750kV沿线避雷器限制操作过电压研究

Adopting line surge arresters to suppress switching overvoltages in 750 kV EHV transmission lines

以中国即将建设的兰州东-银川东750 kV输电线路工程为背景,结合国外对操作过电压水平的研究,利用电磁暂态计算程序(PSCAD/EMTDC)分别计算了沿线装设多组避雷器对三相合空线、单相自动重合闸操作过电压的限制效果。计算表明,如果不装设沿线避雷器,三相合空线、单相自动重合闸操作过电压最大值分别为2.45 p.u.和2.63p.u.,而采用沿线装设多组避雷器的方法可以将上述两种750 kV线路的操作过电压抑制到1.80 p.u.以下,甚至更低。另外,随着避雷器组数的增加,通过避雷器的总能量会有所增加,但单个避雷器的通流容量却有所下降。

Arresters were installed along a 750 kV high voltage transmission line to suppress switching overvoltage. The effects of the number and positions of arrestor on the 750 kV Lanzhoudong-Yinchuandong transmission line on the switching overvoltages, including three phases energizing line without load and single phase auto-reclosing, were analyzed using the electromagnetic transient program PSCAD/EMTDC. The results show that without any arresters, the maximum ovcrvoltage while three phase energizing line with no load is 2.45 p.u. and for single auto-reclosing is 2.63 p.u. With arresters, the two overvoltages are suppressed to 1.80 p.u. or less which show that the attesters effectivity suppress switch overvohages in extra-high voltage （EHV） line. Besides the overvohage amplitudes, the energy passing the arresters is also important. As the number of arresters increases, the total energy passing the arresters increases but the energy passing each arrester decreases.