取消750 kV断路器合闸电阻的可行性研究

取消750 kV线路断路器合闸电阻可节省费用,提高断路器运行可靠性。笔者以即将建设的兰州东-银川东750 kV输电线路工程为背景,结合国外对取消合闸电阻的研究,利用电磁暂态计算程序(ATP/EMTP)计算装设1组避雷器和断路器合闸电阻时,线路三相合空线、单相自动重合闸统计操作过电压水平。计算表明,在首末端装设1组避雷器时,三相合空线、单相自动重合闸统计操作过电压最大值分别为2.38 p.u.和2.57 p.u.,在线路线路长度较短时,两端装设避雷器的方法可以将上述两种统计操作过电压抑制到1.80 p.u.以下,可见在线路较短时取消合闸电阻成为可能。

Studies on the Overvoltage for Eliminating 750 kV Circuit Breaker Pre-inset Resistor

Eliminating pre-inset resistor of 750 kV circuit breaker can save costs and increase operation stability.A arresters were installed at both ends of 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 over voltages,including three phases energizing line without load and single phase auto-reclosing,were analyzed using the electromagnetic transient program(ATP-EMTP).The results show that without any arresters,the maximum overvoltage while three phase energizing line with no load is 2.38 p.u.and for single auto-reclosing is 2.57 p.u.when the line is shorter and the install surge arresters at both ends,the ways can operate the above-mentioned two types of statistical overvoltage suppression to below 1.80,it can be seen when the abolition of the short circuit switch resistance is possible.