基于Levenberg-Marquardt算法和广义S–变换的无绝缘轨道电路补偿电容的故障检测

Compensation capacitor fault detection method in jointless track circuit based on Levenberg-Marquardt algorithm and generalized S-transform

中文关键词  故障检测  广义S变换  莱文伯格–马夸特算法  短路电流  补偿电容

英文关键词  fault detection  generalized S-transform  levenberg-marquardt algorithm  short circuit current  compensation capacitor

中文摘要

      本文利用传输线理论分析了无绝缘轨道电路补偿电容故障对轨道电路短路电流幅度包络的影响, 提出了短路电流幅度包络的回归模型, 并利用Levenberg-Marquardt(L-M)算法验证了该模型的正确性和适用性. 根据机车信号的工作原理, 将对短路电流幅度包络的检测转换为对机车信号感应电压幅度包络的检测. 在利用L-M算法进行分段指数拟合以去除信号的衰减趋势的基础上, 通过广义S变换(GST)得到信号的瞬时频率变化, 最终根据短路电流幅度包络的回归模型, 对瞬时频率变化结果进行判决, 得到发生故障电容的具体位置. 实验表明, GST具有较高的时–频分辨率, 可以此对故障电容进行准确定位. 由于该方法的检测数据全部来自于机车信号的日常运用, 使得利用本文方法可大大缩短补偿电容的检测间隔时间, 在很大程度上克服了目前检测方法在检测的及时性、成本和影 响铁路运输等方面的不足.

英文摘要

      Transmission-line theory is used to study the impact on the short circuit current in the jointless railway track circuit caused by the faulty compensation capacitor. Levenberg-Marquardt(L-M) algorithm is used to verify the validity and adaptability of the regression model for the short circuit current. According to the operation principle of the cab signal, the envelop of the induced voltage recorded in cab signal represents the short circuit current; its attenuation tendency is removed through piecewise exponential fitting based on L-M algorithm. Secondly, Generalized S-transform(GST) is used to compute the instantaneous frequency. Finally, based on the instantaneous frequency, location of the faulty capacitor is determined. Experiment shows that due to the high time-frequency resolution of GST, the faulty capacitor is accurately located. Because the data used are drawn from the cab signal, this method shortens the detection interval, reacts more promptly and with lower cost and less impact on railway transportation than other current methods.