【作者】 钟一俊；

【导师】 周浩；

【作者基本信息】 浙江大学 ， 电力系统及其自动化， 2008， 硕士

【摘要】 我国电网的特点是发电资源和负荷中心的地理分布极不平衡,存在着特高压输电的需求,以实现我国能源资源的优化配置。加强与特高压输电技术紧密相关的研究,已成为当前特高压电网发展迫切需要解决的问题。本文首先从特高压交、直流输电特性入手,探讨特高压输电两种输电模式在我国的适用场合。又对特高压输电研究中的一些重要技术问题,如输电线路的可靠性、稳定性、电磁环境和交直流配合等,分别针对两种输电方式展开了比较论述。然后,针对特高压输电线路的防雷问题,本文提出了基于击距理论的特高压输电线路等效受雷宽度计算模型,用以计算输电线路反击跳闸率,并利用EMTP方法和EGM方法,分别对特高压交、直流输电线路反击耐雷性能和绕击耐雷性能进行了详细计算分析。分析结果表明,特高压输电线路雷击跳闸事故主要是由雷电绕击导线造成的。而特高压直流线路存在极性问题,正极性导线比负极性导线更易遭受雷害。最后,本文对特高压输电工程设备研制现状,特别是特高压交、直流试验基地的建设,作了详细分析和介绍,并就特高压输电系统过电压和绝缘配合,高低压电磁环网运行,交直流并联运行等相关技术问题进行了详细论述。更多还原

【Abstract】 Nowadays, the distribution of energy resource and load determine that we have to construct long distance, great capability UHV transmission line. Thereby, the problem that must be solved in the development of UHV is to strengthen the research of UHV transmission system.Firstly, based on the differences of technical and economic characteristics of UHVAC/UHVDC, their applications in China are compared in the paper. Then, some important technical problems of UHVAC/UHVDC, such as reliability, stability, electromagnetic environment of power grid and DC/AC coordination are discussed and compared.Secondly, for improving the lightning performance of UHV transmission line, the paper proposes the calculating model of lightning strike width of transmission line which is based on the striking distance theory. With such model, the back striking trip-out rate of transmission line is calculated. Then based on both EMTP method and EGM method, the lightning withstand performances of back striking, shielding failure for UHV transmission line are analyzed. Research results show that the shielding failure is the main reason for lightning striking tripping of UHV transmission lines. Because UHVDC transmission line exists polarity problem, the critical current required for flashover of negative line is far higher than that of positive line.Finally, the current status of equipments manufacture of UHV transmission project, especially the establishment of UHV test base, has been introduced in this paper. Then some technical problems of UHV system, such as over-voltage and insulation coordination, high-low voltage electromagnetic, AC-DC hybrid operation, are discussed.更多还原