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| 1 | Study of partial discharge characteristics at repetitive square voltages based on UHF method显示文摘Due to overvoltage produced by inverter output,inverter-fed motor insulation systems often experience fast electrical aging process,especially when partial discharge(PD) is incepted.Before putting into use,the PD detection should be performed on inverter-fed motors at repetitive square voltages to avoid the PD caused insulation deterioration when the motors are collected to inverters having specific characteristics.However,unlike PD tests at AC/DC voltages proposed in IEC 60270,the PD detection at repetitive square voltages is much more complex because of serious interference generated by impulse generator.To solve the problem,ultra-high frequency(UHF) method seems recommendable for its preferable signal-to-noise ratio(SNR).The chief aim of this study is to investigate PD pulse and statistical characteristics of turn-to-turn insulation for inverter-fed traction motors.A square-shaped Archimedes antenna,specially designed for the PD detection at repetitive square voltages of fast rise times,was used to perform PD tests on turn-to-turn insulation models.Time and frequency analysis results indicate that energy component of generator disturbance and PD pulses are mainly distributed in the 0-0.5 GHz and 0.6-1.5 GHz range,respectively.Based on the results,suitable filter was designed for power disturbance suppression.Additionally,resorting to the sensor unit(i.e.antenna and filter) and the PD test system,the PD statistical features at square voltages of different frequencies were obtained.Experimental results show that higher frequency will give rise,statistically,to PD of lower magnitudes distributing at smaller phases.A reasonable interpretation of this phenomenon was presented.Lastly,according to the PD statistical features,some suggestions for the PD detection system design,generator parameter optimization and the PD pulse extracting were given.The results of this work would be beneficial to the increase of the sensitivity when performing the PD detection on insulation systems for inverter-fed motors at repetitive square voltages and thus,improving the reliability of inverter-fed motors. | WANG Peng WU GuangNing GAO Bo LUO Yang CAO KaiJiang | 2013 | Science China(Technological Sciences)2013，56，1： | 15 |
| 2 | Low Frequency Dispersion Mechanism of Dielectric Response for Oil-paper Insulation Diagnosis显示文摘Both the real part and imaginary part of complex permittivity approximately have a log-linear frequency dependency at low fre- quencies, especially at ultra-low frequencies under conditions of different moisture concentrations and temperatures, which is recognized as the low frequency dispersion (LFD). In order to explain this dispersion, a new mechanism of dielectric response of LFD of oil-paper insula- tion is proposed. A simplified one-dimensional mathematical model of concentration polarization carrier caused by slow migration is developed and solved, which indicates that ion mobility is closely related to the size of gap and the adsorption capacity of cellulose molecu- lar chains to ions. A stochastic statistical model of the carrier mobility induced LFD is also developed. Moreover, actual tests under 50 °C and 2% moisture content were put forward, as well as simulations with according current waveforms. The simulation results agreed well with the experimental data in that concentration polarization of carriers caused by slow migration is the probable cause of low frequency dispersion of dielectric response for oil-paper insulation diagnosis. | ZHOU Lijun LI Xianlang WU Guangning | 2013 | 高电压技术2013，39，8： | 14 |
| 3 | Partial discharge characteristics of interturn insulation used for inverter-fed traction motor under bipolar impulses显示文摘Inverter-fed traction motors,which are employed for electric-multiple-units(EMUs),are subjected to Pulse Width Modulated(PWM) impulse voltage.Impulse voltage has fast rise/fall time and high repetition frequency.The failure mechanism of insulation under impulses is different from that of standard 50 Hz sinusoidal condition.Partial discharge(PD) characteristics(discharge number,mean discharge quantity and phase resolved partial discharge(PRPD) pattern) with different frequencies and different rise times of impulse voltage were investigated.The results reveal that discharge number and mean discharge quantity increase,while PRPD pattern moves to the zero of impulse voltage with decrease of rise time.Discharge number and PRPD pattern follow that trend with increase of frequency,the value of mean discharge quantity is similar.Memory effect of the deposited space charges on PD was studied.PRPD pattern moves to the zero of bipolar impulse voltage due to the role of space charges,with increase of frequency and decrease of rise time.It is revealed that available discharge time is prolonged and overvoltage across the cavity increases with augment of frequency,which results in discharge number increasing.Under the condition of shortening the rise time,with the same statistical time lag tL,△V would increase if dV/dt is higher,which results in enhancement of discharge quantity.Discharge number increases with reduction of rise time,because the decreased multiple of td is lower than the increased multiple of dV/dt.Study of PD characteristics and role of space charges is helpful to the exploration of the destructive mechanism of insulating materials under bipolar impulse. | WU GuangNing CAO KaiJiang LUO Yang GAO Bo WANG Peng ZHANG YiQiang XU HuiHui | 2012 | Science China(Technological Sciences)2012，55，8： | 9 |
| 4 | Genomic selection: A breakthrough technology in rice breeding显示文摘Rice(Oryza sativa)provides a staple food source for more than half the world population.However,the current pace of rice breeding in yield growth is insufficient to meet the food demand of the everincreasing global population.Genomic selection(GS)holds a great potential to accelerate breeding progress and is cost-effective via early selection before phenotypes are measured.Previous simulation and experimental studies have demonstrated the usefulness of GS in rice breeding.However,several affecting factors and limitations require careful consideration when performing GS.In this review,we summarize the major genetics and statistical factors affecting predictive performance as well as current progress in the application of GS to rice breeding.We also highlight effective strategies to increase the predictive ability of various models,including GS models incorporating functional markers,genotype by environment interactions,multiple traits,selection index,and multiple omic data.Finally,we envision that integrating GS with other advanced breeding technologies such as unmanned aerial vehicles and open-source breeding platforms will further improve the efficiency and reduce the cost of breeding. | Yang Xu Kexin Ma Yue Zhao Xin Wang Kai Zhou Guangning Yu Cheng Li Pengcheng Li Zefeng Yang Chenwu Xu Shizhong Xu | 2021 | The Crop Journal2021，9，3： | 7 |
| 5 | Characteristics of pantograph‐catenary arc under low air pressure and strong airflow显示文摘Pantograph‐catenary arc fault is the primary factor threatening the stability of the power transmission for high‐speed railway.The motion characteristics of the pantograph‐catenary arc under low air pressure and strong airflow is significantly different from the case under atmospheric pressure.In this paper,an experimental platform of panto-graph‐catenary arc was built to investigate arc root position‐time and arc column lon-gitudinal drift height‐time characteristic curves under different air pressures and airflow velocites.Via analysing the corresponding results,it can be found that there are different arc root-arc column traction mechanisms at different stages of arc development.The arcing time and arc root stagnation time under low air pressure are significantly longer than the case under atmospheric pressure,resulting in more serious electrode ablation.The arc column longitudinal drift velocity and height are greater with the increase of airflow velocity.Two typical irregular arc motion phenomena-arc root jumping and arc reignition are observed.To clarify the internal mechanism of the above phenomenon,a magnetohydrodynamics(MHD)model of the pantograph‐catenary arc was lauched,the influence mechanism of the pantograph‐catenary arc temperature and voltage are studied,and the physical process of arc temperature oscillation is analysed.The research results provide theoretical support for arc protection in high‐altitude areas. | Zhilei Xu Guoqiang Gao Wenfu Wei Zefeng Yang Wenhan Xie Keliang Dong Yaguang Ma Yan Yang Guangning Wu | 2022 | High Voltage2022，7，2： | 7 |
| 6 | Effect of repetitive square voltage frequency on partial discharge features显示文摘The inverter-fed motor is a key component of environmental-friendly hybrid cars, high-speed trains, and other industrial applications. After the widespread use of inverter-fed motors, the repetitive impulse surges from inverters were found to cause new insulation problems in inverter-fed motors that were linked to premature insulation failure. The partial discharge (PD) induced by the overvoltage inner stator windings was found to be the root cause of insulation reliability problems. To mitigate this problem, PD detection and life testing at repetitive square voltages should be performed on new types of insulation models and entire motor insulation systems. The obtained partial discharge inception voltage (PDIV) and lifetime of insulation in the tests can be used to evaluate the insulation status of inverter-fed motor insulation systems and thus to improve the insulation designs. At AC voltage conditions, the voltage frequency can significantly affect PD activity. At repetitive square voltage with rapid rise time, the influence of the square voltage frequency on PD activity should be investigated (1) to suggest values for the repetitive square voltage frequency selection for the PDIV and lifetime tests, and (2) to increase the signal-to-noise ratio when extracting PD pulses from strong disturbances generated by the operating switch of impulse generators. Therefore, the main purpose of this paper was to investigate the effects of repetitive square voltage frequency on PD events. Insulation models of both Type I (low-voltage inverter-fed motor) and Type II (high-voltage inverter-fed motor) were used to obtain single-PD and multi-PD statistical features, respectively. Experimental results indicated that higher frequencies caused less PD events with lower PD magnitudes and shorter delay times in one square voltage cycle. This phenomenon was attributed to the different surface charge decay ratios and the initial electron emission probabilities resulting from different square voltage frequencies. Finally, a number of considerations for PD measurements on inverter-fed motors were provided to improve the sensitivity of the PD test system and to obtain high objective insulation lifetime test results, which are used to assess the insulation status of inverter-fed motors. | WANG Peng WU GuangNing LUO Yang ZHU GuangYa | 2013 | Science China(Technological Sciences)2013，56，6： | 6 |
| 7 | Pantograph-catenary electrical contact system of high-speed railways:recent progress,challenges,and outlooks显示文摘As the unique power entrance,the pantograph-catenary electrical contact system maintains the efficiency and reliability of power transmission for the high-speed train.Along with the fast development of high-speed railways all over the world,some commercialized lines are built for covering the remote places under harsh environment,especially in China;these environmental elements including wind,sand,rain,thunder,ice and snow need to be considered during the design of the pantograph-catenary system.The pantograph-catenary system includes the pantograph,the contact wire and the interface—pantograph slide.As the key component,this pantograph slide plays a critical role in reliable power transmission under dynamic condition.The fundamental material characteristics of the pantograph slide and contact wire such as electrical conductivity,impact resistance,wear resistance,etc.,directly determine the sliding electrical contact performance of the pantograph-catenary system;meanwhile,different detection methods of the pantograph-catenary system are crucial for the reliability of service and maintenance.In addition,the challenges brought from extreme operational conditions are discussed,taking the Sichuan-Tibet Railway currently under construction as a special example with the high-altitude climate.The outlook for developing the ultra-high-speed train equipped with the novel pantograph-catenary system which can address the harsher operational environment is also involved.This paper has provided a comprehensive review of the high-speed railway pantograph-catenary systems,including its progress,challenges,outlooks in the history and future. | Guangning Wu Keliang Dong Zhilei Xu Song Xiao Wenfu Wei Huan Chen Jie Li Zhanglin Huang Jingwei Li Guoqiang Gao Guozheng Kang Chuanjun Tu Xingyi Huang | 2022 | Railway Engineering Science2022，30，4： | 5 |
| 8 | Evolution of the electrical contact of dynamic pantograph–catenary system显示文摘A good contact between the pantograph and catenary is critically important for the working reliability of electric trains, while the basic understanding on the electrical contact evolution during the pantograph–catenary system working is still ambiguous so far. In this paper, the evolution of electric contact was studied in respects of the contact resistance, temperature rise, and microstructure variation,based on a home-made pantograph–catenary simulation system. Pure carbon strips and copper alloy contact wires were used, and the experimental electrical current, sliding speed, and normal force were set as 80 A, 30 km/h, and 80 N,respectively. The contact resistance presented a fluctuation without obvious regularity, concentrating in the region of 25 and 50 mΩ. Temperature rise of the contact point experienced a fast increase at the first several minutes and finally reached a steady state. The surface damage of carbon trips in microstructure analysis revealed a complicated interaction of the sliding friction, joule heating, and arc erosion. | Guangning Wu Wenfu Wei Guoqiang Gao Jie Wu Yue Zhou | 2016 | Journal of Modern Transportation2016，24，2： | 5 |
| 9 | Review of condition monitoring and defect inspection methods for composited cable terminals显示文摘Composited cable terminals are critical for reliable power delivery of traditional and traction power supply systems.During its operation,the cable terminal continually undergoes complex circumstances where humidity,temperature,field strength,mechanical stress and other factors continuously change at different levels.In extreme cases,defects or even failures may occur in the cable terminals,leading to catastrophic accidents.This makes the condition monitoring and defect detection of composited cable terminals become an imperative need for the power industry.The“state-of-the-art”technology of cable terminal condition assessment is focussed and a systematic review of the current research progress of cable terminal condition assessment from the operation circumstances to failure mechanisms is provided.It covers both online/offline condition monitoring methods and defects detection approaches.In addition,challenges and future research directions for cable terminal condition assessment are also addressed.It is concluded that the non-destructive and non-intrusive methods like terahertz imaging and ultrasonic testing,and multi-source information fusion methods as well as the digital twin technology have been gaining popularity for cable terminal defect inspection.It is expected the presented work can provide a global field of vision for further advancement of both scholars and industrial engineers in this field. | Shuaibing Li Binglei Cao Jin Li Yi Cui Yongqiang Kang Guangning Wu | 2023 | High Voltage2023，8，3： | 4 |
| 10 | An optimized transmission line model of grounding electrodes under lightning currents显示文摘In this paper,an optimized transmission line model(OTL) for modeling transient behavior of grounding electrodes under lightning currents is presented.The soil ionization effect is considered in OTL,and all electromagnetic couplings between different parts of grounding electrode are also considered by selecting the size of segment conductor properly and calculating the mutual coupling parameters between segment conductors accurately.Comparing with the traditional transmission line model,the optimized model can be used to accurately predict the effective length and transient potential rise(TPR) of grounding electrodes.Transient behaviors of grounding electrodes are simulated by OTL and the results are in good agreement with those of the electromagnetic model proposed by Grcev,and experiment results performed by Electricité de France and Geri.Furthermore,non-uniform discharging phenomenon of grounding electrode under lightning current is discussed,and the effective lengths of horizontal grounding electrode under lightning currents are presented. | YANG Lin WU GuangNing CAO XiaoBin | 2013 | Science China(Technological Sciences)2013，56，2： | 4 |
| 11 | The biomarkers of immune dysregulation and inflammation response in Parkinson disease显示文摘Parkinson’s disease(PD)is referring to the multi-systemicα-synucleinopathy with Lewy bodies deposited in midbrain.In ageing,the environmental and genetic factors work together and overactive major histocompatibility complex pathway to regulate immune reactions in central nerve system which resulting in neural degeneration,especially in dopaminergic neurons.As a series of biomarkers,the human leukocyte antigen genes with its related proteomics play cortical roles on the antigen presentation of major histocompatibility complex molecules to stimulate the differentiation of T lymphocytes and i-proteasome activities under their immune response to the PD-related environmental alteration and genetic variation.Furthermore,dopaminergic drugs change the biological characteristic of T lymphatic cells,affect theα-synuclein presentation pathway,and inhibit T lymphatic cells to release cytotoxicity in PD development.Taking together,the serum inflammatory factors and blood T cells are involved in the immune dysregulation of PD and inspected as the potential clinic biomarkers for PD prediction. | Li Chen Mingshu Mo Guangning Li Luan Cen Lei Wei Yousheng Xiao Xiang Chen Shaomin Li Xinling Yang Shaogang Qu Pingyi Xu | 2016 | Translational Neurodegeneration2016，5，1： | 3 |
| 12 | Instrument for insulation conditions detection of roof insulator on high-speed-train显示文摘With the rapid development of high-speed-railway,environment around high voltage device on train roof becomes very complicated. Most train accidents happened due to occurrence of flashover on roof insulator,but the insulation condition estimation of insulator in such environment is much difficult. To ensure the insulation property of electric equipment,and guarantee the operation safety of high-speed-train,here established an instrument with high reliability which can on-line monitor insulation condition of roof insulator and give out advanced alarm before the incipient insulator flashover. The instrument consists of three parts,Data Acquisition & Sensor,Data Processing and Back Processing. Anti-interference and protection methods are processed to Rogowski coil sensor for better leakage current signal. To avoid the fluctuation from railway power supply,four modules are set to filter the power supply waveform. Through laboratory measurement,it is shown that the leakage current and the impedance angle can be detected by the instrument accurately. From the comparison of leakage current and impedance angle results under different moisture condition and the alarm operation when leakage current value reached threshold,this instrument can give out enough information for staff to understand the insulation condition of insulator. | ZHANG Xueqin Yin Guolong GAO Guoqiang SHAO Mengchun YIN Xianbin LI Chunmao WU Guangning | 2014 | Instrumentation2014，1，2： | 2 |
| 13 | Multi-physics analysis and optimisation of high-speed train pantograph-catenary systems allowing for velocity skin effect显示文摘A pantograph-catenary system (PCS) - an essential component to supply a high-speed train (HST) - faces a variety of new challenges due to the continuously increasing train speeds. The HST traction system receives power via an electrical contact between the pantograph strip and the high-voltage contact wire. This electrical contact is subject to serious mechanical shocks and significant electrochemical corrosion, making the modelling of the dynamic processes complicated, especially under high-speed and heavy-load conditions. The damage to the PCS - which is particularly noticeable at the edges of the pantograph strip - may become severe as the speed of the train rises. Moreover, as the speed increases, the distribution of the electrical current in the strip becomes uneven due to the velocity skin effect (VSE). To assess the impact of the VSE on the performance of PCSs, a multi-physics model has been created and is reported in this study. The model has been validated through experiments and the main aspects of its functionality - such as the VSE, friction, and air convection - have been identified and analysed at different speeds. The impact of speed on the traction current and the behaviour of thermal sources have been explored. With the increasing speed, the phenomenon of current clustering at the trailing edge of the strip becomes quite dramatic, resulting in a thermal surge in the region of the strip with high current density. To mitigate the negative impact caused by VSE in the PCSs, an improved kriging optimisation methodology has been utilised to optimise the parameters of the PCS. Recommendations regarding the optimal design of the PCS are put forward to improve the current-carrying performance and reduce the local temperature rise in the strip. | Xianrui Liu Zefeng Yang Song Xiao Xuwei Duan Guoqiang Gao Wenfu Wei Guangning Wu Mihai Rotaru Jan K.Sykulski | 2020 | High Voltage2020，5，6： | 2 |
| 14 | Dynamic changes of peptidome and release of polysaccharide in sea cucumber(Apostichopus japonicus) hydrolysates depending on enzymatic hydrolysis approaches显示文摘Enzymatic hydrolysis has been widely used to produce bioactive hydrolysates from sea cucumber body wall.Here,inspired by the clarification of Apostichopus japonicus genome,we investigated the enzymatic hydrolysis of sea cucumber body wall by using the omics strategy.Shared proteins,including major yolk proteins,collagens,extracellular matrix glycoproteins and muscle proteins,were released from the body wall by different hydrolysis condition.A portfolio of 216 shared peptides were detected in the peptidome by papain with different hydrolysis time,while 32 shared peptides were detected in the peptidome by differing proteases.Unshared peptides and the relative abundance distribution profiles of shared peptides changed depending on hydrolysis approaches,indicating dynamic changes of peptidome during hydrolysis.Moreover,release of sulfated fucan and fucosylated chondroitin sulfate changed with the hydrolysis condition.The monitoring of dynamic enzymatic hydrolysis process at a molecular scale would contribute to production and quality control of sea cucumber hydrolysates. | Yanchao Wang Yan Song Yaoguang Chang Yanyan Liu Guangning Chen Changhu Xue | 2022 | Food Science and Human Wellness2022，11，5： | 2 |
| 15 | Self-cleaning of superhydrophobic nanostructured surfaces at low humidity enhanced by vertical electric field显示文摘Self-cleaning is the key factor that makes superhydrophobic nanostructured materials have wide applications.The self-cleaning effect,however,strongly depends on formations and movement of water droplets on superhydrophobic nanostructured surfaces,which is greatly restricted at low humidity(<7.6 g·kg^(-1)).Therefore,we propose a self-cleaning method at low humidity in which the pollution is electro-aggregated and driven in the electric field to achieve the aggregation and cleaning large areas.The cleaning efficiency of this method is much higher than that of water droplet roll-off,and will not produce'pollution bands'.A simplified numerical model describing pollution movements is presented.Simulation results are consistent with experimental results.The proposed method realizes the self-cleaning of superhydrophobic nanostructured surfaces above dew point curve for the first time,which extends applications of superhydrophobic nanostructured materials in low humidity,and is expected to solve self-cleaning problems of outdoor objects in low humidity areas(<5.0 g·kg^(-1)). | Yijie Liu Yujun Guo Xueqin Zhang Guoqiang Gao Chaoqun Shi Guizao Huang Pengli Li Qi Kang Xingyi Huang Guangning Wu | 2022 | Nano Research2022，15，5： | 1 |
| 16 | Dielectric Fre- quency Response of Oil - paper Composite Insulation Mtified by Nanoparticles显示文摘 | Jun l iu Lijun Zhou Guangning Wu | 2012 | IEEE Transactions on Di- electri(''s and Electrical Insulation2012，19，： | 1 |
| 17 | Dielectric Frequency Response of Oil-paper Composite Insulation with Transient Moisture Distribution显示文摘 | Liu Jun Zhou Lijun Wu Guangning | 2013 | IEEE Transactions on Dielectrics and Electrical Insulation2013，20，4： | 1 |
| 18 | Dielectric Frequency Response of Oil-paper Composite Insulation Modified by Nanoparticles显示文摘 | Liu Jun Zhou Lijun Wu Guangning | 2012 | IEEE Transactions on Dielectrics and Electrical Insulation2012，19，2： | 1 |
| 19 | Degradation Mechanism of Polyimide Film Under Square Impulse Voltages显示文摘Partial discharge (PD) under a sequence of high-repetition-rate square pulses is one of the key factors leading to premature failure of insulation systems of inverter-fed motors. Polyimide (PI) film is an important type of insulating material used in the inverter-fed motors. In this paper, micro-morphology and structure change of PI film aged by bipolar continuous square impulse voltage (BCSIV) with ampli- tude above partial discharge inception voltage (PDIV) are investigated by scanning electron microscope (SEM). The chemical bonds of PI chain are analyzed through Fourier transform infrared spectroscopy (FTIR). The results show that the degradation mechanism of PI film is the fracturing of chemical bonds caused by the erosion from PDs. Three layers are displayed in both 100 HN film and 100 CR film. The de- gradation path of PI film is initiated from surface and then gradually extends to the interior with continuous aging. Nano-fillers can retard the degradation of PI film and prolong its lifetime. | LUO Yang WU Guangning XIA Jinfeng ZHU Guangya WANG Peng CAO Kaijiang | 2013 | 高电压技术2013，39，8： | 1 |
| 20 | On-line monitoring technique for multi-component gases dissolved in oil of traction transformer显示文摘 | ZHOU Lijun WU Guangning WANG Hongliang | 2006 | Transactions on Electrical and Electronic Materials2006，7，7： | 1 |
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