Determination of power losses in high-voltage direct current (HVDC) converter stations with line-commutated converters (IEC 61803:2020)

This document applies to all line-commutated high-voltage direct current (HVDC) converter
stations used for power exchange (power transmission or back-to-back installation) in utility
systems. This document presumes the use of 12-pulse thyristor converters but can, with due
care, also be used for 6-pulse thyristor converters.
In some applications, synchronous compensators or static var compensators (SVC) may be
connected to the AC bus of the HVDC converter station. The loss determination procedures
for such equipment are not included in this document.
This document presents a set of standard procedures for determining the total losses of an
HVDC converter station. The procedures cover all parts, except as noted above, and address
no-load operation and operating losses together with their methods of calculation which use,
wherever possible, measured parameters.
Converter station designs employing novel components or circuit configurations compared to
the typical design assumed in this document, or designs equipped with unusual auxiliary
circuits that could affect the losses, are assessed on their own merits.

Bestimmung der Leistungsverluste in Hochspannungsgleichstrom- (HGÜ-)Stromrichterstationen mit netzgeführten Stromrichtern (IEC 61803:2020)

Détermination des pertes en puissance dans les postes de conversion en courant continu à haute tension (CCHT) munis de convertisseurs commutés par la ligne (IEC 61803:2020)

IEC 61803:2020 est disponible sous forme de IEC 61803:2020 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.L'IEC 61803:2020 s'applique à tous les postes de conversion en courant continu à haute tension (CCHT), commutés par la ligne, et utilisés pour l'échange de puissance (transmission de puissance ou installation dos à dos) dans des systèmes de distribution d'énergie. Le présent document présuppose l'utilisation de convertisseurs à thyristors à 12 impulsions mais peut également, en prenant les précautions appropriées, s'appliquer à des convertisseurs à thyristors à 6 impulsions. Dans certaines applications, il est admis de connecter des compensateurs synchrones ou des compensateurs var statiques (CVS) au nœud à courant alternatif du poste de conversion en courant continu à haute tension (CCHT). Les procédures de détermination de pertes pour ce type de matériel ne figurent pas dans le présent document. Le présent document décrit un ensemble de procédures types permettant de déterminer l'ensemble des pertes d'un poste de conversion à CCHT. Les procédures s’appliquent à toutes les pièces, à l'exception de celles susmentionnées, et considèrent les pertes en fonctionnement à vide et les pertes en fonctionnement ainsi que leurs méthodes de calcul utilisant, dans la mesure du possible, des paramètres mesurés. Les conceptions de poste de conversion utilisant des composants ou des configurations de circuit originaux par rapport à la conception type prise pour hypothèse dans le présent document, ou des conceptions équipées de circuits de distribution d'énergie auxiliaires inhabituels susceptibles de modifier les pertes, sont évaluées selon leurs propres mérites. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: - en vue de faciliter l’application de la norme sans en détériorer la qualité, 5.1.8 et 5.8 ont été revus en tenant compte du fait que la technologie de production de thyristors actuelle occasionne considérablement moins de dispersion dans ses paramètres par rapport à la situation de 1999, lorsque la première édition de l'IEC 61803 a été élaborée. Ainsi, les données enregistrées de production de thyristors peuvent être utilisées pour les calculs de pertes de puissance; - le calcul des pertes de charge au poste totales (cas D1 et D2 à l’Annexe C) a été corrigé.

Ugotavljanje močnostnih izgub v visokonapetostnih enosmernih (HVDC) pretvorniških postajah s pretvorniki s komutiranjem (IEC 61803:2020)

General Information

Status
Published
Public Enquiry End Date
12-Apr-2020
Publication Date
23-Dec-2020
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
09-Dec-2020
Due Date
13-Feb-2021
Completion Date
24-Dec-2020

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SLOVENSKI STANDARD
SIST EN IEC 61803:2021
01-februar-2021
Nadomešča:
SIST EN 61803:2001
SIST EN 61803:2001/A1:2011
SIST EN 61803:2001/A2:2016
Ugotavljanje močnostnih izgub v visokonapetostnih enosmernih (HVDC)
pretvorniških postajah s pretvorniki s komutiranjem (IEC 61803:2020)

Determination of power losses in high-voltage direct current (HVDC) converter stations

with line-commutated converters (IEC 61803:2020)
Bestimmung der Leistungsverluste in Hochspannungsgleichstrom-
(HGÜ-)Stromrichterstationen mit netzgeführten Stromrichtern (IEC 61803:2020)
Détermination des pertes en puissance dans les postes de conversion en courant

continu à haute tension (CCHT) munis de convertisseurs commutés par la ligne (IEC

61803:2020)
Ta slovenski standard je istoveten z: EN IEC 61803:2020
ICS:
29.200 Usmerniki. Pretvorniki. Rectifiers. Convertors.
Stabilizirano električno Stabilized power supply
napajanje
SIST EN IEC 61803:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 61803:2021
---------------------- Page: 2 ----------------------
SIST EN IEC 61803:2021
EUROPEAN STANDARD EN IEC 61803
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2020
ICS 29.200 Supersedes EN 61803:1999 and all of its amendments
and corrigenda (if any)
English Version
Determination of power losses in high-voltage direct current
(HVDC) converter stations with line-commutated converters
(IEC 61803:2020)

Détermination des pertes en puissance dans les postes de Bestimmung der Leistungsverluste in

conversion en courant continu à haute tension (CCHT) Hochspannungsgleichstrom- (HGÜ-)Stromrichterstationen

munis de convertisseurs commutés par la ligne mit netzgeführten Stromrichtern
(IEC 61803:2020) (IEC 61803:2020)

This European Standard was approved by CENELEC on 2020-11-23. 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

© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN IEC 61803:2020 E
---------------------- Page: 3 ----------------------
SIST EN IEC 61803:2021
EN IEC 61803:2020 (E)
European foreword

The text of document 22F/563/CDV, future edition 2 of IEC 61803, prepared by SC 22F "Power

electronics for electrical transmission and distribution systems" of IEC/TC 22 "Power electronic

systems and equipment" was submitted to the IEC-CENELEC parallel vote and approved by

CENELEC as EN IEC 61803:2020.
The following dates are fixed:

• latest date by which the document has to be implemented at national (dop) 2021-08-23

level by publication of an identical national standard or by endorsement

• latest date by which the national standards conflicting with the (dow) 2023-11-23

document have to be withdrawn

This document supersedes EN 61803:1999 and all of its amendments and corrigenda (if any).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice

The text of the International Standard IEC 61803:2020 was approved by CENELEC as a European

Standard without any modification.
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SIST EN IEC 61803:2021
EN IEC 61803:2020 (E)
Annex ZA
(normative)
Normative references to international publications with their
corresponding European publications

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.

NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod),

the relevant EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available

here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60076-1 - Power transformers - Part 1: General EN 60076-1 -
IEC 60076-6 - Power transformers - Part 6: Reactors EN 60076-6 -
IEC 60633 - High-voltage direct current (HVDC) EN IEC 60633 -
transmission - Vocabulary
IEC 60700-1 2015 Thyristor valves for high voltage direct EN 60700-1 2015
current (HVDC) power transmission - Part 1:
Electrical testing
IEC 60871-1 - Shunt capacitors for a.c. power systems EN 60871-1 -
having a rated voltage above 1 000 V -
Part 1: General
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SIST EN IEC 61803:2021
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SIST EN IEC 61803:2021
IEC 61803
Edition 2.0 2020-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Determination of power losses in high-voltage direct current (HVDC) converter
stations with line-commutated converters
Détermination des pertes en puissance dans les postes de conversion
en courant continu à haute tension (CCHT) munis de convertisseurs commutés
par la ligne
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.200 ISBN 978-2-8322-8948-8

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 7 ----------------------
SIST EN IEC 61803:2021
– 2 – IEC 61803:2020 © IEC 2020
CONTENTS

FOREWORD ........................................................................................................................... 4

1 Scope .............................................................................................................................. 6

2 Normative references ...................................................................................................... 6

3 Terms, definitions and symbols........................................................................................ 6

3.1 Terms and definitions .............................................................................................. 7

3.2 Symbols .................................................................................................................. 8

4 Overview ......................................................................................................................... 8

4.1 General ................................................................................................................... 8

4.2 Ambient conditions.................................................................................................. 9

4.2.1 General ........................................................................................................... 9

4.2.2 Outdoor standard reference temperature ......................................................... 9

4.2.3 Coolant standard reference temperature .......................................................... 9

4.2.4 Standard reference air pressure .................................................................... 10

4.3 Operating parameters ........................................................................................... 10

5 Determination of equipment losses ................................................................................ 10

5.1 Thyristor valve losses ........................................................................................... 10

5.1.1 General ......................................................................................................... 10

5.1.2 Thyristor conduction loss per valve ................................................................ 11

5.1.3 Thyristor spreading loss per valve ................................................................. 12

5.1.4 Other conduction losses per valve ................................................................. 12

5.1.5 DC voltage-dependent loss per valve ............................................................. 13

5.1.6 Damping loss per valve (resistor-dependent term) ......................................... 14

5.1.7 Damping loss per valve (change of capacitor energy term) ............................ 14

5.1.8 Turn-off losses per valve ............................................................................... 15

5.1.9 Reactor loss per valve ................................................................................... 15

5.1.10 Total valve losses .......................................................................................... 16

5.1.11 Temperature effects....................................................................................... 16

5.1.12 No-load operation loss per valve .................................................................... 16

5.2 Converter transformer losses ................................................................................ 17

5.2.1 General ......................................................................................................... 17

5.2.2 No-load operation losses ............................................................................... 17

5.2.3 Operating losses............................................................................................ 17

5.2.4 Auxiliary power losses ................................................................................... 18

5.3 AC filter losses ..................................................................................................... 19

5.3.1 General ......................................................................................................... 19

5.3.2 AC filter capacitor losses ............................................................................... 19

5.3.3 AC filter reactor losses .................................................................................. 19

5.3.4 AC filter resistor losses .................................................................................. 20

5.3.5 Total AC filter losses ..................................................................................... 20

5.4 Shunt capacitor bank losses ................................................................................. 20

5.5 Shunt reactor losses ............................................................................................. 20

5.6 DC smoothing reactor losses ................................................................................ 21

5.7 DC filter losses ..................................................................................................... 21

5.7.1 General ......................................................................................................... 21

5.7.2 DC filter capacitor losses ............................................................................... 22

5.7.3 DC filter reactor losses .................................................................................. 22

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SIST EN IEC 61803:2021
IEC 61803:2020 © IEC 2020 – 3 –

5.7.4 DC filter resistor losses ................................................................................. 23

5.7.5 Total DC filter losses ..................................................................................... 23

5.8 Auxiliaries and station service losses .................................................................... 23

5.9 Series filter losses ................................................................................................ 24

5.10 Other equipment losses ........................................................................................ 25

Annex A (informative) Calculation of harmonic currents and voltages .................................. 31

A.1 Harmonic currents in converter transformers ......................................................... 31

A.2 Harmonic currents in the AC filters ........................................................................ 31

A.3 Harmonic voltages on the DC side ........................................................................ 32

A.4 DC side harmonic currents in the smoothing reactor ............................................. 32

Annex B (informative) Typical station losses ........................................................................ 33

Annex C (informative) HVDC converter station loss evaluation – An illustration ................... 34

C.1 General ................................................................................................................. 34

C.2 Loss evaluation under various cases ..................................................................... 35

Bibliography .......................................................................................................................... 37

Figure 1 – Typical high-voltage direct current (HVDC) equipment for one pole ...................... 26

Figure 2 – Simplified three-phase diagram of an HVDC 12-pulse converter ........................... 27

Figure 3 – Simplified equivalent circuit of a typical thyristor valve ......................................... 27

Figure 4 – Current and voltage waveforms of a valve operating in a 12-pulse converter ....... 28

Figure 5 – Thyristor on-state characteristic ........................................................................... 29

Figure 6 – Conduction current and voltage drop .................................................................... 29

Figure 7 – Distribution of commutating inductance between L and L .................................. 30

1 2

Figure 8 – Thyristor current during reverse recovery ............................................................. 30

Table B.1 – Typical values of losses ..................................................................................... 33

Table C.1 – Conditions for calculation of losses in case D1 .................................................. 36

Table C.2 – Conditions for calculation of losses in Case D2. ................................................. 36

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SIST EN IEC 61803:2021
– 4 – IEC 61803:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DETERMINATION OF POWER LOSSES IN HIGH-VOLTAGE
DIRECT CURRENT (HVDC) CONVERTER STATIONS WITH
LINE-COMMUTATED CONVERTERS
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC

Publication(s)"). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence

between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in

the latter.

5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC

Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 61803 has been prepared by subcommittee 22F: Power electronics

for electrical transmission and distribution systems, of IEC technical committee 22: Power

electronic systems and equipment.
This second edition cancels and replaces the first edition published in 1999,

Amendment 1:2010 and Amendment 2:2016. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) to facilitate the application of this document and to ensure its quality remains consistent,

5.1.8 and 5.8 have been reviewed, taking into consideration that the present thyristor

production technology provides considerably less thyristor parameters dispersion

comparing with the situation in 1999 when the first edition of IEC 61803 was developed,

and therefore the production records of thyristors can be used for the power losses

calculation;
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SIST EN IEC 61803:2021
IEC 61803:2020 © IEC 2020 – 5 –

b) the calculation of the total station load losses (cases D1 and D2 in Annex C) has been

corrected.
The text of this International Standard is based on the following documents:
CDV Report on voting
22F/563/CDV 22F/580A/RVC

Full information on the voting for the approval of this International Standard can be found in

the report on voting indicated in the above table.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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SIST EN IEC 61803:2021
– 6 – IEC 61803:2020 © IEC 2020
DETERMINATION OF POWER LOSSES IN HIGH-VOLTAGE
DIRECT CURRENT (HVDC) CONVERTER STATIONS WITH
LINE-COMMUTATED CONVERTERS
1 Scope

This document applies to all line-commutated high-voltage direct current (HVDC) converter

stations used for power exchange (power transmission or back-to-back installation) in utility

systems. This document presumes the use of 12-pulse thyristor converters but can, with due

care, also be used for 6-pulse thyristor converters.

In some applications, synchronous compensators or static var compensators (SVC) may be

connected to the AC bus of the HVDC converter station. The loss determination procedures

for such equipment are not included in this document.

This document presents a set of standard procedures for determining the total losses of an

HVDC converter station. The procedures cover all parts, except as noted above, and address

no-load operation and operating losses together with their methods of calculation which use,

wherever possible, measured parameters.

Converter station designs employing novel components or circuit configurations compared to

the typical design assumed in this document, or designs equipped with unusual auxiliary

circuits that could affect the losses, are assessed on their own merits.
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.
IEC 60076-1, Power transformers – Part 1: General
IEC 60076-6, Power transformers – Part 6: Reactors
IEC 60633, High-voltage direct current (HVDC) transmission – Vocabulary

IEC 60700-1:2015, Thyristor valves for high voltage direct current (HVDC) power transmission

– Part 1: Electrical testing

IEC 60871-1, Shunt capacitors for a.c. power systems having a rated voltage above 1 000 V –

Part 1: General
3 Terms, definitions and symbols

For the purposes of this document, the terms and definition given in IEC 60633 and the

following apply.
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SIST EN IEC 61803:2021
IEC 61803:2020 © IEC 2020 – 7 –

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 Terms and definitions
3.1.1
auxiliary losses
electric power required to feed the converter station auxiliary loads

Note 1 to entry: The auxiliary losses depend on the number of converter units used and whether the station is in

no-load operation or carrying load, in which case the auxiliary losses depend on the load level.

3.1.2
equipment no-load operation losses

losses produced in an item of equipment with the converter station energised but with the

converters blocked and all station service loads and auxiliary equipment connected as

required for immediate pick-up of load to specified minimum power
3.1.3
load level

direct current, direct voltage, firing angle, AC voltage, and converter transformer tap-changer

position at which the converter station is operating
3.1.4
equipment operating losses

losses produced in an item of equipment at a given load level with the converter station

energised and the converters operating
3.1.5
rated load

load related to operation at nominal values of DC current, DC voltage, AC voltage and

converter firing angle

Note 1 to entry: The AC system shall be assumed to be at nominal frequency, and its 3-phase voltages are

nominal and balanced. The position of the tap-changer of the converter transformer and the number of AC filters

and shunt reactive elements connected shall be consistent with operation at rated load, coincident with nominal

conditions.
3.1.6
total station no-load operation losses

sum of all equipment no-load operation losses (3.1.2) and corresponding auxiliary losses

(3.1.1)
3.1.7
total station operating losses

sum of all equipment operating losses (3.1.4) and corresponding auxiliary losses (3.1.1) at a

particular load level

Note 1 to entry: An illustrative example using total station operating losses and corresponding loss evaluation is

given in Annex C, case D1.
3.1.8
total station load losses

difference between total station operating losses (3.1.7) and total station no-load operation

losses (3.1.6)

Note 1 to entry: Such calculated total station load losses are considered as being quantitatively equivalent to load

losses as in conventional AC substation practice.
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SIST EN IEC 61803:2021
– 8 – IEC 61803:2020 © IEC 2020

Note 2 to entry: It is recognized that some purchasers evaluate total station no-load operation losses (3.1.6) and

total station load losses individually instead of the evaluating total station operating losses (3.1.7).

Note 3 to entry: An illustrative example to derive load losses, equivalent load losses and corresponding loss

evaluation is given in Annex C, case D2.
3.1.9
station essential auxiliary load

load whose failure will affect the conversion capability of the HVDC converter station (e.g.

valve cooling), as well as load that shall remain working in case of complete loss of AC power

supply (e.g. battery chargers, operating mechanisms)
3.2 Symbols
α (trigger/firing) delay angle, in radians (rad)
overlap angle, in radians (rad)
f AC system frequency, in hertz (Hz)
I direct current, in amperes (A)
I harmonic RMS current of order n, in amperes (A)

L inductance, in henrys (H), referred to the valve winding, between the commutating

voltage source and the point of common coupling between star- and delta-connected

windings. L shall include any external inductance between the transformer line-
winding terminals and the point of connection of the AC harmonic filters.
L inductance, in henrys (H), referred to the valve winding, between the point of
common coupling between star- and delta-connected windings, and the valve. L
shall include the saturated inductance of the valve reactors.
electromagnetic notch coupling factor, m = L /(L + L )
1 1 2
n harmonic order
N number of series-connected thyristors per valve
P power loss in an item of equipment, in watts (W)
quality factor at harmonic order n
resistance value, in ohms (Ω)
U direct voltage, in volts (V)
harmonic RMS voltage of order n, in volts (V)

U RMS value of the phase-to-phase no-load voltage on the valve side of the converter

transformer excluding harmonics, in volts (V)
inductive reactance at harmonic order n, in ohms (Ω)
4 Overview
4.1 General

Suppliers need to know in detail how and where losses are generated, since this affects

component and equipment ratings. Purchasers are interested in a verifiable loss figure which

allows equitable bid comparison and in a procedure after delivery which can objectively verify

the guaranteed performance requirements of the supplier.
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SIST EN IEC 61803:2021
IEC 61803:2020 © IEC 2020 – 9 –

As a general principle, it would be desirable to determine the efficiency of an HVDC converter

station by a direct measurement of its energy losses. However, attempts to determine the

station losses by subtracting the measured output power from the measured input power

should recognize that such measurements have an inherent inaccuracy, especially if

performed at high voltage. The losses of an HVDC converter station at full load are generally

less than 1 % of the transmitted power. Therefore, the loss measured as a small difference

between two large quantities is not likely to be a sufficiently accurate indication of the actual

losses.

In some special circumstances, it may be possible, for example, to arrange a temporary test

connection in which two converters are operated from the same AC source and also

connected together via their DC terminals. In this connection, the power drawn from the AC

source equals the losses in the circuit. However, the AC source shall also provide var support

and commutating voltage to the two converters. Once again, there are practical measurement

difficulties.

In order to avoid the problems described above, this document standardizes a method of

calculating the HVDC converter station losses by summing the losses calculated for each item

of equipment. The standardized calculation method will help the purchaser to mean

...

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