Catenary Contact Wire Research Articles

Multi-domain approach to modeling pantograph-catenary interaction

When a railway pantograph interacts with a catenary during the movement of a rail vehicle, several physical phenomena, both mechanical and electrical, occur in the system. These phenomena affect the quality of power supply of a train from traction devices. The unfavourable arcing occurring when there are disturbances of contact between the pantograph’s slider and the catenary contact wire. In turn, it results in energy loss and increased wear of the components of the system. When designing new solutions, computational models are helpful to predict the quality of interaction between the components of the pantograph-contact line system already at the virtual prototyping stage. In this paper, the authors comprehensively present a multi-domain (multiphysics) model, which takes into account necessary conditions for interaction between pantograph elements and a catenary. Finally, the impact of the individual physical domains are analysed and the ones which have a significant impact on the simulation of the operation results are identified.

Wear analysis and prediction of rigid catenary contact wire and pantograph strip for railway system

With the rapid development of urban rail transit, the operation companies are plagued by the wear issue of metro pantograph-catenary (PAC) system in the last decades. Abnormal wear not only increases the maintenance cost but also seriously affects the stability and safety of the PAC system. In this paper, the models of calculating the wear rate are proposed in the first place, which can be used to approximately predict the wear of the contact wire (CW) and the pantograph strip (PS). After that, the wear distribution on the rigid catenary wire between two adjacent subway stations is analyzed. In addition, the layout of the CW is investigated and a calculation method for estimating and predicting the wear profile on the PS is proposed. The maintenance data recorded by GuangZhou Metro Line 2 and Beijing Metro Line 6 are introduced to validate the proposed models and prediction methods. It shows that the predicted results are in good consistency with the practical wear on the CW and also on the PS. With the help of the wear distribution on the CW, it provides with a reference to take effective measures to extend the service life of the CW and make a differentiated maintenance strategy. In the light of the proposed wear prediction method for PS, a more optimal layout of the CW can be designed to reduce the formation of deep grooves on the PS.

Review on Emission of Radiated Electromagnetic Fields from Train Pantograph Arcing

Pantograph arc is one of the most common and yet unavoidable difficulties in electrified railways. During winter the intensity of arcing increases due to ice layer on the overhead catenary wire. In AC traction system, the sinusoidal waveforms of the supply voltage and current distort due to pantograph arcing. It generates both conducted and radiated emission in a wide band. Both the DC component and higher order conducted and radiated emission increases with line speed. The amplitude of the DC voltage shows a wide variation concerning train speed, applied voltage, type of electrical load, the gap between the contact wire and the pantograph and current. In this paper, pantograph arcing and its effects on the railway vehicles are described. Sliding contact between the pantograph contact strips and the catenary contact wire is illustrated with the emphasis on the pantograph arcing. Arc characteristics, formation methods, extinction and resignation of the arc are studied. This paper presents a comprehensive review on pantograph arcing and its effects near radio-based mobile communications and other signaling instruments and some other related areas.

Analysis of measurement uncertainty for contact-less method used to measure the position of catenary contact wire, performed with the use of Monte Carlo method

Abstract Currently the majority of main railway lines in Europe are electrified, and electric trains have the biggest share in the entire amount of rail transport. Reliability of electrified railways is closely related to the issue of supplying traction vehicles with energy. The problems connected with diagnostics of energy consumption node, namely the contact line and the current collector, are therefore of fundamental importance for maintaining the high reliability level of electrified rail transport. The paper presents a novel diagnostic method of railway traction catenary using image analysis. Verification of the uncertainty of this method was carried out. For this purpose, a simulation model based on the Monte Carlo method. The influence of measurement uncertainty of input parameters on the accuracy of the method was investigated.

Исследование вида распределения экспериментального значения нажатия токоприемника на контактный провод

Current collection, while electric rolling stock is running, is a complex process. The quality of dynamic interaction is estimated at an average contact pressure of current collector and its standard deviation. To measure contact pressing force special equipment is used that is installed on the current collector and provides force measurements in contact “current collector-contact wire” with the required frequency. Obtained contact pressure measurement values are random variables that are affected by many factors, each of which is not possible to take into account simultaneously. Therefore, currently the most effective way to study the contact pressing is to carry an experiment. Preliminary check of obtained experimental distribution of contact pressure for normality was determined considering the basic static distribution parameters. Coefficients of skewness and kurtosis were calculated. To determine the nature of density of the experimental data distribution a histogram, as well as theoretical and experimental graphs of distribution density were built. Probabilistic values for evaluation of law of experimental data distribution are shown. Check on plausibility of the hypothesis about the consistency of theoretical and experimental distribution density was made, applying the criterion of Pearson agreement. The study on type of distribution of experimental value of contact pressing force of the current collector on the contact wire of catenary as a random variable showed that there are deviations from the normal law. Since the cumulative probability for the range ±2σ and ± 3 of normal distribution and the cumulative probability of contact pressure in the respective ranges differ by less than 1 %, in practice, to assess the quality of current collection it is permissible to use the average contact pressing of the current collector and its standard deviation.

Wavelet Transform-Based Approach to Defect Identification in Railway Carbon Contact Strips

Pantographs of electric rail vehicles are fitted with carbon contact strips, which slide along the contact wire of catenary to provide constant electrical contact. Contact strips are exposed to wear and damages. Using damaged contact strips significantly increases the risk of catenary rupture. Therefore, their technical condition has to be inspected frequently. In previous work a 3D laser scanning system was proposed for recording contact strips surface shape when vehicles pass an inspection point on a railway line. The system was complimented with an effective automatic wear estimation algorithm. However, this algorithm is insensitive to some shallow defects which are considered hazardous. This paper presents defects identification approach based on differentiation of contact strips profiles. It is assumed that the hazard of catenary rupture corresponds to the peak value in the differentiated profile. A wavelet transform was used to allow for robust differentiation of profiles featured by low signal-to-noise ratio. A method for choosing well-balanced dilatation parameter was proposed, in order to obtain good accuracy of differentiation of both smooth and narrow-edged contact strip defects. Results of simulations implemented in Matlab confirm that the proposed approach can be applied to an algorithm aiming for automatic defects identification.DOI: http://dx.doi.org/10.5755/j01.eee.21.6.13755

Turbulence intensity on catenary contact wires due to parapets placed on a double track bridge

In this paper the experimental results on the turbulence intensity levels at the catenary contact wires due to the presence of parapets placed on the sides of a double track bridge are presented. Both solid and porous parapets are tested, and the influence of angle of attack, parapet height, parapet porosity, bridge deck height, end eave length is also investigated. The turbulence intensity is obtained from measurement of wind speed using hot wire anemometry at bidimensional models placed at the wind tunnel. To show the effect of the several parameters on the experimental data, the results are referred to the turbulence intensity of the bridge without any parapet by defining a reduced turbulence intensity. Experimental results show that, if the parapet wake acts on the catenary contact wire, the turbulence intensity at catenary location grows. Therefore, when angle of attack or parapet height increases, the turbulence intensity at catenary contact wire generally also increases. Addition of eaves to parapets amplifies the influence of the windbreaks on the catenary contact wires. Porous parapets reduce the turbulence intensity at the windward catenary, but deteriorate flow characteristics at the leeward catenary contact wire location.