prEN 50388-2:2017
(Main)Railway Applications - Fixed installations and rolling stock - Technical criteria for the coordination between power supply and rolling stock to achieve interoperability - Part 2: stability and harmonics
Railway Applications - Fixed installations and rolling stock - Technical criteria for the coordination between power supply and rolling stock to achieve interoperability - Part 2: stability and harmonics
This European Standard, part 2 of EN 50388 is linked to prEN 50388 1 which describes the general items on technical criteria for the coordination between power supply and rolling stock to achieve interoperability This part 2 establishes the acceptance criteria according to prEN 50388 1:2017, 10.4 step 7 for compatibility between traction units and power supply, in relation to: - co-ordination between controlled elements and between them and resonances in the electrical infrastructure in order to achieve network system stability; - co-ordination of harmonic behaviour with respect of excitation of electrical resonances. The following electric traction systems are within scope: - railways; - guided mass transport systems that are integrated with railways; - material transport systems that are integrated with railways. Public three phase grid is out of scope. Railway dedicated grid is included. This European Standard is applied in accordance with the requirements in prEN 50388-1:2017, Clause 10. It does not apply retrospectively to rolling stock already in service. It is the aim of this part 2 to support acceptance of new elements (rolling stock or infrastructure) by specifying precise requirements and methods for demonstration of compliance. However, it is still admissible to use the process as defined in part 1 instead. The process of part 1 shall be applied if the case studied is not covered by part 2. This version of the standard only applies to AC systems. Later versions may include similar effects in DC networks in addition (see Annex D). Main phenomena identified and treated in this standard are: - electrical resonance stability; - low frequency stability; - overvoltages caused by harmonics. This European Standard is structured as showed in Table 1 (Table 1 only shows references to the most important sections). (...)
Bahnanwendungen - Ortsfeste Anlagen und Bahnfahrzeuge - Technische Kriterien für die Koordination zwischen Anlagen der Bahnenergieversorgung und Fahrzeugen zum Erreichen der Interoperabilität - Teil 2: Stabilität und Oberschwingungen
Diese Europäische Norm, Teil 2 von EN 50388, hängt mit prEN 50388 1 zusammen, die allgemein die tech-nischen Kriterien für die Koordination zwischen der Energieversorgung und dem Fahrzeugpark zur Errei¬chung der Interoperabilität beschreibt. Dieser Teil 2 umfasst die Annahmekriterien nach prEN 50388 1:2017, 10.4, Schritt 7, für die Kompatibilität zwischen den Triebfahrzeugeinheiten und der Energieversorgung in Bezug auf: – die Koordination zwischen gesteuerten Elementen sowie zwischen diesen und den Resonanzen in der elektrischen Infrastruktur, um die Systemstabilität eines Netzes zu erreichen; – die Koordination des Oberschwingungsverhaltens hinsichtlich der Erregung der elektrischen Resonan-zen. Der Anwendungsbereich gilt für die folgenden elektrischen Zugförderungssysteme: – Eisenbahnen; – spurgeführte Nahverkehrssysteme, die in Eisenbahnen integriert sind; – Materialtransportsysteme, die in Eisenbahnen integriert sind. Das öffentliche Drehstromnetz ist außerhalb des Anwendungsbereiches. Das bahnspezifische Netz gehört zum Anwendungsbereich. Diese Europäische Norm gilt in Übereinstimmung mit den in prEN 50388 1:2017, Abschnitt 10, aufgeführten Anforderungen. Sie gilt nicht rückwirkend für bereits im Betrieb befindliche Fahrzeugparks. Ziel dieses Teils 2 ist die Unterstützung der Abnahme neuer Elemente (neuer Fahrzeuge oder neuer Infra-struktur) durch die Festlegung präziser Anforderungen und Verfahren für den Nachweis der Konformität. Es ist jedoch weiterhin erlaubt, stattdessen das in Teil 1 festgelegte Verfahren anzuwenden. Das in Teil 1 beschriebene Verfahren muss angewendet werden, wenn der zu prüfende Fall nicht von Teil 2 umfasst ist. Diese Version der Norm gilt ausschließlich für Wechselstromsysteme. Spätere Versionen dürfen auch ähnli-che Effekte in Gleichstromnetzen umfassen (siehe Anhang D). Die in dieser Norm identifizierten und behandelten Hauptphänomene sind: – elektrische Resonanzstabilität; – Niederfrequenzstabilität; – durch Oberschwingungen verursachte Überspannungen. Diese Europäische Norm weist die in Tabelle 1 gezeigte Struktur auf (Tabelle 1 zeigt nur Referenzen zu den wichtigsten Abschnitten). Tabelle 1 – Struktur dieser Europäischen Norm ...
Applications ferroviaires - Installations fixes et matériel roulant - Critères techniques pour la coordination entre les installations fixes de traction électrique et le matériel roulant pour réaliser l’interopérabilité - Partie 2 : stabilité et harmoniques
La présente Norme européenne constitue la Partie 2 de l'EN 50388. Elle est associée au prEN 50388 1, qui décrit les éléments généraux relatifs aux critères techniques pour la coordination entre l'alimentation et le matériel roulant en vue d'assurer l'interopérabilité. La présente Partie 2 définit les critères d'acceptation selon le prEN 50388 1:2017, 10.4, étape 7, qui permettent la compatibilité entre les unités de traction et l'alimentation, en ce qui concerne : - la coordination entre les éléments commandés et entre ces mêmes éléments et les résonances de l'infrastructure électrique, afin d'assurer la stabilité du système dans le réseau ; - la coordination du comportement vis-à-vis des harmoniques par rapport à l'excitation des résonances électriques. Les systèmes de traction électrique suivants relèvent du domaine d'application de la présente norme : - les chemins de fer ; - les systèmes guidés de transport en commun qui sont intégrés avec les chemins de fer ; - les systèmes de transport de matériaux qui sont intégrés avec les chemins de fer. Le réseau public triphasé ne relève pas du domaine d'application de la présente norme. Le réseau dédié aux chemins de fer est couvert. La présente Norme européenne s'applique conformément aux exigences du prEN 50388-1:2017, Article 10. Elle ne s'applique pas rétroactivement aux matériels roulants déjà en service. La Partie 2 traite de l'acceptation des nouveaux éléments (matériel roulant ou infrastructure) et précise notamment les exigences et méthodes de démonstration de la conformité. Toutefois, l'utilisation du processus défini dans la Partie 1 demeure toujours admise. Le processus de la Partie 1 doit s'appliquer si le cas étudié n'est pas couvert par la Partie 2. La présente version de la norme s'applique uniquement aux systèmes en courant alternatif. Les dernières versions peuvent avoir des effets analogues dans les réseaux en courant continu (voir Annexe D). Les principaux phénomènes identifiés et traités dans la présente norme sont les suivants : - la stabilité de résonance électrique ; - la stabilité à basse fréquence ; - les surtensions dues aux harmoniques. Le Tableau 1 décrit la structure de la Norme européenne (le Tableau 1 ne donne que les références aux articles et paragraphes les plus pertinents).
Železniške naprave - Fiksni postroji - Tehnična merila za uskladitev med elektronapajalnimi postajami in elektrovlečnimi vozili za doseganje medobratovalnosti - 2. del: Stabilnost in harmoniki
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2017
1DGRPHãþD
SIST EN 50388:2012
SIST EN 50388:2012/AC:2013
äHOH]QLãNHQDSUDYH6WDELOQHQDSUDYHHOHNWULþQHYOHNHLQYR]QLKVUHGVWHY
7HKQLþQDPHULOD]DXVNODGLWHYPHGHOHNWURQDSDMDOQLPLSRVWDMDPLLQHOHNWURYOHþQLPL
YR]LOL]DGRVHJDQMHPHGREUDWRYDOQRVWLGHO 6WDELOQRVWLQKDUPRQLNL
Railway Applications - Fixed installations and rolling stock - Technical criteria for the
coordination between power supply and rolling stock to achieve interoperability - Part 2:
stability and harmonics
Bahnanwendungen - Ortsfeste Anlagen und Bahnfahrzeuge - Technische Kriterien für
die Koordination zwischen Anlagen der Bahnenergieversorgung und Fahrzeugen zum
Erreichen der Interoperabilität - Teil 2: Stabilität und Oberschwingungen
Applications ferroviaires - Installations fixes et matériel roulant - Critères techniques pour
la coordination entre les installations fixes de traction électrique et le matériel roulant
pour réaliser l’interopérabilité - Partie 2 : stabilité et harmoniques
Ta slovenski standard je istoveten z: prEN 50388-2:2017
ICS:
29.280 (OHNWULþQDYOHþQDRSUHPD Electric traction equipment
45.060.01 Železniška vozila na splošno Railway rolling stock in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD DRAFT
prEN 50388-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2017
ICS 29.280; 45.060.01 Will supersede EN 50388:2012 (PART)
English Version
Railway Applications - Fixed installations and rolling stock -
Technical criteria for the coordination between power supply and
rolling stock to achieve interoperability - Part 2: stability and
harmonics
Applications ferroviaires - Installations fixes et matériel Bahnanwendungen - Ortsfeste Anlagen und Bahnfahrzeuge
roulant - Critères techniques pour la coordination entre les - Technische Kriterien für die Koordination zwischen
installations fixes de traction électrique et le matériel roulant Anlagen der Bahnenergieversorgung und Fahrzeugen zum
pour réaliser l'interopérabilité - Partie 2 : stabilité et Erreichen der Interoperabilität - Teil 2: Stabilität und
harmoniques Oberschwingungen
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2017-07-07.
It has been drawn up by CLC/SC 9XC.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CENELEC 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 60245 Ref. No. prEN 50388-2:2017 E
1 Contents Page
2 European foreword . 3
3 1 Scope . 4
4 2 Normative references . 6
5 3 Terms and definitions . 6
6 4 Requirements . 9
7 4.1 Electrical resonance stability . 9
8 4.2 Low-frequency stability . 11
9 4.3 Overvoltages caused by harmonics . 13
10 4.3.1 General . 13
11 4.3.2 Rolling stock . 13
12 4.3.3 Static converters . 17
13 4.3.4 Infrastructure . 17
14 5 Tests and documentation . 18
15 5.1 Electrical resonance stability . 18
16 5.1.1 Rolling stock . 18
17 5.1.2 Static converters . 22
18 5.1.3 Infrastructure . 22
19 5.2 Low-frequency stability . 24
20 5.3 Overvoltages produced by harmonics . 24
21 5.3.1 Rolling stock . 24
22 5.3.2 Static converters . 25
23 5.3.3 Infrastructure . 25
24 Annex A (informative) Technical background . 26
25 A.1 Electrical resonance stability . 26
26 A.2 Low-frequency stability . 27
27 A.3 Overvoltages caused by harmonics . 33
28 A.4 Depot Cases . 35
29 Annex B (informative) Examples from experienced phenomena (measurements) . 39
30 B.1 Electrical resonance instability . 39
31 B.2 Low-frequency power oscillations . 39
32 B.3 Overvoltages caused by harmonics . 40
33 Annex C (informative) Data related to the compatibility study of harmonics and dynamic effects . 41
34 C.1 Characterization of the traction power supply fixed installations . 41
35 C.2 Characterization of the trains . 44
36 Annex D (informative) Examples experienced in DC Systems . 46
37 Annex ZZ (informative) Relationship between this European Standard and the Essential
38 Requirements of EU Directive 2008/57/EC . 47
39 Bibliography . 48
40 European foreword
41 This document (prEN 50388-2:2017) has been prepared by CLC/SC 9XC, “Electric supply and earthing
42 systems for public transport equipment and auxiliary apparatus (Fixed installations)”, of Technical Committee
43 CLC/TC 9X, “Electrical and electronic applications for railways”. It also concerns the expertise of
44 CLC/SC 9XB, “Electromechanical material on board of rolling stock”.
45 This document is currently submitted to the Enquiry.
46 The following dates are proposed:
— latest date by which the existence of (doa) dor + 6 months
this document has to be announced
at national level
— latest date by which this document has to be (dop) dor + 12 months
implemented at national level by publication of
an identical national standard or by
endorsement
— latest date by which the national standards (dow) dor + 36 months
conflicting with this document have to (to be confirmed or
be withdrawn modified when voting)
47 This document will partly supersede EN 50388:2012.
48 This document has been prepared under a mandate given to CENELEC by the European Commission and
49 the European Free Trade Association, and supports essential requirements of EU Directive(s).
50 For the relationship with EU Directive 2008/57/EC, see informative Annex ZZ, which is an integral part of this
51 document.
52 For TSI lines, modification and amendments should be made within a procedure which is related to the legal
53 status of the HS and CR TSIs.
54 1 Scope
55 This European Standard, part 2 of EN 50388 is linked to prEN 50388-1 which describes the general items on
56 technical criteria for the coordination between power supply and rolling stock to achieve interoperability
57 This part 2 establishes the acceptance criteria according to prEN 50388-1:2017, 10.4 step 7 for compatibility
58 between traction units and power supply, in relation to:
59 — co-ordination between controlled elements and between them and resonances in the electrical
60 infrastructure in order to achieve network system stability;
61 — co-ordination of harmonic behaviour with respect of excitation of electrical resonances.
62 The following electric traction systems are within scope:
63 — railways;
64 — guided mass transport systems that are integrated with railways;
65 — material transport systems that are integrated with railways.
66 Public three phase grid is out of scope. Railway dedicated grid is included.
67 This European Standard is applied in accordance with the requirements in prEN 50388-1:2017, Clause 10. It
68 does not apply retrospectively to rolling stock already in service.
69 It is the aim of this part 2 to support acceptance of new elements (rolling stock or infrastructure) by specifying
70 precise requirements and methods for demonstration of compliance. However, it is still admissible to use the
71 process as defined in part 1 instead. The process of part 1 shall be applied if the case studied is not covered
72 by part 2.
73 This version of the standard only applies to AC systems. Later versions may include similar effects in DC
74 networks in addition (see Annex D).
75 Main phenomena identified and treated in this standard are:
76 — electrical resonance stability;
77 — low frequency stability;
78 — overvoltages caused by harmonics.
79 This European Standard is structured as showed in Table 1 (Table 1 only shows references to the most
80 important sections).
81 Table 1 — Structure of this European Standard
Topic Requirements Tests and documentation
Section Main requirements Sect Most important elements
ion
Electrical 4.1 Definition of a limit frequency f 5.1 For controlled elements, in most
L
resonance cases measurement of
- Lowest power system
stability frequency response of input
resonance frequency shall not
admittance is required.
be < fL
5.1.1.2 Defines in which cases
- All controlled elements shall be
input admittance shall be
passive for all frequencies > fL
measured and how it shall be
- Requirements for filter
measured.
capacitors
5.1.1.3 Defines in which cases
simulation is sufficient and
specifies the requirements for
the simulator.
5.1.1.4 Defines in which cases
declaration of conformity is
sufficient.
5.1.2 Defines the methods to be
used to assess the lowest
resonant frequency of the power
supply.
A.1 Technical background about Electrical resonance stability
B.1 Examples of experienced electrical resonance instability
Low frequency 4.2 Stable operation shall be 5.2 Investigation either by
stability demonstrated for a predefined
— directly in time domain
set of combinations of power
simulation
source(s), electrical network and
— the dq method based on
one or several vehicles at one
characterization from
single location
time domain simulation
A.2 Technical background about Low frequency stability
A.2.2 System definition
A.2.3 Definition of signals for the dq method
A.2.4 Small signal model for one component
A.2.5 Feedback loop
A.2.6 Determination of frequency responses
A.2.7 Stability criterion
B.2 Examples of experienced low frequency power oscillations
Topic Requirements Tests and documentation
Section Main requirements Sect Most important elements
ion
Overvoltages 4.3 4.3.2 Rolling stock 5.3 5.3.1 Demonstration of
caused by compliance for rolling stock by:
Defines the limit of the
harmonics
overvoltage, and specifies the - Calculation of line current
calculation method by using line spectrum incl. plausibilisation by
current spectrum, bandpass measurement
filtering, summation methods - Calculation of harmonic
and standardized power supply voltage using method given in
impedances. 4.3, assessment
4.3.2.2 Overvoltage - Check of interlacing between
detection/protection. units as specified in 4.3.2.1
4.3.3 Defines the overvoltage - Check of overvoltage
limits for static converters and protection as specified in 4.3.2.2
specifies the overvoltage
- If diode rectifying is used to
calculation method by combining
reduce risk of overvoltages (see
the converter with a line of
A.3.3) check of correct transition
variable length.
between pulsing and blocking of
4.3.4 Infrastructure related line converter
topics
A.3 Technical background about overvoltages caused by harmonics
B.3 Examples of experienced overvoltages caused by harmonics
Topics related A.4 Depot cases
to all
Annex C Data related to the compatibility study of harmonics and dynamic effects
phenomenon
Annex D Examples experienced in DC system
82 2 Normative references
83 The following documents, in whole or in part, are normatively referenced in this document and are
84 indispensable for its application. For dated references, only the edition cited applies. For undated references,
85 the latest edition of the referenced document (including any amendments) applies.
86 CLC/TS 50238-2:2015, Railway applications - Compatibility between rolling stock and train detection
87 systems - Part 2: Compatibility with track circuits
88 CEN/TS 50535:2010, Railway applications - Onboard auxiliary power converter systems
89 prEN 50388-1:2017, Railway Applications - Fixed installations and rolling stock - Technical criteria for the
90 coordination between traction power supply and rolling stock to achieve interoperability - Part 1: general
91 3 Terms and definitions
92 For the purposes of this document, the terms and definitions given in prEN 50388-1:2017 and the following
93 apply.
94 3.1
95 new element
96 new, rebuilt or modified traction unit or power supply component (hardware or software) having a possible
97 influence on the stability or harmonic behaviour of the power supply system such as:
98 — transformer;
99 — HV cable;
100 — filter;
101 — converter
102 3.2
103 power system
104 system which includes generation, distribution and consumption of electrical power, i.e. equal to the power
105 supply system plus power circuits of all trains
106 3.3
107 power supply system
108 generation or distribution system for electrical power for the trains
109 Note 1 to entry: In railway systems this includes power stations and frequency converters, transmission lines,
110 substations including HV impedance at the point of common coupling and contact line system as well as the return
111 current circuits.
112 3.4
113 harmonic
114 voltage or current with frequency other than the fundamental frequency
115 Note 1 to entry: In this Standard, applied for explicit generation of such voltages or currents only. Instabilities (caused
116 by feedback loop effects) create voltages and currents at frequencies different from the fundamental frequency as well,
117 but these are normally not referred to as harmonics.
118 3.5
119 stability
120 property of a system such that, for a given operation point, the system always returns to this operation point
121 if a small deviation in one signal occurs
122 Note 1 to entry: The system is referred to as a stable system.
123 3.6
124 instability
125 property of a system such that any small deviation from an operation point leads to an amplification and,
126 therefore, further increase of the deviation
127 Note 1 to entry: The system is referred to as an unstable system.
128 Note 2 to entry: Signals (voltages and / or currents) increase until they are limited by explicit controller action,
129 protective actions, limiting devices (such as surge arrestors) or damage to the system.
130 3.7
131 small-signal behaviour
132 reaction of a system to an infinitesimally small deviation from an operation point
133 Note 1 to entry: The system can then be linearised for each operation point, with the approximation that its behaviour
134 is equal to the operation point plus the small signal behaviour.
135 Note 2 to entry: For the given sort of systems, typically up to 1 or 2 % of the nominal values can be regarded as
136 small signals.
137 3.8
138 active element
139 element which is able to excite instabilities in a system, i.e. it is able to bring in energy into the system on
140 certain frequencies
141 Note 1 to entry: In the given context, «active“(and also «passive“) is always defined for the small-signal behaviour
142 only.
143 Note 2 to entry: The definition of active or passive behaviour is not known for elements in the dq system (coupling of
144 four small signal behaviours). Definition of dq system: see A.2.3.
145 3.9
146 passive element
147 element which is not able to bring energy into the system on a defined frequency or frequency range
148 Note 1 to entry: The above definitions of “active” and “passive” apply throughout this standard and differ from other
149 definitions where “active” is used to designate a controlled element.
150 3.10
151 controlled element
152 electrical component or subsystem that has internal feedback loops controlling its output towards a set-point
153 Note 1 to entry: In the scope of this Standard that will typically be power electronic converters on infrastructure or
154 rolling stock. Controlled elements can be active or passive at different frequencies.
155 3.11
156 traction unit
157 unit that comprises all traction subsystems including auxiliary supplies, which can be collectively switched off
158 by one current collector / pantograph
159 3.12
160 influencing unit
161 set of traction units forming a train which has a communication link in the on-board control system for the
162 purpose of interlacing between the traction units
163 Note 1 to entry: The above definition is not identical with the definition in CLC/TS 50238-2.
164 3.13
165 inverter converter
166 auxiliary converter
167 system with power conversion from one frequency (power supply system) to another (traction motor,
168 auxiliary systems) by means of PWM (pulse width modulation) or other devices with fast control
169 3.14
170 UIC train busbar
171 heating train line
172 train power supply line
173 electrical cable running throughout the train and supplying the heating or the services on each coach
174 Note 1 to entry: See UIC leaflet 552 (Electrical power supply for trains — standard technical characteristics of the
175 train line).
176 3.15
177 AT system or autotransformer power supply system
178 traction power supply system in which energy transportation is at double voltage and uses autotransformers
179 to feed the overhead line
180 4 Requirements
181 4.1 Electrical resonance stability
182 Electrical resonance stability deals with the excitation of electrical resonances in the power systems caused
183 by feedback loop effects in the line converter controllers of rolling stock or static converter for power supply
184 systems. Background information and examples can be found in Annexes A and B.
185 In order to prevent electrical resonances in the power systems from being excited to oscillations and
186 corresponding overvoltages, the following requirements shall be fulfilled:
187 — The lowest resonance in the power system shall not fall below the limit frequency fL.
188 — The power system includes the power supply system with all its components in addition to parked trains
189 with filters or cables which are connected directly to the power supply system. The requirement affects
190 both design and operation of the power system (including degraded modes of feeding). If resonances
191 below fL are unavoidable (e.g. due to harmonic filters or reactive power compensators), sufficient
192 damping shall be provided, based on a stability analysis (see A.1.2) for the specific case.
193 — All controlled elements shall be passive for all frequencies higher than fL, which means that the phase
194 for its frequency dependent input admittance lies between ± 90 degrees
195 NOTE The stability margin is defined to be zero degrees, as experience has shown that this sufficiently takes
196 into account inaccuracies from measurements.
197 — The above requirement concerns rolling stock (traction units), auxiliary converters connected to the UIC
198 train busbar as well as stationary static converters feeding the power supply system.
199 — For equipment connected to the UIC busbar (1000 V, 16,7 Hz or 1500 V, 50 Hz), CLC/TS 50535 already
200 makes reference to EN 50388 for stability. In this case, the requirement is applicable for the input
201 admittance seen between train busbar and ground. For Electrical Multiple Units (EMUs) with networks
202 for auxiliaries with internal supply and return current, only the requirement at the pantograph of the EMU
203 is applicable.
204 The limit frequency f is defined in Table 2 as follows:
L
205 Table 2 — limit frequency for resonance stability
Power supply frequency 16,7 Hz 50 Hz
Limit frequency f for resonance stability 87 Hz 300 Hz
L
206 NOTE These values correspond to the 5th harmonic plus some tolerance for control and prediction of resonances
207 in real systems. The following reasons justify the limit at the 5th harmonic:
208 — Strong line voltage distortions at 3rd and 5th harmonic can be present today. This is mainly due to the operation of
209 vehicles with line commutated rectifiers. These line voltage distortions can lead to excessive harmonic voltage
210 components in the DC-link voltage on inverter vehicles. In order to prevent this it shall remain possible to actively
211 anticontrol larger distortions of the line voltage up to the 5th harmonic, which can make rolling stock active around
212 these frequencies. Thus it is not possible to reduce the limit frequency to the 5th harmonic or below.
213 — With weakly damped networks with resonance near the 5th harmonic (or lower) switching on / energizing under no-
214 load conditions can lead to continuous oscillations which are excited by the nonlinearity of transformers (saturation
215 of the iron core).
216 — Experience has shown that the bandwidth between the 5th harmonic and the f needs to be larger for 50 Hz power
L
217 supply than 16,7 Hz, hence the limit frequency is 300 Hz rather than 270 Hz for 50 Hz power supply frequency.
218 Infrastructure managers may specify different values in case compatibility between rolling stock and
219 signalling equipment can only be reached by anti-control on board of rolling stock (which normally makes
220 traction units active). Also in these cases, one single f is always valid as requirement for the whole
L
221 infrastructure segment (power supply, rolling stock, operation). If an fL value different from the above needs
222 to be chosen by the infrastructure manager, justification shall be given.
223 Different values for fL in 16,7 Hz systems are:
224 f = 103 Hz if 100 Hz track circuits are present
L
225 fL = 120 Hz in networks where old signalling equipment requires anti-control of the 7th harmonic
226 Example: f = 103 Hz is necessary in case of networks having 100-Hz track circuits (100 Hz is a natural
L
227 harmonic of the line frequency, which may lead to large harmonic currents during transients). In case of 95-
228 Hz track circuits, no anti-control is needed, and f can remain on the standard value of 90 Hz.
L
229 With respect to filter capacitors on board of rolling stock the following requirement applies. This requirement
230 applies to new rolling stock only (no modification on existing rolling stock as long as no problems are
231 observed): If no traction converter is being pulsed, the value of c (capacitance per MW installed power at
232 wheel, so that Im(Y(f )) = 2*pi*f *c) based on the imaginary part of the admittance at f shall not exceed the
L L L
233 value as defined as shown in Table 3.
234 Table 3 — Values for c
a
Network frequency [Hz] c [nF / MW] at fL
16,7 210
50 25
a
MW is the maximum power at wheel
235 NOTE This requirement will be necessary in order to guarantee that e.g. parked trains do not lower the critical
236 resonance frequency of a network too much. Values are selected so that the resonance frequency in a critical network
237 (resonance around f ) is not lowered by more than 3,4 Hz (in 16,7-Hz network) or 10 Hz (in 50-Hz networks) if the ratio
L
238 between total installed power at wheel and substation power rating is 4.
239 The following Figure 1 illustrates the requirements for the frequency response of a traction unit.
241 Figure 1 — Example of a frequency response of input admittance of a traction unit and forbidden
242 zones of phase angle
243 For assessment of the above stipulated requirements, see 5.1.
244 4.2 Low-frequency stability
245 Low frequency stability concerns oscillations at a frequency below the line frequency, (50 Hz or 16,7 Hz).
246 These oscillations appear between rolling stock and power supply containing inductive and capacitive
247 elements and are initiated by feedback loops as well as limitations and protection functions within the system.
248 Consequences may be serious interruptions even if no limit of overvoltages are reached.
249 Since low-frequency stability is multi-dimensional (coupled feedback loops for both magnitude and phase of
250 voltage and current), no simple interface requirements for single components are defined so far.
251 The system to be analysed is a simplified case of a railway system which consists of:
252 — a constant or controlled voltage source (power supply system);
253 — a linear network (power supply system);
254 — one or several vehicles at one single location.
255 Stability shall be maintained for a simplified system for a number of predefined cases.
256 Table 4 shows the standardized cases which shall be used for stability analysis. The two columns to the right
257 define which cases have to be analysed. Table 5 shows the data which shall be used.
258 Table 4 — Low frequency stability cases
Case Description System To be checked for the
following new elements
16,7 Hz 50 Hz Rolling Infra
stock components
b
A High line impedance / one or two trains X X X
b
B Depot / large number of trains X X X
a
C Rotary converters against trains X X X
D Static converters / compensators against rolling X X X X
2)
stock
E Converters / compensators against other converters X X X
b
/ compensators
a
Applicable to Sweden and Norway only (rotating synchronous to synchronous converters without damping windings).
Dynamic characteristics for these rotary converters may be given by the infrastructure manager according to C.1.
b
Cases (A and B in case of more than one vehicle type, D and E) defined for future revisions of this standard,
requiring multi-component simulators or MIMO Nyquist stability analysis. Not covered any further in the present revision.
For these cases, the process described in prEN 50388-1:2017, Clause 10 shall be applied.
259 Table 5 — Parameters for low frequency stability cases
a
Case Description f_line U_line [kV] abs(Z_L) angle(Z_L) Load Installed power
A1.1 High line impedance, one 16,7 15,75 30 Ohm 35, 45, 55° no load at least 6 MW
vehicle type
A2.1 High line impedance, two 16,7 15,75 30 Ohm 35, 45, 55° no load at least 3 MW each
vehicle types
A3.1 High line impedance, one 16,7 17,25 17 Ohm 35, 45, 55° 50 % braking at least 6 MW
vehicle type
A4.1 High line impedance, one 16,7 14,25 7 Ohm 35, 45, 55° 80 % traction at least 6 MW
vehicle type
A1.2 High line impedance, one 50 26,25 60 Ohm 60, 70, 80° no load at least 6 MW
vehicle type
A2.2 High line impedance, two 50 26,25 60 Ohm 60, 70, 80° no load at least 3 MW each
vehicle types
A3.2 High line impedance, one 50 27,5 44 Ohm 60, 70, 80° 50 % braking at least 6 MW
vehicle type
A4.2 High line impedance, one 50 23,75 38 Ohm 60, 70, 80° 80 % traction at least 6 MW
vehicle type
B1.1 Depot, one vehicle type 16,7 15,75 1.5 Ohm 90° depot mode at least 90 MW
B2.1 Depot, two vehicle types 16,7 15,75 1.5 Ohm 90° depot mode at least 45 MW +
22,5 MW of ref.
vehicle in normal
mode
B3.1 Depot, one vehicle type 16,7 15,75 7 Ohm 55° depot mode at least 27 MW
B4.1 Depot, two vehicle types 16,7 15,75 7 Ohm 55° depot mode at least 13,5 MW +
7 MW of ref. vehicle in
normal mode
B1.2 Depot, one vehicle type 50 26,25 4.5 Ohm 90° depot mode at least 90 MW
B2.2 Depot, two vehicle types 50 26,25 4.5 Ohm 90° depot mode at least 45 MW +
22,5 MW of ref.
vehicle in normal
mode
B3.2 Depot, one vehicle type 50 26,25 10 Ohm 75° depot mode at least 27 MW
B4.2 Depot, two vehicle types 50 26,25 10 Ohm 75° depot mode at least 13,5 MW +
7 MW of ref. vehicle in
normal mode
C1 Rotary converter type Q38, 16,6667 15,75 30 Ohm 35, 45, 55° no load at least 6 MW
one vehicle type
C2 Rotary converter type Q38, 16,6667 17,25 17 Ohm 35, 45, 55° 50 % braking at least 6 MW
one vehicle type
C3 Rotary converter type Q38, 16,6667 14,25 7 Ohm 35, 45, 55° 80 % traction at least 6 MW
one vehicle type
a
Maximum trainset power, but at least the values stipulated in the columns (power at wheel)
NOTE 1 In cases B1.1 to B4.2 no prove needed if diode rectification is applied
NOTE 2 There is no additional stability margin defined since this is included in the above parameters (impedance).
NOTE 3 Depot means sum of maximum power at wheel of rolling stock is equal to the value in column “installed power”,
e.g. for the case installed power 90 MW, 15 traction units à 6 MW maximum power at wheel. On board circuit breakers
switched on without traction power.
260 For parked trains, pulsing of the line-side traction converters should be switched off if the consumed power
261 (e.g. for auxiliaries) is lower than 12 … 15 % of the rated power at wheel. These values were derived from
262 energy loss considerations in the substation transformer, see A.4.3. However, if this would lead to over
263 dimensioning of the auxiliary converters, the values can be adapted. Auxiliary converters may be supplied
264 via diode rectifiers in this case. This can serve to improve stability if the requirements for a large number of
265 trains cannot be met otherwise.
266 In case of special events onboard a traction unit, such as starting a compressor, reacting to line-side DC
267 currents saturating the transformer, or violating harmonic current limits, short-term pulsing periods of line-
268 side converters are still permitted.
269 For assessment of the above stipulated requirements, see 5.2.
270 4.3 Overvoltages caused by harmonics
271 4.3.1 General
272 Harmonic currents, produced by the pulsing of line converters in rolling stock, may be amplified by electrical
273 resonances in the power systems. Overvoltages may be the result. Other than for the stability phenomena,
274 no feedback loop effect is present in this case. Background information and examples can be found in
275 Annex A.
276 4.3.2 Rolling stock
277 4.3.2.1 Generation of harmonic currents
278 In order to prevent overvoltages caused by harmonics to occur in a.c. railway power systems, the following
279 requirements shall be fulfilled by rolling stock:
280 For a number of N independent influencing units (IU) of identical type, the expected r.m.s. value for the
281 harmonic line voltage UH at any resonance frequency shall be below UmaxH according to the values in
282 Table 6:
283 Table 6 — Values for U
maxH
Power supply system 15 kV, 16,7 Hz system 25 kV, 50 Hz system
UmaxH 3.2 kV 6,4 kV
with
U = U /√2 — U
maxH peak max2
and
U = max. allowed peak voltage of the supply system according to
peak
prEN 50388-1:2017, 10.4.
U = max. voltage according to EN 50163.
max2
284 This limit applies to an IU in all its operation modes. Requirements for degraded modes (e.g. one bogie out
285 of operation due to a hardware failure) are relaxed by means of a different definition of factor N.
286 N is calculated from the maximum power at wheel of the influencing unit, and rounded to the next higher
287 integer number. Two cases shall be considered (roughly representing the different conditions in an
288 interconnected or an isolated network). The IU shall hold the limit for all six cases contained in Table 7.
289 Table 7 — Influencing units (IU)
Number of IUs Interconnected network Isolated system
N (normal operation) 150 MW / Pmax,wheel 50 MW / Pmax,wheel
N (degraded operation) 6 2
N (standstill and no tractive effort; applies 200 MW / Pmax,wheel 150 MW / Pmax,wheel
for both pulsed line converters or diode
rectifying)
290 One influencing unit (IU) may consist of several traction units (TU). TUs and IUs are defined slightly different
291 from CLC/TS 50238-2. Only those TUs which are controlled from or get their reference values from one
292 single master control unit are part of one IU. Independently controlled TUs (individual train driver, or different
293 vehicle type) are not part of one single IU.
295 Figure 2 — Influencing units (IU) and traction units (TU)
296 U , the expected harmonic voltage at resonance, is calculated as follows:
H
297 U = Z * I * k * k
H res IU0 Z N
298 with
299 Z = standardized value for the maximum impedance at resonances; it is ohmic (no imaginary part) (see
res
300 Table 8).
301 Table 8 — Value for Z
res
Impedance at resonance Interconnected network Isolated system
Z 200 Ohm 2000 Ohm
res
302 IIU0 = bandpass-filtered and integrated line current of the influencing unit (see below)
303 kZ = reduction factor, taking into account the influence of the passive impedance of the influencing unit
304 kN = factor taking account summation of harmonics between different IUs
305 IIU0 is calculated as follows:
306 — simulation of the total line current of the IU, at nominal voltage and ideal sinusoidal supply voltage with
307 zero line impedance
308 — operation point where the highest IIU0 of the IU is expected
309 — bandpass filtering with a large number of bandpasses:
310 — each with centre frequency f0, so that 500 Hz ≤ f0 ≤ f0max
311 — difference between two f0 sufficiently small so that the probability is low that higher values for UH
312 are disregarded for frequencies between them
313 — f0max sufficiently high to guarantee that UH can only decrease below already reached values if f0 is
314 further increasing
315 — 2nd order (= 2 * 1st order) bandpass filter, with 3-dB bandwith = 0,1 * f0.
316 NOTE This characteristic is adapted to typical resonances in the railway power supply system.
317 — integration (averaging) by means of a moving r.m.s. value algorithm, with window length T = 0,5 ms:
tx+0,0005
⋅ I()t dt
∫
tx
0,0005
318 (1)
319 NOTE 1 This time constant is independent from f0, and also adapted to the excitation of typical resonances in the
320 railway power supply system.
321 Since the window length is shorter than the line period for the fundamental frequency, the evaluation
322 has to be made in time domain from the line current.
323 — IIU0 is then the highest value reached over one line period, for each centre frequencies f0
324 kZ is calculated as follows:
325 kZ = |Zveh| / (a*N*Zres + |Zveh|) (2)
326 — Zres = standardized impedance at resonance (see above)
327 — Zveh = passive impedance of the IU as seen from the power supply into the train, with internal voltages
328 set to zero. Roof cable capacitances connected directly to the line voltage as well as parasitic effects
329 inside the line circuits (e.g. transformer capacitances) shall be neglected, since their influence is
330 included in the general effect of resonance amplification.
331 — N is the required number of IUs
332 — a = reduction factor taking into account that the line impedance is effective not only at the peak of a
333 resonance, but over a broader bandwidth. a shall be set to 0,5.
334 NOTE 2 The calculation of kZ can be illustrated for the simplified equivalent circuit diagram for N IUs (left),
335 combined into one single unit with modified line parameters (right). The voltage at pantograph is identical in both
336 cases.
338 Figure 3 — Illustration of kz
339 k is defined as follows:
N
340 — if random displacement of the switching angles between different IUs is applied (See Table 9)
341 Table 9 — Values for N if random displacement of the switching angles between different IUs is
342 applied
N 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
k 1 1,95 2,76 3,38 3,86 4,27 4,63 4,98 5,30 5,60 5,90 6,17 6,44 6,68 6,91 7,12
N
343 if N > 16: kN results from linear interpolation of N = [16, 1600] and kN = [7,12; 71,2] in a double-
344 logarithmic scale
345 NOTE 3 These factors for N ≤ 16 are identical to the factor kI for superposition of harmonics with equal
346 magnitude, but random phase as defined in CLC/TS 50238-2:2015, B.8.2.
347 — if no random displacement is applied: kN = N
348 4.3.2.2 Overvoltage detection
349 Traction units shall be equipped with a protection against peak voltages on the supply voltage. If the peak
350 voltage (defined as the highest value during one half of a fundamental period of the line frequency)
351 continuously (i.e. in each line period) exceeds the value defined in the following table for more than the
352 defined time t1, the traction converters shall stop pulsing, and a diagnoses message shall be recorded. Line
353 converters can be restarted after some time (t ; this time can be coordinated with other protection functions
354 of the traction converter). If the exceedance repeatedly occurs for more than t3, the line converters shall be
355 blocked. Otherwise there is a risk that surge arrestors may be overloaded and cause short circuits in the
356 supply system. A restart shall be possible after manual intervention by the train driver. The situation shall be
357 reported by the train driver to the network operation centre. Table 10 shows the limits for the peak voltage for
358 both network frequencies.
359 Table 10 — Limits for the peak voltage monitor
Network frequency Periodic peak Time t1 Time t2 Time t3
voltage for
protection
a b
16,7 Hz 32 kV 1 s 3 . 5 s 20 s
a b
50 Hz 53 kV 1 s 3 . 5 s 20 s
a
Values are derived from max. allowed values according to prEN 50388-1 plus about 6 %
b
This value allows for pantograph bouncing without further intervention
360 Existing voltage sensors can be used on board of rolling stock. No installation of precision sensors with a
361 high accuracy and / or high bandwidth is required. Parameters for the protection functions in the software
362 shall be selected to guarantee the best possible correspondence with the voltage defined in Table 10, for a
363 frequency range up to about 5000 Hz, as far as existing measuring devices allow it. This detection can also
364 be realized by undersampling and does not require a sampling rate of 10 000 Hz (theoretically necessary for
365 precise detection).
366 NOTE This protection mechanism will:
367 — Prevent surge arresters from taking too much energy and fail in critical cases;
368 — Inform the infrastructure manager about the presence of such critical cases, which would be otherwise undetected
369 and could lead to faults in the power systems at a later time (premature ageing, disruption of operation).
370 4.3.2.3 Diode rectifying
371 When the transmitted power of a traction converter is low, and the vehicle is at standstill and does not
372 require tractive or el
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.