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Void discharge behaviours as a function of cavity size and voltage waveform under very low-frequency excitation

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High Voltage 2018年第2期3卷 96-102页

作者： Hong Viet Phuong Nguyen bao toan phung School of Electrical Engineering and Telecommunications University of New South WalesSydneyAustralia Faculty of Electrical Engineering The University of Danang-University of Science and TechnologyDanangVietnam

Measurement of partial discharge(PD)is a vital method to assess the health of the electrical insulation in high-voltage power *** diagnostic testing at very low frequency(VLF)is increasingly being used,it is important to investigate PD behaviours under such a low-frequency voltage *** study presents the PD characteristics at VLF excitation under different applied voltage waveforms,including sinusoidal and trapezoid-based ***,the effects of cavity size on PD behaviours at VLF are *** were performed to measure PDs in a cylindrical void bounded by solid *** results show that discharge activities at VLF,in general,exhibit lower magnitude and repetition rate when compared with power *** revealed is the strong dependency of discharge parameters on the rate of voltage *** mechanisms to explain discharge behaviours are given.

关键词： excitation cavity size

Tracking,erosion and thermal distribution of micro-AlN+nano-SiO_(2) co-filled silicone rubber for high-voltage outdoor insulation

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High Voltage 2018年第4期3卷 289-294页

作者： Muhammad Tariq Nazir bao toan phung Shihu Yu Yuanyuan Zhang Shengtao Li School of Electrical Engineering and Telecommunications University of New South Wales SydneyAustralia State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anPeople's Republic of China

Thermal depolymerisation induced tracking and erosion of polymeric insulators is one of the key insulation failure modes and this process adversely affects the reliability of power delivery *** study reports the tracking,erosion and thermal distribution of micron-AlN and micron-AlN+nano-SiO_(2)co-filled silicone rubber composites.A tracking-erosion model is presented to explain how the co-filled set of particles directly affects such *** nitride(AlN:5-10μm)and silica(SiO_(2):20 nm)particles were procured for fabricating test *** inclined plane test according to IEC 60587 was carried out using tracking voltage method 2 with an initial applied voltage of 3 kV and a ramping rate of 0.25 kV/h over the duration of 240 *** results show co-filled composites exhibit significantly lower physical tracking and erosion as compared to micron-AlN filled *** accumulation and average leakage current in co-filled composites are found noticeably lower than micron-filled ***,the increased surface area of the combined co-filled particles in the composites provides better scattering and reduce secondary electron *** may impede the release of high energy causing thermal degradation.

关键词： composites filled rubber

Transformer components impact on compatibility of measured PDs:comparison of IEC60270 and RF methods

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High Voltage 2019年第1期4卷 33-40页

作者： Keyvan Firuzi Mehdi Vakilian B.toan phung Trevor Blackburn Electrical Engineering Department and Centre of Excellence in Power System Management and Control Sharif University of TechnologyTehranIran School of Electrical Engineering&Telecommunications University of New South WalesSydneyAustralia

Power transformer partial discharge signal measurement using Radio Frequency method has advantages over IEC 60270‘apparent charge’measurement method for online monitoring due to greater immunity against external ***,the lack of a well-defined calibration relationship between the two methods is main disadvantage of RF *** measurements,using these two methods,carried out on various transformer PD source models,in laboratory,to investigate main parameters that affect the relationship of results of these two *** this paper,factors that influence this relationship are classified into three groups:(i)type of PD sources,(ii)transformer windings as PD signal transmitter,and(iii)the inner structure of the ***,the relationship between these two methods has been investigated for some simple types of PD ***,by adding the winding structure model to the void,which is the PD source,its impact on each measurement method and the relationship between them have been *** impact of inner structure on the relation between the two methods is compensated through a formula which is proposed as a means for calibration of the RF partial discharge measurement *** to compensate for internal insulating system effects more research is required.

关键词： winding disadvantage adding

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

Ecoregional variations of aboveground biomass and stand structure in evergreen broadleaved forests

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Journal of Forestry Research 2020年第5期31卷 1713-1722页

作者： Tran Van Do Mamoru Yamamoto Osamu Kozan Vo Dai Hai phung Dinh Trung Nguyen toan Thang Lai Thanh Hai Vu Thanh Nam Trieu Thai Hung Hoang Van Thang Tran Duc Manh Cao Chi Khiem Vu Tien Lam Nguyen Quang Hung Tran Hoang Quy Pham Quang Tuyen Trinh Ngoc Bon Nguyen Thi Thu Phuong Ninh Viet Khuong Nguyen Van Tuan Dang Thi Hai Ha Tran Hai Long Dang Van Thuyet Dang Thinh Trieu Nguyen Van Thinh Tran Anh Hai Duong Quang Trung Nguyen Van Bich Dinh Hai Dang Pham Tien Dung Nguyen Huy Hoang Le Thi Hanh Phan Minh Quang Nguyen Thi Thuy Huong Hoang Thanh Son Nguyen Thanh Son Nguyen Thi Van Anh Nguyen Thi Hoai Anh Pham Dinh Sam Hoang Thi Nhung Hoang Van Thanh Nguyen Huu Thinh Tran Hong Van Ho Trung Luong Bui Kieu Hung Research Institute for Sustainable Humanosphere Kyoto UniversityUjiKyotoJapan Silviculture Research Institute Vietnamese Academy of Forest SciencesNorth Tu LiemHanoiVietnam Center for Southeast Asian Studies Kyoto UniversityKyotoJapan Vietnamese Academy of Forest Sciences North Tu LiemHanoiVietnam Vietnam Administration of Forestry No.2 Ngoc HaBa DinhHanoiVietnam

Biotic and abiotic factors control aboveground biomass(AGB)and the structure of forest *** study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam.A data set of 1731-ha plots from 52 locations in undisturbed old-growth forests was *** results indicate that basal area and AGB are closely correlated with annual precipitation,but not with annual temperature,evaporation or hours of *** area and AGB are positively correlated with trees>30 cm *** areas surveyed(52.6%)in these old-growth forests had AGB of 100–200 Mg ha^-1;5.2%had AGB of 400–500 Mg ha^-1,and 0.6%had AGB of>800 Mg ha^-*** percent of the areas surveyed had stand densities of 300–600 ***^-1,and 64%had basal areas of 20–40 m^2 ha^-*** is an important factor influencing the AGB of old-growth,evergreen broadleaved forests in *** causing the loss of large-diameter trees(e.g.,>100 cm DBH)affects AGB but may not seriously affect stand density.

关键词： Aboveground biomass Carbon storage Climatic variables Ecoregion Edaphic variables Oldgrowth forest

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夏黑葡萄在越南北部栽培表现及其技术要点

南方园艺 2019年第6期30卷 34-37页

作者：黄江流 DO THANH TRUNG 唐其展吕荣华 NGUYEN TUAN DIEP CAN VAN toan NGUYEN CONG THANH phung DUY HIEU BUI THI THU TRANG 黄竟刘淑仪黄芳颖梁芳黄勇策黄克顺广西农业科学院葡萄与葡萄酒研究所广西南宁530007 越南北江农林科技大学越南广西农业科学院国际合作处广西南宁530007 广西无为谷生态农业科技有限公司广西南宁530008

河内、北江等越南北方地区年均温比广西南宁高2℃左右,光温条件比较优越,应越方要求新引入种植比巨峰葡萄早熟优质的无核夏黑葡萄,以期调节产期,满足市场需求。采用广西夏黑葡萄当年种当年收和一年两收栽培技术管理,在越南北部地区于3... 详细信息

河内、北江等越南北方地区年均温比广西南宁高2℃左右,光温条件比较优越,应越方要求新引入种植比巨峰葡萄早熟优质的无核夏黑葡萄,以期调节产期,满足市场需求。采用广西夏黑葡萄当年种当年收和一年两收栽培技术管理,在越南北部地区于3月上旬种植夏黑葡萄,种后4个半月于7月下旬修剪促花,剪后1个月于8月下旬开花,剪后2个月于9日下旬着色,剪后3个月于10月中下旬成熟上市,从种到收获全程9个月,平均每hm^2产量8517.0 kg,实现了当年种植当年投产的目标。为越南葡萄产业增加新的经济增长点。

关键词：夏黑葡萄当年种当年投产栽培表现技术要点