Pantograph and Contact Line System

By Jiqin Wu

Pantograph and Contact Line System comprehensively introduces pantographs, contact lines and their interactions in many areas including geometrics, dynamics, materials, and electrics—helpful to understanding the basic theories of interaction between pantographs and contact lines. The book examines application techniques for system design, construction and maintenance, and includes suggestions to keep pantograph and contact lines working in a safe and stable manner over the long term. In railway traction power supply system, the match between pantograph and contact lines is critical for reliable power transfer. The book provides application techniques for system management and parameter selection in design, construction and maintenance.

This book is useful for people who are in catenary and pantograph-related areas such as college teachers and students, researchers and other professional and technical personnel in design, manufacture, construction, operation and maintenance.

• Includes comprehensive coverage of all types of electric-powered trains
• Presents pantographs and contact lines as a whole system
• Explores electrical acting between pantograph and contact line systems for the first time
• Summarizes techniques in geometrics, dynamics, materials and electrics
• Establishes theories specific to pantograph and contact line systems
• Applies theories of pantograph, contact lines and other interactions into system management and parameter selection in design, construction and maintenance
• Provides the techniques applied in measurement and maintenance

• Language: English
• Publisher: Academic Press
• Release date: Nov 15, 2017
• ISBN: 9780128129333

Jiqin Wu

Professor Wu graduated from Southwest Jiaotong University in 1988 and received his BSc degree. He has nearly 20 years’ of experience in teaching and researching on basic theory of pantograph and contact line system, and has participated in the projects of design, construction and maintenance of Chinese overhead contact line system. He directed high-speed overhead contact line system vibration tests for high-speed railways such as Beijing-Tianjin, Wuhan-Guangzhou, Zhengzhou-Xi’an, Beijing-Shanghai, and construction of contact test bed of pantograph and contact line system in National Laboratory in Rail Transportation. He has published 3 books and more than 40 papers in pantograph and contact line system.

Book preview

Pantograph and Contact Line System

The 11th Five-year Plan of National Important Books Critical Technology Series of Traction Power Supply System of Dedicated Passenger Line

By

Jiqin Wu

Southwest Jiaotong University, China

Table of Contents

Cover

Title page

Copyright

Foreword

Preface

Chapter 1: Introduction

Abstract

1.1. Overview

1.2. Origin and development of pantograph and overhead contact line systems

1.3. Requirement and specification of pantograph and overhead contact line systems

1.4. Core issues of pantograph and overhead contact line systems and the framework of this book

Brief summary

Chapter 2: Pantograph

Abstract

2.1. Overview

2.2. Basic structure of pantograph

2.3. Characteristics of pantographs

2.4. Main test of pantograph

2.5. Application and development of pantographs in Chinese railways

2.6. Application of pantographs in urban rail transit

Brief summary

Chapter 3: Geometric Properties of Pantographs and Contact Lines

Abstract

3.1. Overview

3.2. Gauge

3.3. Pantograph and contact line areas

3.4. Geometric properties of pantographs

3.5. Geometric properties of overhead contact lines

3.6. Geometrical characteristics of pantographs and contact lines on typical high-speed railways

Brief summary

Chapter 4: Dynamic Interaction Between Pantograph and Contact Line

Abstract

4.1. Overview

4.2. Elasticity and nonuniformity coefficient of elasticity of contact line

4.3. Dynamic property of contact line

4.4. Requirement for dynamic interaction between pantograph and contact line

4.5. Measurement requirements for dynamic interaction between pantograph and contact line

4.6. Simulation requirement for dynamic interaction between pantograph and contact line

Brief summary

Chapter 5: Material Interface of Pantograph and Contact Line

Abstract

5.1. Overview

5.2. Performance of contact material

5.3. Pantograph strip

5.4. Contact wire

5.5. Material combination of strip and contact wire

Brief summary

Chapter 6: Electric Contact Properties of Pantograph and Contact Line

Abstract

6.1. Overview

6.2. Static electric contact between pantograph and contact line

6.3. Static electric contact test

6.4. Sliding electric contact

6.5. Open–close contact

6.6. Friction abrasion mechanism of pantograph and contact line

Brief summary

Chapter 7: Design and Construction of Pantograph and Contact Line Systems

Abstract

7.1. Overview

7.2. Basic pantograph requirements

7.3. Basic requirements on contact line

7.4. System design of pantograph and contact line

7.5. Selection of equipment and parts of contact line

7.6. Construction design for contact line

7.7. Construction of contact lines

7.8. Handover and operation

Brief summary

Chapter 8: Operation and Maintenance of Pantograph and Contact Line Systems

Abstract

8.1. Overview

8.2. Operational strategy for pantographs and contact lines covered by ice

8.3. Swinging of contact line wire

8.4. Burn and protection of contact line wires

8.5. Corrosion property of contact line material

8.6. Maintenance of pantographs

8.7. Maintenance of contact line

Brief summary

Chapter 9: Parameter Measurements of Pantographs and Contact Line Systems

Abstract

9.1. Overview

9.2. Measurement of dynamic characteristic parameters of pantographs

9.3. Measurement of spatial position parameters of contact wires

9.4. Measurements of elasticity of contact lines

9.5. Measurement of pantographs and overhead contact line contact forces

9.6. Measuring uplift of contact wires at registration points

9.7. Measurement of contact line temperatures

Brief summary

References

Index

Copyright

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Foreword

Critical Technology Series of Traction Power Supply System of Dedicated Passenger Line is the first work of China that studies the traction power supply systems of high-speed railways from the aspect of a macrosystem. It marks the transition of our study on traction power supply systems from an elementary level of a simple study on independent subsystems to a high level of integrated study on the entire system. Beyond all doubts, the release of this series is just at the right time for the development of traction power supply systems of high-speed railways of China at a special stage.

Electrified railways began in China in 1958. China completed the process, which advanced countries took 100 years to complete, by using only over 50 years through constant endeavor, from nothing, from common speed to high speed, and from low load to heavy load. The 11th Five-Year Plan is the stage when we realize new leaps in railway technology innovation and enter the era of high-speed railways. The reasons for success in high-speed rail innovation are based on original innovation, integrated innovation, and innovation after introduction, digestion, and absorption. In such a situation, Critical Technology Series of Traction Power Supply System of Dedicated Passenger Line is included into the 11th Five-Year Plan of the National Important Books.

A traction power supply system is the power source of an electric traction car, including both stationary equipment (traction substation) similar to the power supply and a pantograph and contact line system as the connection link between stationary equipment and mobile energy consumption equipment (vehicle). Traction power supply systems need to be highly reliable and also need to provide high-quality electric energy.

Considering AT feeding mode used by traction power supply systems of high-speed railways, AC–DC–AC drive technology applied to EMU and mass and decentralized objectives for dispatch by power supply line relay protection principle and failure distance measurement principle of new traction power supply systems, which need to be updated constantly. Functionality of automation systems, integrated dispatching systems, and management information systems of traction substations need to be optimized constantly.

Pantograph and contact line systems, as electric energy transmission media of traction substations and power traction units, should provide safe and reliable power transmission for stationary power consumption by the auxiliary facility of vehicle, living facility, and for mobile power consumption by the traction vehicle. Besides, in the case of a regenerative brake of vehicle, pantograph and contact line systems should fulfill the backward feeding. Interaction between a pantograph and a contact line is dependent on many factors. The study method separating pantographs and contact lines into two independent subsystems is no longer applicable to the operational requirement of high-speed railways. Pantograph and contact line systems are also closely linked to design, construction, operation, and maintenance.

Quality of electric energy of electrified railways is a long-standing problem. It shows up as negative sequence, reactive power, and harmonics on lines of AC–DC electric locomotives. On lines of AC–DC–AC electric locomotive/EMU, the development of technology significantly improves reactive power and harmonic-related problems. However, negative sequence becomes worse due to growth of power of a single electric locomotive/EMU. It is expected that negative sequence will become the major factor influencing power quality of electrified railways. Difficulty of treatment and capacity input will also increase. It is urgent to apply some innovative technical schemes.

I’m very pleased to share that the teachers of College of Electrical Engineering, Southwest Jiaotong University have systematically summarized their achievements in research and practice and provided this series of books, Traction Power Supply Automation for Dedicated Passenger Line, Pantograph and Contact Line System, and Electric Energy Quality Analysis and Control for Electrified Railway, covering the critical technical field of traction power supply systems of high-speed railways. The series of books takes the opportunity to face the challenge of the development of traction power supply systems and forms the concepts and achievements in compliance with the development requirements of traction power supply systems of our high-speed railways. It not only provides technical support for construction and operation of our high-speed railways, but also theoretical support for cultivating high-speed railway construction and management talents.

I firmly believe that Critical Technology Series of Traction Power Supply System of Dedicated Passenger Line will be widely used and has unlimited development potential, both in disciplinary development or engineering application.

Qingquan Qian

Academician of the China Engineering Academy

November 2010

Preface

Baoji–Fengzhou section of Baoji–Chengdu railway was approx. 91-km long and was built between 1958 and 1961. It began operation on August 15, 1961 and was the first AC-electrified railway of China. The completion of the Baoji–Fengzhou section marks the first step of traction power innovation in the history of Chinese railways.

The selection of the current mode of power supply systems and pantograph and contact line systems is a priority for the construction of electrified railways. Through overall comparisons and intensive studies, single-phase industrial frequency AC 25 kV was finally chosen. Compared with the current system, confirmation of the pantograph and contact line system mode is much easier. The first batch of 6Y1 mainline electric locomotives trial produced by China use a ДЖ-5 four-wrist diamond-shaped dual-arm pantograph, so the contact line of the Baoji–Fengzhou section should be compliant and designed depending on characteristics of such a pantograph.

In the process of evolution over 50 years, pantographs and contact lines of the Chinese electrified railways have experienced some changes. Considering interconnection and interworking requirements of the Chinese railways, the basics of content of interaction between pantographs and contact lines can no longer be changed fundamentally.

In the current circuit of traction power supply systems of railways, pantographs are mobile devices while overhead contact lines are stationary. The exact match between them is the precondition for completing electric energy transmission needed by electric trains. To enable hundreds of amperes of current to flow through the contact point of a pantograph and contact line smoothly, the system of pantographs and contact lines should meet very tight requirements of electrical performance, mechanical performance, and material.

Limited by economic and technical conditions, an affluent design for a pantograph and contact line system is impossible. Thus, professional design for pantographs and contact lines, conscious planning for each facility, and careful use and installation of those advanced and tested components are very important. Together with scientific operation and maintenance measures, the system can reach the expected life cycle.

Reliable transmission of electric energy is the final target of the pantograph and contact line system. The theoretical basis for realizing this target is closely related to electrical engineering, mechanical engineering, and material. With an increase in operation speed, impact of factors, such as aerodynamics on pantograph and contact line systems, cannot be ignored. Problems derived from extreme weather events have attracted more attention.

These topics promoted the author to write a textbook closely relate to pantograph and contact line systems and have transdisciplinary characteristics to help students of colleges and universities of traction power supply, field technicians, and other personnel interested in this field to acquire professional knowledge of the design, construction, operation, and maintenance of pantograph and contact line systems. This will also promote the improvement of technical expertise of pantograph and contact line systems of the Chinese railways.

Pantograph and contact line systems are two subsystems belonging to one current collection system and coupled together by a contact point. On the basis of the contact points of pantograph and contact line systems, this book introduces in detail: pantographs, the geometrical characteristics of pantographs and contact lines, dynamic interactions, and material interfaces and electrical contacts, and describes the method of applying basic knowledge to system design, construction, operation, and maintenance.

This book consists of nine chapters in total. Sections 3.5.2, 3.5.6, and 7.7.2 are written by Fang Yan; Sections 9.6 and 9.7 are written by Zeng Ming; Section 8.6 is written by Han Feng; and the rest are written by Jiqin Wu. The compiling editor of the entire book is Jiqin Wu.

Gao Shibin and Chen Weirong reviewed the content of this book.

This book is written with assistance of the Transportation Bureau, Ministry of Railways, CSR Zhuzhou Electric Locomotive Co., Beijing CED Railway Electric Tech Co., Ltd., and relevant people.

Wang Baoguo, Wang Zufeng, Jin Baiquan, Hou Rigen, Ren Xingtang, Pan Ying, Li Zongzhi, Xu Jianguo, Zhang Weihua, Li Lan, and Dong Zhaode provided numerous precious opinions and advice during the compilation of this book.

With the full support of Southwest Jiaotong University Press, this book is included into the 11th Five-Year Plan of the National Important Books. The graduate school of Southwest Jiaotong University has included this book into the textbook construction project of postgraduate students and provided assistance in compilation and publication. The author thanks these organizations and individuals for their support!

Due to my limited knowledge, shortcomings and omissions may be unavoidable. Your comment is appreciated.

Jiqin Wu

Southwest Jiaotong University

October 2010

Chapter 1

Introduction

Abstract

The current collection system is an electric energy exchange interface between electric trains and traction substations. It can be divided into pantograph and overhead contact line systems, pantograph and overhead contact rail systems, and collector shoe and contact rail systems. Different pantographs should work with their matching overhead contact line system. The interaction of pantograph and overhead contact lines presents in several aspects, such as geometrical parameter, dynamic performance, material interface, and electrical contact performance, which are independent but related to each other.

Keywords

overhead contact line system

Tokaido Shinkansen

TGV Sud-Est

Wurzburg–Fulda line

Baoji–Chengdu Railway

stagger

1.1. Overview

Energy for electric trains [including electric locomotive and electric multiple units (EMU)] running on electrified railways comes from a stationary power source, power plant. Electric energy is transmitted via substations and different voltage class transmission lines, and finally to electric trains, as shown in Fig. 1.1.

Figure 1.1   Transmission of electric energy required by electric trains.

Traction substations are distributed along the railway. They convert electric energy into the voltage class required by electric trains and feed electric trains through two conductor groups: contact lines above electric trains and tracks under electric trains. During regenerative brakes, these two conductor groups transmit electric energy from electric train to substation.

Contact lines are the main part of contact line system. They can be divided into trolley-type contact lines, where there are only contact lines and no continuous messenger wires (Fig. 1.2A), or overhead contact lines with catenary suspension, where contact lines hang onto messenger wires through droppers. Overhead contact lines with catenary suspension can be divided into contact lines with stitch suspension (Fig. 1.2B) or contact lines without stitch suspension (Fig. 1.2C). Contact wire is the most important part of contact lines.

Figure 1.2   Contact lines.

(A) Trolley-type contact lines, (B) contact lines with stitch suspension, and (C) contact lines without stitch suspension.

Electric energy required or fed out by electric trains is transmitted through direct contact between one or several current collectors called pantographs, which are mounted on the roof of the train and the contact lines above it, as shown in Fig. 1.3.

Figure 1.3   Electric train collects electric energy from contact lines through pantograph.

The part of pantographs that touches contact wires directly is called the contact strip. Certain contact forces between the contact strip and the contact wire are maintained to keep constant electric contact between them.

Forms of contact lines are decided depending on the operating requirement of the electric train and the characteristics of pantograph used. Contact lines cannot exist independently. The supports, poles, and foundations along the line are called overhead contact line systems.

In sections, the single-cantilever suspension shown in Fig. 1.4 is used in priority.

Figure 1.4   Single-cantilever catenary suspension overhead contact line.

1, Pole; 2, cantilever; 3, messenger wire; 4, contact wire; 5, insulator; 6, feeder; 7, pole foundation; 8, rail connection; 9, up-down track connection; 10, return wire; 11, stitch wire; 12, dropper.

In multitrack sections, the head span shown in Fig. 1.5 is often used to replace cantilever support.

Figure 1.5   Head span of contact line.

1, Diagonal steel pole; 2, cross bar pole; 3, lateral messenger wire; 4, messenger wire; 5, contact wire; 6, suspension point; 7, electric connection; 8, upper safety rope; 9, lower safety rope; 10, insulator; 11, section insulator; 12, curve steady arm; 13 and 14, switch jumper; 15, isolating switch; 16, cross arm; 17, electric operating mechanism; 18, return wire; 19, pole grounding; 20, pole foundation; 21, safety rope compensation; 22, feeder.

For high-speed contact lines, the combination of portal structure and the inverted pole shown in Fig. 1.6 is often used to replace the pole to realize mechanical isolation between overhead contact lines of different tracks.

Figure 1.6   Portal structure contact line.

Wires and their insulators are suspended above the line by supports at certain intervals. Spatial orientation of contact wires in horizontal directions vertical to the line is realized by a steady arm. The connecting point between the steady arm and contact wire is called the steady point. The distance between the two adjacent supporting points or suspension points of a contact line is called a span.

In tunnels, on some low-speed electrified railways or urban rail transit lines, current collection systems consisting of pantographs and overhead contact rails (or overhead rigid contact lines) can be used to feed electric trains. Overhead contacts or rails hung over tracks in tunnels are shown in Fig. 1.7.

Figure 1.7   (A) Rigid contact line and (B) bus bar with embedded contact wire.

The contact wire of the conductor rail is embedded directly into a bus bar (Fig. 1.7B); it is not subject to the tension along the line. To distinguish from rigid contact lines, we often call contact lines with tensile devices flexible contact lines.

In urban rail transit, contact rails insulated against the ground can also be used to feed electric trains. Contact rails can be horizontally close to the track as a third rail and parallel to the running rail. The collector shoe is used as a current collector, as shown in Fig. 1.8.

Figure 1.8   Collector shoe and contact rail.

(A) Collector shoe and (B) contact rail.

Due to the diversity and long history of contact lines, one objective, or its meaning, gradually evolved into different terms. IEC60050-811 has defined some major terms. They are:

1. Contact line system:

Support networks for supplying electrical energy from substations to electrically powered traction units, which cover overhead contact line systems and conductor rail systems; the electrical limits of the system are the feeding point and the contact point to the current collector. The system comprises:

a. the contact line;

b. structures and foundations;

c. supports and any components supporting or registering the conductors;

d. head and cross spans;

e. tensioning devices;

f. along-track feeders, reinforcing feeders, and other lines, such as earth wires and return conductors, as far as they are supported from contact line system structures;

g. any other equipment necessary for operating the contact line; and

h. conductors connected permanently to the contact line for supply of other electrical equipment, such as lights, signal operation, point control, and point heating.

2. Contact line:

Conductor systems for supplying traction unit electric energy via a current collector, mainly consisting of:

a. reinforcing feeders,

b. cross-track feeders,

c. disconnectors,

d. section insulators,

e. overvoltage protection devices,

f. supports that are not insulated from the conductors, and

g. insulators connected to live parts.

But excluding other conductors, such as:

a. along-track feeder sand,

b. earth wires and return conductors.

3. Contact lines:

A device of which one or more double-groove contact wires are hung on one or more longitudinal catenaries.

4. Overhead contact line system:

Contact line systems using an overhead contact line to supply current for use by traction units.

5. Overhead contact lines:

Contact lines placed above or beside the upper limit of the vehicle gauge, supplying traction units with electrical energy via roof-mounted current collection equipment.

6. Contact rail systems:

Contact line systems using conductor rails for current collection.

7. Overhead contact rails:

Rigid overhead contact lines, of simple or composite section, mounted above or beside the upper limit of the vehicle gauge, supplying traction units with electrical energy via roof-mounted current collection equipment.

8. Contact rails:

Contact lines made of a rigid metallic section or rail, mounted on insulators located near the running rails.

Fig. 1.9 shows the overall structure of contact line systems.

Figure 1.9   Overall structure of contact line system.

Unless otherwise specified, the contact line system described herein includes an overhead contact line and overhead contact rail.

The combination of pantograph and overhead contact line system (pantograph and overhead contact line system) is one of the ways that running electric trains obtain electric energy from traction substation. The load current of the train flows in from the contact point between pantograph and overhead contact line (pantograph–contact line contact point) and out from the contact point between wheel and rail (wheel–rail contact point), and returns to traction substation through a return circuit. The current direction is on the contrary in regenerative brake.

In certain economic and technical conditions, very tight electric and mechanical requirements on pantograph and overhead contact line system should be provided to ensure that the electric train passes through the pantograph–contact line contact point, reliably and steadily in extreme weather at the highest speed and to realize expected life cycle of the pantograph and overhead contact line system.

1.2. Origin and development of pantograph and overhead contact line systems

1.2.1. Origin of Pantograph and Overhead Contact Line Systems

At the World Trade Fair, Berlin, Germany, on May 31, 1879, Ernst Werner von Siemens exhibited the first electric locomotive in the world, as shown in Fig. 1.10.

Figure 1.10   The first electric locomotive in the world.

An electric locomotive was supplied by tracks and consisted of three cars. It ran on a 300 m circular rail at a speed up to 7 km/h. In 1881, Siemens applied such technology to the first tram of Spandau, Berlin. However, it had a major defect. Horses would get an electric shock when touching DC 180-V double rails at the time of crossing the rail. Apparently, the method transmitting electric energy through two rails was technically infeasible and dangerous, especially under a higher-supply voltage. To sustain the tram service in Spandau, two contact wires were erected above the track, and a double-contact bus bar dragged by flexible wires connected with a tramcar was hung over the contact wire. However, the bus bar derailed frequently, which was too unreliable for commercial operation. In 1889, a German engineer of Siemens first proposed a kind of current collector that looks like a bow shown in Fig. 1.11. Through this current collector, current was supplied from single contact wire above the track to the traction unit and returned via the tracks.

Figure 1.11   Car received electric energy through a current collector.

It now appears that such a current collection system is not only an important breakthrough in train current collection technology, but also the germ of modern pantograph and overhead contact line systems.

1.2.2. Development of Pantograph and Overhead Contact Line Systems

To date, all high-speed electric trains in the world use pantograph and overhead contact line systems to collect electric energy. In Japan, France, and Germany, which have advanced high-speed railway systems, their pantograph and overhead contact line systems are different.

1.2.2.1. Shinkansen

In October 1964, Tokaido Shinkansen, the AC 25-kV electrified railway with the speed up to 210 km/h, was completed in Japan, which became the first country with a high-speed railway.

At the beginning of the operation of Shinkansen, pantograph PS200A, shown in Fig. 1.12, was used for 0 series EMUs running on Tokaido Shinkansen.

Figure 1.12   Pantograph PS200A.

PS200A is a double-arm diamond pantograph with lower arms crossed with each other. It uses a spring-type drive system. Upper and lower frames are welded using special-shaped steel tubes. A double-acting damper is used. Copper-base powder metallurgy material is used for strips, with an extension range of 800 mm, operating range of 500 mm, and static contact force of 54 + 15 N.

The pantograph head is 1800-mm long, the strip is 1110-mm long, and the pantograph head is 234-mm high.

The contact line of Tokaido Shinkansen, matching pantograph PS200A, uses compound contact lines with total tensile of 30 kN and elastic combined dropper, as shown in Fig. 1.13. For this contact line, a special combined dropper is mounted near the suspension point to make the elasticity of contact line more uniform and to improve dynamic interaction of pantograph and overhead contact line system.

Figure 1.13   Compound catenary suspension contact line with elastic combined dropper.

For contact lines of Tokaido Shinkansen, 80- and 60-mm² Cu–Cd wires are used as messenger wires and auxiliary messenger wires, respectively, and 110-mm² hard copper wire is used as a contact wire. Their wire tension is 10 kN, standard tension length is 1500 m, and maximum tension length is 1700 m. Designed at the wind speed of 25–30 m/s, the standard span of contact line is 50–60 m and that in the tunnel and on the truss is 45 m.

The compound catenary suspension contact line with elastic combined dropper meets the speed requirement of 210 km/h, but the use of elastic combined droppers increase vibration of the contact line. Especially in a strong side wind, dynamic interaction between pantograph and contact lines will be decreased. In such a case, the train speed should be reduced to 160 km/h or lower.

Through tests and long-term operations, Japan thought compound catenary suspension with elastic combined droppers could not meet high-speed operation requirements and removed elastic combined droppers from new contact lines and existing contact lines. Heavy compound catenary suspension with Y-shaped stitch wires and increased messenger wires and contact wire tension is used. Such contact lines then became the standard suspension of Shinkansen.

At the beginning of Shinkansen, a single train often used multiple pantographs for current collection. This led to obvious pantograph and overhead contact line disconnection. Besides, most strips were made of powder metallurgy material, and both strips and contact wires were badly worn out and needed to be replaced every 4–5 years.

With an accumulation of operational experience and progress of research, Japan changed multipantographs of single trains to double pantographs, and pantographs became lighter and lighter. Carbon strips were used. In addition to reducing the noise of the pantograph and the overhead contact line system, these optimization measures of pantograph also promoted simplification of contact line suspension. For instance, Hokuriku Shinkansen used catenary suspension to increase the operation speed of trains and to extend the life cycle of the contact wire.

Fig. 1.14 shows the T-shaped pantograph with a wing pantograph head used on 500 series EMUs of Shinkansen. Fig. 1.15 shows the V-shaped single-arm pantograph with wing pantograph head used on 700 series EMUs.

Figure 1.14   T-shaped pantograph with wing head.

Figure 1.15   V-shaped single-arm pantograph with wing head (PS207).

Both pantographs can effectively reduce air resistance and noise, and pantograph heads are lighter. Therefore, requirements on uniform elasticity of contact line can be reduced.

Since 1964, when the first high-speed electrified railway was opened, contact lines of Shinkansen were changed from compound catenary suspension with elastic combined dropper to heavy compound catenary suspension and now to catenary suspension shown in Fig. 1.16 over 40 years.

Figure 1.16   Catenary suspension contact line used in Shinkansen.

1.2.2.2. AC railway in France

At the early 1950s, to meet the increasing requirement of operation speed, Société nationale des chemins de fer français (SNCF) designed the AC 25-kV contact line with designed speed of 120 km/h, which changed the history of having a DC power traction alone. Early in the 1980s, TGV Sud-Est was built in France under the guideline of selecting a higher speed.

TGV-PSE high-speed EMUs of TGV Sud-Est uses AMDE pantographs made by Faiveley. As shown in Fig. 1.17, its pantograph head is only 1450-mm long and its strip is 800-mm long.

Figure 1.17   AMDE pantograph.

AMDE is double-layer small-opening two-level Z-shaped pantograph (also called mother–son pantograph). The lower part tracks the variation of contact wire height while the upper part tracks the vibration of the contact wire. Static contact force is 70–80 N. A carbon strip is used. When electric trains use a pantograph and run at 270 km/h, the pantograph performs well. However, if the train runs at a higher speed, the dynamic lifting force of AMDE will increase quickly.

Fig. 1.18 shows the structure of the contact line used for TGV Sud-Est, matching pantograph AMDE. Stitch suspension is used for the contact line. Tin bronze messenger wire with 14-kN tension and 65-mm² sectional area and hard copper contact wire with 14-kN tension and 120-mm² sectional areas are used. For tin bronze stitch wire, the sectional area is 35 mm², length is 15 m, and tension is 4 kN. The standard span of the contact line is 63 m.