Impact of overhead line irregularity on current collection and diagnostics based on the measurement of pantograph dynamics

Author(s):  
A Collina ◽  
F Fossati ◽  
M Papi ◽  
F Resta

As train speed increases, contact wire irregularity affects the quality of current collection more and more. The possibility of achieving the maximum operating speed depends also on the maintenance level of the overhead line (OHL). In the present paper, the influence of contact wire irregularity (in terms of vertical deviation of its position) is investigated both experimentally and by means of numerical simulation of the dynamic interaction of pantograph and catenary. In a first step, the capability of the simulation to reproduce the effect of a singularity in the contact wire height along the line has been tested by comparison with available experimental results. The same model has been subsequently used to perform numerical experiments concerning the effects of several types of distributed defects on the catenary. Afterwards, considering the data generated with the simulation as experimental data, a procedure to find the signature in terms of the contact force of the considered distributed defects on the OHL has been proposed. In this procedure, the contact force is not measured, but estimated from the motion of the pantograph, by means of an application of the extended Kalman filter. The adoption of an estimation procedure for the contact force, instead of a direct measurement, would allow the installation of a measurement system that is much simpler than the one required for the direct measurement of contact force. For this feature, it could be installed, at least in principle, on ordinary trains, allowing to perform an extensive monitoring and diagnostic activity with a large database.

1983 ◽  
Vol 105 (4) ◽  
pp. 287-294 ◽  
Author(s):  
T. Vinayagalingam

A digital computer simulation technique is used to study the effects of changing pantograph characteristics upon the quality of current collection from simple catenary overhead equipment at high speed. In particular, the likely benefits to be derived by the use of controlled pantographs are assessed. Pantograph performance is judged on the basis of contact force variation and displacement responses of pantograph and contact wire. These studies have shown that the dynamic displacements of the combined system are determined primarily by the overhead line parameters rather than by the pantograph. At higher speeds droppers in the vicinity of the pantograph slacken and this is seen to influence significantly the contact force profile. On a “constant height” overhead line, the proposed “frame compensated” and “panhead inertia compensated” pantographs do not show any marked improvement in the quality of current collection.


2014 ◽  
Vol 654 ◽  
pp. 78-81 ◽  
Author(s):  
Mei Li Yu ◽  
Wen Zheng Liu ◽  
Jian Zhang ◽  
Cai Ying Yan

Elasticity variations in railway overhead contact line would lead to the fluctuation of contact force between pantograph and contact wire and produce a negative effect on the stability of current collection. Dropper distribution is one of the key factors affecting the elasticity of the contact wire. In this paper, the influence of dropper spacing on elasticity and quality of current collection have been studied using finite element analysis method by simulation. By analyzing the changes of elasticity value and contact force under different conditions of dropper distribution, the effect laws of dropper spacing on the contact wire elasticity and the quality of current collection under the speeds of 300km/h, 350km/h and 400km/h have been obtained.


2012 ◽  
Vol 251 ◽  
pp. 158-163 ◽  
Author(s):  
Gang Yang ◽  
Zhong Mei Dai ◽  
Fu Li ◽  
Zheng Zhi Luo

The regular current collection is very important for high-speed train, and can be obviously improved by the use of active control. In order to study the impact of the fuzzy active control on pantograph-catenary system, the model ohe simulation model is created with the software of simulink. Finally the influences of fuzzy active control on dynamic performances and quality of current collection of the pantograph-catenary system are analyzed. It seems that, the performances of the system with or without active control is established, the fuzzy controller is constructed, and tf the pantograph- catenary system can be improved obviously under the fuzzy active control, the maximum value of the contact force is reduced to 50 percent, the minimum is increased to 80 percent, and the fluctuation extent of the contact force is reduced to 70 percent.


2013 ◽  
Vol 397-400 ◽  
pp. 1378-1382 ◽  
Author(s):  
Chuan Xi Li ◽  
Lin Dong

In order to reduce the wear of pantograph and catenary, prolong working time of the friction pair, and ensure the quality of current collection, a new type of pantograph active control strategy is designed. The strategy is based on the theory of friction and wears with electric current, control theory and micro-control technology, and is characterized by the dynamic wear test of catenary and the contact force control. The results show that the wear of the pantograph and catenary can be significantly reduced, the contact force fluctuation also can be effectively controlled, and the quality of the current collection of pantograph-catenary can be improved, while the active control strategy is applied.


Author(s):  
Ramiro Remigio Gaibor Fernández ◽  
Abraham Adalberto Bayas Zamora ◽  
Galo Israel Muñoz Sánchez ◽  
Cristhian Adrián Rivas Santacruz

The objective of the present investigation was to evaluate the physical characteristics of the vermicompost and the quality of the purine of the red Californian (Eisenia foetida) using different substrates of feed for these worms. For this purpose, nine treatments were studied: 75% African palm rachis + 25% cattle manure, 50% African palm rachis + 50% cattle manure, 25% African palm rachis + 75% livestock manure, 50% manure of cattle, 50% of manure of cattle, 25% of manure of cattle, 50% of manure of cattle, 50% of manure of cattle, 50% of rach of coconut + 50% of manure of Livestock, 25% coccus rachis + 75% livestock manure. The substrate made up of 50% of rachis of coconut and 50% of livestock manure can be used in nurseries or nurseries for being the one that registered a value of pH 7.3 plus the closest to the neutral compared to the others, besides this (75% of oil palm rachis and 25% of cattle manure) showed a higher content of humic and fulvic acids (0.87 and 0.45 p / p, respectively), compounds that are important for agriculture by stimulating plant growth, in addition to this reflection 0.06% sulfur content, 4.0 ppm boron, 7.0 ppm copper, 47.5 ppm iron, 6.0 ppm manganese, with a presence of microorganisms of the species Trichoderma, Penicillium, Cladosporium sp. in amounts of 1.91x105 UFC / ml, however in this substrate was obtained between 13.3 and 43.5% less liquid slurry in Comparison with other treatments.


2012 ◽  
Vol 58 (2) ◽  
pp. 1-6
Author(s):  
Radim Pavlík ◽  
Vlastimil Řepka
Keyword(s):  
The One ◽  

Abstract In its introduction, this contribution deals with the usage of magnetite during the process of coal separation in the Karviná Mine's preparation plant of the Lazy Plant. Next it deals with the evaluation of quality of magnetite used in the preparation plant, losses of magnetite adhering to the products leaving the preparation plant, the recovery of a diluted suspension with focus on the efficiency of magnetite separation of the diluted suspension and the comparison of the magnetite consumption with the one in the ČSM preparation plant. In conclusions, the article presents options leading to the reduction of the magnetite consumption in the Karviná Mine's preparation plant of the Lazy plant. For comparison, the data of the ČSM Mine is stated here.


2020 ◽  
Vol 26 (11) ◽  
pp. 2567-2593
Author(s):  
M.V. Pomazanov

Subject. The study addresses the improvement of risk management efficiency and the quality of lending decisions made by banks. Objectives. The aim is to present the bank management with a fair algorithm for risk management motivation on the one hand, and the credit management (business) on the other hand. Within the framework of the common goal to maximize risk-adjusted income from loans, this algorithm will provide guidelines for ‘risk management’ and ‘business’ functions on how to improve individual and overall efficiency. Methods. The study employs the discriminant analysis, type I and II errors, Lorentz curve modeling, statistical analysis, economic modeling. Results. The paper offers a mechanism for assessing the quality of risk management decisions as opposed to (or in support of) decisions of the lending business when approving transactions. The mechanism rests on the approach of stating type I and II errors and the corresponding classical metric of the Gini coefficient. On the ‘business’ side, the mechanism monitors the improvement or deterioration of the indicator of changes in losses in comparison with the market average. Conclusions. The study substantiates the stimulating ‘rules of the game’ between the ‘business’ and ‘risk management’ to improve the efficiency of the entire business, to optimize interactions within the framework of internal competition. It presents mathematical tools to calculate corresponding indicators of the efficiency of internally competing entities.


2017 ◽  
Vol 13 ◽  
pp. 244-261
Author(s):  
Mariola Tracz ◽  
Małgorzata Bajgier-Kowalska ◽  
Radosław Uliszak

Podkarpackie Voivodeship is one of the regions of Poland in which the number of agritourism entities is very high. Therefore tourism plays a significant role in its development strategy. The aim of the paper is to identify the current state of agritourism and the changes that have occurred in the region in the years 2000–2016. Specific objectives are to determine the distribution of agritourism farms and their offer, together with a comprehensive analysis of the environmental and socio-economic factors, as well as the impact of the Slovak-Ukrainian border. The report was developed on the statistical materials from the Polish Central Statistical Office, Podkarpackie Agricultural Advisory Centre in Boguchwała and data collected from municipalities and district offices that is published on their websites, as well as through interviews with 100 owners of agritourism farms in the Podkarpackie Voivodeship. The research has shown, on the one hand, the decline in the number of farms in the region and, on the other hand, the increase in the diversity of the tourist offer of these entities. Distribution of agritourism farms is closely linked to the attractiveness of natural environment and quality of secondary tourism resources. Traditional agritourism has not yet fully used its countryside, as well as cross-border advantages of its location.


Sign in / Sign up

Export Citation Format

Share Document