Influence of Pressboard Orientation in the Electric Field on Lightning Impulse Discharge Characteristics of Oil-Pressboard Insulation

2019 ◽  
Author(s):  
Jiansheng Li ◽  
Chao Wei ◽  
Yiming Wu ◽  
Shengquan Wang ◽  
Yuandi Lin ◽  
...  
Keyword(s):  
Electric Field ◽  
Discharge Characteristics ◽  
Impulse Discharge ◽  
Lightning Impulse

Discharge and Flashover Behavior in Oil-Paper

2020 ◽  
pp. 105-128
Keyword(s):  
Electric Field ◽  
Operating Conditions ◽  
Surface Discharge ◽  
Discharge Characteristics ◽  
Dc Voltage ◽  
Composite Field ◽  
Field Distortion ◽  
Lightning Impulse ◽  
Creeping Discharge ◽  
Paper Insulation

Due to special operating conditions, the valve side bushing of the converter transformer connected to the converter valve is subject to complex voltage excitation, including DC voltage, AC/DC composite voltage, lightning impulse overvoltage, or composite voltage of operating overvoltage and DC. Under the action of this complicated electric field, the oil-paper insulation of the valve-side bushing of the converter transformer is prone to electric field distortion due to charge accumulation, which causes a surface discharge, which will seriously cause the edge breakdown. At the same time, since the temperature in the converter transformer rises due to a large amount of loss during the operation of the transformer, creeping discharge is more likely to occur under the electrothermal composite field. Hence, it is significant to carry out research on the surface discharge characteristics of the oil-paper insulation on the valve side of the converter transformer under the electrothermal composite field.

Test Research on Phase-to-Ground Air-Gap Discharge Characteristics of UHV Substation

2014 ◽  
Vol 492 ◽  
pp. 162-168
Author(s):  
Qi Ming Ye ◽  
Liang Xie ◽  
Xiao Qing Luo ◽  
Feng Huo
Keyword(s):  
Minimum Distance ◽  
Discharge Voltage ◽  
Air Gap ◽  
Test Results ◽  
Discharge Characteristics ◽  
Voltage Rise ◽  
Test Base ◽  
Impulse Discharge ◽  
Lightning Impulse

In order to optimize the design of UHV substation and reduce its construction investment, it is necessary to take further research of UHV substation air-gap discharge characteristics. In this paper, by using sub-conductor and tower to simulate UHV substation air-gap, lightning and switching impulse discharge characteristics tests of UHV substation are taken in the UHV AC test base of SGCC. The results show that, when the distance of conductor between tower is in range of 4m to 7m, the 50% lightning impulse and switching impulse discharge voltage rise along with the rise of air gap distance. As the air-gap increases, the switching impulse discharge voltage presents the trend of saturation. According to the analysis of test results, we can draw a conclusion that the gap factor of switching impulse discharge can be 1.22 when the minimum distance between conductors and tower is 5~8m.

Sign in / Sign up

Export Citation Format

Share Document