1000kV输电系统中性点小电抗过电压和绝缘水平  

Overvoltage and Insulation Level of Neutral Reactor on 1000 kV Transmisson Syetem

作　　者：谷定燮[1] 李振强[1] 伍志荣[1] 

机构地区：[1]国网电力科学研究院,武汉30074

出　　处：《高电压技术》2010年第6期1429-1436,共8页High Voltage Engineering

基　　金：国家"十一五"科技支撑计划重大项目(2006BAA02A02)~~

摘　　要：为深入研究系统中性点电抗的过电压和绝缘水平,首先指出简单地断开两相高抗来确定该过电压不符合实际运行情况且严重偏高,提出了1000kV交流同塔双回输电系统中性点小电抗的过电压计算方法、应考虑的工况;采用稳态计算确定暂态过电压,采用瞬态计算确定瞬态过电压和避雷器吸收能量介绍了淮南至上海1000kV交流同塔双回输电系统的计算结果。根据中性点过电压水平提出中性点避雷器的额定电压并进行了故障或操作状态下避雷器吸收能量的校核;依据避雷器的保护水平和中性点的各类过电压计算值提出了中性点绝缘水平要求值并建议在进行小电抗工频耐压试验的过程中同时检测局部放电量。最后对长治特高压变电站中性点小电抗在调试时的故障原因进行分析,并介绍了国内外中性点小电抗绝缘水平的选择情况及运行经验。We pointed out it did not match practical situation to simply open two-phase shunt reactors to obtain neutral reactor overvoltage,and this method obtained a sharp-increased result.Then we put forward the calculation procedure of neutral reactor overvoltage and required working condition of 1000 kV AC double circuits on the same tower transmission system.The method required to use steady calculation to get the power frequency overvoltage,and to use transient calculation to get transient overvoltage and MOA aquired energy.Furthermore,we presented the calculation results of Huianan-Shanghai 1000 kV AC double circuits on the same tower transmission system.On the basis of the neutral overvoltage,we presented the voltage rating of neutral MOA and checked the MOA aquired energy under fault or operating conditions.Based on the protact level of MOA and calculation results of neutral overvoltage,the required value of neutral insulation level was also presented.It is suggested that neutral reactor power frequency withstand voltage test should be needed,and the partial discharge should be detected at the same time.Moreover,neutral reactor failure cause was analyzed which happened at the Changzhi UHV substation when the system was set,and the choice of insulation level and operating experience home and abroad were introduced.

关 键 词：1000kV 同塔双回线路 输电系统 中性点电抗器 过电压 绝缘 

分 类 号：TM862[电气工程—高电压与绝缘技术]