摘要
沁北电厂设计安装两台 60 0 MW发电机组 ,经双回50 0 k V沁新郑线接入华中电网 ,线路全长 1 65.8km。针对沁北电厂 50 0 k V出线是否需要安装高压并联电抗器问题 ,利用 EMTP程序进行了较为详细的过电压计算和分析 ,得出的结论是 :1沁新线路较短 ,没有必要装设并联电抗器 ;2如果沁新线沁北侧装设高压并联电抗器 ,非全相运行时 ,断开相上的工频电压为 2 0 5.8k V,比较高 ,潜供电流和恢复电压分别为 1 2 .7A和 1 91 .0 k V,在这样高的恢复电压下 ,潜供电弧熄灭较困难 ,会影响单相快速重合闸的使用 ;3沁新线不装设并联电抗器 ,如果新乡变电站建设晚于沁郑线 ,沁北电厂单机通过沁郑单回线和系统相连 ,在这种情况下发电机不会发生自励磁 ,线路的工频过电压也低于规程允许水平 ,从沁北侧合沁郑线时 ,合闸过电压低于 2 .0 pu,相间绝缘和金属氧化物避雷器 ( MOA)通流能力能满足要求 ,沁北侧断路器仍可取消合闸电阻。此外 ,文章还提出了一些有关的建议。
In this paper the problem that whether it is proper or not to connect the high voltage parallel reactor group (2×90MVar) to 500kV out going line of Qinbei power plant is presented. The results of calculation and analysis with EMTP are: (1) For this out going line is short, to connect the parallel reactor group to the line is not necessary;.(2) If the parallel reactor is connected, the power frequency voltage of the open line would be 205.8kV and the restoring voltage would be 191.0kV. Such a high value of restoring voltage makes the blowing out of secondary arc difficult. Thus the single phase automatic reclosing would be affected. (3) According to the concrete condition of Qinbei power plant, although the parallel reactor group is absent, the self excitation of generators will not happen. Otherwise, some proposals on reactive power balance and the connection of parallel reactor are suggested.
出处
《电网技术》
EI
CSCD
北大核心
2000年第7期14-16,32,共4页
Power System Technology
关键词
输电系统
高压并联补偿
并联电抗器
电厂
parallel reactor
power frequency overvoltage
power frequency resonance overvoltage
secondary arc current
restoring voltage
