Wenfu Wei

Prof. Wenfu Wei

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 August 2022 in Railway Engineering Science
Verified
Journal Article
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GWGuangning Wu
Guangning Wu
KDKeliang Dong
Keliang Dong
ZXZhilei Xu
Zhilei Xu
SXSong Xiao
Song Xiao
WWWenfu Wei
Wenfu Wei
XHXingyi Huang
Xingyi Huang
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.

28 June 2013 in Journal of Applied Physics
Verified
Journal Article
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XLXingwen Li
Xingwen Li
WWWenfu Wei
Wenfu Wei
JWJian Wu
Jian Wu
SJShenli Jia
Shenli Jia
AQAici Qiu
Aici Qiu
Laser produced copper plasmas of different spot sizes in air were investigated using fast photography and optical emission spectroscopy (OES). The laser energy was 33 mJ. There were dramatic changes in the plasma plume expansion into the ambient air when spot sizes changed from ∼0.1 mm to ∼0.6 mm. A stream-like structure and a hemispherical structure were, respectively, observed. It appeared that the same spot size resulted in similar expansion dynamics no matter whether the target was located in the front of or behind the focal point, although laser-induced air breakdown sometimes occurred in the latter case. Plasma plume front positions agree well with the classic blast wave model for the large spot-size cases, while an unexpected stagnation of ∼80 ns occurred after the laser pulse ends for the small spot size cases. This stagnation can be understood in terms of the evolution of enhanced plasma shielding effects near the plasma front. Axial distributions of plasma components by OES revealed a good confinement effect. Electron number densities were estimated and interpreted using the recorded Intensified Charge Coupled Device (ICCD) images.

29 July 2020 in IEEE Transactions on Plasma Science
Verified
Journal Article
Closed access
ZYZefeng Yang
Zefeng Yang
PXPan Xu
Pan Xu
WWWenfu Wei
Wenfu Wei
GGGuoqiang Gao
Guoqiang Gao
NZNing Zhou
Ning Zhou
GWGuangning Wu
Guangning Wu
As one of the most important electrified railway components, the pantograph-catenary (PC) system plays a key role in the energy transfer for the train through the sliding electric contact. However, the performance of the PC system is severely limited by pantograph arcing, and the study on the dynamic characteristics of pantograph arcing is still far away from satisfactory. In this article, a magnetohydrodynamic (MHD) model of pantograph arcing is first established, which focused on the impact of crosswind as well as the input current on the arcing dynamics. Once the model was validated by laboratory experiment, the influences of the crosswind and input current on the arc temperature and voltage are studied in detail. Two parameters, namely the diameter of the catenary and the gap distance between the pantograph strip and the catenary, were varied to see what effects that might have. An interesting periodic phenomenon for both the temperature and voltage fall has been found, which was explained based on the Karman vortex street of fluid theory.

27 December 2021 in High Voltage
Verified
Journal Article
Open access
PDF file
ZXZhilei Xu
Zhilei Xu
GGGuoqiang Gao
Guoqiang Gao
WWWenfu Wei
Wenfu Wei
ZYZefeng Yang
Zefeng Yang
WXWenhan Xie
Wenhan Xie
GWGuangning Wu
Guangning Wu
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 pantograph‐catenary arc was built to investigate arc root position‐time and arc column longitudinal 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.

29 August 2016 in IEEE Transactions on Plasma Science
Verified
Journal Article
Closed access
GGGuoqiang Gao
Guoqiang Gao
JHJing Hao
Jing Hao
WWWenfu Wei
Wenfu Wei
HHHaixing Hu
Haixing Hu
GZGuangya Zhu
Guangya Zhu
GWGuangning Wu
Guangning Wu
Pantograph-catenary (PC) arc has become an obstacle for the further development of high-speed railway. Understanding on the underlying physical mechanisms of PC arc dynamics is still far away from satisfactory; therefore, researches from both experimental and numerical aspects are urgently required. This paper focused on the dynamic characteristics of PC arc during the pantograph lowering process by numerical simulation method. A PC arc model was established based on the classical magnetohydrodynamics theory, with the temporal evolution of PC arc dynamics considered. The dynamic mesh technique was utilized to take care of the departure process between the pantograph and the catenary. Detailed behaviors of arc plasmas during the pantograph lowering process were presented by the temperature distribution and flow filed. Two interesting vortexes located below the catenary were found. The vortexes rotated in the opposite direction, resulting from the special gas flow motion during the pantograph movement. Furthermore, the gas flow brought about a thermal pinch effect on arc column, which had a significant influence on the next behaviors of arc plasmas. Besides, the effects of input current on the arc characteristics were studied.

27 July 2020 in Composite Interfaces
Verified
Journal Article
Closed access
QLQianhua Liao
Qianhua Liao
WWWenfu Wei
Wenfu Wei
HZHaozi Zuo
Haozi Zuo
XLXiaobo Li
Xiaobo Li
ZYZefeng Yang
Zefeng Yang
GWGuangning Wu
Guangning Wu
Carbon/copper composites are widely used in collector brushes, pantograph sliders, collector shoes and other fields due to their excellent mechanical friction, wear, thermal conductivity and electrical conductivity. However, the interfacial bonding force of composites is weak because of the natural non-wetting of copper and carbon graphite matrix, which restricts its comprehensive mechanical and electrical properties. In this paper, the nickel element was doped and introduced in the preparation process of the carbon graphite matrix, and the carbon/copper composites were further prepared by the pressure impregnation method. The results showed that the modified carbon matrix doped with nickel was denser, and the nickel element could evenly distribute in the carbon matrix. The porosity of the modified carbon/copper composites was significantly reduced and the interfacial bonding method was changed from the original simple mechanical interlock to solid solution bonding so that the interfacial state was obviously improved. The effect of nickel content on the mechanical and electrical properties of composites was systematically studied. It was found that when the nickel content was 3 wt%, the compressive strength and flexural strength were increased by nearly 52% and 58%, and the electrical conductivity was increased by nearly 35%.