Estimation Method of Contact Line Unevenness using Dynamic Simulation

Abstract

One of the most important subjects for the current collection system of high-speed railways is to reduce the contact force fluctuation between contact line and pantograph. The unevenness of contact line is one of the factors that considerably affect the dynamic characteristics of contact line and pantograph system. This paper describes the methods to estimate the static installation quality of contact lines by calculating dynamic characteristics and reports some examples of the estimation of real line conditions.The flowchart of the dynamic estimation method of contact line is shown in Fig. 1. The dynamic characteristics, such as contact force fluctuations of pantographs and motion of contact lines, are calculated from the measured unevenness of contact wires, and the calculated results are diagnosed quantitatively. The static parameters, such as the tension of contact wire and the longitudinal force working on hangers, are derived from the unevenness of contact wire between hangers. The estimation conditions, such as pantograph type and train speed, are set at actual values of the section under estimation.In order to verify the accuracy of the estimating method, the calculated results based on a real unevenness data are compared with the measured results in the same section. Fig. 2 shows a comparison between calculated results and measured results of the maximum strain of contact wire at a support point. The calculated values agree well with the measured values. It is also confirmed that the uplift of contact wire and the contact force of pantograph are similarly in agreement.An example of dynamic estimation of contact line is shown in Fig. 3. In this case, since the calculated values do not exceed the This estimating method is useful for quantitative diagnose, such as detection of abnormal equipment, inspection after construction work and assessment of the amount of repair. This method is expected to contribute to efficient maintenance of contact lines for high-speed operation.

Estimation of the characteristic of contact line uplift and strain in the neighborhood of a tunnel inlet by computer simulation

“…The dynamic-characteristics calculation method shown in the reference was used for the simulation [2]. The appraisal method of unevenness the fictitious overhead contact line by dynamic-characteristics calculation can take into consideration the influence of wave reflection of the contact line.…”

“…By this method, however, only that gauge pasted at a point is evaluated. On the other hand, the evaluation method of dynamic characteristics of the overhead contact line unevenness has been developed based on erection conditions of the overhead contact line, such as unevenness of contact wire, the mounting position of suspension clamp like hanger etc [2]. By carrying out the simulation of the dynamic characteristics of the contact wire at the time of pantograph passage with use of this valuation method, it is possible to predict the location where the maximum of the uplift and strain of contact wire will be generated.…”

<b>Development of Simple Catenary System for Operation over 300 km/h</b>

“…Furthermore, in a train set with more than one pantograph, the rear pantograph is affected by overhead-contact-line oscillation caused by the front pantograph which depends on train speed, the distance between the pantographs and the span length. Therefore, to quantitatively evaluate the effect of the pantograph interval on the current collection performance of the rear pantograph, dynamic characteristic evaluation [6] was performed using the dynamic simulation of overhead contact lines and pantographs.…”

<b>Effect of Temperature Change and Contact-wire Wear on Current Collection Performance</b>

“…A simulation was conducted of the overhead contact line -pantograph [6] to verify the effect of temperature change and contact-wire wear on current collection performance. The conditions for the calculation of overhead contact lines are shown in Table 2, and Fig.…”