![[EMC York 2004]](/img/conf/EMC2004/EMCYork-xss.png){kind=small}
Andrew Rowell, York EMC Services Ltd
What is EMC and why is it important? Talks and practical demonstrations introducing the causes and effects of the various phenomena associated with EMC together with some of the mitigation techniques used to reduce interference problems.
Les McCormack, York EMC Services Ltd
An overview of the current EMC legislation in the UK including an identification of the various European Directives that contain EMC requirements and a guide to the routes to compliance with the EMC Directive.
Darren Hayes, York EMC Services Ltd
The introduction of new standards, amendments to existing standards and the withdrawal of obsolete standards; this session is always popular and provides an update on the current main issues associated with EMC standards used to demonstrate compliance with the EMC Directive.
Martin Alexander, National Physical Laboratory
For some years the IEC and Cenelec have published standards giving methods and limits for EMC testing up to 1 GHz, but now standards are being written to include higher frequencies, mainly driven by the fast clock speeds of microprocessors. A rigorous measurement of emissions over a sphere surrounding the product, and whether they should be far-field or near-field, would be considered unmanageable by commercial test houses. Test methods that have a chance of being acceptable to test labs and members of national committees, are a compromise between what is commercially viable, in terms of what facilities are required and how long the tests take, and ensuring that there is a low risk that the product will not be electromagnetically compatible. The talk will discuss the proposed CISPR standards on test methods in anechoic chambers and the validation of chambers.
Prof Michael Koch, University of Hannover
The testing of electromagnetic interference presents, in general, enormous problems due to the very high costs involved in constructing and preparing test equipment. Over the past years, investigations have been carried out as to how these very complex field tests could be carried out using simpler, less expensive equipment.
Various new test installations have been proposed based upon far field measurements of an antenna. The aim of these installations was to test the emission or interference resistance of a device under far field conditions as realistic as possible. TEM cells and other TEM wave guide constructions have already become part of today's standards. Well-enclosed housings no longer require expensive, shielded rooms. Therefore, a large market has evolved for this type of inexpensive test equipment. Recently, a lot of test facilities have been offered on the market as further possibilities for field measurements. They all claim to fulfil the function of TEM wave guides.
In March 2003 the new standard IEC 61000-4-20 “Emission and Immunity Testing in Transverse Electromagnetic (TEM) Waveguides” was published. It relates to emission and immunity test methods for electrical and electronic equipment using various types of Transverse Electromagnetic (TEM) wave guides. This includes open (for example, strip lines and EMP simulators) and closed structures (for example TEM cells), which can be further classified as one- or two-port, or multi-port, TEM wave guides. The frequency range depends on the specific testing requirements and the specific TEM wave guide type. The objectives of this standard are to describe as:
The intention of this presentation is to investigate how it could be determined whether they fulfil TEM wave conditions as mentioned in IEC 61000-4-20. The general definitions from the standard will be clarified to allow a comparison between the test devices. The proposed limits for field homogeneity and depolarisation angle are justified.
Identifying TEM-fields we have to look for the following criteria:
The presentation will give some examples, how to verify these criteria.
Furthermore a new statistical approach characterising the field homogeneity will be given.
John Dawson, University of York
The presentation is intended to give an introduction to the reverberation chamber (Stirred mode chamber). Topics covered include:
David Bulgin, Rail Safety & Standards Board
Railway Group Standard GE/RT8015, issued in October 2002, was an attempt to provide a framework for the management of EMC between trains and infrastructure within the fragmented UK railway system. A review of this standard is currently under way. The Interoperability Directives require EMC issues to be addressed, both internally (between trains and infrastructure) and externally (between the railway as a system and the outside world). However, it is recognised that neither the Technical Specifications for Interoperability (TSIs) produced to support the High-Speed Rail Interoperability Directive, nor the forthcoming TSIs for Conventional Rail Interoperability, adequately cover EMC. Further work is proposed to revise the TSIs to improve coverage of this area.
The TSIs call up relevant European Standards, including EN50121 and EN50238. There are still unresolved issues over the status of EN50121. EN50238 addresses the issue of compatibility between rolling stock, traction power supply systems and train detection systems, but primarily deals with processes for demonstrating compatibility rather than defining system parameters. A CENELEC working group is looking at the production of ‘gabarits’ which will attempt to define compatibility parameters. This work is intended for eventual publication as an additional part of EN50238, but it is proposed that it will initially be published as part of the TSIs.
The paper will include consideration of:
Gary Crawshaw, Bombardier Transportation
EN50121 was originally published against a background of reluctant acceptance because of complaints about radio interference from the German Authorities. This presentation describes what has happened to alleviate these concerns and previews new proposals for modifications to the Standards.
Gary Crawshaw has represented the UK in the technical committee TC9X, for many years and as the Chairman of TC9X Working Group 9, is responsible for the further development of EN50121.
Gary has experience in managing EMC both to meet the EMC Directive and also safety issues such as compatibility with railway signalling systems. He is one of a few people who have managed EMC for a complete new tramway system.
Maya Petkova, Network Rail
This paper will provide a summary of the EMC knowledge base Network Rail has built up from the start of the EMC Standards Project in August last year until now.
The project was initiated in response to the requirements of group standard GE/RT8015. From this an initial programme was put in place. This paper will discuss the practical, and proactive approach taken by Network Rail to deliver its obligations to the industry in terms of EMC. These obligations require Network Rail to provide the industry with acceptance criteria (susceptibility levels) for its infrastructure against which new systems and rolling stock can be designed so that electromagnetic compatibility between such new systems and the existing ones can be assured.
The development of NR’s response in this respect has been prioritised for certain types of equipment. This is the equipment for which no validated susceptibility information was available from previous train safety cases. Under this category fell telecommunication equipment, non-immune track circuits, axle counters, TPWS and DC track circuits.
Axle counters and DC track circuits have been fully characterised with both steady state, and transient interference levels. Emissions from multiple train sources have also been taken into account. A number of criteria have been applied very conscientiously to whittle down the enormity of telecommunication systems to a manageable number of equipment types that will be subject to testing to establish susceptibility. Modelling of the transfer function has been undertaken concurrently to translate those limits into line current values as required by GE/RT8015. Non-immune track circuits are being characterised, and with the use of Pspice modelling the work is expected to be brought to a conclusion by the end of the summer months.
These are positive results that NR is proud to report back to the industry. They speak of growing awareness of the importance that EMC has to play in upgrading the infrastructure to sustain new services.
Chris Marshman, York EMC Services Ltd
A guide to assuring EMC of the infrastructure for the WCRM programme has been established. This takes account of the need to establish EMC in respect of safety and also the requirements of Network Rail to meet its obligations under the UK EMC regulations implementing the EMCD 89/336/EEC. The requirements of the EN 50121 series of standards are set out and a gap analysis in respect of the industrial generic standards has been determined. The role of the legally required Technical Construction File for equipment and system manufacturers is laid out. Further an ‘EMC Technical File’ is defined for use with infrastructure installations that demonstrates conformance of railway excluded or fixed installations with the protection requirements defined in 89/336/EEC.
Tony McClumpha, Network Rail
At the inception of the West Coast Main Line Project, Railtrack (Now Network Rail) did not have a specific policy for the management of EMC for the major works defined as part of the programme. The whole railway infrastructure is an excluded system under the EC EMC Directive.
It was recognised however that certain Safety Risks associated with EMC effects had to be managed and that a “whole railway” EMC Management Policy had to be developed so that other EMC risks could be properly managed.
This paper will be a short case study of the closure of the risks associated with the introduction of a new signalling system power supply at Ledburn Junction.
Emmanuel Boutard, Alstom Transport Information Solutions
The purpose of the investigation campaign covered in this paper was to determine risks of interference of track to train communication systems by the electromagnetic noise generated by the current collection. The proximity between the third rail 750Vdc supply and the bi-directional waveguide together with the near field immediacy of the collecting shoe to the spot transmission function, rose potential hazards of malfunctioning of the driver-less signalling system.
Indeed, the arc produced by the sliding contacts of the shoe against the 3rd rail (or pantograph against the overhead wire) generate conducted and radiated interference. The conducted EMI has the possibility to interfere with the wireless communication systems within the vehicle and with equipment on the side of the tracks.
The overall constraint in terms of arc electromagnetic noise remains that EN50121-2 which also covers potential emission from current collection. However, this latter standard has proved to be insufficient in particular cases where communication equipment are exposed to near field interference due to arcing effect. Indeed, the direct contribution of the physical arc to the radiated fields is rather low, however the near field effects may be very high (the arc acts as a current source whose currents spreads over the conductor systems acting as antennas and create the dominant radiated fields). Thus, the arc can be viewed as a source producing interference currents and the collecting shoe and rails can be considered as radiating antennas propagating the noise in a wide frequency range. With the current knowledge, it is not possible to predict is effects on neighbouring equipment. The objective was to define the frequency range impacted by the arc and its near field levels at location of communication equipment.
This document gives a detailed analysis of the measurements of the electromagnetic noise produced by an arc generated by a non-bridgeable gap in the power supply circuit. Its purpose is to give the electromagnetic signature of the arc generated by poor current collection, and define the frequency range which may be affected by the radiated noise.
György Varjú, Budapest University of Technology and Economics
Topics covered will include:
Dominic Kelsey, CTRL
Rail Link Engineering (RLE) are designing and managing the construction of a new high-speed railway between London St. Pancras and the Channel Tunnel, known as the Channel Tunnel Rail Link (CTRL). The railway is constructed in two Sections, Section 1 between Fawkham Junction and Dollands Moor and Section 2 between Southfleet and St Pancras. This paper outlines the EMC Strategy implemented for both sections of the Project.
The CTRL is an AC electrified railway with a fundamental operating voltage of 25-0-25kV utilising autotransformers. The principal electric traction that will use this new rail link will be the Class 373 Eurostar train, the Rolling Stock to be used by the Reserve Domestic Operator (high speed domestic services from north Kent) and also Class 92 locomotives.
In the case of the CTRL the principal sources of EMI from the railway are the Rolling Stock (RS), the Overhead Catenary System (OCS), the Static Var Compensators (SVC) at the traction feeder stations, the Signalling and the Control and Communications (C&C) systems. In addition the Temple Mills Depot and the stations contain similar control and communications systems together with other possible EMI sources such as lifts & escalators in the stations. Each of these systems is also susceptible to EMI together with any 3rd party electrical and electronic infrastructure adjacent to the CTRL.
The purpose of the RLE EMC Strategy is to ensure that all potential generators and receivers of EMI are identified and where required identify suitable mitigation works to prevent intolerable EMI to those susceptible, and that the safe operation of existing infrastructure is not adversely impacted upon.
RLE will lead the management of EMC issues throughout the Project Lifecycle. RLE will be assisted by Contractors who will bear responsibility for their own EMC Management and Design. RLE have appointed an EMC Team (comprising an EMC Manager, an EMC Engineer and an EMC Compliance Engineer) to ensure that the electrical infrastructure installed on the CTRL will comply wherever possible with relevant EMC Standards and work towards EMC acceptance of the integrated railway.
EMC management across interfaces have been divided into two parts, Internal (Intra-System & Inter-System) and External (Extra-System) Interfaces. Internal interfaces (Intra-System) are those within designated Contracts (e.g. DTN & Telephones) and those interfaces between (Inter-System) designated Contracts (e.g. SCADA and Voltage Transformer monitoring). External interfaces (Extra-System) are those between CTRL designated Contractors and 3rd Party infrastructure owners (e.g. Network Rail, London Underground, Highways Agency).
RLE will identify all external interfaces and will support the identification of generic internal interfaces between Contractors.
Where 3rd Parties do not comply with the current EMC Standards, mitigation works will maybe required to ensure that the Infrastructure may be operated safely.
Where necessary, mathematical models will be used to assess the impact of the CTRL traction system on adjacent parallel running (e.g. Network Rail, Highways Agency) and serial (end to end) connection (e.g. Network Rail) infrastructures. The modelling will principally be used to ensure that; Mandatory voltage thresholds for safety of personnel are not exceeded, and Equipment functionality is not adversely affected.
Any mathematical modelling carried out by RLE will utilise techniques and methods used elsewhere in the rail industry and/or certified by appropriate Industry Technical Organisations, results will be verified by physical measurement during dynamic testing.
The principal deliverable of this Management Strategy is an EMC Safety Case for acceptance by suitably competence Acceptance Bodies.
Alex Finlayson, Atkins Rail
This paper explains the principles of managing electromagnetic compatibility (EMC) in a metro environment. It will assess the processes and techniques used to ensure that EMC is achieved between the assets of the metro railway and third parties within the immediate environment of the metro railway
Peter Price, Metronet Rail BCV
Metronet Rail BCV Ltd are replacing the existing rolling stock and signalling on the Victoria Line with brand new trains and signalling. Due to the need to maintain a full train service throughout the Project, the migration strategy involves both old and new systems operating in parallel with each other. There are also a significant number of affected third parties to be considered. This paper will outline the management of EMC on the project to ensure that Electromagnetic Compatibility will be achieved at all stages of the Project.
Dave Imeson, Compliance Europe, ECACB Chairman
The new EMC Directive started as the SLIM process in 1968 and it is probable that the final text will be published in the Official Journal of the European Commission sometime within the next 4 – 6 months.
The existing text released in April 2004 is likely to be very close to the final text. This paper will discuss the major items in the Directive and assess their impact on the process of EMC compliance both from the viewpoint of the manufacturers and the test laboratories.
Dai Davis, Nabarro Nathanson
General Product Safety Update
On 3 December 2001 the European Union passed a new Directive on general product safety (2001/95/EC, L11). This directive repeals the old General Product Safety Directive (Directive 92/59/EEC) with effect from 15 January 2004. This was also the date on which the new Directive was supposed to have been implemented by. The DTI has already announced that the new legislation will be the subject of a consultation exercise over the summer of 2004.
Dai Davis, consultant and Head of It Law (North) at Nabarro Nathanson will explain the significance of the new legislation which includes for the first time a comprehensive inclusion of second hand products. Indeed, all new, used or reconditioned products, which are intended for consumers or likely, under reasonably foreseeable conditions, to be used by consumers are covered by the new directive.
Andrew Lunnon, Sustainable Development, DTI
The presentation will give an update on the progress towards implementation of these two Directives and how they will work in the UK. There will also be an update on the work of the Technical Adaptation Committee on the establishment of maximum concentration values & exemptions under RoHS.
Andrew Lunnon, Sustainable Development, DTI
The presentation will give an outline of the requirements of this proposed Framework Directive. There will also be the latest information on the progress towards agreement of this Directive in Brussels.
Last updated: 2004-Jun-11 (Friday)
