基于HHT、DBWT的无绝缘轨道电路补偿电容故障诊断

通过基于传输线理论的无绝缘轨道电路分路状态仿真模型,分析补偿电容断线故障对轨道短路电流的影响规律,利用机车信号感应电压包络与轨道电路短路电流的关系,提出基于机车信号记录信息的补偿电容故障诊断方法。该方法采用B样条离散二进小波变换对机车信号所记录的感应电压幅度包络信号进行降噪,再通过对Hilbert-Huang变换的改进,计算各IMF分量经逐级累加后的相位信息,最后利用相位卷绕,根据相位信息中突变点的分布变化和补偿电容状态的对应关系,实现对补偿电容的故障诊断。实验表明,该方法适应性较强,受轨道电路长度和道砟电阻等轨道参数影响很小,能够准确检测出轨道电路单一补偿电容的故障位置,并且由于该方法的分析数据直接来自于机车信号自身的记录器,不需要额外增加硬件和单独安排运行交路,因此能够降低检测成本和满足对检测及时性等方面的要求。

The Method of Diagnosis of Compensation Capacitor Failures with Jointless Track Circuits Based on HHT and DBWT

The shunt state model of jointless track circuits based on the transmission line theory was used to simulation the influence of compensation capacitor failures on the short-circuit currens of track circuits.The method of diagnose compensation capacitor failures based on cab signal recorder information was proposed by analyzing the relationship between the short circuit currents of track circuits and the voltages induced by cab signals.With this detecting method,DBWT was adopted to reduce the noises in the induced voltage signals;the HHT was improved to calculate the phase information via the stepwise accumulation of the IMF components;the relationship between the condition of compensation capacitors and the change of the distribution of the discontinuation points in phase information was analyzed by means of the phase unwrapping technique so as to realize diagnosis of compensation capacitor failures.Experiment results show that the proposed method has good adaptability with little dependence on track circuit parameters such as the lengths of track circuits and ballast resistances,and it can accurately detect the location of a failed compensation capacitor under the condition that other capacitors are in good condition;because the analysis data are directly obtained from the cab signal recorder and additional hardware or separate arrangement of train running routes is not needed,the proposed method remedies the defects of the existing detecting methods in respect of detecting costs and timeliness and is able to meet the requirements of application on railway sites.