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Calculation of Photo-Ionisation Cross Sections and Radiative Recombination Rate Coefficients for CO and CO^+ Molecules

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plasma Science and Technology 2014年第11期16卷 1013-1019页

作者： Raja dHOUIOUI Philippe TEULet Yann CRESSAULT Hassen GHALILA Riadh RIAHI Nejm Eddine JAIdANE Zohra BEN LAKHdAR Université de Toulouse UPSINPTLAPLACE(Laboratoire Plasma et Conversion d'Energie)118 route de NarbonneF-31062 Toulouse cedex 9France laboratoire de Spectroscopic Atomique Moléculaire et Applications(LSAMA)Faculté des Sciences de TunisUniversité de Tunis el Manar1060 TunisTunisia

A method based upon the weighted total cross section （WTCS） theory is proposed to calculate the photo-ionisation cross sections and the radiative recombination rate coefficients between the fundamental level of CO and the main electronic states of its corresponding ion. Total photo-ionisation cross sections and radiative recombination rate coefficients are determined from the calculation of elementary vibrational photo-ionisation cross sections. Transitions be- tween CO＋（X, A and B） and CO（X） are considered. Total photo-ionisation cross sections and recombination coefficients are computed in the temperature interval 500-15000 K.

关键词： CO photo-ionisation cross sections radiative recombination rate coefficients

Charge vibration behaviour in polyimide under the pulse voltage with different rise and fall times

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High Voltage 2022年第1期7卷 64-74页

作者： Tao Zhang dongxin He Junyu Wei Hongshun Liu Qingquan Li Gilbert Teyssedre Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment School of Electrical Engineering Shandong UniversityJinanChina UPS INPTCNRSLAPLACE(Laboratoire Plasma et Conversion d’Energie)University of ToulouseToulouseFrance

High‐voltage electronic equipment is widely used in power systems,which normally operate under the pulse voltage ***,compared to dC or AC stress,the electrical insulation suffers a more severe ageing process under a pulse voltage with steep edges and so may cause electrical equipments to fail *** charge behaviour in polyimide under the pulse voltage with different edge times was investigated in this *** experimental results show that charges vibrate at the pulse edge,while the amplitude of charge vibration increases with decreasing edge ***,the detected vibration signal is strong within the nanosecond edge times,while being negligible in the microsecond ***,the amplitude of charge vibration at the falling edge is larger than that at the rising edge in the presence of the column‐plate *** is believed that the resultant force acting on the charge increases drasti-cally at the pulse edges,leading to the charge movement and the generation of ultra-sonic waves,with the resultant force becoming larger when the edge times *** vibration behaviour is harmful to the microstructure of insulation materials,and so it may be concluded that the rise and fall times of the pulse voltage play an important role in insulation failure.

关键词： pulse behaviour insulation

Behaviour and mechanisms of molecular vibrations induced by a pulsed voltage in a silicone elastomer used for device encapsulation

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High Voltage 2023年第5期8卷 1020-1029页

作者： Junyu Wei dongxin He Teng Gao Lin Zhu Haochen Wang Qingquan Li Gilbert Teyssedre Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment School of Electrical Engineering Shandong UniversityJinanChina School of Materials Science and Engineering Shandong UniversityJinanChina UPS INPTCNRSLAPLACE(Laboratoire Plasma et Conversion d’Energie)University of ToulouseToulouseFrance

Silicone elastomers are widely used to encapsulate power electronic ***,such devices may be subjected to square‐wave pulsed voltages with a high rate of change,which can create significant challenges for encapsulation *** this article,the molecular vibration of silicon elastomer at the edge of pulsed electric field is ***,the relationship between the intensity of molecular vibration and the parameters of pulsed electric field is *** experimental results show that the amplitude of the vibrations decreases as the pulse‐edge time increases,and it increases linearly as the pulseedge slope ***,the amplitude of the vibrations is proportional to the square of the amplitude of the pulsed electric field,and it increases as the space charge density ***,the force analysis of charged molecule at the pulse edges is calculated,and the theoretical change law of molecular vibration intensity with pulse edge slope is *** the theoretical results with the experimental results,it is found that they are highly ***,electrically induced mechanical stress caused by molecular vibration was shown to be an important factor in insulation failure.

关键词： pulsed insulation vibrations

A passive optical fibre sensor based on Fabry-Perot interferometry for bipolar electrostatic monitoring of insulating dielectrics

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High Voltage 2023年第4期8卷 682-689页

作者： Jiawei Zhang Zifan Ye Li Wang Zelei Zhang Fan Xu Weichen dang Takao Matsumoto Sombel diaham Chatchai Putson School of Electrical Engineering Xi'an University of TechnologyXi'anShaanxiChina Universitéde Toulouse UPSINPTLAPLACE(Laboratoire Plasma et Conversion d'Energie)Toulouse Cedex 9France Materials Physics Laboratory Department of PhysicsFaculty of SciencePrince of Songkla University(PSU)SongkhlaThailand

The measurement of the surface charge on the insulating dielectrics is critical to estimate the insulation strength of electrical equipment in *** interactions with the electromagnetic field,however,generally result in distortion measurement of active ***,it is of great significance to investigate a passive sensor for monitoring the deposited ***,a passive optical fibre electrostatic sensor is developed on the principle of Fabry–Perot interference to quantify the surface potential of the insulating *** sensitivity of quantifying the electrostatic charge is explored in terms of the wavelength shift in the interference spectrum,and the linear correlation is ***,the sensor can identify a negative quadratic trend with the increase of the surface roughness of the insulating *** merits of the proposed sensor such as passive monitoring,bipolar electrostatic detection,and the excellent ability of antielectromagnetic interference are highlighted in the ***,this sensor can serve as an effective tool to monitor the electrostatic charge in the fields of smart electrical equipment,fuel transportation,aerospace,integrate circuit etc.

关键词： electrostatic passive fibre

degradation of PAI/PEI Enamel under High Temperature (Up to 400°C)

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Materials Sciences and Applications 2022年第1期13卷 1-21页

作者： Fabrice Aymonino Thierry Lebey david Malec dominique Mary laboratoire plasma et conversion d’Energie (LAPLACE) Université de Toulouse Toulouse France

This work deals with the understanding of the degradation of the primary insulation (PEI/PAI) of rotating machines working temporarily under high-temperature. The main domain of application of these motors is the smoke extraction either from tunnels or underground parking when a fire occurs. In such a critical situation, the internal temperature of the motor winding may reach temperatures up to 400°C. Under such very high thermal stresses, the behaviour of the electrical insulation is not well understood. This work proposes an analysis of the decomposition gases under very high temperatures and the corresponding degradation pathway. A simple method is proposed to identify whether the insulation of such motors has been strongly damaged during the working time at very high temperatures, thus allowing estimating if it can still continue to operate.

关键词： Polyesterimide (PEI) Polyamide-Imide (PAI) Enamel Electrical Insulation Rotating Machine High Temperature Thermal degradation

Simulation of Space Charge Impact on Partial discharge Inception Voltage in Power Busbars dedicated to Future Hybrid Aircrafts

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Circuits and Systems 2018年第11期9卷 196-212页

作者： Mallys Elliazar Banda david Malec Jean-Pascal Cambronne laboratoire de plasma et conversion d’Energie Université de Toulouse-CNRS-INPT-UPS France

Reducing greenhouse gases, saving energy resources and mass optimization require technological changes towards increasingly electric vehicles. At the same time, performance improvement of semiconductor and dielectric materials further promotes electronic components confinement, resulting in a significant increase of embedded power densities. In the particular case of future hybrid propulsion aircrafts, electrical power that intended to supply reactors would be converted through power electronics components mounted on power busbars and insulated by solid dielectrics materials. These dielectrics materials have to respond to various electrical constraints of use (HVdC), in spite of environment change of aircraft parameters such as low pressure, temperature and thermal cycles, humidity... Unfortunately, partial discharges phenomenon is the most problem within electrical insulation system (EIS). Based on a topological model of power busbars designed for power converters dedicated to hybrid aircraft, partial discharge studies were conducted by simulation in various charging conditions of a PTFE insulator. Simulation results, which focus on electric field thresholds criteria of partial discharge inception voltage in air, reveal a net sensitivity of a space charge accumulation and distribution on dielectrics behaviour even for low space charge density, depending on their location in dielectrics. Compared to the behaviour observed with implanted homocharges, when by increasing homocharges density from 0.5 C/m3 to 2 C/m3 we observe a decrease of electric field by 450%, simulation results show a highest risk of partial discharge inception when heterocharges are accumulated inside dielectrics. Their accumulation increases the electric field in triple points beyond electric field thresholds of partial discharge inception in air. The simulated electric field reaching 22 kV/mm with only 2 C/m3 of heterocharges density accumulated in dielectric/busbars interfaces.

关键词： Simulation Partial discharge Space Charge Power Busbars Hybrid Aircraft

Simulation of Ultrasonic Propagation in Transformers within Thermal Fields and Intelligent Methodology for Hot-spot Temperature Recognition

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Chinese Journal of Electrical Engineering 2024年第1期10卷 35-47页

作者： dongxin He dechao Yang Xinhua Guo Jiefeng Liu Haoxin Guo Qingquan Li Gilbert Teyssedre School of Electrical Engineering Shandong UniversityJinan 250061China School of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan 430070China School of Electrical Engineering Guangxi UniversityGuangxi 530004China UPS INPTCNRSLAPLACE(Laboratoire Plasma et Conversion d’Energie)University of ToulouseToulouse 31100France

Hot-spot temperature of transformer windings is a crucial indicator of internal ***,current methods for measuring the hot-spot temperature of transformers do not apply to those already in operation and suffer from data *** study introduces a novel inversion method that combines ultrasonic sensing technology,multiphysics simulation,and the K-nearest neighbors *** the penetrative ability and temperature sensitivity of ultrasonic sensing,a detailed physical field simulation model was *** study extensively investigates the characteristics of ultrasonic wave signals inside *** investigation includes different temperature fields,ranging from 40℃ to 110℃ at 10℃ intervals,and various ultrasonic wave emitter *** extracting the key features of the acoustic signals,such as the peak time,propagation time,and peak amplitude,an accurate inversion of the winding hot-spot temperature is successfully *** results demonstrate that this method achieves a high accuracy rate(98.57%)in inverting the internal winding hot-spot temperatures of transformers,offering an efficient and reliable new approach for measuring winding hot-spot temperatures.

关键词： Ultrasonic temperature measurement non-destructive testing oil-immersed transformers machine learning

Synthesis of (B-C-N) Nanomaterials by Arc discharge Using Heterogeneous Anodes

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plasma Science and Technology 2016年第5期18卷 465-468页

作者： djamel Eddine GOURARI Manitra RAZAFINIMANANA Marc MONTHIOUX Raul ARENAL Flavien VALENSI Sebastien JOULIE Virginie SERIN LAPLACE (laboratoire plasma et conversion d'Energie) CNRS-INPT-Universite Toulouse III 118 Route de Narbonne 31062 Toulouse Cedex 9 France CEMES (Centre d'Elaboration des Materiaux et d'etudes Structurales) CNRS-Universite Toulouse III 29 rue Jeanne Marvig F-31055 Toulouse Cedex 4 France Instituto de Nanociencia de Aragon (INA) Universidad de Zaragoza Calle Mariano Esquillor 50018 Zaragoza Spain

In spite of the current prevalence of the CVd-based processes, the electric arc remains an interesting process for the synthesis of carbon nanoforms, thanks to its versatility, robustness and easiness. It also allows performing in-situ substitution of carbon atoms by hetero-elements in the graphene lattice. Our work aims to establish a correlation between the plasma properties, type and chemical composition （and the substitution rate） of the obtained single-wall carbon nan- otubes. The plasma was characterized by optical emission spectroscopy and the products were analyzed by high resolution transmission electron microscopy and core level Electron Energy-Loss Spectroscopy （EELS）. Results show that a high boron content leads to a plasma temperature decrease and hinders the formation of nanotubes. This effect can be compensated by increasing the arc current and/or yttrium content. The optimal conditions for the synthesis of boron- and/or nitrogen-substituted nanotubes correspond to a high axial plasma temperature associated to a strong radial gradient. EELS analysis confirmed that the boron incorporates into the graphenic lattice.

关键词： arc discharge plasma nanomaterials synthesis optical spectroscopy boronnitride doped carbon nanotubes HRTEM EELS

Space charge behaviors in cable insulation under a direct current‐superimposed pulsed electric field

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High Voltage 2021年第3期6卷 426-434页

作者： dongxin He Tao Zhang Fansong Meng Qingquan Li Wei Wang Hongshun Liu Gilbert Teyssedre Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment School of Electrical Engineering Shandong UniversityJinanChina Beijing Key Laboratory of High Voltage&Electromagnetic Compatibility North China Electric Power UniversityBeijingChina LAPLACE(laboratoire plasma et conversion d'Energie) UPSINPTCNRSUniversity of ToulouseToulouseFrance

When high‐voltage direct current(HVdC)cables are subjected to a direct current(dC)‐superimposed pulsed electric stress,the pulsed voltage applied facilitates electrical tree generation and breakdown;however,the mechanism involved remains *** study the deterioration mechanism of cable insulation under a pulsed electric field,an experi-ment on the dynamic characteristics of space charge under a dC‐superimposed pulsed electric field was *** this experiment,a pulsed time trigger control circuit was developed to accurately measure the change law of the space charge in cross‐linked polyethylene samples at the rising and falling edges of the pulsed electric *** experimental results showed an unusual change law:the space charge density increases with falling voltage amplitude and decreases with rising voltage *** sudden change in the electric field breaks the balance of the forces acting on the space charge,leading to injection,extraction and *** energy released during these dynamic processes may destroy the microstructure of the insulation material and contributes to the growth of the electrical *** study provides an insight on the initiation mechanism of electrical tree in HVdC cables and proposes a strategy to suppress electrical tree initiation.

关键词： insulation charge field