摘要
石墨基柔性接地体在解决金属类接地体腐蚀方面提供了一种新的手段,但其冲击接地特性需要进一步论证。本文利用有限元法对二维涡流场求解,对比分析了石墨基柔性接地体与圆钢接地体在高频电流作用下的自感与等效电阻。计算结果表明,由于圆钢磁导率高,随着频率增加,圆钢等效电阻显著增大,并在频率达到35kHz时超过同等半径下的石墨基柔性接地体。频率5kHz时圆钢内自感迅速下降至10^-6H/m量级,然后逐渐平缓下降至10^-7H/m,与石墨基柔性接地体、铜接近。采用正交试验设计方法确定土壤电阻率、接地体长度、雷电流幅值仿真参数组合,仿真结果表明,石墨基柔性接地体冲击接地电阻小于圆钢,并通过冲击接地对比试验,验证了仿真结果的准确性。
Flexible graphite grounding material provides a new method to solve the corrosion problem of grounding grid, but its impulse grounding performance needs further analysis.Consequently,we employed a finite element method to solve the two-dimensional eddy current field,and comparatively analyzed the inductance and resistance of flexible graph- ite grounding material and steel grounding material under the action of high frequency current.Calculation results show that,due to high permeability,the equivalent resistance of steel increases significantly when frequency increasing,and exceeds that of flexible graphite grounding material with the same radius when the frequency reaches 35 kHz.In addition, when the frequency reaches 5 kHz,the self-inductance of steel quickly falls to the level of 10^-6 H/m,and then gradually decreases to the level of 10^-7 H/m,close to that of flexible graphite and copper.The method of orthogonal experiment de- sign is used to determine the simulation parameter combination of the soil resistivity,the length of grounding material,and the amplitude of lightning current so as to compare and analyze the impulse grounding resistance.The calculation results show that the impulse grounding resistance of flexible graphite grounding material is smaller than that of the round steel. Finally,the simulation results are verified by actual impulse grounding tests.
作者
肖微
黄道春
阮江军
魏晗
詹清华
胡元潮
XIAO Wei;HUANG Daochun;RUAN Jiangjun;WEI Han;ZHAN Qinghua;HU Yuanchao(Foshan Power Supply Bureau,Guangdong Power Grid Company Limited,Foshan 528000,China;School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China;School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2018年第12期3808-3813,共6页
High Voltage Engineering
关键词
石墨基柔性接地体
有限元法
正交设计
电磁参数
冲击接地电阻
flexible graphite grounding material
finite element method
orthogonal experimental design
electromagnetic parameters
impulse grounding resistance
