Results 151 to 160 of about 940 (189)

Measurement of VFTO Based on the Transformer Bushing Sensor

IEEE Transactions on Power Delivery, 2011
Disconnector switching operations in large gas-insulated switchgear (GIS) systems may produce very fast transient overvoltages (VFTOs), causing high electric stress to other apparatuses in the substation, such as power transformers. This paper presents a VFTO measuring technique based on a transformer bushing sensor, which consists of the transformer ...
Guo-Ming Ma, Cheng-Rong Li, Jiang-Tao Quan, Jian Jiang   +3 more
openaire   +1 more source

Characteristic Analysis on Suppressing VFTO in GIS by Ferrite

Advanced Materials Research, 2013
When disconnecting switches were operated,Very Fast Transient Overvoltage (VFTO) did great harm to power systems and their equipments in Gas Insulated Substations (GIS). Although VFTO can be suppressed by a few of known methods, there were some problems.
Xiang Gen Gan, Shui Ping Zhong, Sheng Wei, Dong Bao Yang   +3 more
openaire   +1 more source

Damping of VFTO by RF resonator and nanocrystalline materials

2013 IEEE Electrical Insulation Conference (EIC), 2013
Very fast transient overvoltages (VFTO) are a well known phenomena in gas insulated switchgears (GIS). The main reasons for VFTO are switching operations of disconnectors. Thereby, several pre- or restrikes between the switching contacts occur and initiate steep voltage rises propagating inside the GIS.
S. Burow, W. Kohler, S. Tenbohlen, U. Straumann   +3 more
openaire   +1 more source

Design of Triggering Device for VFTO Measurement System

Advanced Materials Research, 2012
Very fast transient overvoltage (VFTO) can be generated during the operation of disconnect switch (DS). Especially in ultra high voltage (UHV) gas insulated substation (GIS), VFTO is a threat to the safety of the power system equipment. It is very important to measure VFTO waveforms accurately.
Gong Chang Yue, Yu Rong Jia, Jia Xi He, Wei Dong Liu   +3 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

Design Optimization of Ferrite Rings for VFTO Mitigation

IEEE Transactions on Power Delivery, 2017
Very fast transient overvoltage (VFTO)-related problems are raising growing concerns in China with the development of ultra-high voltage. The practice of fitting ferrite rings on gas-insulated switchgear busbars for VFTO mitigation has long been proposed but few investigations on its' design optimization were conducted. Based on theoretical analysis of
Jiaxi He, Yonggang Guan, Weidong Liu, Weijiang Chen, Zhibing Li   +4 more
openaire   +1 more source

Estimating the Size of Ferrite for Suppressing VFTO in GIS

2006 IEEE 8th International Conference on Properties and applications of Dielectric Materials, 2006
The insulation of apparatus in the power system is often broken by the very fast transient over voltage (VFTO), which cause from the operation of disconnector in gas insulate substation (GIS). In this paper, a new idea for the Suppressing VFTO by ferrite is put forward, and the characteristic of ferrite is analyzed.
Jin Lijun, Zheng Yuanbing, Pen Ge, Yuan Zheng, Zheng xianggong   +4 more
openaire   +1 more source

Lumped parameter modeling of transformer windings under VFTO

2011 4th IEEE International Symposium on Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, 2011
Very fast transient overvoltage (VFTO) is very dangerous for the transformer which is directly connected to gas insulated substations (GIS). In order to study the voltage distribution in transformer windings under VFTO, a new model named the Piecewise Lumped Parameter (PLP) model is proposed.
Juan Du, Guishu Liang, Haifeng Sun, Xin Liu, Xixiao Liu   +4 more
openaire   +1 more source

Transient modeling and analysis of transformer windings under VFTO

2008 7th World Congress on Intelligent Control and Automation, 2008
Calculation of over-voltage distribution of transformer windings under Very Fast Transient Over-voltage (VFTO) is very important to insulate design of transformers windings. In order to investigate over-voltage distribution under VFTOs, a proposed model using lumped-parameter components is presented in this paper. In the case of easily destroyed former
null Ping Zhang, null Youhua Wang, null Xinpeng Nie, null Weili Yan, null Haijiao Zhang   +4 more
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