考虑轨面设备的无绝缘轨道电路道砟电阻回归测量方法

针对无绝缘轨道电路中因补偿电容和调谐区单元等轨面设备影响而难以准确测量道砟电阻的问题,提出由轨面电流幅值测量、参数拟合和回归计算3部分组成的道砟电阻回归测量方法。根据传输线理论,构建轨面电流幅值包络模型,分析道砟电阻、补偿电容和调谐区设备对轨面电流幅值的影响规律;对轨面电流幅值进行指数拟合,得到不同道砟电阻所对应的衰减因子,构建衰减因子与道砟电阻的回归计算式;基于人工方式实地测量的轨面电流幅值,回归计算得到道砟电阻;通过轨道电路半实物仿真实验平台,对该测量方法分别进行功能验证和性能验证。结果表明:功能验证中,仅测量指定3个位置点的轨面电流,即可较为准确地估算出道砟电阻,绝对误差为0.08Ω?km,相对误差为4.04%;性能验证中,计算得到道砟电阻的最大绝对误差仅为0.157Ω?km,对应的相对误差为7.9%,且测量结果受补偿电容和调谐区设备故障的影响较小。

Regression Measurement Method of Ballast Resistance in Jointless Track Circuit Considering Track Surface Equipment

Aiming at the problem that it is difficult to accurately measure the ballast resistance in jointless track circuit due to the influence of track surface equipment such as compensation capacitor and tuning zone unit,a regression measurement method of ballast resistance is designed,which consists of three parts:track surface current amplitude measurement,parameter fitting and regression calculation.Based on the transmission line theory,the envelope model of rail surface current amplitude was built to analyze the influence of ballast resistance,compensation capacitor and tuning zone equipment on the rail surface current amplitude.The attenuation factors corresponding to different ballast resistances were obtained by the exponential fitting of rail surface current amplitude,and the regression formula of attenuation factors and ballast resistance was then built.Based on the manual field measurement of rail surface current amplitude,the ballast resistance was obtained by regression calculation.The function and performance of the proposed measurement method were verified respectively by the hardware-in-the-loop simulation experiment platform of track circuit.Results show that:in the functional verification,the ballast resistance can be estimated more accurately by only measuring the rail surface current of the three specified position points,with the absolute error of 0.08Ω·km and the relative error of 4.04%.In the performance verification,the maximum absolute error of ballast resistance calculated is only 0.157Ω·km,the corresponding relative error is 7.9%.The measurement results are less affected by the compensation capacitor and the equipment fault in the tuning zone.