Results 191 to 200 of about 1,585 (211)

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

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

Dynamic arcing model of switching and its effect on VFTO

2011 1st International Conference on Electric Power Equipment - Switching Technology, 2011
In computational process of very fast transient over-voltage, it is essential to find an accurate model of the gas insulated substation. The arcing model of disconnector is particularly important. The general arc-resistance model is not available to give better simulation for the changing of status during the development of arc.
null Lin Xin, null Wang Na, null Xu Jian-yuan   +2 more
openaire   +1 more source

VFTO Spectrum Analysis Method Based on Continuous Wavelet Transform

2018 10th International Conference on Communications, Circuits and Systems (ICCCAS), 2018
Gas insulated substation (GIS) is widely used in urban and densely populated areas. Moreover, GIS equipment is used in all UHV AC transmission projects. The operation of the isolating switch in GIS produces very fast transient overvoltage (VFTO). When the frequency component contained in the VFTO is matched with the resonant frequency of the winding ...
openaire   +1 more source

Estimation and analysis of VFTO in 420kV Gas Insulated substation

2014 International Conference on Circuits, Power and Computing Technologies [ICCPCT-2014], 2014
Very Fast Transient Overvoltages (VFTOs) which are caused mostly due to disconnector operations in Gas Insulated substations (GIS) impose several problems on the insulation of the system and also to the connected high voltage equipment. Therefore, it is important to do a VFTO study in GIS.
Reuban Samikkannu, Santosh Kumar Annadurai   +1 more
openaire   +1 more source

Study on measurement of VFTO based on electric field sensor

2010 URSI International Symposium on Electromagnetic Theory, 2010
In power system, pulse voltage is measured by both the circuit and the electric field. The special measure of VFTO is determined by non-alterable equipments of GIS. In this paper, external transient voltage is measured by electric spherical probe which means it is not necessary to access any equipment to the system.
null Zhang Weidong, null Zhang Zhilong, null Cui Xiang, null Ma Guoming, null Li chengrong, null Wang xin   +5 more
openaire   +1 more source

Arcing Model of a Disconnector and its Effect on VFTO

Plasma Science and Technology, 2013
In the computational process of very fast transient over-voltage (VFTO), it is essential to find an accurate model for a gas insulated substation. The arcing model of the disconnector is particularly important. The general arcing model is not able to give a good description of the arc development process. In this paper, based on the physical process of
Xin Lin, Na Wang, Jianyuan Xu
openaire   +1 more source

Simulation of VFTO by ATP/EMTP with Various Arc Models

Applied Mechanics and Materials, 2014
Several arc models representing a disconnector’s closing operation in a 252kV gas insulated switchgear (GIS) are implemented with a computer program ATP/EMTP to simulate very fast transient overvoltage (VFTO). Arc models are used as black box models in connection with a test circuit.
Hang Dai, Xiao Fan Liu, Wei Dong Zhang
openaire   +1 more source

Modeling of The Transformer Windings under VFTO based on Transfer Function

2006 International Conference on Power System Technology, 2006
A systematic methodology is presented for establishing the high frequency circuit model of transformer windings under VFTO based on transfer functions in this paper. Firstly, the voltage transfer functions are deduced from the S parameters which are measured by network analyzer.
Xile Zhang, Guishu Liang, Qing Xie, Haifeng Sun   +3 more
openaire   +1 more source