The electric field distributions of cleanness and covered with snow , the electric field variety of covered with ice , and the break down electric strength of covered with snow and ice were analyzed . the affect of the angle of medium loss for insulation performance was analyzed 对冠雪绝缘子与清洁(无雪)绝缘子的电场分布作了比较；分析了覆冰后电场分布的变化；对覆冰、冠雪时的击穿场强进行了分析；还分析了介质损失角正切对绝缘性能的影响等。
On the test investigation , a lot of flashover tests are made in 10kv , 35kv and 63kv voltage condition on post insulators and suspensor insulators , including all conditions covered with snow or ice . which included different environment temperature , different melted ice and melted snow etc multi - condition 试验中，对不同冠雪量、不同覆冰量、不同温度及不同融冰、融雪等多种情况，环境温度在零上几度，零下十几度到几十度等不同情况进行了试验。
Based on the currently laboratory investigation results and the iced insulators leakage current performance during icing process , in this paper a leakage current measurement system is designed with graphical programming language laboratory virtual instrument engineering workbench 本文在国内外现有研究成果的基础上，根据覆冰绝缘子闪络过程中泄漏电流特性和测量要求，应用图形化编程语言labview设计了基于虚拟仪器的绝缘子冰闪过程泄漏电流检测系统。
By applying related theory of gas discharge and mathematical statistics , this paper more in - depth and systemic study the influence of the length of air gap , ice state , water conductivity and air pressure on the inception corona and pulse discharge characteristics , included the discharge frequency , discharge amplitude and time interval 根据试验结果,用气体放电和数理统计方法,分析了覆冰水电导率、冰的状态(干冰和湿冰) 、空气间隙长度、气压和施加电压等参数的变化对间隙模型的起始放电电压、脉冲放电特性、放电频率、放电幅值和时间间隔等的影响。
The main tests and researches are as following : to study the ac flashover characteristic of composite insulator in different icing states by imitating tests in multifunctional artificial climate chamber , and analyze the effect of ice amount and icing water conductivity on flashover voltage , put forward a flashover mechanism by analyzing the icing flashover process . to study the ac flashover characteristic of composite insulator in different altitude and icing states together by imitating tests in multifunctional artificial climate chamber , and mainly analyze the effect of altitude ( air pressure ) and ice amount on flashover voltage , and investigate the flashover mechanism . to investigate the effect of high altitude and icing on the hydrophobicity of composite insulators 本文主要进行了以下试验研究： 1 )在多功能人工气候室里模拟不同覆冰程度下合成绝缘子的交流闪络特性，主要分析覆冰量和覆冰水电导率对闪络电压的影响，并对其覆冰闪络过程进行机理分析； 2 )在多功能人工气候室里模拟不同海拔高度和覆冰程度综合作用下合成绝缘子的交流闪络特性，主要分析海拔高度(即气压)和覆冰量对闪络电压的影响，并进行闪络机理分析； 3 )研究高海拔和覆冰对合成绝缘子憎水性的影响。
The study results show that the minimum ac flashover voltage decreases with the increase of the ice amount accreted on the insulator surface by an exponential law , and the down - trend of the minimum ac flashover voltage will slow gradually with the bridging of the shed of the insulators by icicles , both the average saturated ice amount and the special exponent m of effect of ice amount for different insulators depend on the radius of shed and the air - gaps of the sheds of the insulators , and that the ac ice flashover voltage decrease with the decrease pressure ratio p / p0 ( rise of the altitude ) by power - law for different esdd and icing - states when the altitude is from 4000m to 5500m . the special exponent n , which show the effects of altitude on the flashover voltage , is various with the type of insulator , icing - states and the surface status of iced insulator etc . , and that the minimum ac flashover voltage of iced insulators decreases by power - law with esdd or the freezing water conductivity for different ice amount and atmospheric 研究结果表明：在不同海拔高度和等值盐密esdd下，绝缘子的最低交流冰闪电压均随覆冰量的增加而呈指数规律降低；当覆冰量增加到一定程度后，最低交流冰闪电压随覆冰量增加而降低的趋势趋于饱和；不同绝缘子串的平均饱和覆冰量及闪络电压的覆冰量影响特征指数m均与绝缘子的盘径和伞距等因素有关；在海拔4000 5500m之间，不同等值盐密esdd和覆冰状态下，绝缘子的交流冰闪电压随海拔高度的增加(气压的降低)与p / p0呈乘幂关系降低，气压影响特征指数n与绝缘子类型、覆冰类型、覆冰表面状况等因素有关；当覆冰量和气压一定时，绝缘子的最低冰闪电压均随着等值盐密( esdd )或覆冰水电导率的增加而呈乘幂关系降低，并逐渐趋于饱和。
Upon existent theoretical and experimental results and based on a great of laboratory investigations carried out in chongqing university , for the first time this paper studies systematically the insulators dc discharge performance and flashover mechanism of iced insulators in the complex atmospheric environment , which will contribute to the understanding of flashover phenomena observed on ice surface at low air pressure and provide the test and theoretical reference for hv and ehv transmission lines design and safety service 为此，在国内外现有工作的基础上，通过大量的试验研究，本文主要研究了复杂环境中绝缘子的直流闪络特性及闪络机理。其结果有助于进一步了解低气压下覆冰绝缘子的闪络现象，并可为输电线路的设计和安全运行提供理论依据。
All the transmission lines of west - east electricity transmitting project are inevitable to crossing the high altitude and icing areas . for the reducing of the air pressure and the absolute humidity , the electricity strength of insulators will drop obviously . therefore , it must be considered the effect on the insulators " flashover voltage caused by the change of altitude and ice when the insulation cooperation of transmission lines are being designed “西电东送”工程的所有输电线路都不可避免的要经过高海拔和覆冰地区，由于大气压力和绝对湿度的降低会使绝缘子的电气强度显著下降，因此在进行输电线路的绝缘配合设计时必须考虑到海拔高度和覆冰的变化对绝缘子的闪络电压影响。
