SIST EN 50238-1:2021
(Main)Railway applications - Compatibility between rolling stock and train detection systems - Part 1: General
Railway applications - Compatibility between rolling stock and train detection systems - Part 1: General
This document describes a process to demonstrate compatibility between Rolling Stock (RST) and Train Detection Systems (TDS). It describes the characterization of train detection systems, rolling stock and traction power supply systems.
It is worth noting that the demonstration of technical compatibility between the rolling stock and infrastructure with respect to physical dimensions is not detailed in this document.
This document is not generally applicable to those combinations of rolling stock, traction power supply and train detection system which were accepted as compatible prior to the issue of this document. However, as far as is reasonably practicable, this document can be applied to modifications of rolling stock, traction power supply or train detection systems which may affect compatibility. The detailed process can be used where no rules and processes for compatibility are established.
Bahnanwendungen - Kompatibilität zwischen Fahrzeugen und Gleisfreimeldesystemen - Teil 1: Allgemein
Applications ferroviaires - Compatibilité entre matériel roulant et systèmes de détection de train - Partie 1 : Généralités
La présente Norme européenne décrit une procédure permettant de démontrer la compatibilité entre le matériel roulant (MR) et les systèmes de détection de train (SDT) sur un itinéraire donné. Elle référence également les méthodes de mesure des courants et des champs magnétiques perturbateurs, les méthodes de mesure de la susceptibilité des systèmes de détection de train, ainsi que la caractérisation des alimentations de traction. La procédure décrite dans la présente norme s'applique également aux trains de grande ligne, aux véhicules légers et de type métro.
Les paramètres fondamentaux de compatibilité concernant les grandes lignes sont couverts par le document Interface de l'ERA (ERA/ERTMS/033281).
Il convient de noter que la présente norme ne couvre pas la démonstration de la compatibilité entre le matériel roulant et l'infrastructure en ce qui concerne les dimensions physiques.
Selon la Directive d'interopérabilité, l'évaluation de la compatibilité comprend deux étapes. La première étape concerne l'autorisation de mise en service vis-à-vis des limites générales. La seconde étape concerne la mise en service, lorsque les limites spécifiques de compatibilité avec les SDT sont en dehors des limites générales ou que des SDT non interopérables ont été installés sur la ligne où le MR circulera.
En dehors des trains de grande ligne ou des lignes isolées de types véhicule léger/métro, les exigences de compatibilité sont abordées dans une même étape d'autorisation.
La présente Norme européenne ne s'applique généralement pas aux ensembles matériels roulants, alimentations de traction et systèmes de détection de train qui ont déjà été reconnus compatibles avant l'édition du présent document. Toutefois, la présente Norme européenne peut être appliquée, dans des limites raisonnables, aux modifications de matériels roulants, d'alimentations de traction et de systèmes de détection de train susceptibles d'affecter la compatibilité.
Železniške naprave - Združljivost voznih sredstev in sistemov za detekcijo vlaka - 1. del: Splošno
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2021
Nadomešča:
SIST EN 50238:2003
SIST EN 50238-1:2003/AC:2015
Železniške naprave - Združljivost voznih sredstev in sistemov za detekcijo vlaka -
1. del: Splošno
Railway applications - Compatibility between rolling stock and train detection systems -
Part 1: General
Bahnanwendungen - Kompatibilität zwischen Fahrzeugen und Gleisfreimeldesystemen -
Teil 1: Allgemein
Applications ferroviaires - Compatibilité entre matériel roulant et systèmes de détection
de train - Partie 1 : Généralités
Ta slovenski standard je istoveten z: EN 50238-1:2019
ICS:
29.280 Električna vlečna oprema Electric traction equipment
45.060.10 Vlečna vozila Tractive stock
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN 50238-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2019
ICS 29.180; 45.060.10 Supersedes EN 50238-1:2003 and all of its amendments
and corrigenda (if any)
English Version
Railway applications - Compatibility between rolling stock and
train detection systems - Part 1: General
Applications ferroviaires - Compatibilité entre matériel Bahnanwendungen - Kompatibilität zwischen Fahrzeugen
roulant et systèmes de détection de train - Partie 1 : und Gleisfreimeldesystemen - Teil 1: Allgemein
Généralités
This European Standard was approved by CENELEC on 2019-09-09. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50238-1:2019 E
Contents
European foreword . 4
Introduction . 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviations . 7
3.1 Terms and definitions . 7
3.2 Abbreviations . 8
4 Compatibility process . 8
4.1 Overview . 8
4.2 Detailed compatibility process . 9
4.3 Compatibility case . 10
4.4 Quality management . 11
4.5 Route identification for introduction of RST (new or changed) . 11
4.6 Introduction of infrastructure elements (new or changed) . 11
4.7 Characterization . 11
4.8 Compatibility analyses . 11
5 Characterization of train detection systems . 14
5.1 Objective of procedure . 14
5.2 Track circuit systems - Standards, regulations and technical specifications . 14
5.3 Axle counter systems - Standards, regulations and technical specifications . 14
5.4 Wheel detectors (treadle applications) . 14
5.5 Loops . 15
6 Characterization of rolling stock. 16
6.1 Objective . 16
6.2 General procedure . 16
7 Characterization of traction power supply systems . 16
7.1 Objective . 16
7.2 DC traction power supplies . 17
7.3 AC traction power supplies . 17
7.4 Test procedures . 17
8 Test report . 18
8.1 General . 18
8.2 Introduction . 18
8.3 Test organization . 18
8.4 Configuration. 18
8.5 Reference documents . 18
8.6 Application of the test plan . 18
8.7 Test results . 18
8.8 Comments . 18
8.9 Archive of test results . 18
Annex A (informative) Guidelines for the determination of susceptibility of train detection systems . 19
A.1 Examples of system configurations . 19
A.2 “Normal” configuration . 19
A.3 Interference mechanism with broken signal rail . 19
A.4 Interference mechanism with broken return rail . 20
A.5 Double rail track circuits . 21
A.6 Voltage between axles of rolling stock . 22
A.7 Effect of resistance between coupled vehicles . 23
A.8 Radiated interference . 25
A.9 Example of sensitive zone of wheel detector . 25
A.10 Factor of safety . 25
A.11 Multiple interference sources . 26
Annex B (informative) General characterization of rolling stock . 27
B.1 Objective of procedure . 27
B.2 Description of rolling stock and factors affecting its characteristics . 27
B.3 Configuration (design status) . 27
B.4 Test plan . 27
Annex C (informative) Factors affecting rolling stock characteristics and compatibility . 30
Annex D (informative) DC traction power supplies . 33
D.1 General . 33
D.2 Interference currents generated by the rolling stock . 33
D.3 Interference currents generated by the traction power supply system . 33
Annex E (informative) Compatibility parameters for loops (example) . 36
E.1 Principles of operation - Electrical background . 36
E.2 Vehicle metal construction . 36
Bibliography . 39
European foreword
This document (EN 50238-1:2019) has been prepared by CLC/SC 9XA “Communication, signalling and
processing systems” of CLC/TC 9X “Electrical and electronic applications for railways”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2020-09-09
implemented at national level by publication of an
identical national standard or by endorsement
• latest date by which the national standards conflicting (dow) 2022-09-09
with this document have to be withdrawn
This document supersedes EN 50238-1:2003 and all of its amendments and corrigenda (if any).
Generic compatibility process to be followed irrespective of whether the trigger is a change to the
signalling system, rolling stock or the power system:
1) generic Compatibility Process, which is broken into two stage process depending on whether there
are established compatibility limits or not;
2) rules for characterization of train detection systems;
3) rules for characterization of Rolling Stock;
4) rules for characterization of the Power System;
5) references are provided to established CENELEC standards for compatibility;
6) terminology is updated.
Introduction
This document defines a process to demonstrate compatibility between rolling stock operating on an area
of use or network and train detection systems installed in this area of use or network.
Currently, general rules for the maximum levels of interference allowed, and maximum susceptibility
levels (or minimum required immunity levels) are not established in every country. This is due to the great
diversity of rolling stock, power supply and return current systems, and train detection systems installed in
Europe. This diversity leads to consideration of compatibility of rolling stock and train detection systems
on a ‘route by route’ or “network by network” basis, to avoid unnecessarily restrictive specifications.
The compatibility process described in this document is generic. The process refers to all types of Train
Detection Systems (TDS), which may be influenced by electromagnetic emissions of rolling stock or
traction power supply systems, (e.g. axle counters, track circuits, wheel detectors, loops).
Compatibility is determined by both physical and electromagnetic considerations. With regard to the
Electro Magnetic Compatibility, the need is not for general values for maximum levels of interference
permitted, and maximum susceptibility levels (or minimum required immunity levels) but for convenient
methods by which to specify the level of interference allowed for operation on routes or a network.
Main interference sources are considered to be:
— rail currents and voltage sources;
— electromagnetic fields;
— differential voltage between adjacent axles of the train;
as shown in Figure 1.
Figure 1 — Sources of electromagnetic interference
In practice, the susceptibility of the system is determined by:
— the sensitivity of individual components of the system and the type of interference it is susceptible to;
— the application of the components, i.e. the configuration of the system.
Therefore the problems concerning TDS are considered separately for each type.
• CLC/TS 50238-2 or national rules define compatibility limits for track circuits;
• CLC/TS 50238-3 or national rules define compatibility limits for axle counters and wheel detectors;
• EN 50592 defines the testing method of rolling stock for electromagnetic compatibility with axle
counters;
• Compatibility with other types of wheel detectors (mechanical or magnetic) is described in 5.4;
• Compatibility with loops can be established following the guidance in 5.5;
• Compatibility with any other type of TDS not explicitely covered by this document can also be
established following the generic process in this document.
For determining the susceptibility of signalling systems, laboratory/simulation testing methods and in situ
tests on the “real railway” are proposed. Modelling enables worst-case conditions to be simulated. In
addition, particular test sites are selected because, from experience, they are expected to provide the test
evidence required.
Then, taking account of the experience of the railways, it is possible to establish a general method for
determining the susceptibility of train detection systems, described in this document. General
requirements how to establish immunity have been defined in EN 50617-1 and EN 50617-2.
Before assessing the electromagnetic emissions of rolling stock, sufficient knowledge of the electric circuit
diagram of the power equipment is necessary, including switching frequencies of on-board power
converters, type of regulation used for power converters, resonant frequency of each filter, operating
limits under high and low supply voltages, degraded modes of operation, etc. EN 50592 defines the
testing method of rolling stock for electromagnetic compatibility with axle counters.
1 Scope
This document describes a process to demonstrate compatibility between Rolling Stock (RST) and Train
Detection Systems (TDS). It describes the characterization of train detection systems, rolling stock and
traction power supply systems.
It is worth noting that the demonstration of technical compatibility between the rolling stock and
infrastructure with respect to physical dimensions is not detailed in this document.
This document is not generally applicable to those combinations of rolling stock, traction power supply
and train detection system which were accepted as compatible prior to the issue of this document.
However, as far as is reasonably practicable, this document can be applied to modifications of rolling
stock, traction power supply or train detection systems which may affect compatibility. The detailed
process can be used where no rules and processes for compatibility are established.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 50617-1, Railway applications – Technical parameters of train detection systems for the
interoperability of the trans-European railway system – Part 1: Track circuits
EN 50617-2, Railway Applications – Technical parameters of train detection systems for the
interoperability of the trans-European railway system –- Part 2: Axle counters
EN 50592, Railway applications – Testing of rolling stock for electromagnetic compatibility with axle
counters
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
competent body
body responsible for the independent evaluation of the compatibility case
Note 1 to entry: This can be an accredited conformity body or an Independent Safety Assessor. This role is not
limited to external parties, unless mandated under the applicable legislation.
3.1.2
compatibility case
set of documents which records the evidence demonstrating the compatibility between rolling stock,
traction power supplies and train detection systems for a specific route or specific railway network
[SOURCE: IEC 60050-821:2017, 821-03-47]
3.1.3
degraded mode
mode of operation in the presence of faults which have been anticipated in the design of the signalling
system or the rolling stock
[SOURCE: IEC 60050-821:2017, 821-01-52]
3.1.4
traction power supply system
part of the overall electricity energy supply system, not extending beyond the dedicated feeder stations on
the rail network
Note 1 to entry: EN 50388 applies at the interface to the national electricity supply network.
3.1.5
wheel detector
sensor which detects the passage of a wheel
Note 1 to entry: A wheel detector can be used as part of an axle counter system or as a treadle.
[SOURCE: IEC 60050-821:2017, 821-03-53]
3.2 Abbreviations
For the purposes of this document, the following abbreviations apply.
IM Infrastructure Manager
MVA Mega Volt-Ampere
NTR National Technical Rule
RINF Register of Infrastructure
RST Rolling Stock
TDS Train Detection System
WSF Wrong side failure
4 Compatibility process
4.1 Overview
The party which introduces a new element or introduces a change of an existing element or system is
responsible for demonstrating compatibility between rolling stock, train detection, traction power supply
systems and neighbouring infrastructure, if applicable. The party is responsible for intiating the
compatibility process. The relevant data shall be made available to the party responsible for
constructing/amending the compatibility case. If data are not available or not sufficient, alternative
arrangements can be made by both the responsible party and the affected party to demonstrate
compatibility, for example by making specific compatibility tests. It is recommended that a competent
body assesses the compatibility case if the modification is deemed a significant change. Hereunder the
specific tasks to demonstrate compatibility are listed and explained.
4.2 Detailed compatibility process
The compatibility process is summarized in Figure 2.
Figure 2 — The compatibility process
4.3 Compatibility case
A compatibility case shall be prepared, following the process depicted in Figure 2, including but not
limited to the:
— definition of the scope of the compatibility case including:
• new element to be introduced;
• identification of the route or area of use (network) if applicable;
• operational conditions;
— description of the overall rail system including:
• infrastructure:
– train detection system (frequency-wide immunity limits if available);
– track parameters relevant for the train detection system (e.g. earthing and bonding);
– traction power supply and line parameters;
• rolling stock in any configuration, incl. degraded modes:
– relevant operational conditions e.g. power limitations;
– factors affecting rolling stock characteristics and compatibility as listed in Annex C,
identification of disturbance sources, their behaviour and/or applicable summation rules;
• adjacent infrastructure and other rolling stock, if applicable;
— theoretical analysis (e.g. simulation) against requirements of the scope including assumptions:
• derive the permissible interference per on-board source using the analysis in 4.8;
— test plan taking account of the results of the theoretical analysis;
— test reports – see Clause 8;
— assessment of theoretical analysis and test reports against requirements:
• related compatibility cases;
• check of validity of assumptions;
• check if restrictions may be lifted or relaxed;
— quality management plan and evidence.
If a Competent Body is appointed, then it is recommended to involve them at each step of the
compatibility case.
It is recognized that characterization of interference generated and propagated by rolling stock can be a
time consuming process, which may require a significant amount of testing during service operations in
order to refine the characteristics. Therefore, provided that the risks to all parties can be demonstrated to
be acceptable, temporary operational conditions may be imposed prior to full compatibility established.
Hereunder specific aspects of the compatibility case will be further outlined.
4.4 Quality management
Quality management systems shall be in place. The importance of configuration management should be
noted.
The configuration state of the relevant infrastructure and rolling stock (including maintenance processes
and schedules) shall be recorded and referenced within the compatibility case. Any subsequent changes
to these configurations shall lead to an examination of the continued validity of the compatibility case.
4.5 Route identification for introduction of RST (new or changed)
In order to accept a particular rolling stock in respect of a particular route or network, the different types
and applications of train detection systems and traction power supply systems, if applicable, on the
network or on the route and on adjacent routes which may be affected shall be identified. In addition to
the intended operational route(s), alternative route(s), which may be required in the event of disruption to
traffic shall also be considered.
4.6 Introduction of infrastructure elements (new or changed)
In order to accept a particular infrastructure change (e.g. TDS or traction power supply) in respect of a
particular route or network, the different types of RST, TDS and traction power supply systems on the
network or on the route and on adjacent routes, which may be affected, shall be identified.
4.7 Characterization
The characteristics of the identified systems shall be obtained in accordance with the following clauses:
• For train detection systems: Clause 5;
• For rolling stock: Clause 6;
• For power supply system: Clause 7.
4.8 Compatibility analyses
4.8.1 General terms
It is demonstrated that the rolling stock characteristics for generated and propagated interference comply
with the train detection system limits, under defined operating conditions, including degraded modes,
such as described in EN 50617-1, EN 50617-2, EN 50592. Their relationship is shown in Figure 3. The
information flow may be in either direction depending on which system is to be changed.
NOTE 1 Compatibility is now based on worst-case conditions. This results in very harsh requirements for rolling
stock interference limits, while in practice the tolerable interference level is much higher due to overall degradation of
older systems and interference produced by the current collecting system. Despite this situation, the cases with
hazards caused by interference are very rare. It is obvious that a perspective of risk calculation will ease the
interference current requirement by probably a decade.
The safety margin is applicable for safety related tests, where train detection technology implies WSF.
The availability margin is applicable for availability related tests. All applicable parameters for
compatibility cases of track circuits and axle counters can be identified from EN 50617-1 and EN 50617-2
respectively.
The compatibility analysis is mandatory and shall explain the technical principles which ensure
compatibility, including (or giving reference to) all supporting evidence e.g. calculations, test plans and
results etc.
The method of analysis of fault modes shall be agreed between the parties listed in 4.3.
The scenario for compatibility including the worst case shall be described with the following parameters:
• transfer function between interference sources (rolling stock and infrastructure) and sensitivity level
of the used TDS in the specified frequency band;
• characteristics, operating modes and conditions of rolling stock (normal and degraded modes of RST
and maximum torque, speed or other operating conditions);
• characteristics and operating conditions (normal and degraded modes) of traction power supply
including substation parameters and traction return path.
• safety and/or availability margin taking account of the above modes and conditions. Track circuit
sequencing is considered when safety or availability margins are agreed.
NOTE 2 Testing during operation in service on one vehicle will establish a probability for generated interference,
e.g. a level down to once per 1 000 h during several months of testing. This is only sufficient for the basic level of
generated interference current.
Both on-board systems and/or infra-side systems can be used to monitor the probability of occurrence of high levels
of interference currents, provided they remain compatible with the various immunity levels of the propagation and
detection systems.
4.8.2 Transfer function
The “transfer function” expresses the relation between the received interference signal at the train
detection system equipment and the total interference signal generated by rolling stock.
Let the transfer function be denoted by F.
Let the interference signal at the train detection system equipment caused by a single train / multiple
trains at the electric section be denoted by I .
TDS
Let the interference signal generated by the rolling stock be denoted by I .
RS
The interference signal is then:
I = F x I
TDS RS
The maximum permissible interference signal at the train detection system equipment I is
TDSmax
determined by the sensitivity of the train detection system equipment. Let the total permissible
interference generated by rolling stock be denoted by I . Then:
RStot
I = I / F
RStot TDSmax
Where multiple sources (Rolling Stock and Substations) may contribute to the total interference signal,
the permissible interference per source shall take this into account.
NOTE Line resonances and phase sensitive receivers can be part of the evaluation of compatibility.
CLC/TS 50238-2 provides the possible guidance on the application of the transfer function considering
multiple sources.
Note that the permissible interference signal will have two values determined by the following criteria:
• the signal which may cause the train detection system to show clear when it is in fact occupied
(a wrong side failure, i.e. a matter of safety);
• the signal which may cause the train detection system to show occupied when it is in fact clear (a
right side failure, i.e. a matter of availability). The effect on interlocking logic shall however be
considered.
The process of application of the summation rules can be applied in both directions as depicted in
Figure 3.
Infrastructure - Substation Rolling Stock Limits and Margins
Permissible
Permissible
Permissible
Permissible
interference of
interference of
interference per
interference per
infrastructure
infrastructure
on-board source
on-board source
sources
sources
Summation
Summation
rules
rules
Total
Total
interference from
interference from
on-board sources
on-board sources
Summation
Summation
rules
rules
Total
Total
interference
interference
N Y
Transfer Non-compliance compare compliance
Transfer Non-compliance compare compliance
function
function
Equipment
Infrastructure Equipment
Margin Compatibility limit
Margin Compatibility limit
Train detection system susceptibility
susceptibility
Note: Margin includes two different levels:
- Safety Margin
- Availability Margin
Figure 3 — Relationship between compatibility limits and permissible interference
5 Characterization of train detection systems
5.1 Objective of procedure
To ensure the correct operation of axle counter systems, wheel detectors and track circuit systems, their
physical and electromagnetic properties are defined in the detailed Standards and Regulations (see 5.2,
5.3 and 5.4 for details) for as well as the measurement methodology and how to report the compatibility
with these standards.
For other train detection systems not covered by standards (e.g. loops, wheel detectors/treadles), their
relevant properties shall be defined by the infrastructure manager in collaboration with the manufacturers.
Relevant information shall be described by the manufacturers in the product documentation.
5.2 Track circuit systems - Standards, regulations and technical specifications
EN 50617-1 defines parameters for track circuits. All requirements to be fulfilled by a track circuit system
are listed and defined there in detail. EN 50617-1 directly includes the requirements for physical and
electrical aspects (e.g. axle resistance, ballast resistance, broken rail behaviour) as well as the
electromagnetic parameters (e.g. behaviour to interferences and immunity limits), the measurements to
be executed and the reporting to show the compatibility with this document.
The methodology defined in EN 50617-1 shall be used where practically applicable.
NOTE Guidance to establish compatibility limits is contained in Annex A. Some known track circuits
compatibility limits are published in CLC/TS 50238-2.
5.3 Axle counter systems - Standards, regulations and technical specifications
EN 50617-2 defines parameters for axle counter systems. All requirements to be fulfilled by an axle
counter system are listed and defined there in detail. EN 50617-2 directly includes the requirements in
accordance to physical and electrical aspects (e.g. axle distances, fastenings to the rail, environmental
conditions) as well as the electromagnetic parameters (e.g. behaviour to interferences and immunity
limits), the measurements to be executed and the reporting to show the compatibility with this document.
The methodology defined in EN 50617-2 shall be used where practically applicable.
NOTE Some known axle counter compatibility limits are published in CLC/TS 50238-3.
5.4 Wheel detectors (treadle applications)
5.4.1 General
Treadle applications are mainly switch on/off functionalities, direction detection or speed measurement.
Requirements for wheel detectors applied as treadles are not explicitly described in EN 50617-2 because
they are not used for axle counter systems.
5.4.2 Wheel detectors based on inductive technology
Due to the principle of discrete detection of wheels passing a wheel detector, transient and continuous
interference limits may be considered as equivalent to the limits defined for axle counter detectors or axle
counter sensors.
EN 50617-2 shall be taken into account where applicable for wheel detectors based on inductive
technology with respect to the physical, electromechanical and electromagnetic interface.
Due to the inherent difficulties of designing a sufficiently complete electrical equivalent circuit for an
inductive wheel detector, field testing or alternatively laboratory tests injecting interference currents into
the rail and applying external electromagnetic fields shall be used for measuring the susceptibility of
wheel detectors.
To allow for uncertainties in the accuracy of measurements and simulations, the susceptibility of the train
detection system as determined above shall be increased by a factor of safety (margin). The uncertainties
shall be estimated and the factor of safety shall be sufficient to allow for them (see EN 50617-2).
Interference due to DC substation ripple (e.g. harmonics of the substation voltage source) may need to be
taken into account in the factor of safety.
5.4.3 Wheel detectors based on other technology
Wheel detectors based on other technology (e.g.mechanical or optical) are not described in details in this
subclause.
5.5 Loops
5.5.1 General aspects
Loops are mainly used for level crossing applications, to command the lowering / raising of barriers. A
loop application based on the principle of continuous detection of a large metal mass has a different
influencing mechanism compared to axle counter sensors and track circuits which shall be taken into
account.
Loops have a greater area to be influenced by trains than wheel sensors, on the other hand the sensitivity
of a loop against rail currents are not directly linked because the loops are not connected to the rails. Due
to this induction is the main interference mechanism. Loops for communication tasks and/or automatic
train protection applications are not part of this technical standard.
For reliable train detection with loops the definition of compatibility requirements with the train shall be
taken into account as shown in the example in Annex E, for a specific type of loops. Loops are usually
used as one component of an applicable solution. The necessary level of reliability shall be documented
within the application the loops are used for.
5.5.2 Interfering mechanisms
The variation of the loop inductance is caused by generation of eddy currents and mutual induction with
conductive elements interacting with the magnetic field of the loop.
Loops might be influenced by magnetic fields and by the metal construction of the vehicles. Up to now,
magnetic fields have shown no negative effect on the operation of the loops. Specific strong radiating
sources on board the RST, for example track circuit shunt assisting devices may affect the operation of
loops.
Railway vehicles metal construction can vary the inductance by the following influencing factors:
a) metal construction (bogies, metal parts of the vehicle, metal vehicle floor) above the loop within a
defined distance to the rail and within a defined conductivity;
b) electrical short circuit rings (electrical conducting loops) made up from construction elements of a
vehicle e.g. frame beams with cross connections or electrically connected and conducting
construction parts below the vehicle floor within a defined distance to the rail. These parts are
electrically connected in a suitable way to form electrically conducting short circuit rings with defined
dimensions and defined electrical resistances.
c) electrical short circuit rings formed by the wheels, axles and rails, with a sufficient low impedance
between wheels as well as between the wheels and rails.
5.5.3 Characterization
Compatibility requirements can be established in different ways (e.g. lab tests, safety assessment, field
tests).
Lab tests and field tests shall be performed to prove compatibility between newly developed loops and
trains in accordance to the level of availability for the infrastructure function. It shall be proven that no
detection will be lost while the train is inside the loop area and no occupation will occur in the absence of
a train.
6 Characterization of rolling stock
6.1 Objective
Tests shall be made on rolling stock to verify that the generated interferences comply with the train
detection systems compatibility limits.
The procedure used for the tests depends on the applicable scope. The described compatibility tests for
rolling stock with train detection systems are derived from the general procedure described in the
following subclause.
6.2 General procedure
Clause 4 defines the generic compatibility process. Tests shall be based on analysis of the potential
sources of interferences. The compatibility analysis of 4.8 shall be used to define the tests.
European Standards or national standards can be used as far as applicable.
Compatibility case may be established by adherence to existing rules if available. The generic procedure
defined in this document applies to cases where compatibility limits do not exist.
The general procedure for rolling stock characteristics is described in Annex B.
Compatibility limits are defined in CLC/TS 50238-2 for some track circuits and in CLC/TS 50238-3 for
some axle counters. EN 50592 describes also the test procedure and post processing for demonstrating
compatibility with axle counters.
The compatibility with loops, if applicable, shall be demonstrated by checking compliance with
construction requirements (e.g. Annex E) or by train testing following functional requirements (for
example the variation of the inductance of the loop explained in 5.5.2).
7 Characterization of traction power supply systems
7.1 Objective
The objective is to determine the influence of the traction power supply system on the generation and
transmission of interference.
Relevant factors include but are not limited to the following:
• nominal voltage characteristics (AC or DC);
• voltage tolerance;
• frequency tolerance;
• harmonic content;
• transients;
• MVA rating;
• impedance of substation;
• impedance of catenary or conductor rail(s);
• impedance of return system;
• normal and degraded modes of operation;
• protective elements – e.g overvoltage protection.
Information about power supply characteristics are defined in EN 50163 (nominal values and tolerances)
and EN 50388 (impedances, resonances) or are provided by the IM.
Certain interference frequencies may be generated by both the substation and rolling stock. The
superposition rules applicable to the corresponding interference generation mechanisms shall be
considered. In order to limit the influence of interference generated by the substation at the location of
rolling stock, minimum impedance requirements for rolling stock may be formulated.
Resonances and oscillations shall also be considered when defining a test location for characterization
purposes. The rolling stock's interaction with the electric traction system should be included due to the
fact that resonances and oscillations are mainly provoked by rolling stock interaction with the electric
traction system.
7.2 DC traction power supplies
DC traction power supplies are, due to their rectifiers, particularly likely to produce interference currents
which can affect track circuits or axle counters. The voltage ripple is mainly due to the rectifier bridge and
to phase unbalance in the high voltage supply. Annex D briefly describes the interaction of interference
currents between the rolling stock and the DC traction power supply.
7.3 AC traction power supplies
In AC traction power supply systems, the following effects shall be considered:
• Feeding of the lines by static converters. In this case, the converter (substation) can create
harmonics, which have similar effects as the harmonics created by the substation in DC traction
power supply systems.
• Harmonics created by other rolling stock. AC rolling stock can create significant magnitudes of
harmonic currents, which produce harmonics in the line voltage due to voltage drop over the line
impedance. Emissions of different rolling stock in the section may be mixed by this effect.
• In the audio frequency range, local resonance effects between capacitive inpu
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