电气化铁路弓网接触压力功率谱的特征提取

Feature Extraction of Pantograph-catenary Contact Force Power Spectrum of Electrified Railway

电气化铁路中,弓网间的接触压力数据是表征弓网受流质量和动态特性的重要参数,现行弓网技术标准中的时域平稳统计参数难以准确全面地反映弓网动态特性。本文使用自回归模型功率谱估计方法,利用信息理论准则选择合适的模型阶数,得到接触压力的功率谱估计。根据接触压力谱的趋势和波动提出了一种接触压力谱的特征提取方法,该方法通过使用二次多项式拟合接触压力谱下包络线表征谱的趋势特征,用谱中极大值点所对应的波长和谱幅值表征谱的波动特征,以此制定固定线路和固定受电弓类型时一定车速下的接触压力谱标准。比较和分析表明,该方法提取的特征参数具有一定规律性和实际意义,为弓网动态性能评价、弓网系列化标准的建立提供了参考。

The pantograph-catenary contact force is an important parameter that characterizes the quality of cur-rent collection and dynamic characteristics between pantograph and catenary.The current pantograph-catenary technology standards which compute stationary statistic values cannot reflect the dynamic characteristics accu-rately.In this paper,the autoregressive model was used for spectrum estimation and the order of AR model was determined by the Akaike information criterion.A new method was proposed to extract features of the contact force spectrum according to the trend and fluctuation of the spectrum.The trend of contact force spec-trum was characterized by using a quadratic polynomial to fit the lower envelope of the spectrum.The fluctua-tions of contact force spectrum were characterized by the wavelengths and amplitudes of the maximum points of spectrum.Thus the contact force spectrum standard for certain railways and pantographs under certain train speeds was developed.Comparison and analysis show that the feature parameters extracted with the proposed method have certain regularity and practical significance and so provide references to evaluation of dynamic per-formance and to formulation of serialization standards of pantograph-catenary systems.