【作者】 王益；

【导师】 汪沨； 黄福勇；

【作者基本信息】 湖南大学 ， 电气工程， 2011， 硕士

【摘要】 随着输电线路电压等级的提高,对绝缘子的绝缘性能要求越来越高,绝缘子在电气性能方面除了承受长期工作电压的作用外,还要承受暂态的操作过电压和雷电过电压的作用,要求绝缘子应能承受这些电压的作用,不发生绝缘击穿,不发生沿面闪络。如何提高输电线路绝缘水平是高电压外绝缘领域的主要研究内容。本文首先对湖南气候及其污秽特点进行了调查,分析了湖南电网输电线路的运行状况,指出了各种类型绝缘子的优缺点,总结了四种类型绝缘子选取的典型方法。文中讨论了根据污秽级别和爬电比距法确定绝缘子串片数方法选择绝缘子所涉及的关键问题。选择绝缘子过程中可根据污耐受法选择绝缘子串长和片数,再按绝缘子耐操作过电压特性的选取方法、绝缘子耐雷水平的选取方法来校核,可互相验证选择结果的合理性和可靠性。随着湖南省污秽的加重,省内线路的外绝缘配置无法满足当前污秽等级的需要。运行单位只能采取停电清扫线路绝缘子和线路雷击跳闸率超标,同时冰灾的出现,使得省内线路外绝缘优化配置尤为紧迫。本文分析了绝缘子污闪与冰闪形成的原因,提出了如何防止污闪及其冰闪的措施。比较V型绝缘子串与I型绝缘子串的优缺点,认为采用V型绝缘子串可以有效的提高绝缘子的冰闪电压。加强线路绝缘性能虽然可有效减少污闪事故、减小线路反击率,但也可能会对变电站的绝缘配合构成威胁。针对此问题,本文建立了基于电磁暂态程序ATP的仿真计算模型,计算了加强线路绝缘后雷电侵入波在变电站电气设备上产生的过电压或过电流,研究了加强线路绝缘对变电站绝缘的影响。更多还原

【Abstract】 As the upgrading of voltage of power transmission lines,the requirement of insulation performance for insulators becomes stricter. Insulators not only need to continuously run in operating-voltage for a long time but also need to bear the switching overvoltage and the lighting overvoltage under transient state. And most importantly they must avoid any kind of insulation breakdown and surface flashover. How to improve the insulation performance becomes the main purpose in the research of external insulation of power transmission and transformation equipment.The essay based on the research of weather condition and pollution situation in Hunan province analyzes the operation status of power transmission lines,compares the advantages and disadvantages of various types of insulators and put forward four typical methods to choose insulators. This essay focuses on some critical problems about choosing insulators and insulator string pieces on a basis of pollution flashover tolerance. Actually we can choose the insulator,its length and pieces based on the pollution tolerance and then apply the method of specific creep age distance,the selection of switching over-voltage of insulators’characteristics and the line lighting withstand level to check the reasonableness and reliability of the results.As the pollution becoming worse in Hunan,the external insulation equipment cannot satisfy the need of pollution level nowadays. The operating department has no way but to cut off the power to clean the insulators on lines or to tolerate the lighting outrage to be exceed. The optimization of insulators becomes an urgent demand when ice storms occur. The paper analyze the causes of insulators’pollution flashover o icing flashover,recommend some measures to prevent pollution flashover and icing flashover,compare the advantages and disadvantages between V-insulator strings and Insulator strings. The research result shows that V-insulator strings can improve icing flashover voltage more effectively.Although reinforcing the insulation’s performance of transmission lines can decrease the accidents caused by pollution flashover and the risks of flashback of transmission lines , it may threaten the insulation coordination of substation. Therefore,a stimulating calculation model of ATP has been established to solve this problem. This model calculates the over-voltage or the over-current produced by the lighting traveling waves on the equipment of substation and analyzes the impact on strengthening the insulation of transmission lines.更多还原