轨地过渡电阻对钢轨互阻抗频谱特性的影响研究  

Research on the Influence of Rail to Ground Transition Resistance on Rail Mutual Impedance Frequency Characteristics

作　　者：曹晓斌[1] 沈豪 陈友 陶鑫 CAO Xiaobin;SHEN Hao;CHEN You;TAO Xin(School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学电气工程学院,成都610031

出　　处：《高压电器》2020年第2期135-141,共7页High Voltage Apparatus

摘　　要：城市轨道交通的杂散电流会导致周边金属设施发生不同程度的电化学腐蚀,而走行轨对地过渡电阻是控制杂散电流大小的关键。文中通过研究走行轨之间互阻抗的频谱特性,探寻过渡电阻的测量方法。首先建立了地铁钢轨仿真模型,得到了钢轨短接线位置、土壤电阻率、过渡电阻对钢轨互阻抗频谱特性的影响规律,提出了用钢轨互阻抗判别钢轨对地过渡电阻不达标的方法。研究发现:钢轨短接线将影响低频段互阻抗的频谱特性,短接线离测量点越近,其影响越大,短接线距注入点500 m时测量频率需要达到4 k Hz以上;土壤电阻率对钢轨过渡电阻频谱特性主要影响在100 kHz以下;通过对比不同频率钢轨互阻抗与50 Hz互阻抗的比例关系,提出在100 kHz及以上时,该阻抗比的值大于18.2时,可以认为其对地过渡电阻小于3Ω·km。文中研究发现可用钢轨互阻抗的频谱特性检测钢轨对地过渡电阻,为城市轨道交通过渡电阻的检测提供了新的思路。The stray current in urban rail transit will cause different degrees of electrochemical corrosion to the surrounding metal facilities.And the transition resistance of rail to ground is the key factor to control the scale of stray current.This paper tries to explore a measurement method of the transition resistance by studying the spectral characteristics of the mutual impedance between the tracks.Firstly,a subway rail simulation model is established to obtain the influences of rail short-circuit location,soil resistivity,and transition resistance on the spectral characteristics of the mutual impedance of two rails.A method for using the mutual impedance to identify the rail-to-ground transition resistance is put forward.It is found that:1)Rail short-circuit wiring affects the spectrum characteristics of the mutual impedance in low frequency section,and the closer the short-circuit wiring is to the measuring point,the greater the impact becomes;2)When the short-circuit wiring is 500 m away from the injection point,the measurement frequency needs to reach more than 4 kHz;and 3)Most of the effect of soil resistivity on the spectrum characteristics of the transition resistance occurs below 100 kHz.By comparing the proportions of the mutual impedance at different frequencies and the mutual impedance at 50 Hz,it is concluded that when the value of the impedance ratio is greater than 18.2 at 100 kHz or above,the transition resistance is considered less than 3Ω·km.This study suggests that the rail-to-earth transition resistance can be detected by the spectrum characteristics of rails’mutual impedance,which provides a new idea for the detection of the transition resistance in urban rail transit.

关 键 词：地铁 钢轨电压 频率响应 频谱特性 过渡电阻 

分 类 号：U231[交通运输工程—道路与铁道工程]