2. Marco Teórico
2.8. Herramientas de gamificación para el aprendizaje de las matemáticas
6.8 Turnout wiring section added.
6.11.7 Spanwire portal added.
This document has been prepared for use within Scott Wilson's Railway Electrification and Power Engineering (REPE) Unit. It is addressed to and for the sole use and reliance of Scott Wilson's REPE staff. Scott Wilson accepts no liability for any use of this document other than by REPE staff and only for the purposes, stated in the document, for which it was prepared and provided. No person other than REPE staff may copy (in whole or in part) use or rely on the contents of this document, without the prior written permission of the Company Secretary of Scott Wilson Ltd. Any advice, opinions, or recommendations within this document should be read and relied upon only in the context of the document as a whole. The contents of this document are not to be construed as providing legal, business or tax advice or opinion.
© Scott Wilson Group PLC 2008
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
TABLE OF CONTENTS
1. PURPOSE ...16
2. SCOPE ...16
3. DEFINITION OF TERMS...16
4. BASICS OF OLE...16
4.1 What is OLE? ...16
4.2 Unique Features of OLE...17
4.3 Advantages and Disadvantages of the System ...18
4.4 RAMS ...18
4.4.1 Reliability ...19
4.4.2 Availability...19
4.4.3 Maintainability ...19
4.4.4 Safety...19
4.5 Development of OLE systems ...19
4.5.1 Electric Beginnings ...20
4.5.2 Mainline DC Growth...21
4.5.3 AC Developments...22
4.5.4 High Speed Lines ...23
4.5.5 UK Developments...26
4.6 Categories of OLE System...29
4.6.1 Tram Systems...29
4.6.2 Light Rail Systems ...29
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
4.6.4 High Speed Systems ...29
5. ELECTRICAL PRINCIPLES ...31
5.1 Supply voltages and currents ...31
5.1.1 Transmission and Supply Voltages ...31
5.1.2 Supply Current...32
5.5 AC Feeding and Immunisation Methods ...39
5.5.1 Classic feeding arrangement ...39
5.5.2 Auto Transformer Feeding Arrangement ...42
5.6 DC Supply Principals ...44
5.7 DC Sectioning Principles ...44
5.8 Protection, Monitoring and Control ...46
5.8.1 Fault Protection...46
5.8.2 Control and Monitoring ...47
5.9 Electrical Clearances...48
5.10 Earthing and Bonding ...50
5.10.1 AC Systems ...53
5.10.2 DC Systems and Stray Currents...53
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5.10.3 Temporary Earthing Arrangements ...53
5.10.4 Buffer Sections and Permanent Earths ...53
6. MECHANICAL PRINCIPLES ...55
6.1 Interface with the Pantograph ...55
6.2 Materials ...59
6.3 Wire Types...59
6.3.1 Contact Wire ...59
6.3.2 Contact Bar...61
6.3.3 Catenary Wire and Auxiliary Catenary...61
6.3.4 Droppers ...61
6.7 Transferring the Pan between Tension Lengths ...70
6.7.1 Zero Span Overlap ...70
6.7.2 Single Span Overlap...72
6.7.3 Multiple Span Overlaps...73
6.8 Turnout Wiring ...74
6.8.1 Low Speed Tangential Method ...74
6.8.2 Cross Contact Method ...74
6.8.3 Cross-Droppered Cross Contact Method ...75
6.8.4 High Speed Tangential Method ...76
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
6.8.5 High Speed Three Wire System ...76
6.9 Other Electrical Break Devices...76
6.11.8 Bridge and Tunnel Supports ...88
6.11.9 Anchors...91
6.12.7 Attachment to Other Infrastructure ...96
6.12.8 Basic Design Ranges ...97
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6.13 OLE Assemblies Overview ...98
6.14 OLE Geometry...100
6.14.1 Vertical Limitations...100
6.14.2 Horizontal Limitations ...102
6.14.3 Load Limitations...105
7. OLE DESIGN AND CONSTRUCTION PROCESSES ...106
7.1 Process Overview...106
7.2 Form EA and Form EB Processes ...106
7.3 Design Documentation...106
7.3.1 Major Feeding Diagram ...107
7.3.2 Section Diagram and Switching Instructions ...108
7.3.3 Wire Run Diagram ...109
7.3.12 Operation & Maintenance Manuals ...113
7.4 Checking Process...113
7.5 Design Licensing ...114
7.6 Basic Design Ranges ...116
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
7.6.1 GE/MSW Range ...117
7.7 Mark 1 Range ...118
7.7.1 OLEMI Range ...119
7.7.2 UK1 Range ...120
7.7.3 Auto Transformer Range ...121
7.7.4 Other Assemblies ...121
7.8 Construction Methodology ...122
7.9 OLE Maintenance...123
7.10 Types of UK Equipment ...125
7.11 Interfaces with Other Subsystems...125
7.11.1 Permanent Way ...125
7.11.2 Civil & Structural ...125
7.11.3 Signalling ...125
7.11.4 Telecomms ...125
7.11.5 Electrical & Mechanical Services...126
7.11.6 Operations ...126
7.11.7 Highways ...126
7.11.8 Environment...126
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REPE Handbook: Introduction to Overhead Line Electrification
Table of Figures
Figure 1: A shortened TGV train takes the world rail speed record on 3 April 2007...17
Figure 2: 6.7kV AC OLE on the London, Brighton and South Coast Railway; circa 1910...20
Figure 3: The Sheffield – Manchester route via Wath, electrified with 1500V DC OLE...21
Figure 4: 1500V DC at Gidea Park on the Great Eastern; this was converted, first to 6.25kV AC and then 25kV ...22
Figure 5: Mark 1 25kV AC, WCML, London Euston ...23
Figure 6: Track damage after 1955 high speed run; France ...24
Figure 7: 0 series Shinkansen; Japan ...25
Figure 8: Extreme gradients on the TGV; Tonnerre, France ...25
Figure 9: APT tilting on neutral section tests; Murthat, WCML, UK ...27
Figure 10: Eurostar in preparation for record breaking run; Medway Viaduct, UK ...28
Figure 11: Typical feeding arrangements for AC OLE...35
Figure 12: Sectioning arrangements for Perturbation Crossovers ...38
Figure 14: Booster Transformer arrangement for OLE...41
Figure 16: Auto Transformer arrangement for OLE...43
Figure 17: Typical feeding arrangements for DC OLE...45
Figure 18: Detection of a fault ...46
Figure 19: ECR display screens; Melbourne, Australia ...47
Figure 20: Step potential ...50
Figure 21: Touch potential...51
Figure 23: Principal of secondary insulation...53
Figure 24: Principal of permanent earthing and buffer sections ...54
Figure 25: A pantograph on test; Old Dalby, UK ...55
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
Figure 26: Standard UK pan profile ...56
Figure 27: Differential wind force on pantograph...57
Figure 28: Typical Contact Wire Cross Section...59
Figure 29: Contact Wire Strength against Conductivity...60
Figure 30: Overhead contact bar; Paris, France ...61
Figure 31: Lightweight shedded polymeric 25kV insulator; WCML, UK ...62
Figure 32: Polymeric 25kV rod tension insulator; Stone, UK...63
Figure 33: 25kV shedded porcelain tension insulator formed of 3 cap & pin sections; Norton Bridge, UK ...63
Figure 34: 25kV shedded porcelain post insulator; WCML, UK...64
Figure 35: 25kV porcelain switching insulators with shed protectors; Norton Bridge, UK ...64
Figure 36: Tramway OLE ...66
Figure 37: Stitched tramway OLE...66
Figure 38: Simple catenary OLE ...67
Figure 39: Presagged simple catenary OLE...67
Figure 40: Stitched simple catenary OLE ...68
Figure 41: Compound catenary OLE...68
Figure 42: Fixed termination OLE...69
Figure 43: Auto tensioned OLE ...69
Figure 44: Uninsulated zero span overlap...70
Figure 45: Insulated zero span overlap ...71
Figure 46: Uninsulated single span overlap ...72
Figure 47: Insulated single span overlap...72
Figure 48: Uninsulated three span overlap...73
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Figure 49: Insulated three span overlap ...73
Figure 50: Low Speed Tangential Turnout Wiring ...74
Figure 51: Cross contact turnout wiring...74
Figure 52: Cross contact arrangement ...75
FFigure 51: Cross-Droppering Arrangement, Brinklow, UK...75
Figure 52: Discontinuous SI ...76
Figure 53: Continuous SI (plan view) ...77
Figure 54: High speed continuous SI; Rugby, UK ...78
Figure 55: Principle of a neutral section ...78
Figure 56: APC magnets at a neutral section...79
Figure 57: Arthur Flury type (left) and BICC glass bead type (right) neutral sections; Rugby, UK ..79
Figure 58: Typical single cantilever ...82
Figure 59: Typical double cantilever...83
Figure 60: Typical back to back cantilever ...84
Figure 61: Typical twin track cantilever ...85
Figure 62: Typical portal for four tracks with wideway ...86
Figure 63: Hinge-based portal leg on a viaduct, showing hinge pin ...86
Figure 64: Typical headspan for four tracks ...87
Figure 65: Typical headspan for four tracks ...88
Figure 66: Tunnel cantilever arrangement...89
Figure 67: Tunnel arm arrangement...89
Figure 68: Glass fibre bridge arm; Ripple Lane, UK ...90
Figure 69: Back-tied balance weight anchor with 3:1 anti-fall drumwheel and twin weight stacks; Newbold, UK ...91
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
Figure 70: MPA arrangement for cantilevers...92
Figure 71: Typical MPA arrangement for portals; Norton Bridge, UK...92
Figure 72: Planted mast; WCML ...94
Figure 74: TTC with gravity pad; Aveley Marsh, UK...96
Figure 75: Pull-off single cantilever ...98
Figure 76: Push-off single cantilever ...99
Figure 77: Height and stagger for OLE...100
Figure 78: Typical contact wire profile (y axis exaggerated)...101
Figure 79: Determining minimum stagger ...102
Figure 80: MSO, blowoff, stagger effect and MTO ...103
Figure 81: Typical MFD detail...107
Figure 82: Typical section diagram detail ...108
Figure 83: Typical wire run diagram detail...109
Figure 84: Typical layout plan detail ...110
Figure 85: Typical cross section detail ...111
Figure 86: Typical composite bonding plan detail ...112
Figure 87: Typical basic design drawing ...116
Figure 88: GE OLE; Stratford, UK ...117
Figure 89: Mark 1 portal; Norton Bridge, UK ...118
Figure 90: APT under Mark 3a headspans; Winwick Jct, WCML UK ...119
Figure 91: UK1 overlap portals; Millmeece, UK...120
Figure 92: Auxiliary Feeder on CTRL section 1; Ashford, UK ...121
Figure 93: OLE construction; Temple Mills, UK...122
Figure 94: OLE Maintenance; Stafford, UK ...123
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REPE Handbook: Introduction to Overhead Line Electrification
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
1. PURPOSE
The purpose of this advisory note is to give an introduction to Overhead Line Electrification systems for railways. This document covers all types of railway and Overhead Line Equipment;
all developments are covered, together with examples of UK systems.
2. SCOPE
This document applies to all OLE for tram systems, light or heavy rail, low speed or high speed.
Discipline Applies?
Overhead Line Equipment (OLE) 9
Electric Traction Equipment (3rd/4th rail) 8
Mechanical & Electrical Systems 8
3. DEFINITION OF TERMS
Term Definition
High speed Speeds above 200kph
Heavy rail Traditional railway systems; as opposed to light rail and tram systems
Overbridge A bridge over the railway Underbridge A bridge under the railway
All other terms are defined in the body text.
4. BASICS OF OLE
4.1 What is OLE?
Overhead Line Equipment (OLE) is a system used to deliver continuous electrical energy to a stationary or moving train. It is also known in the UK as OHL or OHLE. In Europe & the US, it is known as Overhead Catenary System (OCS), and in New Zealand, as Overhead Wiring System (OWS). The generic term for the system is Overhead Contact Lines.
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This document will use OLE, as it is the preferred term in the UK.
4.2 Unique Features of OLE
Unlike other power transmission systems, OLE is required to transmit high power (up to ~ 10MVA per train) to a load at a distance of several miles, which may be stationary or moving at up to 574kph1. The contact wire is therefore a twin system; it functions as both power
transmission mechanism and sliding contact with the train.
Figure 1: A shortened TGV train takes the world rail speed record on 3 April 2007
The key requirement for any OLE system is to provide continuous power at the train. For this to happen there must be continuous contact between OLE and the pantograph (see section 6.1).
Loss of contact leads to degradation of energy transfer and unwelcome damage to the contact wire and pantograph.
OLE is a very exposed system, and is vulnerable to:
• climate (especially wind, snow and ice);
• wildlife (particularly birds);
1 The current railway speed record is held by a French TGV unit, which reached 574.8kph on 3 April 2007 travelling under modified and super-tensioned (40kN) 31kV OLE. See http://en.wikipedia.org/wiki/TGV_world_speed_record for details.
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
• pollution;
• vandalism.
It must be capable of withstanding frequent fault conditions without degradation of performance.
The system tends to be constrained by other railway infrastructure, particularly in the UK where it has been retrofitted to railways dating from the 19th century, which were not built with OLE in mind.
Due to the continuous contact requirements, the contact wire position is paramount. There is no redundancy in this part of the system; a second contact wire is economically and practically unsound. If contact wire strays outside position limits, the pantograph will usually damage a significant length of the OLE.
OLE is therefore both an electrical and mechanical system, and the requirements of each must be balanced in the design.
4.3 Advantages and Disadvantages of the System
The key advantages of OLE systems over train-borne traction (e.g. diesel, gas turbine) can be summarised as:
• Flexibility of energy source;
• Reduced emissions;
• Concentration of emissions at single source;
• Lower energy usage through regenerative braking;
• Lower rolling stock maintenance costs;
• Greater reliability leading to smaller fleet requirements;
• Reduced noise.
Additionally, OLE has the advantage over conductor rail transmission system at high speeds;
the conductor rail is limited by current collection requirements to about 160kph with current technology.
Set against this are the disadvantages of the system:
• High capital cost of installation;
• Lack of redundancy in contact wire;
• Management of safety risks from high voltages;
• System is vulnerable if badly designed.
Because of the high capital cost of OLE, it has historically been difficult to gain funding for new electrification schemes; especially in the UK. Therefore the OLE designer should at all stages seek to minimise the installation costs, while balancing this against the Reliability, Availability, Maintainability and Safety (RAMS) criteria for the system.
4.4 RAMS
RAMS analysis is a technique used to optimise the performance of a system. The ideal is to reach, but not exceed, the required levels of Reliability, Availability, Maintainability and Safety
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using the most cost-effective means over the life of the system – the lifecycle. This takes into account not only the capital cost of the system installation, but the maintenance and operation costs over the lifecycle.
4.4.1 Reliability
It is essential that an OLE system be reliable, as measured in mean time between failures. The reliability should be set at a level that is the same, or better than, the other railway systems at that location. Reliability is especially important for OLE, as it is critical for electric train service.
For instance, financial constraints at the time of the East Coast Mainline (ECML) electrification mean that both the electrical supply and the mechanical support arrangements are less reliable than the other systems. The ECML is subject to frequent and serious service delays due to traction supply failure, and this can lead to a reduction in the credibility of electric traction systems in general – particularly in the eyes of those financing the system.
4.4.2 Availability
Availability is a measure of the amount of time the system has to be taken out of service for routine maintenance. Poor design leads to more frequent maintenance requirements, and lower availability.
For instance, poor choice of contact wire material can lead to increased wear; this in turn means the wire must be replaced more frequently, necessitating longer periods out of service.
4.4.3 Maintainability
OLE is an exposed system and is subject to wear and damage from a variety of causes. It is essential that the ability to access the equipment for maintenance is built into the design.
High maintenance items should be readily accessible. For instance, manually-operated switching sites should be placed near access points, and configured to cause minimum disruption to services.
4.4.4 Safety
The electrical and mechanical energy contained within OLE can cause serious injury and death if not controlled. It is the designer’s role under the Construction Design & Management (CDM or CONDAM) regulations, to ensure that safe construction, operation, maintenance and decommissioning of the system is fully integrated with the design. While it is impossible to achieve absolute safety, the risks inherent in the system must be analysed, and any
unacceptable risk reduced to an acceptable level. For instance, placing live OLE adjacent to a school playground fence creates an unacceptable risk. The addition of a suitable screen at this location reduces the risk to a degree known as ALARP (As Low As Reasonably Practicable).
4.5 Development of OLE systems
The following sections give an overview of the history of OLE development. For a more detailed list of UK builds, see APPENDIX III.
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
4.5.1 Electric Beginnings
The first OLE systems were used with passenger trams in the last years of the 19th century.
These generally consisted of a simple single wire (trolley) system, suspended from poles and buildings, and fed at a low voltage. This was preferred to the previous 3rd rail systems, which had safety implications for on-street running.
The first thirty years of the 20th century saw these principles extended to mainline systems as the advantages of OLE over 3rd rail became clear. Due to the increasing distances covered and the I2R losses encountered, voltages were increased. At the same time, more sophisticated suspension systems were required to maintain good current collection at increasing linespeeds.
Figure 2: 6.7kV AC OLE on the London, Brighton and South Coast Railway; circa 1910
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Experimental AC schemes were implemented for Lancaster to Heysham (1908) and London Victoria to London Bridge (1909) schemes, both at 6.7kV, 25Hz AC. AC motor technology was not developed at this time, necessitating complex train-borne rectification equipment; this was not yet reliable, so AC did not make any further headway until after World War Two.
On Tyneside, the Newport – Shildon line, which featured heavy coal trains running over steep gradients, was electrified with 1500V DC OLE in 1915.
4.5.2 Mainline DC Growth
The problems with AC, coupled with the transmission limitations of DC current, meant OLE was only used for suburban and freight systems; heavy electrical loads and short distances meant DC OLE made economic sense. In the UK, 1500V DC OLE was agreed in the 1930s as the national standard. The Sheffield to Manchester (via Wath) route, which required very heavy coal trains to be hauled over the steep gradients of the Derbyshire peaks, was authorised for
electrification in 1939. However World War Two brought this (and all other electrification schemes in Europe) to an abrupt halt.
These recommenced after the war, but at a much reduced rate; the railways’ priority was
rebuilding their battered infrastructure rather than funding new schemes. The Wath scheme was eventually completed in 1952: this turned out to be a pyrrhic victory, as within 6 years the DC standard was obsolete. The line survived until 1981, by which time it was an isolated system.
Figure 3: The Sheffield – Manchester route via Wath, electrified with 1500V DC OLE
Railway Electrification & Power Engineering
REPE Handbook: Introduction to Overhead Line Electrification
Unlike the UK, where overhead electrification proceeded only falteringly, the rest of Europe installed a large amount of 1500V DC in the pre- and post-war years, and much of this network still exists.
4.5.3 AC Developments
The 1950s saw increased interest in AC OLE; this was driven by the emergence of reliable industrial frequency AC technologies in the electricity supply industry. This meant that high voltage, long-distance AC transmission – and by inference, inter-city OLE systems – was now feasible. Across Europe, the 1500V DC standard was dropped in favour of 25kV at 50Hz AC; in the UK this was approved as the standard for future schemes in 19562.
The Lancaster to Heysham route, which had pioneered HV AC OLE in 1908, was converted from 25Hz to 50Hz in 1951 to serve as a test bed for industrial frequency supply. These tests confirmed the choice as the right one. A test scheme was installed between Colchester and Clacton in 1959. Various types of OLE were trialled, including simple and stitched, but compound was chosen as giving the best current collection at speed3.
It was initially assumed that 25kV AC systems would require substantial electrical clearances to existing infrastructure; in particular, it was felt that 275mm clearance would be required for bridges. In the UK this would not be possible without reconstruction work, particularly for many bridges in the vicinity of large stations. For these areas a reduced voltage of 6.25kV was proposed; trains would be dual-voltage and switch between them on the move as necessary.
Figure 4: 1500V DC at Gidea Park on the Great Eastern; this was converted, first to 6.25kV AC and then 25kV
2 Electric Railways, 1880 – 1990, Michael C Duffy, The Institution of Electrical Engineers, 2003, p321
3 Paper; A D Suddards, T H Rosbotham, T B Bamford
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Experience on the lines out of Liverpool St, where the 1500V DC lines were converted to 6.25kV AC, showed that there was excessive caution in the standard clearances. Reduced and
Experience on the lines out of Liverpool St, where the 1500V DC lines were converted to 6.25kV AC, showed that there was excessive caution in the standard clearances. Reduced and