雷击输电杆塔时埋地管道感应电压的影响因素及防护措施

Influencing Factors and Protective Measures of Induced Voltage of Buried Pipeline When Lightning Strikes Transmission Tower

雷击输电杆塔时,通过接地装置流入大地电流和流过地线的电流都会在附近埋地管道的防腐层上形成干扰电压,对管道形成威胁。本研究利用频域矩量法结合时频转化的方法,建立了雷击输电杆塔时附近埋地管道防腐层电压的计算模型,给出了土壤电阻率、管道与输电线路的间距、管道尺寸、防腐层电阻率和防腐层厚度对防腐层电压的影响,并对安装排流带和改变杆塔接地装置结构的防护措施的效果进行了计算,结果表明合理的布置排流带和改变接地装置结构,可降低管道防腐层的电压。

When lightning strikes the transmission tower,the current flowing into the ground through the grounding device and the current flowing through the ground wire will form an interference voltage on the anti-corrosive layer of the buried pipelines nearby,posing a threat to them.Based on the method of frequency domain moment method combined with time-frequency conversion,the calculation model is established to analyze the anti-corrosion coating voltage of buried oil and gas pipelines when lightning strike transmission tower.Influencing factors on the voltage of anti-corrosive layer inclding soil resistivity,distance between pipeline and transmission line,pipeline size,resistivity and thickness of anti-corrosive layer are considered.Effect of protective measures like installing drainage belts and changing the structure of the tower grounding device are also calculated.The results show that a reasonable arrangement of drainage belts and changes in the structure of the grounding device can reduce the coating voltage.