equal distance of the high-voltage line is approximately equal is obtained. Furthermore, the influence of the crane on the electric field strength of a high-voltage line is analyzed, and the linear correction function of electric field strength is obtained. Based on the research in this paper, the field strength sensor can be used to obtain the value of the electric field strength, calculate the distance between the crane and the high-voltage line, and make a safety warning response. The simulation results verify the feasibility and effectiveness of the proposed model and method.
17
Long, Zhaozhi, Feng Zhou, Fuchang Lin, Jiawei Fan, Wenting Li, Yinglong Diao e Kangmin Hu. "Development of a Wideband Precision Electric Field Measuring Sensor". Sensors 23, n. 23 (25 novembre 2023): 9409. http://dx.doi.org/10.3390/s23239409.
Abstract (sommario):
High-voltage electric field measurement technology has certain applications in electric field measurement of power systems, but due to the limitation of its measurement accuracy and bandwidth, it cannot be used for the measurement of lightning-impulse voltage. In order to calibrate the nonlinearity of the MV-level lightning-impulse voltage measurement system, this paper proposes the design and implementation of a high-precision inductive wideband electric field measuring sensor (EFMS). The influence of the metal shell on the electric field distribution was simulated, and the influence of the electric field non-uniformity coefficient was studied. The characteristics of the EFMS were tested, and the results showed that the EFMS can accurately reproduce the waveform of lightning-impulse voltage and power-frequency voltage, with a proportionality coefficient of 0.05664 V/(kV/m). In mostly uniform and extremely non-uniform fields, the nonlinearity of the EFMS for impulse voltage is less than ±0.25%, and the nonlinearity of the EFMS for power-frequency voltage is less than 0.1%. It is shown that the EFMS can be used for the nonlinearity calibration of ultra-high voltage impulse measurement devices.
18
Huang, Weian, Ming Lei, Jingwen Wang, Kaihe Lv, Lin Jiang, Hailong Zhao e Weiqing Chen. "Method and Mechanism of Regulating Rheological Properties of Water-Based Drilling Fluid by High-Frequency and High-Voltage Alternating Current Electric Field". SPE Journal 25, n. 05 (29 maggio 2020): 2220–33. http://dx.doi.org/10.2118/201192-pa.
Abstract (sommario):
Summary The rheology of drilling fluid is commonly regulated by chemical methods. In this work, a physical method of a high-frequency and high-voltage alternating current (AC) electric field to regulate the rheological properties of water-based drilling fluid is established. The effects of the electric field on the continuous phase and dispersed phase, as well as two kinds of water-based drilling fluids, were investigated, and the response relationship among rheological properties modeled by Bingham and Herschel-Bulkley (H-B) models and electric-field parameters was explored. Results showed that water conductivity increased when voltage reached 4 kV, whereas it was restored to the original state after 3 hours in the absence of an electric field, showing a memory effect. The effect was also observed on bentonite suspension, whose plastic viscosity increased with the aid of an electric field and decreased over time. Voltage showed the greatest effect on bentonite-suspension viscosity, followed by frequency and pulse-width ratio. Under the condition of voltage of 5 kV, frequency of 5 kHz, and pulse-width ratio of 80%, there was a maximum increase of 50% in viscosity. The addition of salts caused bentonite-suspension flocculation, and electric field reduced the consistency coefficient and relieved flocculation state. When polymers were incorporated in bentonite suspension, the electric field could decrease the adsorption amount between clay particles and polymeric additives such as amphoteric and acrylamide-based polymers. For two typical drilling fluids, the voltage of an introduced electric field was the main controlling factor to change the rheological properties; their plastic viscosity and consistency coefficient both started to increase when voltage reached 4 kV.
19
Liu, Haiting, Zhiming Xu e Junqi Zhang. "Low-Energy-Consumption Wastewater Evaporation Using Single-Electrode High-Voltage Electric Field Enhancement". Processes 11, n. 12 (10 dicembre 2023): 3400. http://dx.doi.org/10.3390/pr11123400.
Abstract (sommario):
High energy consumption is a pressing issue in the development of wastewater evaporation technologies. In this paper, a low-energy-consumption approach utilizing single-electrode high-voltage electric field-enhanced evaporation is proposed. Experimental studies were conducted on the evaporation process of adhered liquid droplets in a single-electrode high-voltage electric field environment. The influence of the electric field on the liquid surface morphology and evaporation modes was analyzed, and the effects of droplet salt concentration, ambient temperature, and voltage on droplet evaporation were investigated. The results indicate that the evaporation enhancement effect of a high-voltage single electrode on droplets mainly occurs when the gas–liquid interface of droplets is unstable. At a voltage of 8 kV, evaporation occurs on the droplet surface, reducing the evaporation time by 5.3% compared to no-electric-field conditions. Furthermore, the effect of the single-electrode high-voltage electric field on droplet evaporation weakens with increasing temperature and salt concentration.
20
Kusakari, Shin-ichi, Kiyotsugu Okada, Manabu Shibao e Hideyoshi Toyoda. "High Voltage Electric Fields Have Potential to Create New Physical Pest Control Systems". Insects 11, n. 7 (15 luglio 2020): 447. http://dx.doi.org/10.3390/insects11070447.
Abstract (sommario):
An electric field is the space surrounding an electric charge, within which it is capable of exerting a perceptible force on another electric charge. Especially under high voltage, electric fields induce various electrostatic phenomena, some of which could be utilized to provide remarkable pest control measures. The main focus of the present study was to introduce an attractive force generated by a surface charge on an insulated electrified conductor, which was successfully used to construct an electric field screen that prevented airborne nuisances (spores, flying insects, pollen, and fine smoke) from entering the interiors of various facilities. Another focus was the disinclination of insects to enter the electric field, thus, giving the electric field screen the ability to repel insects. Charges accumulated on the surfaces of non-insulated conductors are mobile through discharge, based on their potential difference. Such arc discharge was strong enough to destroy insects that were exposed to it. Some precedent illustrative examples are cited to explain the principles of attraction, dielectrophoretic movement of spores, and discharge-mediated positive electrification of insects, and to discuss how electric fields are generated and used in electric field-based pest control strategies.
21
Ma, Xing Ke, Zheng Wei Du, Min Zhu e Bo Jia Mu. "Research on Direct Effects of High-Voltage Electrostatic Field on Lactoperoxidase's Activity". Advanced Materials Research 781-784 (settembre 2013): 372–78. http://dx.doi.org/10.4028/www.scientific.net/amr.781-784.372.
Abstract (sommario):
At present, indirect effects of high-voltage electrostatic field on organisms and biological materials have been extensively studied. However, the investigations on direct interaction between the electrostatic field and enzyme are scarce. In this paper, the direct effect of high-voltage electrostatic field on the LP and the protective effects of sucrose fatty acid ester on the activity of enzyme in high-voltage electrostatic field have been experimentally investigated. The results show that, high-voltage electrostatic field has direct effects on the LP and the best condition to enhance the activity of enzyme can be obtained. When the electric-field strength is low, with the increasing of the electric-field strength, the activity of the LP will be weakened. When the electric-field strength exceeds a certain level, the activity of the LP will be enhanced with the increasing of electric-field strength. For too higher electric-field strength , the activity of the LP will be again weakened with the increasing of electric-field strength. The sucrose fatty acid ester in low concentration provides a proper hydrophobic microenvironment for enzyme, which leads to the enhancement of enzyme's activity, while sucrose fatty acid ester in high concentration leads to the weakening of enzyme's activity. Moreover, sucrose fatty acid ester in enzyme solutions has protective effects on enzyme in the electric field and can reduce the impacts of high-voltage electrostatic field on the LP.
22
Peng, Ye, Tao Liu, Haifeng Gong e Xianming Zhang. "Review of the Dynamics of Coalescence and Demulsification by High-Voltage Pulsed Electric Fields". International Journal of Chemical Engineering 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/2492453.
Abstract (sommario):
The coalescence of droplets in oil can be implemented rapidly by high-voltage pulse electric field, which is an effective demulsification dehydration technological method. At present, it is widely believed that the main reason of pulse electric field promoting droplets coalescence is the dipole coalescence and oscillation coalescence in pulse electric field, and the optimal coalescence pulse electric field parameters exist. Around the above content, the dynamics of high-voltage pulse electric field promoting the coalescence of emulsified droplets is studied by researchers domestically and abroad. By review, the progress of high-voltage pulse electric field demulsification technology can get a better understanding, which has an effect of throwing a sprat to catch a whale on promoting the industrial application.
23
Бирюков, С. В., А. В. Тюкин e Л. В. Тюкина. "DUAL SPHERICAL ELECTRIC FIELD VOLTAGE SENSOR". ВЕСТНИК ВОРОНЕЖСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА, n. 5 (19 novembre 2021): 85–91. http://dx.doi.org/10.36622/vstu.2021.15.5.012.
Abstract (sommario):
Мы живем в мире высоких энергетических технологий, способных передавать электрическую энергию на большие расстояния. Эту энергию невозможно сосредоточить только внутри передающих энергетических систем. Она выплескивается наружу в виде электрических полей. Эти электрические поля неблагоприятно воздействуют на окружающую среду, технические и биологические объекты. В связи с этим необходимо контролировать уровни электрических полей, важной характеристикой которых является напряженность электрического поля. Для восприятия электрического поля необходимы датчики напряженности электрического поля. Существующие датчики неудобны в эксплуатации и имеют высокую погрешность восприятия напряженности электрического поля, достигающую ± 20%. Bыдвигается идея создания универсального датчика нового вида, относящeгося к виду сдвоенных датчиков. Его универсальность заключается в том, что он воплощает в себе все виды известных датчиков - одинарные, сдвоенные и теперь еще двойные. Погрешность восприятия напряженности неоднородного электрического поля сдвоенных датчиков не превышает +5 % во всем пространственном диапазоне измерения 0£ a £1. При этом расстояние d до источника поля ограничено только радиусом сферического основания датчика, т.е. d » R , в то время как для датчиков, входящих в состав сдвоенного датчика, в том же пространственном диапазоне измерение погрешности составляет ± 35 %. Используя сдвоенный датчик, можно добиться значительного повышения точности измерения напряженности неоднородных электрических полей в широком пространственном диапазоне измерений по сравнению с известными датчиками We live in a world of high energy technologies capable of transmitting electrical energy over long distances. This energy cannot be concentrated only within the transmitting energy systems. It spills out in the form of electric fields. These electric fields adversely affect the environment, technical and biological objects. In this regard, it is necessary to control the levels of electric fields, an important characteristic of which is the strength of the electric field. Sensors of the electric field strength are required to sense the electric field. The existing sensors are inconvenient in operation and have a high error in the perception of the electric field strength, reaching ± 20%. In the work under consideration, the idea of creating a universal sensor of a new type, related to the type of dual sensors, is put forward. Its versatility lies in the fact that it embodies all types of known sensors - single, twin, and now dual. The error in the perception of the intensity of the inhomogeneous electric field of the dual sensors does not exceed + 5% in the entire spatial measurement range 0£ a £1. In this case, the distance d to the field source is limited only by the radius of the spherical base of the sensor, i.e. d » R . At the same time, for sensors that are part of a dual sensor in the same spatial measurement range, the error is ± 35%. Using a dual sensor, it is possible to achieve a significant increase in the accuracy of measuring the strength of inhomogeneous electric fields in a wide spatial measurement range in comparison with known sensors.
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Yu, Yang Tao, Peng Cheng Zhao, Xin Wang e Ye Tian. "Research on High Voltage Electromagnetic Electrostatic Spinning Machine Electric Field Analysis". Applied Mechanics and Materials 684 (ottobre 2014): 259–63. http://dx.doi.org/10.4028/www.scientific.net/amm.684.259.
Abstract (sommario):
The main approach to obtain nanomaterial is nanospinning technology at present. Due to the inherent characteristics of nanomaterial itself, which are easily affected by the electric field force effect of spinning. And for the spinning machine nozzle electric field is relatively complex, so nanospinning products at present, is easily affected by the electric field force and dissipated. So, the nanospinning collection efficiency is low. This paper adopts an oval enhanced electrostatic mechanism, method of using additional electric field to improve the balance obtained nanomaterial collection rate. And the construct high voltage electrostatic spinning machine virtual prototype,complete the analysis of the improved method of static electric field. The analysis results indicate that the electric field can effectively improve the collection rate of nanospinning. Through the study of the additional electric field strength further size on the electric field force and the ellipse, can more effectively improve the collection rate of nanospinning products.
25
Kriengkriwut, Teera, e Boonchai Techaumnat. "Simulation of Electric Field in Co-Field Treatment Chamber Using FEM". Applied Mechanics and Materials 781 (agosto 2015): 612–15. http://dx.doi.org/10.4028/www.scientific.net/amm.781.612.
Abstract (sommario):
The technique of pulsed electric field is used for killing microbes causing food spoilage. This paper presents the calculation of electric field in co-field treatment chamber with the elliptic insulator type by the finite element method. The chamber diameter is 5 mm, and the insulator gap is 6 mm. The length of high-voltage electrode and the height of insulator were varied. The results show that too short voltage electrode length can generate high electric field spot at the junction of electrode and insulator. Increasing insulator height by 0.01 mm can decrease the maximum of the electric field by 1 percent. The results suggest that the dimensions of electrode and insulator are important to investigate the electric field for eliminating microbes.
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Zudov V.N. e Tupikin A. V. "Influence of external electric field on optical breakdown in high-speed flow". Technical Physics 92, n. 2 (2022): 176. http://dx.doi.org/10.21883/tp.2022.02.52943.244-21.
Abstract (sommario):
The influence of an electric field on the plasma of an optical discharge in subsonic and supersonic air flows has been studied experimentally. The presence of a weak electric field practically does not affect the size of the plasma formation, but, regardless of the configuration of the field lines and the polarity of the applied voltage, it leads to a decrease in the probability of optical breakdown. The experiment has shown that the plasma created by focused laser radiation is very sensitive to the presence of an electric field. When a voltage exceeding 22 kV was applied to the ring electrodes, powerful quasi-stationary streamers were formed in the flow. The presence of an optical discharge plasma made it possible to create an electric discharge in fields with an intensity below the breakdown threshold of the medium. The effect of quenching and the processes of development of an optical discharge were studied depending on the speed and characteristics of the electric field. Quenching of the optical discharge was observed when a voltage of 22 kV and higher was applied. Despite the preservation of the geometric dimensions of the optical discharge, the high-temperature region in the flow can be increased by using electric streamers. This leads to an increase in the energy supplied to the flow, and thus allows combustion to be initiated and flame stabilized at higher flow rates. Keywords: experimental modeling, laser radiation, optical breakdown, electric field, electric discharge, sub- and supersonic air flow.
27
Ri, Na, e Guo Rong Li. "Effect of the Corona Discharge on ZnTe Film". Advanced Materials Research 314-316 (agosto 2011): 171–75. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.171.
Abstract (sommario):
The effect of corona electric field on the surface of Pr-doped ZnTe thin film was studied. The device which can produce the high-voltage corona electric field is developed and used. The V-A characteristics of positive and negative corona discharge between the adjacent needle plates were measured. Whether positive or negative corona discharge, the corona discharge current of the plate is increased with the applied voltage increasing; the voltage range of negative corona discharge is wider than that of the positive corona discharge, meanwhile under the same applied voltage, the negative corona discharge current is bigger, not only its curve is smooth, but also its discharge is stable. The thermal effect of electric field is small. The electric field strength is 7.0 kV•cm-1. By atomic force microscope, it is found that the size of particles becomes large and uniform, and the surface becomes rough with electric field treatment. The measurement results reveal that the average radius of particles is 108.70nm before the effect and 227.27nm after the effect. By UV-Vis Spectrophotometer, it is found that a strong optical absorption peak appears at the region of 220 - 250nm with electric field treatment. This means that the stronger light absorption peak turn out a blue shift under the effect of electric field. The phenomenon of the blue shift proves that the high-voltage corona electric field has an impact on the band gap of the film. The voltage range of the negative corona discharge is wide and stable. The thermal effect produced by the high-voltage corona electric field on the sample is very small, so usually it can be ignored. The high-voltage corona electric field can change the surface morphology of some films, makes the current density of the sample location increase in a small cross section. The negative high-voltage corona discharge should well be used to research in biophysics such as the transgenic plants. High-voltage corona discharge mutagenesis has become a new physical mutation technique. Introduction
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Frick, Georges, Francis Osswald e Bernard Heusch. "Vivitron 1995 Transient voltage simulation, high voltage insulator tests, electric field calculation". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 382, n. 1-2 (novembre 1996): 37–50. http://dx.doi.org/10.1016/s0168-9002(96)00406-8.
29
Gu, Liang, Xin Gang Chen, Xiao Dong Liu e Wei Liu. "Ion Distribution in Saltwater under High-Voltage Static Electric Field". Advanced Materials Research 361-363 (ottobre 2011): 865–69. http://dx.doi.org/10.4028/www.scientific.net/amr.361-363.865.
Abstract (sommario):
The world is facing a severe crisis of fresh water shortage. Seawater desalination technology is the ideal answer to this crisis. However, the conventional technologies consume too much energy, which greatly restrict their popularization. A method for saltwater desalination is proposed based on high-voltage static electric field eliminating the dissolved ions in saltwater. The desalination function is realized by static high-voltage electric field exerting electric force on the ions in the salt solution to strongly separate the ions of the contrary sign. Three factors were simulated to reveal their effects on the ion distribution or the separation efficiency, including salt concentration, electric field intensity and width of water pipeline. Results shows that the above three factors greatly affect the ion distribution characteristics in the water pipeline. This method is helpful in energy saving for seawater desalination.
30
Qin, B. L., G. Z. Chen, Q. Qiao e J. N. Sheng. "Efficient computation of electric field in high voltage equipment". IEEE Transactions on Magnetics 26, n. 2 (marzo 1990): 387–90. http://dx.doi.org/10.1109/20.106335.
31
Eleperuma, K., T. P. Saha e T. Gillespie. "Electric field modelling of non–Ceramic high voltage insulators". Australian Journal of Electrical and Electronics Engineering 4, n. 3 (gennaio 2008): 239–48. http://dx.doi.org/10.1080/1448837x.2008.11464190.
32
Radwan, R. M., A. M. Mahdy, M. Abdel-Salam e M. M. Samy. "Electric field mitigation under extra high voltage power lines". IEEE Transactions on Dielectrics and Electrical Insulation 20, n. 1 (febbraio 2013): 54–62. http://dx.doi.org/10.1109/tdei.2013.6451341.
33
Abbasi, Elham, e Ali A. Orouji. "High-blocking-voltage UMOSFETs with reformed electric field distribution". Journal of Computational Electronics 17, n. 4 (6 settembre 2018): 1584–95. http://dx.doi.org/10.1007/s10825-018-1239-0.
34
Meza-Jimenez, M. L., M. R. Robles-López, F. Reyes-Espinosa, A. Hernández-Arana, H. Hernández-Sánchez e R. R. Robles-de la Torre. "Efect of high voltage electric field on food grade papain". Revista Mexicana de Ingeniería Química 16, n. 1 (24 ottobre 2016): 101–8. http://dx.doi.org/10.24275/rmiq/alim742.
35
Koliushko, D. G., S. S. Rudenko, S. O. Tyutyuma e B. V. Vorobiov. "Determination of the electric field strength of high-voltage substations". Electrical Engineering & Electromechanics, n. 5 (21 agosto 2023): 63–68. http://dx.doi.org/10.20998/2074-272x.2023.5.09.
Abstract (sommario):
The electric field strength is one of the main factors influencing sensitive microprocessor equipment and personnel on power stations and substations, power lines. Determining its level is an important applied task for ensuring the safe operation of electrical installations. The aim is to develop calculation relationships for determining the electric field strength created by the busbar of high-voltage substations in the working areas of personnel. The solution of the problem was based on the use of the method of equivalent charges to determine the strength of the electric field created by the complex busbar of high-voltage substations. Methodology. The development was based on solving the problem of the potential of the electric field of a point charge located in a dielectric half-space for a cylindrical coordinate system. By representing the electrode in the form of a set of point charges and subsequent integration, an expression for calculating the potential is obtained, created by a busbar of arbitrary orientation of finite length in an analytical form. Using the principle of superposition of fields and the definition of the derivative, expressions were obtained for calculating the vertical component of the electric field strength at given heights. Results. Based on the obtained expressions, using Visual Basic, the simulation of the distribution of the electric field strength under a three-phase power line with a voltage of 150 kV was performed. Comparison with the known calculation results obtained on the basis of analytical expressions for infinitely long conductors showed that the obtained expressions have an error of no more than 7%. The scientific novelty lies in the fact that for the first time expressions were obtained for determining the electric field strength created by a system of electrodes of finite length, based on the analytical method for solving differential equations. Practical significance. The proposed technique is implemented as a test module of the LiGro specialized software package, which allows modeling complex busbar systems typical for power stations and substations and power lines. A test calculation was carried out for an operating substation of regional electric networks with a voltage class of 110 kV. By comparing the duration of the calculation of switchgears with a diagonal of about 500 m, it was found that the calculation time in the LiGro complex based on the analytical method is several tens of times less than the calculation based on the finite element method. In addition, a more powerful computer was used for the end element simulation.
36
Shi, Ming Fei, Juan Juan Fan, Shi Jun Li, Xiu Ling Yu e Xue Mei Liang. "The Influence of High Voltage Electric Field for Barley Seed Germination and its Mechanism". Applied Mechanics and Materials 675-677 (ottobre 2014): 1142–45. http://dx.doi.org/10.4028/www.scientific.net/amm.675-677.1142.
Abstract (sommario):
This paper through the effect of seed germination under different voltage that it can concluded that the influence of electric field on seed growth.Experiment to select different gradient field acts on the barley seed, the results show that the appropriate voltage of the electric field and action time has obvious promoting effect to seed germination. By discussing the electric field effect on the cell membrane permeability, using a planar lipid double model, discussed that high voltage electric field makes the cell membrane barrier height change.Ion through the barrier of risk as a result of the existence of tunneling effect will be affected by the barrier height, namely transmembrane potential.Thus an effect on the permeability of cell membrane.
37
ELSBAAY, ATEF MOHAMED, ASMAA AHMED ELATTAR e ROWIDA YOUNIS ESSA. "Influence of high-voltage electric field thawing on frozen tilapia fillets quality". Romanian Biotechnological Letters 27, n. 1/2022 (10 gennaio 2022): 3200–3207. http://dx.doi.org/10.25083/rbl/27.1/3200-3207.
Abstract (sommario):
In the food sector, high voltage electric field (HVEF) has recently been regarded as a novel thawing technique. The variance in the quality was compared between frozen tilapia fish fillets thawed by high voltage electrostatic field (HVE) and those thawed conventionally as control. Frozen tilapia fish fillets were thawed under HVEF and were exposed to three different corona voltages from 4.5 to 14 kV at electrode gaps of 3, 4.5, and 6 cm; the control was thawed at 20°C without HVEF treatment. Thawing rate, evaporation, thawing, and drip losses, as well as total volatile binding nitrogen (TVB-N), thiobarbituric acid reactive substances, protein solubility, and color variations, have been employed as the quality indicators. The results revealed that thawing under HVEF greatly enhances the thawing rates of frozen tilapia fish fillets. The greatest rate of thawing was 2.16 times that of the control specimen. However, thawing HVEF reduced the protein solubility and color of fish specimens. In comparison to the control, increasing the applied voltage reduced the protein solubility of the fish specimens High electrostatic field intensities caused frozen tilapia fish fillets to oxidize quicker than lower ones.
38
Xinling, Tang, Pan Yan, Chen Yanfang, Fu Pengyu e Zhao Zhibin. "Electric Field Analysis of Press-Pack IGBTs". E3S Web of Conferences 64 (2018): 04006. http://dx.doi.org/10.1051/e3sconf/20186404006.
Abstract (sommario):
High voltage IGBT module is the ideal option for the VSC-HVDC power transmission application. At present, wire-bonded technology and press-pack technology are available packaging technologies for high voltage IGBT. The press-pack IGBTs have such advantages as low inductance, low thermal impedance and short circuit failure mode than the wire-bonded IGBT module, which especially suit for high voltage power transmission application by series connection. However, the electrical insulation failure modes of press-pack IGBTs are much less known with limited literature published. In this paper, we presented the electric field analysis of a 3D press-pack IGBT model under DC rating voltage test condition. The electric field distribution of the press-pack IGBT stack was solved as an electrostatic problem by employing the finite element method. The results revealed the potential electrical insulation failure modes of the press-pack IGBTs: corona discharge at the edge of silver plate, partial discharge at the micro gap between die and PEEK frame and creeping discharge at the surface of PEEK frame.
39
Yudaev, Igor V., Yulia V. Daus, Valery A. Eviev, Elena V. Soumyanova e Tatiana B. Goldvarg. "Pre-sowing stimulation of cereal seeds in high voltage electric field". BIO Web of Conferences 103 (2024): 00063. http://dx.doi.org/10.1051/bioconf/202410300063.
Abstract (sommario):
The main challenge of modern land management is the need to increase the yield of cultivated crops, while maintaining quality, minimising total energy inputs into cultivation and minimising the negative impact on the environment. This is quite possible if we have healthy seeds characterised, first of all, by improved sowing qualities. In order to realise the mentioned approaches, it is possible to use seed preparation for sowing, using for this purpose various electrophysical effects, including treatment of seed material in the electric field of high voltage. The purpose of the presented article is to analyse the results obtained to study the process of treatment of cereal seeds before sowing in the electric field of constant and alternating high voltage, as well as the electric field of pulsed high-voltage discharges. A universal experimental laboratory setup was assembled for the research. According to the results of the experiments, there was a clear dependence of the speed and friendliness of germination of winter triticale and barley seeds on the effects of electrical nature on them. Efficiency of such influences is also shown in plant protection against various pests, so against bread fleas and meromysa it is treatment in the electric field of alternating high voltage with duration of 120 s, as well as against Swedish fly, but with duration of treatment of 60 s; against wheat thrips – in the electric field of constant high voltage with duration of 60 s. Besides optimisation of phytosanitary condition of crops, the stimulating effect of high voltage electric field on yield structure of cereal crops (winter barley and triticale) was revealed, as productivity increases, bushiness and more dense productive stalks are formed. Electrostimulation has a positive effect on such hard-to-regulate parameter as ear fineness – the total number of grains in the ear increases by 13.8…31.0%; the weight of 1000 grains slightly increases – by 3.0…6.2%; grain yield to total weight increases by 40.3…57.8%; positive effect on all elements of yield structure is traced.
40
Can-Ortiz, Alejandro, Lionel Laudebat, Zarel Valdez-Nava e Sombel Diaham. "Nonlinear Electrical Conduction in Polymer Composites for Field Grading in High-Voltage Applications: A Review". Polymers 13, n. 9 (22 aprile 2021): 1370. http://dx.doi.org/10.3390/polym13091370.
Abstract (sommario):
Applications of polymeric materials in electrical engineering increasingly require improvements in operating voltages, performance, reliability, and size reduction. However, the resulting increase on the electric field in electrical systems can prevent achieving these goals. Polymer composites, functionalized with conductive or semiconductive particles, can allow us to reduce the electric field, thus grading the field within the system. In this paper, a comprehensive review of field-grading materials, their properties, and recent developments and applications is provided to realize high-performance high-voltage engineering applications.
41
Larson, David J., Patrick P. Camus e Thomas F. Kelly. "Scanning EM in very high electric fields near field ion/emission specimens". Proceedings, annual meeting, Electron Microscopy Society of America 53 (13 agosto 1995): 624–25. http://dx.doi.org/10.1017/s0424820100139494.
Abstract (sommario):
An atom probe field ion microscope (APFIM) has been constructed inside a NORAN Instruments Automated Digital Electron Microscope (ADEM). The ADEM is a scanning electron microscope (SEM) with a field emission source and a very large vacuum chamber. The APFIM has positive and negative high voltage capability and uses a microchannel-plate/phosphor screen assembly as an imaging and single-ion detector. The APFIM specimen can be cooled by a cryogenic refrigerator. The motivation for this study was the need to deliver an electron beam to the apex of an APFIM specimen while a high field is applied. The beam will be used to thermally pulse the field evaporation rate. The expected field-induced image shift and distortion has been studied previously in a transmission EM with a liquid metal field emission source as a specimen.Fig. 1 shows the interior of the instrument. Computer simulations were done for electron trajectories with negative and positive voltages applied to the emitter based on a simple paraboloidal electric field model described previously.
42
Cai, Guo Wei, Yi Gong Wang, Dong Han e Wen Guo Song. "Power-Frequency Electric Field Calculation of Ultra-High Voltage Substation". Applied Mechanics and Materials 448-453 (ottobre 2013): 2132–36. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.2132.
Abstract (sommario):
To ensure the normal operation, calculation of electric field in ultra-high voltage substation is particularly important. A line model is proposed to simplify current model and improve computational efficiency. Combining this model with boundary element method, this article described a method to calculate the electric field at the vicinity of complex equipment of ultra-high voltage substation. An actual substation environment is also simulated, with detailed analysis of simulation results, proposed model and method are verified as valid and effective.
43
Wang, Qing, Jie Min e Jia Tian. "The Effect of High-Voltage Electrostatic Field on the Water Performance". Advanced Materials Research 441 (gennaio 2012): 695–98. http://dx.doi.org/10.4028/www.scientific.net/amr.441.695.
Abstract (sommario):
Water treated by external electric field with different field intensity. The absorbency of water, the changes of dyes solubility, the effect of treatment time and the changes of wool swelling were studied. The results showed that electric field treatments can alter the water physical properties to various degrees. The absorbance of water increased with increasing electric field intensity. The swelling ratio indicated the ability of solvent to penetrate the wool fibers and to swell them.
44
Simpson, Fiona, e Karsten Bahr. "Estimating the electric field response to the Halloween 2003 and September 2017 magnetic storms across Scotland using observed geomagnetic fields, magnetotelluric impedances and perturbation tensors". Journal of Space Weather and Space Climate 10 (2020): 48. http://dx.doi.org/10.1051/swsc/2020049.
Abstract (sommario):
Geomagnetic storms generate heightened magnetovariational activity, which induces electric fields that drive hazardous currents known as geomagnetically induced currents (GICs) through man-made technological conductors including power transmission lines, railway networks and gas pipelines. We multiply magnetotelluric (MT) impedances from 23 sites in Scotland and northern England with measured geomagnetic field spectra from the Halloween 2003 and September 2017 storms to estimate maximum peak-to-peak, electric field magnitudes and directions for these storms, which we present as hazard maps. By sampling these electric fields in the direction of the longest (>50 km), high-voltage (275 and 400 kV) Scottish power transmission lines and integrating along their lengths, we estimate their associated transmission-line voltages. Lateral electrical conductivity variations in the Earth generate horizontal magnetic field gradients. We investigate the effect of these gradients on electric field estimates obtained using remote magnetic fields by applying a correction to the impedance tensor derived from the magnetic perturbation tensor between the local MT site and the remote magnetic field site. For the September 2017 storm, we also compare our estimated electric fields with a unique dataset comprising measured storm-time electric fields from 7 MT sites. We find that peak-to-peak, electric field magnitudes may have reached 13 V/km during the Halloween storm in some areas of the Scottish Highlands, with line-averaged electric fields >5 V/km sustained along a number of long-distance, high-voltage power transmission lines; line-averaged electric fields for the September 2017 storm are 1 V/km or less. Our surface electric fields show significant site-to-site variability that arises due to Earth’s internal 3D electrical conductivity structure, as characterised by the MT impedance tensors.
45
Shen, Chih-Lung, Jye-Chau Su e Tsair-Chun Liang. "A Novel Dual-Electrode Plug to Achieve Intensive Electric Field for High Performance Ignition". Mathematical Problems in Engineering 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/351594.
Abstract (sommario):
A thorough analysis of electric field is carried out so as to verify that a novel dual-electrode plug can build intensive electric field and can improve the main drawbacks of feeble electric field and low ignition efficiency of the traditional plug. With intensive electric field, the proposed novel plug can achieve high performance ignition, resulting in fuel saving and exhaust reduction. Gauss law is applied for electric field analysis to show that intensive electric field can be built by the novel plug. Then, according to Faraday law a lower-voltage ignition feature accomplished by the plug is discussed. Compared with traditional plug, the novel dual-electrode plug has the following advantages. (1) Much higher energy density is built between the plug electrodes, lowering ignition voltage requirement. (2) Electromagnetic interference (EMI) problem caused by high ignition voltage is readily resolved. (3) Ignition time delay can be improved. (4) The feature to save fuel consuming is achieved. (5) The exhaust of CO and HC is reduced significantly. Practical measurements are fulfilled to validate the electric field analysis and to demonstrate the features of the proposed dual-electrode plug.
46
Chao, Yanpu, Hao Yi, Fulai Cao, Yaohui Li, Hui Cen e Shuai Lu. "Experimental Analysis of Wax Micro-Droplet 3D Printing Based on a High-Voltage Electric Field-Driven Jet Deposition Technology". Crystals 12, n. 2 (17 febbraio 2022): 277. http://dx.doi.org/10.3390/cryst12020277.
Abstract (sommario):
High-voltage electric field-driven jet deposition technology is a novel high resolution micro scale 3D printing method. In this paper, a novel micro 3D printing method is proposed to fabricate wax micro-structures. The mechanism of the Taylor cone generation and droplet eject deposition was analyzed, and a high-voltage electric field-driven jet printing experimental system was developed based on the principle of forming. The effects of process parameters, such as pulse voltages, gas pressures, pulse width, pulse frequency, and movement velocity, on wax printing were investigated. The experimental results show that the increasing of pulse width and duration of pulse high voltage increased at the same pulse frequency, resulting in the micro-droplet diameter being increased. The deposited droplet underwent a process of spreading, shrinking, and solidifying. The local remelting and bonding were acquired between the contact surfaces of the adjacent deposited droplets. According to the experiment results, a horizontal line and a vertical micro-column were fabricated by adjusting the process parameters; their size deviation was controlled within 2%. This research shows that it is feasible to fabricate the micro-scale wax structure using high-voltage electric field-driven jet deposition technology.
47
Jörgens, Christoph, e Markus Clemens. "Thermal breakdown in high voltage direct current cable insulations due to space charges". COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, n. 5 (3 settembre 2018): 1689–97. http://dx.doi.org/10.1108/compel-12-2017-0531.
Abstract (sommario):
Purpose In high voltage direct current (HVDC), power cables heat is generated inside the conductor and the insulation during operation. A higher amount of the generated heat in comparison to the dissipated one, results in a possible thermal breakdown. The accumulation of space charges inside the insulation results in an electric field that contributes to the geometric electric field, which comes from the applied voltage. The total electric field decreases in the vicinity of the conductor, while it increases near the sheath, causing a possible change of the breakdown voltage. Design/methodology/approach Here, the thermal breakdown is studied, also incorporating the presence of space charges. For a developed electro-thermal HVDC cable model, at different temperatures, the breakdown voltage is computed through numerical simulations. Findings The simulation results show a dependence of the breakdown voltage on the temperature at the location of the sheath. The results also show only limited influence of the space charges on the breakdown voltage. Research limitations/implications The study is restricted to one-dimensional problems, using radial symmetry of the cable, and does not include any aging or long-term effect of space charges. Such aging effect can locally increase the electric field, resulting in a reduced breakdown voltage. Originality/value A comparison of the breakdown voltage with and without space charges is novel. The chosen approach allows for the first time to assess the influence of space charges and field inversion on the thermal breakdown.
48
Liao, Wei, Qing Yang, Kun Ke, Zhenhui Qiu, Yuqing Lei e Fei Jiao. "Non-Intrusive Voltage-Inversion Measurement Method for Overhead Transmission Lines Based on Near-End Electric-Field Integration". Energies 16, n. 8 (13 aprile 2023): 3415. http://dx.doi.org/10.3390/en16083415.
Abstract (sommario):
Existing electric-field integral inversion methods have limited field application conditions, and they are difficult to arrange electric-field measurement points on high-span overhead lines. This paper proposes a non-intrusive voltage measurement method for overhead transmission lines based on the near-end electric-field integration method. First, the electric-field distribution under 10 kV lines is calculated by finite element simulation software. The electric-field distribution of the plumb line and the discrete integral node below the wire are analyzed. Then, based on traditional electric-field integration, a line-voltage-inversion measurement method based on near-end electric-field integration is proposed. In addition, a voltage-monitoring system based on near-end electric-field integration is constructed. Next, the numerical integration types, the number of integration nodes, and the scale coefficient of the near-end region of the inversion algorithm are optimized with the electric-field simulation data. Finally, to verify the voltage-inversion method proposed in this paper, a test platform for overhead-line voltage is constructed using a MEMS electric-field sensor. The results indicate that the voltage-inversion error is 5.75%. The research results will provide theoretical guidance for non-intrusive voltage-inversion measurement of overhead lines.
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Wang, Man, Tianhong Zhou e Jie Shen. "Development of low power and high voltage RF signal generator". Journal of Physics: Conference Series 2387, n. 1 (1 novembre 2022): 012014. http://dx.doi.org/10.1088/1742-6596/2387/1/012014.
Abstract (sommario):
Abstract Ion confinement technology can be widely used in quantum computation and precision measurement. In ion trapping system, ions are stably trapped in ion trap by the action of external forces.Multi-ion confinement requires the joint action of electric field and magnetic field to make the trapped ions overcome the interaction force between ions and be stably confined in the same specific space. Therefore, the stability of the electric force and the magnetic force determines the stability of ion confinement. Although the electric field and magnetic field provided by traditional commercial instruments is stable, it is not conducive to the miniaturization of the device. According to the previous experiment of ion confinement, we have designed a radio frequency(RF) signal generator that can provide continuous low power and stable high voltage RF electric field for multi-ion confinement system to guarantee the stability of trapped ions in quadrupole linear ion trap, also to improve the tapped ions density.
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Jörgens, Christoph, e Markus Clemens. "Modeling the electric field at interfaces and surfaces in high-voltage cable systems". COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 39, n. 5 (8 maggio 2020): 1099–111. http://dx.doi.org/10.1108/compel-01-2020-0041.
Abstract (sommario):
Purpose In high-voltage direct current (HVDC) cable systems, space charges accumulate because of the constant applied voltage and the nonlinear electric conductivity of the insulating material. The change in the charge distribution results in a slowly time-varying electric field. Space charges accumulate within the insulation bulk and at interfaces. With an operation time of several years of HVDC systems, typically the stationary electric field is of interest. The purpose of this study is to investigate the influence of interfaces on the stationary electric field stress and space charge density. Design/methodology/approach An analytic description of the stationary electric field inside cable insulation is developed and numerical simulations of a cable joint geometry are applied, considering spatial variations of the conductivity in the vicinity of the electrodes and interfaces. Findings With increasing conductivity values toward the electrodes, the resulting field stress decreases, whereas a decreasing conductivity results in an increasing electric field. The increased electric field may cause partial discharge, resulting in accelerated aging of the insulation material. Thus, interfaces and surfaces are characterized as critical areas for the reliability of HVDC cable systems. Research limitations/implications This study is restricted to stationary electric field and temperature distributions. The electric field variations during a polarity reversal or a time-varying temperature may result in an increased electric conductivity and electric field at interfaces and surfaces. Originality/value An analytical description of the electric field, considering surface effects, is developed. The used conductivity model is applicable for cable and cable-joint insulations, where homo- and hetero-charge effects are simulated. These simulations compare well against measurements.