±800kV同塔双回直流线路杆塔空气间隙的放电特性影响因素研究  

Research on the Influence Factors of Discharge Characteristics of Air Gaps for ±800 kV Double Line Transmission Towers

作　　者：丁玉剑[1] 廖蔚明[1] 宿志一[1] 张泽[2] 律方成[2] 

机构地区：[1]中国电力科学研究院,北京市海淀区100192 [2]华北电力大学(保定),河北省保定市071003

出　　处：《中国电机工程学报》2014年第18期2983-2989,共7页Proceedings of the CSEE

摘　　要：±800 kV同塔双回线路电压等级较高,且杆塔形状和杆塔尺寸较±500、±660 kV直流输电线路杆塔都有很大差别,因此其空气间隙的放电特性有不同特点。为选择合适的±800 kV同塔双回直流线路空气间隙距离值,对影响±800 kV同塔双回输电线路杆塔上、下层空气间隙冲击放电特性的因素进行了真型尺寸模拟试验研究。研究了下层塔身宽度对杆塔下层间隙操作冲击放电特性的影响,均压环尺寸对直流V串塔头空气间隙放电特性的影响,直流运行电压对塔头间隙冲击放电特性的影响,±800 kV同塔双回输电线路杆塔下横担对上层间隙操作冲击放电特性的影响,并校核了下横担到上导线距离减小后杆塔的耐雷性能。研究结果表明:原有的塔身宽度对间隙操作冲击放电影响的修正公式已不适用于±800 kV同塔双回直流线路塔头;均压环尺寸大小与放电电压正相关;导线直流电场对间隙的放电路径有明显影响,但对放电电压影响不大;杆塔上导线到下横担的间隙距离可适当减小,但间隙距离减小后,杆塔的反击耐雷性能及绕击耐雷性能都略有降低。该研究结果可用于指导±800 kV同塔双回输电工程的设计。As the voltage grade is higher for the ±800 kV double line transmission tower, and the shape and sizes of the tower are different from that of ±500 kV, ±660 kV double line transmission towers, so the discharge characteristics of the tower gaps tend to be different. In order to choose the appropriate air gap distances, the factors which could affect the impulse discharge characteristics of the upper and lower air gaps of ±800 kV DC double circuit transmission towers were studied by tests on real size simulation towers in this paper. The influence of the width of the lower level vertical frame to the switching impulse discharge characteristics of lower air gaps, the influence of the grading ring sizes and the DC operation voltage to the discharge characteristics of the tower air gaps, and the influence of the lower frame to the discharge characteristics of the upper air gaps for ±800 kV DC double circuit transmission towers were discussed. Also the lightning protection performance of the tower was checked in the case of shorter the distances between the upper line and the lower frame. The results show： the formula used before for correction of the influence of tower width to the switching impulse discharge voltage of air gaps is inapplicable to the _±800 kV DC double circuit transmission towers; the relationship between the sizes of grading rings and discharge voltages is in positive correlation; the existing of DC electrical field has obvious influence to the discharge paths but not to the discharge voltage value. The distance between upper lines and lower frames can be decreased, which would tend to decline the lightning protection performance of the tower a little. The research results could be used to guide the design of the ±800 kV double circuit transmission projects.

关 键 词：±800KV直流 同塔双回 空气间隙 冲击放电 

分 类 号：TM85[电气工程—高电压与绝缘技术]