高铁轨道电路隔离变压器雷电暂态模型  

Lightning Transient Model of Isolation Transformer for High-speed Railway Track Circuit System

作　　者：向念文[1,2] 陈维江[3] 李成榕[1] 谷山强[2] 阳晋[4] 孙峥[1] 

机构地区：[1]华北电力大学高电压与电磁兼容北京市重点实验室,北京102206 [2]国网电力科学研究院,武汉430074 [3]国家电网公司,北京100031 [4]北京全路通信信号研究设计院有限公司,北京100073

出　　处：《高电压技术》2016年第5期1594-1599,共6页High Voltage Engineering

基　　金：铁道部重大科技研究开发计划项目(2011T008);国家自然科学基金(U1134106)~~

摘　　要：隔离变压器是高铁轨道电路中重要的雷电过电压抑制设备。为了获得准确的雷电暂态过电压计算模型,通过导纳频域参数提取、矢量匹配拟合和电网络综合3个步骤,建立了隔离变压器共模传输和差模传输二端口等效电路模型,其适用频率范围为5 Hz^1 MHz。通过开展暂态响应试验验证了模型的有效性,模型计算结果与试验结果一致性较好,其中共模传输模型幅值偏差小于4%,差模传输模型幅值偏差小于2%。并利用模型分析了影响隔离变压器过电压抑制效果的2个重要因素,分析得到:随屏蔽层接地引线电感增大,过电压抑制效果迅速下降,当引线长度小于0.5 m时,过电压抑制效果大于40 d B;随次级侧对地阻抗增加,过电压抑制效果呈现下降趋势,阻抗在100?内,随阻抗增大抑制效果直线下降,阻抗大于100?后,抑制效果逐渐趋于稳定。Isolation transformer is an important lightning overvoltage suppression device for high-speed railway track circuit system. In order to obtain an accurate model of isolation transformer to calculate the lightning transient overvoltage, the calculation model was performed by three steps： extraction of admittance parameter matrix of apparatus in the frequency domain, rational function approximation of admittance frequency-domain responses by vector fitting procedure, and synthesis of the equivalent circuit by electrical network. The two-port common-mode（CM） model and two-port differential-mode（DM） model were established in the frequency range of 5 Hz-1 MHz. Moreover, the transient response experiments of isolation transformer were carried out, the deviation between the calculation results of the CM model and experiments was below 4%, and it was below 2% for DM model. The model was used to analyze two major factors influencing over-voltage suppression properties.The results are as follows： as the length of shielding grounding wire increases, the suppression effectiveness of isolation transformer will rapidly decline. If the length of grounding wire is less than 0.5 m, the voltage peak attenuation is greater than 40 d B. With the increasing of the secondary side to ground impedance, the shielding effectiveness will reduce. If the impedance is below 100Ω, the suppression effectiveness decreases rapidly with increasing of impedance. When the impedance is greater than 100Ω, the suppression effectiveness is stabilized.

关 键 词：高速铁路 轨道电路系统 隔离变压器 共模传输 差模传输 雷电暂态模型 

分 类 号：U284.26[交通运输工程—交通信息工程及控制]