特高压交流输电线路绕击耐雷性能及其防雷措施研究

发布时间：2018-01-28 08:34

本文关键词： 特高压雷电绕击电气几何模型 ATP-EMTP 冲击电晕 ANSYS 差异化防雷　出处：《西华大学》2014年硕士论文　论文类型：学位论文

【摘要】：特高压电网具有输电距离远、送电容量大、线路损耗低、相对节省工程建设投资、减少土地使用面积等优点，对我国电力资源的优化配置和国民经济可持续健康发展战有特别重要的意义，然而其自身的特殊性也决定了运行过程中往往伴随着各种问题，本文重点分析了1000kV特高压电网的过电压问题和线路周围电场环境问题。运行经验表明:超/特高压交流输电线路雷击跳闸事故主要是由雷电绕击相导线造成的。本文利用改进电气几何模型(EGM)分别对不同雷电流幅值、沿线地形地貌、地线保护角和导线工作电压下输电线路的绕击耐雷性能做了定性分析，，还阐述线路绝缘水平、地面植被对绕击的影响。最后，分别归纳总结了各影响因素下线路绕击性能的一般规律。为了弥补EGM分析模型无法反映绕击时，导线上雷电过电压波的传播过程的缺陷，又建立了一种既考虑地线上电晕和起晕导线间耦合作用，又考虑输电线路与大地间电晕电容分布特点的多导线冲击电晕模型，并运用电磁暂态计算软件ATP-EMTP搭建了特高压单回交流输电线路绕击仿真模型，通过仿真得到了计及冲击电晕线路上雷电过电压波的传播特性；本文利用ANSYS有限元分析软件分析了特高压单回交流输电线路正常运行时周围电场环境，以及正常运行和存在雷电放电两种情形下输电线路表面电场强度分布状况。仿真结果表明：特高压单回交流输电线路下方电场环境满足国家相关标准的限值要求；雷电放电对地线表面场强分布影响很大，但对相导线的影响很有限，地线上极易产生上行先导。最后，在以上分析计算基础上给出了特高压单回交流输电线路差异化防雷综合治理措施的建议：即应采用“疏”和“堵”结合因地制宜的差异化综合配置思路，有针对性地开展差异化绕击防治工作，采取重点加强重要线路段和多雷区、强雷区及易绕击闪络段线路保护的策略，提高防雷的整体技术经济性。
[Abstract]:UHV power grid has the advantages of long transmission distance, large transmission capacity, low line loss, relatively saving construction investment, reducing land use area and so on. It is of great significance for the optimal allocation of power resources and the sustainable and healthy development of the national economy. However, its particularity also determines the operation process is often accompanied by a variety of problems. In this paper, the overvoltage problem of 1000kV UHV network and the electric field environment around the transmission line are analyzed emphatically. The operation experience shows that:. The lightning tripping accident in UHV / UHV AC transmission lines is mainly caused by lightning wound phase conductors. EGM) for different lightning current amplitudes. The characteristics of lightning resistance of transmission line under ground protection angle and conductor voltage are analyzed qualitatively, and the influence of line insulation level and ground vegetation on wound failure is also discussed. In order to make up for the defects in the propagation process of lightning overvoltage wave on the conductor, the EGM analysis model can not reflect the propagation process of the lightning overvoltage wave under the influence of various factors, in order to compensate for the defects of the EGM analysis model can not reflect the propagation process of the lightning overvoltage wave. A multi-conductor impulse corona model considering the coupling between corona and corona conductor on ground wire and the characteristics of corona capacitance distribution between transmission line and earth is also established. The simulation model of EHV single circuit AC transmission line is built by using electromagnetic transient calculation software ATP-EMTP, and the propagation characteristics of lightning overvoltage wave on impulse corona line are obtained by simulation. In this paper, ANSYS finite element analysis software is used to analyze the electric field surrounding UHV single circuit AC transmission line when it is in normal operation. And the distribution of electric field intensity on the surface of transmission line under the condition of normal operation and lightning discharge. The simulation results show that:. The electric field environment under UHV single circuit AC transmission line meets the limit requirement of relevant national standards; Lightning discharge has a great influence on the distribution of field intensity on the surface of ground wire, but the influence on phase conductor is very limited. On the basis of the above analysis and calculation, the paper gives the suggestion of comprehensive measures for the differential lightning protection of UHV single circuit AC transmission lines: that is, we should adopt the "sparse" and "blocking" combined with local conditions of the differential comprehensive configuration thinking. In order to improve the overall technical and economic efficiency of lightning protection, the prevention and control work of differential wound strike is carried out, and the strategy of strengthening the line protection of important line sections and multiple mined areas, strong minefields and flashover sections is adopted to improve the overall technical and economic efficiency of lightning protection.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM863

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