交流电场强度对导线雾凇覆冰特性的影响  

Influences of AC Electric Field Strength on Conductor Rime Icing Performance

作　　者：舒立春[1] 李特[1] 蒋兴良[1] 胡琴[1] 罗保松[1] 杨占刚[1] 

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市沙坪坝区400044

出　　处：《中国电机工程学报》2012年第19期140-147,197,共8页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973项目)(2009CB724502;2009CB724501);国家自然科学基金项目(51007099);国家创新研究群体基金项目(51021005)~~

摘　　要：输电线路覆冰严重威胁着电力系统的安全,国内外对导线覆冰开展了大量研究,但绝大部分研究都没有考虑电场对覆冰特性的影响,这与工程实际情况不相符。在人工气候室内对导线进行带电覆冰,测取了覆冰量和覆冰密度,并通过Q–V法测得了覆冰过程中导线的电晕放电量。为了解释电场对覆冰的影响机制,对交流电晕下水珠的荷电和所受库仑力进行了计算。试验结果表明:试验条件下,覆冰量和覆冰密度随交流场强增加均有先增大后减小的趋势。计算结果表明;电场将对水滴施加电吸力,导致在电晕出现之前或电晕较弱时覆冰量、覆冰密度增加;电晕较强时,空间电荷浓度增加,水滴荷电后所受库仑力起排斥作用,这可能是强电场下导线覆冰量和覆冰密度降低的原因。The icing on transmission lines seriously threatens the security of power systems. It is necessary to investigate the icing characteristics on conductors with the influences of electric field strength as the practical iced lines. A series of energized icing tests of conductors were implemented in the artificial climate chamber. The corona discharge quality during the icing procedure was measured by the Q-V trace method, and icing characteristics such as ice amount and ice density were also achieved. To explain the mechanisms of the effects of electric field on icing characteristics, the effect of dielectrophoresis and the Coulomb force created by the charging of droplets under AC corona field were calculated. Experimental results indicate that under the test condition, both the ice amount and the ice density firstly increase and then decrease with the field strength. The calculation shows that when corona is weak, the effect of dielectrophoresis will propel the droplets forward to the conductors, which will increase the ice amount and density. When the values of electric field strength and space charge density are large, the Coulomb force from the droplet charging will apparently obstruct the droplets from approaching the conductor. This obstruction effect may be the reason of the decline of the ice amount and ice density under a strong electric field.

关 键 词：带电覆冰 覆冰特性 电吸力 电晕放电 水滴荷电 

分 类 号：TM85[电气工程—高电压与绝缘技术]