scholarly journals Calculation of aerial contact wire volume heated by a moving electric ARC

2021 ◽  
Vol 2131 (4) ◽  
pp. 042069
Author(s):  
Yu G Semenov ◽  
I A Kondrashov
Keyword(s):  
Emergency Situation ◽  
Heat Propagation ◽  
Electric Arc ◽  
Technical Diagnostics ◽  
Heating Zone ◽  
Electric Locomotive ◽  
Destructive Effect ◽  
Contact Wire ◽  
Current Collection ◽  
Heated Area

Abstract The article is devoted to the study of the problem of electrified railways electric locomotive current collectors’ interaction violation with an aerial contact wire, accompanied by the occurrence of an electric arc. Current collection disorders, accompanied by arcing, have a destructive effect on the contacting elements, causing their thermal erosion. Places where current collection violations occur should be registered and diagnosed in a timely manner in order to prevent an emergency situation associated with burnout or breakage of the aerial contact wire. In order to further develop the system of technical diagnostics for current collection disorders accompanied by arcing, it is necessary to study the nature and parameters of the processes occurring during these violations. The main part of the article is devoted to the study of the area of heating the aerial contact wire by a moving electric arc. The characteristics describing the heated area are geometric parameters, including the area in the cross section of the wire and the volume of the area. To obtain the necessary data, the method of heat sources was applied, which is a mathematical model that describes the process of heat propagation in an aerial contact wire. The electric arc arising when the current collector breaks off is considered as a mobile heat source distributed over the aerial contact wire surface in the heating zone and having a limited radius of the heating spot. Based on the heat propagation process peculiarities inside the aerial contact wire, a method for calculating the volume of the heated area bounded by an isothermal surface of a certain temperature is presented. The heated area was visualized using the PTC MathCAD.

scholarly journals Maintenance service technology and analysis of operation results of electronic equipment of AC electric locomotives on the railways of the Eastern operational area

2019 ◽  
Vol 78 (3) ◽  
pp. 169-176
Author(s):  
S. A. Boginskiy ◽  
V. V. Semchenko ◽  
N. G. Shabalin
Keyword(s):  
Control System ◽  
Electronic Equipment ◽  
Technical Diagnostics ◽  
Electric Locomotive ◽  
Microprocessor Control ◽  
Maintenance And Repair ◽  
Functional Scheme ◽  
Maintenance Service ◽  
Microprocessor Control System ◽  
Microprocessor Technology

The article presents the relevance of the topic associated with the introduction of technical diagnostics tools and the service system of electronic equipment for AC electric locomotives. Results of operating a microprocessor control system and diagnostics of AC electric locomotives on the Eastern operational area are presented in the form of failure statistics of elements of microprocessor technology. Structure of the technological process of servicing AC electric locomotives on the railways of the Eastern operational area is shown. Authors revealed features of building a system of locomotive maintenance points (LMP), which carry out repair and maintenance of electronic equipment for AC electric locomotives of various series. Functional scheme of the system for servicing electronic equipment for AC electric locomotives has been developed. Bench and technological equipment of the service area for the maintenance of electronic equipment is shown. The article describes development of an automated workplace (AWP) for optimization and repair of a microprocessor control system (MCS) for an electric locomotive, which was not previously in the locomotive sector. Examples of performing technological processes of repairing cassettes of MCS using AWP are given. The following conclusions were made: 1. Statistics of MCS failures and malfunctions of their cells on AC electric locomotives at the Eastern operational area for the period from 2016 to 2018 (LMP of station Tayshet and Karymskaya) shows that the number of failures of MCS decreased by 30 % and the number of malfunctioning MCS cells, received for repair, decreased by 45 %. 2. Automated workplaces created in the JSC “DTsV of the Krasnoyarskaya Railway” for optimizing and repairing the local government of AC electric locomotive made it possible to optimize repairs and create an automated process for the maintenance and repair of electronic equipment for electric locomotives. 3. Developed by specialists of the JSC “DTsV of the Krasnoyarskaya Railway” together with the employees of the LLC “Lokotech-Service” technological model of full service maintenance and repair of electronic equipment for AC electric locomotives on the railways of the Eastern operational area was implemented and well proved itself in the work of the LMP.

Milwaukee Streetcar Overhead Contact System: A Challenging Design Effort

2019 ◽  
Author(s):  
Paul F. White ◽  
Gerti Kola
Keyword(s):  
Contact System ◽  
Electrical Safety ◽  
Light Rail ◽  
Original Design ◽  
Foundation Design ◽  
Pendulum System ◽  
Contact Wire ◽  
Current Collection ◽  
Final Design ◽  
Design And Construction

The new Milwaukee Streetcar system has been in the planning, design and construction phases for over 10 years and on November 2, 2018, operations with a combined overhead contact system and streetcar battery power commenced ushering in a new era of growth for the City of Milwaukee. Many challenges in the design and construction of the overhead contact line and power system were encountered during this time period including budgetary constraints, multiple pole location changes, underground obstacles, low clearance bridges, alignment changes, utility conflicts, and changing vehicle requirements. The line was originally designed for pantograph operation but soon adapted for pole/pantograph current collection and then changed back to pantograph only current collection during the final design. The original design consisted of underground feeder cables to supplement a 4/0 contact wire but eventually not utilized due to budgetary constraints. Instead, a larger 350 kcmil contact wire was used with no paralleling feeder cables. The added weight of a 350 kcmil wire with wind, ice and low temperatures created high forces in the overhead contact system (OCS) leading to challenges in pole and foundation design where compliance to the National Electrical Safety Code (NESC) was required. The OCS style originally proposed and finally constructed used an inclined pendulum suspension (IPS) system that was constant tensioned with rotating springs deemed by the installing contractor superior to balance weights. The pendulum system was chosen as it is simple, lightweight, less visually obtrusive, and more economical than other suspension systems such as stitch and steady arm that are being used on other streetcar or light rail systems. IPS has provided Milwaukee with an excellent operating overhead contact system. Buildings along the route that were not historic structures were utilized where possible for span wire attachment but in many locations long bracket arms up to 40 feet long had to be used requiring special designs to keep the size of the pipes standard with the rest of the system. Challenges arose at low bridge underpasses where the contact wire had to be below required code height and special precautions had to be undertaken. Other areas such as the St. Paul Lift Bridge proved challenging as well where special electrically interlocked OCS devices were initially designed to de-energize the overhead wires and is further discussed with the reasoning for their use. This paper outlines the phases of design, the changes to the design that occurred over time, the challenges encountered to the OCS design, the method of design, and the final disposition of the design for construction. It further outlines the construction of the system and problems encountered with poles, foundations, bracket arms, traction power substations, contact wire, feeder cables, and winter conditions affecting the integrity of these structures and how some of these problems were solved.

scholarly journals Increasing the forecasting fidelity of current collection system operating capability by means of contact pressure simulation modelling

2020 ◽  
Vol 217 ◽  
pp. 03003
Author(s):  
Anton Golubkov ◽  
Gleb Ermachkov ◽  
Aleksandr Smerdin ◽  
Oleg Sidorov ◽  
Victor Philippov
Keyword(s):  
Automatic Control ◽  
Control Systems ◽  
Contact Pressure ◽  
Current Collector ◽  
Limiting Factors ◽  
Movement Speed ◽  
Contact Wire ◽  
Current Collection ◽  
Automatic Control Systems ◽  
The Impact

Current collection quality is one of the limiting factors when increasing trains movement speed in the rail sector. With the movement speed growth, the impact forces on the current collector from the rolling stock and the aerodynamic influence increase, which leads to the spread in the contact pressure values, separation of the current collector head from the contact wire, contact arcing and excessive wear of the contact elements. The upcoming trend in resolving this issue is the use of the automatic control systems providing stabilization of the contact pressure value. The present paper considers the features of the contemporary automatic control systems of the current collector’s pressure; their major disadvantages have been stated. A scheme of current collector pressure automatic control has been proposed, distinguished by a proactive influence on undesirable effects. A mathematical model of contact strips wearing has been presented, obtained in accordance with the provisions of the central composition rotatable design program. The analysis of the obtained dependencies has been carried out. The procedures for determining the optimal current collector pressure on the contact wire and the pressure control principle in the pneumatic drive have been described.

scholarly journals Effect of Temperature Change and Contact-wire Wear on Current Collection Performance

2016 ◽  
Vol 57 (3) ◽  
pp. 199-206
Author(s):  
Mizuki TSUNEMOTO ◽  
Masatoshi SHIMIZU ◽  
Hiroyuki SAITO ◽  
Hiroshi KAJIYAMA
Keyword(s):  
Temperature Change ◽  
Effect Of Temperature ◽  
Contact Wire ◽  
Current Collection ◽  
Wire Wear

scholarly journals Dynamic Performance Simulation and Stable Current Collection Analysis of a Pantograph Catenary System for Trolley Wire Overhead Electrically Actuated LHD

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1015 ◽  
Author(s):  
Yinping Li ◽  
Tianxu Jin ◽  
Li Liu ◽  
Kun Yuan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Performance ◽  
Element Model ◽  
Contact Wire ◽  
Current Collection ◽  
Electrically Actuated ◽  
Catenary System ◽  
Stable Current ◽  
The Finite Element Model

The pantograph catenary system plays an important role in the power performance of electric mining vehicles. A pantograph catenary system combining both a pantograph and a catenary is one of the most promising solutions. As a case study, this paper discusses the dynamic performance and the stable current collection of a pantograph catenary system for a 14 ton underground overhead wire electrical actuated load, haul, dump machine (LHD). First, based on the optimized finite element simulation process, finite element models of the pantograph system and the catenary system are established. Second, the motion equation of the catenary is improved, and the finite element model of the pantograph catenary system is established. Finally, a dynamic simulation experiment is performed to determine the dynamic performance of the pantograph catenary system. The results show that when the radius of the contact wire is set to 0.00564 m and the tension of contact wire is set to 30 KN, the current collection indexes of the pantograph catenary system meet the requirements of stable current collection and are superior to the simulation results of related references. Therefore, the validity of the finite element model is verified; thus, the pantograph catenary system can stably charge and supply energy for the trolley wire overhead electrically actuated LHD and ensure sufficient power.

The dynamics of a current collection system for an electric locomotive

1971 ◽  
Vol 322 (1551) ◽  
pp. 447-468 ◽  
Keyword(s):  
Contact Force ◽  
Wave Speed ◽  
Operating Conditions ◽  
Electric Locomotive ◽  
Current Collection ◽  
Loss Of Contact ◽  
The Wire ◽  
Linear Differential ◽  
Valid Solution ◽  
A Current

The motion of an overhead trolley wire, suspended at equal intervals by stiff springs, in response to a pantograph moving with constant speed is analysed. The pantograph is modelled by two discrete masses connected by springs and dampers. Away from the supports the inertia and elasticity of the pantograph can be neglected and a simple solution for the wire and pantograph displacement is obtained. Near a support this solution is not valid as it predicts discontinuities in the vertical pantograph velocity. A different first approximation is then required in which the support elasticity and the pantograph inertia and elasticity must be included. This problem is reduced to that of solving a system of four linear differential equations containing one term with a stretched argument. The numerical and asymptotic solution of such a system is discussed and results are obtained for the contact force and pantograph displacement near a support in typical operating conditions. This disturbance at the support is propagated with the wire wave speed and reflected at the subsequent support, thus interacting with the pantograph again. This interaction is analysed and a uniformly valid solution obtained for the contact force over a complete span. Some conclusions are made about possible operating conditions in which loss of contact between the pantograph and the wire may occur.

DESTRUCTION MECHANISMS OF CU-ETP COPPER GUIDES FOR SECTIONAL INSULATORS OF RAILWAY TRACTION

2021 ◽  
Vol 113 ◽  
pp. 101-113
Author(s):  
Jarosław KONIECZNY
Keyword(s):  
Cross Section ◽  
Oxidation Process ◽  
Current Collector ◽  
Electric Arc ◽  
Destructive Effect ◽  
X Ray ◽  
Graphite Plate ◽  
Railway Traction ◽  
Layer Characteristic ◽  
Scanning Electron

This article presents the results of a research on the operational damage to sectional insulator guides made of hard electrolytic copper Cu-ETP (Electrolytic Tough Pitch Copper). The guides were used on various rail routes, in real conditions, on which the trains ran at maximum speeds between 40 and 120 km/h for periods of 6 or 12 months. The microstructure of the surface, the working layer of the guide, which contacts the graphite plate of the current collector and the cross-section of the guide in the place where it was damaged was examined using the Olympus light microscope. The analysis of the chemical composition in the EDS micro-regions was performed using the Zeiss Supra 53 scanning electron microscope (SEM), while the qualitative X-ray phase analysis was performed with the use of the Panalytical X'Pert diffractometer. Scratches and deformations of the surface layer characteristic of the phenomenon of friction caused by the current collector were observed in the microstructure of the damaged parts of the guides of section insulators. The effect of a very intense oxidation process was also observed, as well as the effects of an electric arc, which according to the author, is the factor that has the most destructive effect on the condition of the guides.

scholarly journals Possibilities of diagnosing the condition of contact wire in terms of thermal wear

2018 ◽  
Vol 239 ◽  
pp. 01050 ◽  
Author(s):  
Sergey Klimenko ◽  
Vladimir Li
Keyword(s):  
Residual Life ◽  
Thermal Softening ◽  
Electric Arc ◽  
Negative Consequences ◽  
Structural Diagram ◽  
Diagnostic Device ◽  
Contact Wire ◽  
Wire Material ◽  
Thermal Wear ◽  
The Wire

The paper considers the negative consequences of thermal softening of the contact wire material under the action of an electric arc, which is thermal wear. In order to determine the degree of softening of the contact wire in real time, the methodology for assessing the condition of the contact wire of electrified railways by the value of thermal wear is presented. The presented method is based on the criterial approach. The criteria for softening the material of the wire and the transition of the material to the liquid state are introduced. By comparing the amount of heat entering the wire in the event of an electric arc (with these criteria), the contact wire is diagnosed in terms of thermal wear. Calculations have been made using the proposed method; graphical dependences of the amount of heat entering the wire element on the current intensity of the electric arc for various times of its influence on the contact wire are constructed. A device for diagnosing the condition of the contact wire in terms of the amount of thermal wear is proposed, designed to record the place of occurrence of the electric arc, to collect and transmit the necessary initial data. The operating principle of the device is described and its structural diagram is given. The use of the method for assessing the condition of the contact wire in terms of the amount of thermal wear and the diagnostic device will make it possible to quantify the degree of thermal softening of the contact wire material in order to further determine its residual life.

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