Railway Electrification Infrastructure and Systems (REIS) technical training course

Session 14: Integrated protection and control

Dr David Hewings, Head of Engineering & Asset Management, Electrification & Plant, Network Rail

Modern traction power systems are now utilising the digital substation architectures of IEC 61850 to bring a common approach to protection and control systems.

This session looks at this technology and its application in traction system design, including the developments in rationalised traction systems (RATS).

Session 15: Workshop 3 - Requirements, constraints, and electrification solutions

Professor Stuart Hillmansen, Professor of Railway Traction Systems, University of Birmingham

The session will review the important physics and electrical engineering which underpins the principles of power transmission in Electrical Railway Traction Systems.

Session 16a: AC / DC Interfaces dual voltage

Dr David Hewings, Head of Engineering & Asset Management, Electrification & Plant, Network Rail

Where DC and AC railways pass in close proximity at interchange stations or where there is operation in parallel, there is the possibility of disturbances due to physical and electrical interfaces including: physical clearances, galvanic coupling, electric fields, radiated fields and electromagnetic coupling.

This session examines the interfaces and controlling the interferences between the DC and AC traction systems.

At this interface there is a conflict for the design criteria for the return current paths, and the mitigation required for earthing and bonding of metallic structures in the presence of DC traction return current and touch potentials due to AC traction return current.

The design of the AC/DC interface it is therefore necessary to control key characteristics of the traction return current paths, stray DC current, rail potentials and induced voltage.

The close physical proximity, of the railways and the low impedance of rails and LV earths means that traction return current and fault currents also may not remain in their intended path.

Session 8: Stray current corrosion and civil infrastructure protection

Dr David Buxton, Corrosion Consultant, Intertek CAPCIS

The production of stray currents by DC transit systems can lead to the corrosion of nearby buried metallic structures, such as rail supporting structures, pipelines and cable sheaths.

This presentation describes why stray current is produced by a DC transit system, measures that can be taken to control stray current and the possible impact it can have on the transit and surrounding infrastructure.

Session 9: Railway electrical systems compatibility - protecting everyone from each other

David Bradley, Independent – was Director, Northwood Rail Consultancy

The session will consider the situation of multi-disciplinary electrical systems on railways and how they may be identified, characterised and analysed to enable satisfactory operation.

It will draw on past problems, and their resolutions, and indicate the effective methods of dealing with future situations.

Session 11: DC System Design

Richard Catlow, Head of Electric Traction Design, Alstom.

This session examines the major factors that affect the design of DC electrification across light, Metro, heavy and freight rail. The session examines the major challenges they pose to designers and the options typically used to overcome them.

The session closes by looking at some recent developments in the field that are set to make DC ever more relevant in the future.

Session 13: Electrification system testing

Richard Catlow, Head of Electric Traction Design, Alstom.

This session examines testing of complete electrification systems at the time of a project's final entry into service.

Customarily delivered by full scale short circuit testing, these tests are literally "make or break" for the system, right at the end of the project. Review of electrical clearances and legal requirements for electrification.