Study on a Method for Measuring Discontact Discharge Occurrence Frequencies in High Speed Liding Current Collecting System Using Impulisive Noise Currents

本研究的目的是提供一种利用滑动式集电器中流动的高频电流(噪声电流)来测量放电发生频率(脱触率)的新方法。对于非接触弧的对象，获得了以下结果。该原理基于连续测量VHF频段内单一频率的带通滤波器(BPF)对流经受电弓的噪声电流的最大响应之间的时间间隔，因为该时间间隔大致对应于弧光或非弧光的持续时间。在使用高斯带通滤波器的情况下，计算机计算表明，上述方法可以估计脱触率。推导了粗略估算脱触率的理论公式。为了验证本文方法的理论正确性和有效性，将计算结果与理论结果进行了比较。在非GA…情况下比较常用的带通滤波方法，计算机计算表明，该方法具有测量误差。为了减小这种误差，提出了一些算法，利用从滤波响应的包络中采样的数据。文中还提出了一种新的估计方法，该方法采用统计检验，不需要电弧电压和受流系统的电路参数等先验信息。为了对所得结果进行实验验证，用个人计算机构建了光谱分析装置。通过测量循环脉冲和伪随机脉冲的占空比来检查操作。利用模拟集电体的滑动接触装置进行了实验。结果表明，虽然在滑动接触处没有出现短弧的情况下，这种方法的有效性得到了验证，但在出现短弧的情况下，该方法的估计误差很大，而且这是由带通滤波器的响应和叠加在采样数据上的噪声重叠造成的。目前，我们一直在研究另一种利用电弧放电过程中的比电流波动来估计脱触率的方法。较少

The purpose of this study is to offer a new method for measuring the discharge occurrence frequency ( discontact rate) using the high frequency currents ( noise currents ) flowing in the sliding current collector. The following results are obtained for the subject of the discontact arcs. The principle is based upon the successive measurement of the time interval between the maximum responses of the band-pass-filter (BPF) at the single frequency in the VHF band to noise currents flowing through the pantograph, since this interval approximately corresponds to the duratio of the arc or the non-arc. In the case where the gaussian BPF is used, the computer computation shows that the above method can estimate the discontact rate. The theoretical equation is derived to roughly estimate the discontact rate. For confirming the theoretical validity and the effectiveness of the method presented here, comparison is made between the computation and the theoretical results. In the case of the non-ga … More ussian BPF commonlyused, the computer computation shows that this method gives the measurement error. For reducing this error, some algorithms are presented by using the data sampled from the envelopes of the filter response. A new estimation method is also presented by using a statistical test, which requires no apriori informations such as the arc voltage and the circuit parameters of the current collecting system. For experimentally confirming the results obtained, the spectrum analyzingequipment is constructed by using a personal computer. The operation is checked by measuring the duty ratios of the recurrent pulses and the pseudo-random pulses. The experiment is performed by using the sliding contact apparatus simulating the current collector. It is found that although in the case where the short arcs do not occur across the sliding contacts the validity of this method is verified, in the case where the short arcs appear the method gives the large estimation error and also that this results from the overlapped responses of the BPF and the noises superimposed on the sampled data. At present, we have been investigating an another estimation method of the discontact rate using the specific current fluctuation during the arc discharge. Less