Analysis of the influencing factors of electric field distortion caused by the lightning rod

2019 ◽  
Vol 61 (3) ◽  
pp. 391-401
Author(s):  
Yunfeng Zhang ◽  
Huan Ren ◽  
Chenlong Zhao ◽  
Jiawen Chen
Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2271 ◽  
Author(s):  
Qingguo Chen ◽  
Jinfeng Zhang ◽  
Minghe Chi ◽  
Peng Tan ◽  
Wenxin Sun

The electric field distortion caused by space charge is an important factor affecting the operation reliability of oil–paper insulation in a converter transformer. To study the accumulation and decay characteristics of the space charge within oil-impregnated pressboard under DC and polarity reversal voltage, and consider the possible operating conditions of the converter transformer, the space charge behavior of oil-impregnated pressboard was measured by the pulsed electro-acoustic (PEA) method in the temperature range from −20 °C to 60 °C. The effect of temperature on the accumulation and decay characteristics of space charge is also analyzed. The space charge accumulated within the pressboard at low temperature is mainly homocharge injected by the electrode, while heterocharge formed by ion dissociation counteracts some of the homocharge at high temperature. Thus, the space charge of pressboard first increases, then decreases, with an increase in temperature. However, slow decay of the space charge causes severe distortion of the electric field distribution in the pressboard during voltage polarity reversal.


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.


Author(s):  
Ahmed M. Samy ◽  
Mohamed E. Ibrahim ◽  
Amr M. Abd-Elhady ◽  
Mohamed A. Izzularab

2013 ◽  
Vol 303-306 ◽  
pp. 482-488
Author(s):  
Kai Mao ◽  
Jin Gang Wang ◽  
Xu Dong Deng ◽  
Wei He ◽  
Zuo Peng Zhang

Based on the basic theory of electromagnetic field, the Electric Field Distortion (EFD) in power frequency electric field caused by induced current of human body has been analyzed. The enhancement factor of the electric field distortion is introduced to reduce the influences caused by human body in the measurement of high voltage electric fields. The Ansoft Maxwell is used to simulate and calculate the electric field distribution under the influence of the human body to have the value of enhancement factor. In addition, the enhancement factor has been corrected by experiment with the electromagnetic field analyzer EFA300. With the enhancement factor introduced in this paper, the measurement error can be reduced.


2021 ◽  
Vol 8 ◽  
pp. 23
Author(s):  
Guowei Li ◽  
Yong Wang ◽  
Xuexia Xu

The electric field distortion caused by the high voltage current environment in the cable terminal will greatly increase the failure probability and reduce the operation safety; therefore, it is necessary to ensure the uniform distribution of the electric field in the terminal. This paper briefly introduced the high-voltage cable terminal and non-linear materials. The traditional silicone rubber and the silicone rubber added with nano-SiO2 were prepared. The electrical conductivity of the two silicone rubbers was tested, and the electric field of the cable terminal was simulated. The results demonstrated that the nano-SiO2 improved silicone rubber had a higher non-linear conductivity and was less affected by temperature. The calculation results of the simulation model also showed that the distribution of the internal field strength was more uniform, and the maximum field strength on the reinforced insulation was smaller after the improved silicone rubber was used as the reinforced insulation.


Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3596 ◽  
Author(s):  
Ziheng Pu ◽  
Chenqu Zhou ◽  
Yuyao Xiong ◽  
Tian Wu ◽  
Guowei Zhao ◽  
...  

In recent years, extreme high temperature weather occurs frequently, which easily causes forest fires. The forest fire is prone to the trip accident of the transmission line. Previous studies show that charged combustion particles cause electric field distortion in the gap below the transmission line, and trigger discharges near the conductor area. The motion and distribution characteristics of combustion particles in the gap have an important influence on the discharge characteristics. Therefore, the size and morphology of combustion particles are analyzed through combustion experiments with typical vegetation. The combustion particles are mainly affected by the air drag force, electric field force and gravity. The interaction and influence of temperature, fluid, electric field and the multi-physical field of particle motion are comprehensively analyzed. A two dimensional (2D) axisymmetric simulation model is established by simplifying the flame region. According to the heat release rate of vegetation flame combustion, the fluid temperature and velocity are calculated. Combined with the fluid field and electric field, the forces on particles and movement are calculated. The results can provide a basis for the analysis of the electric field distortion, and further study the discharge mechanism of the gap under the condition of vegetation flame.


Sign in / Sign up

Export Citation Format

Share Document