GIS母线结构及参数对VFTO波形的影响  

Effect of GIS Bus Structure and Parameters on VFTO Waveform

作　　者：杨钰[1] 王赞基[1] 邵冲[1] 

机构地区：[1]清华大学电机系电力系统国家重点实验室,北京100084

出　　处：《高电压技术》2009年第9期2306-2312,共7页High Voltage Engineering

基　　金：国家自然科学基金(50577034)~~

摘　　要：在绝缘结构设计阶段,对变压器线圈内特快速暂态过电压(VFTO)分布进行仿真需要了解侵入线圈内的VFTO的波形特性。为此从理论上分析了SF6气体绝缘变电站(GIS)中的VFTO从开关到变压器线端的传输特性。分别针对连接变压器的无分岔母线和有分岔支路母线结构,采用传输线等效电路模型和戴维南等效定理,推导出到达变压器线端的VFTO波形的解析公式;分析了VFTO波形基本特征及其主要频率分布;讨论了母线长度、波阻抗、变压器入口电容等电路参数对VFTO波形的影响。PSCAD电磁暂态仿真软件计算结果验证了理论分析和解析公式的正确性,表明了该方法不仅物理意义明确,而且使用方便,计算效率高,对工程设计具有实际意义。It is necessary to understand the characteristics of very fast transient over-voltages （VFTO） invaded into the windings when simulating VFTO distributions in larger power transformer windings at the design stage. We an- alytically studied the characteristics of VFTO produced in gas-insulated substation （GIS） during disconnector （DS） operation and traveling along GIS bus from the gas-insulated switchgear to the terminal of the transformer. The ana- lytical expressions of the VFTO waveform at the transformer end were theoretically developed based on the Theve- nin theorem and transmission line ＇equivalent circuit for two simplified GIS systems, one of which contained only a single bus between DS and transformer and the other contained a different kind of branch at the mid-point of the bu- ses. The effects of bus length, the bus characteristic impedance and the equivalent capacitance of the transformer on VFTO waveform were also analyzed, and some results of practical importance were obtained. The PSCAD simula- tion results verified the correctness of the analytical results. The analytical formulations not only give the clear ex- planation for the dependence of VFTO waveform on GIS topology and circuit parameters, but also have the advantages of convenience and high computational efficiency in practical applications.

关 键 词：气体绝缘变电站 特快速暂态过电压 传输特性 电力变压器 戴维南定理 传输线模型 

分 类 号：TM595[电气工程—电器]