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The effect of pulse voltage rise rate on the polypropylene surface hydrophilic modification by ns pulsed nitrogen DBD

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Plasma Science and Technology 2023年第10期25卷 6-14页

作者：刘峰李舒豪赵昱雷 shakeel akram 张丽方志 College of Electrical Engineering and Control Science Nanjing Tech UniversityNanjing 211816People's Republic of China

The nanosecond(ns) pulsed nitrogen dielectric barrier discharge(DBD) is employed to enhance the hydrophilicity of polypropylene(PP) surface and improve its application *** discharge characteristics of the ns pulsed nitrogen DBD with different pulse rise times(from 50to 500 ns) are investigated by electrical and optical diagnostic methods and the discharge uniformity is quantitatively analyzed by image processing *** characterize the surface hydrophilicity,the water contact angle(WCA) is measured,and the physical morphology and chemical composition of PP before and after modification are analyzed to explore the effect of plasma on PP *** is found that with increasing pulse rise time from 50 to 500 ns,DBD uniformity becomes worse,energy efficiency decreases from 20% to 10.8%,and electron density decrease from 6.6 × 10^(11)to 5.5 × 10^(11)cm^(-3).The tendency of electron temperature is characterized with the intensity ratio of N_(2)/N_(2)^(+)emission spectrum,which decreases from 17.4 to15.9 indicating the decreasing of T_(e) with increasing pulse rise time from 50 to 500 *** PP surface treated with 50 ns pulse rise time DBD has a lower WCA(~47°),while the WCA of PP treated with 100 to 500 ns pulse rise time DBD expands gradually(~50°–57°).According to the study of the fixed-point WCA values,the DBD-treated PP surface has superior uniformity under50 ns pulse rise time(3° variation) than under 300 ns pulse rise time(8° variation).After DBD treatment,the increased surface roughness from 2.0 to 9.8 nm and hydrophilic oxygencontaining groups on the surface,***(-OH) and carbonyl(C=O) have played the significant role to improve the sample’s surface *** short pulse voltage rise time enhances the reduced electric field strength(E/n) in the discharge space and improves the discharge uniformity,which makes relatively sufficient physical and chemical reactions have taken place on the PP surface,resulting in better treatment uniformit

关键词： dielectric barrier discharge pulse rise time material surface modification polypropylene uniformity

Improving the polarisation and depolarisation current measuring method to avoid ground wire interference

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High Voltage 2022年第5期7卷 847-855页

作者： Fan Yang Kai Zhou shakeel akram Muhammad Tariq Nazir School of Electrical Engineering and Electronic Information Xihua UniversityChengduChina College of Electrical Engineering Sichuan UniversityChengduSichuanChina School of Electrical Engineering and Telecommunications University of New South WalesSydneyNew South WalesAustralia

The ground wire is significantly interfered by the current above 1μA in the industrial field during the traditional polarisation and depolarisation current(PDC)*** paper explains a method to test PDC from high-voltage wire using a principle of equipotential picoammeter,which is completely isolated from the ground wire and connected in series with the high voltage *** this method,a device is designed with a multi-range automatic switching *** device can automatically switch the test range current from 1 pA to 10 mA with a resolution of 1 *** demonstrate the device and effectiveness of this new method,the traditional and the proposed new device are used to test the PDC of cable samples in the laboratory as well as in an industrial *** is worth noting that there is almost no interference on the Earth wire in the laboratory environment but massive interference in the industrial environment using a traditional method of PDC measurement from ground or Earth *** new method of high-voltage testing can efficiently eliminate the interference and accurately measure PDC in a strong industrial interference ***,the wiring of this new method and device is relatively simple,which is convenient for industrial applications.

关键词： ground polar method

Significantly enhanced flashover voltage of epoxy in vacuum by graded surface roughness modification

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High Voltage 2023年第5期8卷 997-1010页

作者： Inzamam Ul Haq Feipeng Wang shakeel akram Muneeb Ahmed Muhammad Tariq Nazir State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqingChina College of Electrical Engineering and Control Science Nanjing Tech UniversityNanjingChina State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anChina School of Engineering RMIT UniversityMelbourneVictoriaAustralia

The flashover strength of epoxy(EP)insulations in the High voltage direct current applications of future energy grids can be improved by tailoring their surface *** work aims to improve the DC surface flashover characteristics of EP after being treated with sandpaper of different *** with virgin EP and homogenously modified EP considering varying surface roughness(R_(a)=0.54,3.16,5.24,and 8.35μm)are *** experimental characterisations,such as water contact angle,surface intrinsic conductivity,surface voltages,flashover strength,and trap distributions are conducted and evaluated to analyse the difference between virgin and treated ***,based on the obtained experimental results of homogenously treated EP and theoretical analysis,the concept of surface functionally graded materials(SFGMs)is put *** flashover voltages of homogenously treated EP are augmented significantly compared to virgin EP regardless of the voltage polarity and enhanced by enhancing the surface *** sample T_(Model‐C) with SFGM design shows a 45.02%and 43.75%improvement in the negative and positive flashover voltages than that of the virgin *** the end,COMSOL simulations are conducted to justify the experimental findings and to analyse the difference between virgin and modified samples in terms of electric field distribution.

关键词： flash graded roughness

Pulse width modulation voltage source deadtime effect on partial discharge and lifetime of inverter‐fed motor insulation

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High Voltage 2022年第6期7卷 1185-1193页

作者： shakeel akram Peng Wang Pengfei Meng Gian Carlo Montanari Farhan Hameed Malik College of Electrical Engineering Sichuan UniversityChengduChina Center for Advanced Power Systems Florida State UniversityTallahasseeFloridaUSA Department of Electromechanical Engineering Abu Dhabi PolytechnicAbu DhabiUnited Arab Emirates

This paper analyses the impact of square wave pulse voltage deadtime on the partial discharge(PD)and the lifetime of turn-to-turn insulation.A bipolar repetitive pulse voltage with a deadtime of 0–10μs is produced using double half-bridge solid-state switches having push–pull technology controlled by a field-programmable gate *** mechanism of the discharge process at rising and falling edges of the pulse voltage before and after deadtime is analysed in *** discharge amplitude and PD probability at the rising/falling edges of the voltage waveform increase as the deadtime increases from 0 to 10μs due to the remanent *** number of PD and their intensity is higher at the first rising/falling edges of pulse voltage as compared to the second rising/falling edges for all deadtimes 0–10μ*** the deadtime increases beyond 2μs,the number of PDs increases and concentrates at a specific phase angle of rising/falling *** localise discharges degrade the insulation material and reduce its *** study helps to identify the inverter-fed motor insulation faults due to *** can provide guidelines to motor insulation designers to determine the limit value of deadtime to compensate PD and ensure the safer operation of such motors.

关键词： dead insulation inverter

Hydrogen evolution and electromigration in the corrosion of aluminium metal sheath inside high‐voltage cables

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High Voltage 2022年第2期7卷 260-268页

作者： Yidong Chen Kai Zhou Jiamin Kong shakeel akram Xiancheng Ren Xiaoshan Zhang Yuan Li Qi Zhao College of Electrical Engineering Sichuan UniversityChengduChina College of Polymer Science and Engineering Sichuan UniversityChengduChina College of Materials Science and Engineering Sichuan UniversityChengduChina

The urgent need for power transmission is the reason for leading research on the safer operation of high‐voltage *** high‐voltage cables are emerging as an efficient technology for underground power ***,the electrochemical corrosion of aluminium(Al)metal sheaths in these cables is a common and challenging degradation ***,the corrosion mechanisms and electrochemical analysis are investigated by using scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),electrochemical impedance spectroscopy(EIS)and laboratory‐designed electro-chemical characterisation *** the corrosion experiments,the authors evaluated the corrosion rate by measuring the release rate of hydrogen gas and explored the different roles of sodium polyacrylate(NaPA)during the corrosion *** is found that the complexation reactions between NaPA and Al inhibited corrosion while increased the resistance of the buffer *** proposed mechanisms of corrosion in this study can improve the lifespan and sustainability of high‐voltage power transmission.

关键词： corrosion process. electrochemical

Physical,Thermal and Partial Discharge Evaluation of Nano Alumina Filled Silicone Rubber in an Inclined Plane Test

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CSEE Journal of Power and Energy Systems 2022年第4期8卷 1242-1249页

作者： M.Tariq Nazir Faizan Tahir Butt Haider Hussain B.Toan Phung shakeel akram M.Shoaib Bhutta Ghulam Yasin School of Engineering RMIT UniversityMelbourneVIC 3000Australiaand the School of Mechanical and Manufacturing EngineeringUniversity of New South Wales SydneyNSW 2052Australia School of Electrical Engineering and Telecommunications University of New South Wales SydneyNSW 2052Australia Institut d'Electronique et des Systès(IES) UMR 5214CNRSUniversitéde Montpellier34095 MontpellierFrance State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing UniversityChonging 400044China State Key Laboratory of Chemical Resource Engineering College of EnergyBeijing University of Chemical TechnologyBeijing 100029China

Silicone rubber(SiR)composite material is a modern-day insulator for high voltage outdoor *** imperfection attributed to SiR is its weak resistance to tracking and erosion when exposed to an outdoor polluted environment which reduces its operational *** paper investigates the performance of SiR with the addition of 0,1,2.5,5,10 and 20%by weight contents of nano alumina(Al_(2)O_(3)).Inclined plane tests are performed according to IEC 60587 using the step up tracking voltage method with an initial voltage of 3.0 kV and the contaminant solution flow rate is maintained at 0.3 ml/min using a peristaltic *** applied voltage level is increased at a rate of 0.25 kV/*** suggest that physical tracking,erosion,RMS leakage current and surface partial discharge(PD)performance of samples is improved with the addition of nano *** tracking length,eroded mass,RMS leakage current and average PD magnitude are measured 22%,79%,30%and 52%lesser in 20 wt%relative to 0 wt%,respectively.A thermal distribution analysis is undertaken with infrared camera and it is discovered that heat is accumulated in the discharge area of the liquid *** maximum temperature on the insulating specimen is decreased with increasing nanofiller *** above promising findings can be due to better thermal stability with low chain mobility at the interaction zone of SiR and ***,less liquid evaporation due to better thermal conduction and improved physical bonding between SiR and nano alumina are possible reasons behind the excellent performance of nanocomposites.

关键词： Alumina(Al_(2)O_(3)) dry band arcing(DBA) inclined plane test(IPT) infrared thermal analysis leakage current partial discharge(PD) silicone rubber(SiR) thermal properties

Electrical Tracking,Erosion and Fire Retardancy Performance of Silicone Rubber Insulation Containing Aluminum Trihydrate,Graphene and Glass Fiber Additives

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CSEE Journal of Power and Energy Systems 2023年第5期9卷 1918-1925页

作者： M.Tariq Nazir Arslan Khalid B.Toan Phung Arup K.Das Peter Cheetham Ashish Paramane shakeel akram Khoi Loon Wong School of Engineering RMIT UniversityMelbourneVIC 3000Australia. the Center for Advanced Power Systems(CAPS) Florida State UniversityFL 32310USA the Flame Security International Pty Limited Australia the School of Electrical Engineering and Telecommunications University of New South Wales SydneyNSW 2052Australia Department of Electrical Engineering National Institute of TechnologySilcharAssam 788010India the College of Electrical Engineering and Control Science Nanjing Tech UniversityNanjingJiangsu 211816China

Silicone rubber composite is a priority electrical insulating material used in high-voltage outdoor insulation *** electrical tracking/erosion and poor flame resistance performance of silicone rubber once ignited,substantially reduce its working *** paper attempts to investigate tracking/erosion performance of room temperature vulcanized(RTV)silicone rubber along with flame retardant parameters using aluminum trihydrate(ATH),graphene nanosheets(GN)and milled glass fiber(GF)*** inclined plane test(IPT)was performed in line with criteria defined in IEC 60587 using step-up tracking voltage method while flame retardancy is evaluated according to ASTM E 1354.0 using a cone *** suggest 30% of ATH assists in improving physical tracking/erosion resistance of pristine silicone elastomer rubber by impeding development of leakage current and a great reduction in maximum average temperatures on the surface of *** improvement in performance of RTV2 is achieved through introduction of 1%of GN and 5% of GF as seen in ***,30% of ATH reduces heat release rate and smoke production rate,and this trend is improved with the introduction of GN/***4 has pop up as the most promising silicone rubber composite with excellent electrical tracking,erosion,and flame resistance performance relative to its counterparts in this study.

关键词： Dry band arcing electrical tracking heat release rate leakage current silicone rubber smoke production rate

纳米氮化铝改性对芳纶1313绝缘纸介电特性的影响

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高电压技术 2015年第2期41卷 461-467页

作者：柏舸廖瑞金刘娜柳海滨杨丽君 shakeel akram 重庆大学输配电装备及系统安全与新技术国家重点实验室重庆400030 重庆城市管理职业学院重庆401331

聚合物纳米复合材料因其优良的介电性能在电介质绝缘领域得到了广泛的应用。为获得性能优良的绝缘纸,将纳米氮化铝(AlN)添加到芳纶1313中。将改性后的绝缘纸进行浸油处理,研究了AlN对油浸芳纶1313介电性能的影响。结果表明:纳米Al N能... 详细信息

聚合物纳米复合材料因其优良的介电性能在电介质绝缘领域得到了广泛的应用。为获得性能优良的绝缘纸,将纳米氮化铝(AlN)添加到芳纶1313中。将改性后的绝缘纸进行浸油处理,研究了AlN对油浸芳纶1313介电性能的影响。结果表明:纳米Al N能有效降低绝缘纸的电导电流,以及提升其交流击穿电场强度;同时Al N能够抑制空间电荷向介质内的注入、迁移和积聚,使绝缘纸内空间电荷分布更加均匀。另外聚合物纳米材料的界面特性使得改性后绝缘纸的相对介电常数和介电损耗值有所升高,介损松弛峰值也向低频段移动。芳纶1313/Al N油浸绝缘纸介电性能的变化归因于纳米粒子与聚合物之间的界面效应使界面区域陷阱浓度和深度增大,限制了电荷的运动。

关键词：芳纶1313 氮化铝空间电荷介电特性抗张强度击穿电场强度

高压电缆阻水缓冲层的白斑现象及析氢腐蚀机理

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中国电机工程学报 2023年第12期43卷 4830-4839页

作者：陈熠东周凯雷清泉任显诚孔佳民李原赵琦李泽瑞 shakeel akram 四川大学电气工程学院四川省成都市610065 四川大学高分子科学与工程学院四川省成都市610065

近年来,高压电缆中的电化学腐蚀诱发了多起本体击穿故障,造成了重大的经济损失。这种故障的特点是击穿的电缆中的缓冲层上有明显的白斑,然而,产生这种故障的机理尚未明确。针对这一问题,该文研究不同样本中白斑的成分,并用电化学手段定... 详细信息

近年来,高压电缆中的电化学腐蚀诱发了多起本体击穿故障,造成了重大的经济损失。这种故障的特点是击穿的电缆中的缓冲层上有明显的白斑,然而,产生这种故障的机理尚未明确。针对这一问题,该文研究不同样本中白斑的成分,并用电化学手段定量分析白斑产生的过程,并研究白斑产生的电化学机理。首先,通过红外光谱(Fourier transform infrared spectroscopy,FTIR)、X射线能谱(energy dispersive spectrometer, EDS)和扫描电子显微镜(scanning electron microscope,SEM)分析事故现场白斑的化学成分和形貌。随后,在实验室培养了白斑,分析其化学成分,并把结果与事故现场的分析结果进行对比。通过对比FTIR和EDS结果可以发现,故障电缆和实验室培养的白斑的主要成分都是氢氧化铝,根据相应的电化学反应方程,可认为这是一种在交流电场下的析氢腐蚀现象。通过对腐蚀副产物氢气的浓度检测,水分、电流密度和是否含有阻水粉等会影响腐蚀速率。根据电化学分析,聚丙烯酸钠在腐蚀初期吸收水分,加速了腐蚀;而在腐蚀过程中,其与铝离子络合形成不吸水的络合物,反而抑制了腐蚀,但增加了缓冲层的电阻率,这可能会导致局部过热。最后提出了白斑产生的电化学机理,该研究可为高压电缆的腐蚀检测和新的缓冲层设计提供理论依据。

关键词：高压电缆缓冲层腐蚀析氢阻水