Results 141 to 150 of about 889 (166)

Mitigation of VFTO from a Power Transformer bushing in a 275 kV Gas Insulated Substation

International Seminar on Intelligent Technology and Its Applications
Very Fast Transient Overvoltage (VFTO) is a potential cause of transformer bushing failures in Gas Insulated Substations (GIS). Protecting the power transformer from this dangerous overvoltage becomes imperative for the equipment safety.
Nasiru Yahaya Ahmed, H. Illias, H. Mokhlis, Daniar Fahmi, Mohd Taufiq Bin Mohd Khairi, Noradlina Abdullah   +5 more
semanticscholar   +1 more source

Fractional Lumped Parameter Modeling of Transformer Windings under VFTO

Applied Mechanics and Materials, 2014
Very fast transient overvoltage (VFTO) is very dangerous for the transformer which is directly connected to gas insulated substations (GIS). At the same time, due to the continuous increasing of operating frequency in the power system, under the high frequencies of the transmission line calculation and simulation process, it is necessary to consider ...
Gui Shu Liang, Guang Bo Zhang, Xin Liu
openaire   +1 more source

Exploring the Test Plan for the Impact of VFTO on Localized Protection Devices

Information Security Practice and Experience, 2021
The State Grid Corporation of China is steadily promoting the research and trial operation of localized protection devices, and the very fast transient overvoltage (VFTO) nuisance caused by disconnecting switch operation in GIS may affect the normal ...
Ye Xia, Huihai Liu, Jun Zhao, Zhiyang Zou, Xiaoli Zhang, Wei Li   +5 more
semanticscholar   +1 more source

Measurement And Analysis Of VFTO In a 750kV Substation

2010 Asia-Pacific Power and Energy Engineering Conference, 2010
Disconnector operations in GIS may generate very fast transient overvoltage (VFTO), which is characterized by its high peak value, short rise time, and high frequencies. Mostly, researches on VFTO are focusing on the apparatus involving in the active circuit. However, VFTO may pass through open devices by electromagnetic coupling. To measure VFTO under
Jian Jiang, Guo-ming Ma, Cheng-rong Li, Jiang-tao Quan, Hao Wu, Hai-rui Xu, Bo Zhang   +6 more
openaire   +1 more source

Simulation of VFTO Suppression Methods for 1100kV GIS Substation

2019 IEEE 3rd Information Technology, Networking, Electronic and Automation Control Conference (ITNEC), 2019
Disconnector switch operation in GIS will generate VFTO, which will harm the equipment. Because there are many limitations in field measurement, simulation can overcome the limitations of experimental research, which can replace test measurement to a certain extent. In this paper, three VFTO suppression methods are simulated in ATP-EMTP.
Wenxiu Gong, Peijin Wang, Qingquan Li, Weijian Xue, Mu Qiao, Xiao Wang, Yumei Pan   +6 more
openaire   +1 more source

Modeling for transformer windings under VFTO based on s-parameters

2008 International Conference on Machine Learning and Cybernetics, 2008
To study the very fast transient over-voltage (VFTO) distribution in transformer windings in gas insulated substation (GIS), a systematic methodology based on s-parameters is presented for establishing high-frequency model of transformer windings in this paper.
null Ping Zhang, null You-Hua Wang, null Xin-Peng Nie, null Wei-Li Yan, null Hai-Jiao Zhang   +4 more
openaire   +1 more source

Design and Verification of VFTO Differentiating-Integrating Measurement Equivalent Circuit

Integrated Ferroelectrics, 2020
Operation of isolating switches and circuit breakers in fully enclosed gas insulated substations (GIS) produces very fast transient overvoltage (VFTO).
Ke Wang, Xiangyu Tan, Xiaowei Xu, Wenbin Zhang   +3 more
openaire   +1 more source

The influence of the distributed trapped charge on VFTO

2010 5th International Conference on Critical Infrastructure (CRIS), 2010
In this paper, the nodal admittance equation is derived for analyzing the response of the transmission line under the residual voltage due to uniformly distributed charge along the line in Laplace domain. We equivalent the trapped charge to the current sources which are located at near-end and far-end when the disconnector switching is operated.
Hongyang Yu, Binxian Lu
openaire   +1 more source

Analysis of VFTO during the failure of a 550-kV gas-insulated substation

, 2020
This paper presents an analysis of a very fast transient overvoltage (VFTO) experienced by a 550-kV gas-insulated substation (GIS) that caused the failure of a disconnector switch (DS) and circuit breaker (CB), after manual closure of the DS. Simulations
D. C. Moreira, M. V. A. Nunes, D. Moreira, D.K.D. Costa   +3 more
semanticscholar   +1 more source

Experimental Research on Suppressing VFTO in GIS by Magnetic Rings

IEEE Transactions on Power Delivery, 2013
Very-fast transient overvoltage (VFTO) is a serious threat to the insulation of extra-high voltage and ultra-high voltage power-system equipment and should be suppressed. A simpler and more reliable VFTO suppressing method than a shunt resistor is presented in this paper, which uses magnetic rings installed on the center conductor of gas-insulated ...
Yonggang Guan, Gongchang Yue, Weijiang Chen, Zhibing Li, Weidong Liu   +4 more
openaire   +1 more source