Results 31 to 40 of about 229 (144)

Modeling of Common Mode Interference of Secondary Side of Potential Transformer in VFTO Excitation

Shanghai Jiaotong Daxue xuebao
Very fast transient overvoltage (VFTO) is generated during the operation of isolation switches and circuit breakers in substations, which can affect the safe and reliable operation of power secondary equipment through cable transmission and spatial ...
PANG Fubin, JI Jianfei, WU Xianqiang, ZHOU Mengxia, YAN Wei, XU Dong
doaj   +1 more source

The electromagnetic effect study of GIS enclosure under high‐frequency electromagnetic pulse

The Journal of Engineering, Volume 2019, Issue 16, Page 2837-2841, March 2019., 2019
In gas insulated switchgear (GIS) substation, due to the operation of disconnect switch and circuit breaker, as well as short‐circuit fault, SF6 will break down very rapidly. The superposition of refraction and reflection of high‐frequency travelling waves will cause the very fast transient electromagnetic pulse (EMP).
Shu Chen, Jie Guo, Chengbo Hu, Fengbo Tao, Tianxi Xie, Yang Xu, Jun Jia   +6 more
wiley   +1 more source

New equivalent circuit model of UHVDC converter transformer winding for surge propagation investigation

The Journal of Engineering, Volume 2019, Issue 16, Page 2921-2925, March 2019., 2019
An accurate computational model of transformer winding for potential distribution analysis under impulse voltage is very important for the design of transformer inter‐turn insulation, especially for large capacity transformers such as ultrahigh‐voltage DC (UHVDC) converter transformer.
Shuang He, Yuhao Liu, Zheng Zhao, Chenjie Li, Yifeng Wang, Ziyuan Ren, Hai Qian, Jun Deng   +7 more
wiley   +1 more source

A novel GIS breakdown location method based on natural frequency of transient voltage

High Voltage, Volume 10, Issue 4, Page 856-875, August 2025.
Abstract During on‐site withstand voltage tests of gas‐insulated switchgears (GIS), once a breakdown occurs, it is hard to locate the breakdown position due to the intricate branch structures and minimal breakdown energy. The existing methods may require the placement of a large number of sensors with unsatisfactory accuracy, which adversely affects ...
Qiang Sun, Dengwei Ding, Yanpeng Ge, Ziwei Zhang, Wensheng Gao, Weidong Liu, Ke Zhao, Bo Liu, Lei Wang, Jiaqi Qu   +9 more
wiley   +1 more source

Diagnostic analysis and protective measures of transient ground potential rise in a 1000 kv UHV substation

The Journal of Engineering, Volume 2019, Issue 16, Page 1144-1148, March 2019., 2019
With the continuous expansion of power grid capacity and growth of voltage levels, the transient ground potential rise (GPR) caused by the switchgear operation has become great threaten to the safety of the grid. In the startup operation of 500 kV part of Taizhou 1000 kV ultra‐high voltage (UHV) substation, the electromagnetic lock installed in the ...
Fubin Pang, Qiangsheng Bu, Yu Liu, Yubo Yuan   +3 more
wiley   +1 more source

A novel embedded voltage‐clamped circuit for multilevel modular converters submodule to suppress very fast transient overvoltage

High Voltage, Volume 9, Issue 6, Page 1202-1207, December 2024.
Abstract The submodule in multilevel modular converters experiences a very fast transient overvoltage (VFTO) during switch operation of gas‐insulated switchgear, which also results in overvoltage on power devices, such as thyristors and insulated gate bipolar transistors (IGBTs). This work presents an embedded circuit that utilises a gap in conjunction
Hong Shen, Zhonghao Dongye, Mian Xiao, Jiayi Shao, Xiangyu Zhang, Yao Yao, Zifan Dong, Lei Qi   +7 more
wiley   +1 more source

Defect recognition of oil‐pressboard insulation based on frequent arc reignition phenomenon under switching impulse voltage

High Voltage, Volume 9, Issue 4, Page 773-785, August 2024.
Abstract In the past three years, a number of oil‐immersed ultra‐high‐voltage shunt reactors have experienced discharge defects when being put into operation, resulting in an overload of acetylene. However, detecting and identifying these discharge defects caused by switching impulse voltage is challenging under steady‐state conditions.
Simeng Li, Yukun Zhang, Yunfei Jia, Shengchang Ji, Yanhua Han, Wensen Wang   +5 more
wiley   +1 more source

Transforming characteristics of the Rogowski coil current transformer with a digital integrator for high‐frequency signals

The Journal of Engineering, Volume 2019, Issue 16, Page 3337-3340, March 2019., 2019
The Rogowski coil current transformer is widely used in intelligent substations for its rapid response, wide bandwidth measurement, and non‐magnetic saturation. In most cases, it works with a digital integrator to restore the differential signal output by the coil.
Fubin Pang, Yu Liu, Jianfei Ji, Chi Zhang   +3 more
wiley   +1 more source

A Review of Research Progress in Very Fast Transient Overvoltage (VFTO) Suppression Technology

Energies
The very fast transient overvoltage (VFTO) is characterized by steep wavefronts, high amplitude, and wide spectrum. These characteristics can lead to partial discharges or insulation breakdowns in potted insulators, which can lead to localized ...
Huan Wang, Yinglong Diao, Xixiu Wu, Bolun Du   +3 more
doaj   +1 more source

A high speed and sensitive protection for distribution network with DGs using ferrite rings as line boundary

IET Generation, Transmission &Distribution, Volume 18, Issue 8, Page 1611-1623, April 2024.
This paper proposes a peak time of voltage travelling wave‐based protection scheme for DN with distributed generators using FRs as line boundary. Numerical simulation and experimental results verify that the proposed method can quickly and sensitively distinguish internal and external faults, and has high resistance to transition resistance.
Zhongxue Chang, Jifei Yan, Chenhao Zhang, Guobing Song   +3 more
wiley   +1 more source