应用纵联差动保护防止雷击同塔双回线路同时跳闸停电  

Applying Longitudinal Differential Protection Against Simultaneous Lightning Outage for Double-circuit Transmission Lines on Same Tower

作　　者：周浩[1] 邓旭[1] 沈志恒[1] 王东举[1] 孙可[2] 沈扬[3] 

机构地区：[1]浙江大学电气工程学院,杭州310027 [2]浙江省电力公司,杭州310027 [3]浙江省电力设计院,杭州310014

出　　处：《高电压技术》2014年第1期24-32,共9页High Voltage Engineering

摘　　要：为防止雷击同塔双回线路导致双回路同时跳闸(同跳)停电事故的发生,研究了采用纵联差动保护的防同跳效果。首先归纳总结了雷击同塔双回线路同时跳闸特点及继电保护现状,分析了同塔双回线路相序布置、杆塔接地电阻、杆塔高度、档距和线路绝缘强度等因素对双回线路耐雷性能的影响。然后详细比较了各保护装置在雷击同塔双回线路典型闪络故障下的动作情况,并结合实际线路定量分析了采用纵联差动保护的防同跳效果。研究结果表明,线路的两相耐雷水平曲线和三相耐雷水平曲线之间存在一个较大的"跳跃间隔";同塔双回线路中采用纵联差动保护后在雷击导致三相闪络时才会导致一回线路停电,在四相闪络时才会导致双回线路同时停电,因此与采用纵联距离和纵联方向保护相比,纵联差动保护具有更好的防同跳效果。最后,从继电保护角度提出了同塔双回线路防同跳的一些措施和建议。To prevent tripping accidents on doublecircuit transmission lines on the same tower （DCSTTL） caused by simultaneous lightning outage, we studied the effect of using longitudinal differential protection. Firstly, we sununarized the tripping characteristics and the actualities of relay application for DCSTTL, and analyzed the effects of some key fac tors, including phase sequence configuration, ground resistance, tower height, span of line and insulation level of tower, on lightning protection of transmission lines. Then, we compared the operations of different relay protection equipment on DCSTTL under typical lightning faults, and analyzed the effectiveness of using longitudinal differential protection to prevent simultaneous lightning outage for DCSTTL in quantity after considering practical line parameters. Results show that there is a large gap between the twophase level and the threephase lightning withstand level for DCSTTL. With longitudinal differential protection, a DCSTTL will only have power failure on a single circuit under threephase flashover, and only flashovers on four and more phases will cause doublecircuit line poweroff on the line. Therefore, compared with pilot distance relays and directional pilot relays, longitudinal differential protection performs better in preventing si multaneous lightning outage. We also proposed some other suggestions from the perspective of relay protection for protecting DCSTTL.

关 键 词：同塔双回 同时跳闸 纵联差动保护 耐雷水平 继电保护 雷击跳闸 

分 类 号：TM862[电气工程—高电压与绝缘技术] TM75