Research On Lightning Protection And Scheme Evaluation In6-10kV Distribution Lines Of Oil Field

6-10kV distribution lines of oil field are more easily damaged by lightning. Lightning seriously affects the normal production of oil field. Therefore, the research on lightning protection of6-10kV distribution lines of oil field has great significance for the safety in production of oil field.This dissertation takes the actual6-10kV distribution lines in Jiiin oil field as the prototype, it applys risk matrix evaluation theory to ray against risk assessment of the lines. Depending on the results, the lines are divided into five different grades:the lowest, the lower, the ordinary, the higher and the highest. Lightning risk assessment results lay a foundation for the study of the subsequent specific measures for lightning protection and it can also provide reference for the differentiation lightning protection evaluation of overhead lines.In this dissertation, the electromagnetic transient software ATP-EMTP is used to establish the simulation models of oil field lines. Then the performance of many lightning protection measurements just as lightning shield wire, arrester, the arcing gap, reducing the ground resistance is checked by the simulation analysis. The results from the calculation and..simulation-show that:1) The lightning shield wire can effectively improve the lightning resisting level and decrease the lightning trip rate. Compared with the line which is without lightning protection measurements, the lightning trip rate (time/100km/year) decreases from2.82to1.73, the lightning resisting level increases from1.47kA to9.36kA and14.21kA for the situation of lightning tower top and lightning lines from the midspan.2) Compared with the line without lightning protection measurements, installing a group of arresters on every three stems can make the lightning trip rate (time/100km/year) decreases from2.82to2.47. The lightning resisting level can increases from1.47kA to5.30kA for the situation of lightning the arrester tower; The lightning resisting level is high enough and the lightning trip rate is close to0in theory for the situation of installing arrester on all tower; The lightning resisting level can increases respectively from1.47kA to126.9kA and11.10kA for the situation of installing arrester on three towers on both sides of easy strike tower including itselt and installing arrester on easy strike phase.3) The length of the arcing gap of P-15insulator for oil field lines should be between14.6cm to15.8cm, the arcing gap can make the lightning trip rate (time/100km/year) slightly increases from2.82to2.84.Based on the simulation analysis above, combining the technical and economic evaluation of various measures and ray against risk assessment results, this dissertation gets lightning protection scheme of lines in different risk level:For the lines of the lowest grades, use the arcing gap and automatic reclosing combination, strengthen the maintenance of existing lightning protection facilities; For the lines of the lower grade, if the line is without arrester, install arrester on three towers on both sides of easy strike tower including itselt, the rest of the line install a group of arrester every three stem, easy to strike phase all installed arrester, reduce the arrester grounding resistance; If the line installed lightning arrester, reduce large grounding resistance to comply with the requirements; For the lines of the general grade, erect lightning shield wire, reduce grounding resistance; For the lines of the higher grade, install arrester on every tower, reduce grounding resistance. For the lines of the highest grade, erect lightning shield wire and install arrester on every tower, reduce the grounding resistance. Finally, base on the research above, developed a set of lightning protection analysis system of oil field power line for users.