SIST EN 61071:2007
Capacitors for power electronics
Capacitors for power electronics
This International Standard applies to capacitors for power electronics applications. The operating frequency of the systems in which these capacitors are used is usually up to 15kHz, while the pulse frequencies may be up to 5 to 10 times the operating frequency. The standard distinguishes between a.c. and d.c. capacitors which are considered as components when mounted in enclosures. This standard covers an extremely wide range of capacitor technologies for numerous applications, e.g. overvoltage protection, d.c. and a.c. filtering, switching circuits, d.c. energy storage, auxiliary inverters, etc.
Kondensatoren der Leistungselektronik
Condensateurs pour électronique de puissance
La présente Norme internationale s'applique aux condensateurs pour les applications de l'électronique de puissance. La fréquence de fonctionnement des systèmes utilisant ces condensateurs atteint généralement 15 kHz, mais les fréquences d'impulsions peuvent atteindre 5 à 10 fois la fréquence de fonctionnement. Une distinction est faite dans la présente norme entre les condensateurs à courants alternatifs et les condensateurs à courants continus qui sont considérés comme des composants lorsqu'ils sont montés dans un boîtier fermé. Cette norme couvre une très grande variété de technologies de condensateurs pour répondre à de nombreuses applications, par exemple protection contre les surtensions, filtrage à courant continu et à courant alternatif, circuits de commutation, stockage d'énergie à courant continu, convertisseurs auxiliaires, etc.
Kondenzatorji za močnostno elektroniko
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2007
1DGRPHãþD
SIST EN 61071-1:1999
SIST EN 61071-2:1999
.RQGHQ]DWRUML]DPRþQRVWQRHOHNWURQLNR
Capacitors for power electronics
Kondensatoren der Leistungselektronik
Condensateurs pour électronique de puissance
Ta slovenski standard je istoveten z: EN 61071:2007
ICS:
31.060.70 0RþQRVWQLNRQGHQ]DWRUML Power capacitors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 61071
NORME EUROPÉENNE
April 2007
EUROPÄISCHE NORM
ICS 31.060.70 Supersedes EN 61071-1:1996 and EN 61071-2:1996
English version
Capacitors for power electronics
(IEC 61071:2007)
Condensateurs Kondensatoren
pour électronique de puissance der Leistungselektronik
(CEI 61071:2007) (IEC 61071:2007)
This European Standard was approved by CENELEC on 2007-04-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61071:2007 E
Foreword
The text of document 33/432/FDIS, future edition 1 of IEC 61071, prepared by IEC TC 33, Power
capacitors, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 61071 on 2007-04-01.
This European Standard supersedes EN 61071-1:1996 and EN 61071-2:1996.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2008-01-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2010-04-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61071:2007 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60077-1 NOTE Harmonized as EN 60077-1:2002 (modified).
IEC 60077-2 NOTE Harmonized as EN 60077-2:2002 (modified).
IEC 60146-1-1 NOTE Harmonized as EN 60146-1-1:1993 (not modified).
IEC 61287-1 NOTE Harmonized as EN 61287-1:2006 (not modified).
IEC 60110-1 NOTE Harmonized as EN 60110-1:1998 (not modified).
IEC 60143 NOTE Harmonized in EN 60143 series (partially modified).
IEC 60252-1 NOTE Harmonized as EN 60252-1:2001 (not modified).
IEC 60252-2 NOTE Harmonized as EN 60252-2:2003 (not modified).
IEC 60358 NOTE Harmonized as HD 597 S1:1992 (not modified).
IEC 60384-14 NOTE Harmonized as EN 60384-14:2005 (not modified).
IEC 60831-1 NOTE Harmonized as EN 60831-1:1996 (not modified).
IEC 60831-2 NOTE Harmonized as EN 60831-2:1996 (not modified).
IEC 60871-1 NOTE Harmonized as EN 60871-1:2005 (not modified).
IEC 60931-1 NOTE Harmonized as EN 60931-1:1996 (not modified).
IEC 60931-2 NOTE Harmonized as EN 60931-2:1996 (not modified).
- 3 - EN 61071:2007
IEC 61048 NOTE Harmonized as EN 61048:2006 (not modified).
IEC 61049 NOTE Harmonized as EN 61049:1993 (modified).
IEC 61270-1 NOTE Harmonized as EN 61270-1:1996 (not modified).
IEC 61881 NOTE Harmonized as EN 61881:1999 (not modified).
__________
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application 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 When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year
1) 2)
IEC 60068-2-6 - Environmental testing - EN 60068-2-6 1995
Part 2: Tests - Test Fc: Vibration (sinusoidal)
1) 2)
IEC 60068-2-14 - Environmental testing - EN 60068-2-14 1999
Part 2: Tests - Test N: Change of temperature
1) 2)
IEC 60068-2-20 - Environmental testing - HD 323.2.20 S3 1988
Part 2: Tests - Test T: Soldering
1) 2)
IEC 60068-2-21 - Environmental testing - EN 60068-2-21 2006
Part 2-21: Tests - Test U: Robustness of
terminations and integral mounting devices
1) 2)
IEC 60068-2-78 - Environmental testing - EN 60068-2-78 2001
Part 2-78: Tests - Test Cab: Damp heat,
steady state
1) 2)
IEC 60071-1 - Insulation co-ordination - EN 60071-1 2006
Part 1: Definitions, principles and rules
1) 2)
IEC 60071-2 - Insulation co-ordination - EN 60071-2 1997
Part 2: Application guide
1) 3)
IEC 60269-1 - Low-voltage fuses - EN 60269-1 200X
Part 1: General requirements
1) 2)
IEC 60664-1 - Insulation coordination for equipment within EN 60664-1 2003
low-voltage systems -
Part 1: Principles, requirements and tests
1) 2)
IEC 60695-2-11 - Fire hazard testing - EN 60695-2-11 2001
Part 2-11: Glowing/hot-wire based test
methods - Glow-wire flammability test method
for end-products
1) 2)
IEC 60695-2-12 - Fire hazard testing - EN 60695-2-12 2001
Part 2-12: Glowing/hot-wire based test
methods - Glow-wire flammability test method
for materials
1) 2)
IEC 60947-1 - Low-voltage switchgear and controlgear - EN 60947-1 2004
Part 1: General rules + corr. November 2004
1)
Undated reference.
2)
Valid edition at date of issue.
3)
To be published.
NORME CEI
INTERNATIONALE
IEC
INTERNATIONAL
Première édition
STANDARD
First edition
2007-01
Condensateurs pour électronique
de puissance
Capacitors for power electronics
© IEC 2007 Droits de reproduction réservés ⎯ Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
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МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue
61071 © IEC:2007 – 3 –
CONTENTS
FOREWORD.7
Scope.11
2 Normative references.13
3 Terms and definitions .13
4 Service conditions.23
4.1 Normal service conditions.23
4.2 Unusual service conditions .25
5 Quality requirements and tests.25
5.1 Test requirements.25
5.2 Classification of tests.27
5.3 Capacitance and tan δ measurements (routine test) .29
5.4 Measurement of the tangent of the loss angle (tan δ) of a capacitor (type test) .29
5.5 Voltage test between terminals .31
5.6 AC voltage test between terminals and case .33
5.7 Test of internal discharge device.33
5.8 Sealing test .33
5.9 Surge discharge test.35
5.10 Thermal stability test.35
5.11 Self-healing test.37
5.12 Resonance frequency measurement .39
5.13 Environmental testing .39
5.14 Mechanical testing.39
5.15 Endurance test .41
5.16 Destruction test .45
5.17 Disconnecting test on internal fuses.55
6 Overloads.59
6.1 Maximum permissible voltages .59
7 Safety requirements.61
7.1 Discharge device .61
7.2 Case connections .61
7.3 Protection of the environment .61
7.4 Other safety requirements.61
8 Markings.63
8.1 Marking of the units .63
9 Guide to installation and operation .63
9.1 General .63
9.2 Choice of rated voltage.65
9.3 Operating temperature.65
9.4 Special service conditions.67
9.5 Overvoltages .69
9.6 Overcurrents .69
9.7 Switching and protective devices .69
9.8 Choice of creepage distance and clearance .69
9.9 Connections .71
61071 © IEC:2007 – 5 –
9.10 Parallel connections of capacitors.71
9.11 Series connections of capacitors.71
9.12 Magnetic losses and eddy currents .73
9.13 Guide for internal fuse and disconnector protection in capacitors.73
9.14 Guide for unprotected capacitors .73
Annex A (informative) Waveforms .75
Annex B (normative) Operational limits of capacitors with sinusoidal voltages as a
function of frequency and at maximum temperature (θ ) .79
max
Annex C (normative) Resonance frequency measuring methods – Examples .83
Bibliography .87
Figure 1 – Destruction test arrangement.49
Figure 2 – N source d.c., type 1.53
Figure 3 – N source d.c., type 2.53
Figure A.1 – Example of waveforms and their circuits .77
Figure B.1 – Supply conditions .79
Figure C.1 – Measuring circuit.83
Figure C.2 – Relation between the voltage across the capacitor and the supply
frequency.83
Figure C.3 – Discharge current wave shape.85
Table 1 – Test voltage between terminals.31
Table 2 – Testing the robustness of terminals.41
Table 3 – Endurance test .43
Table 4 – Destruction test as a function of type of safety system.45
Table 5 – Maximum permissible voltages .59
61071 © IEC:2007 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
CAPACITORS FOR POWER ELECTRONICS
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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 61071-1 has been prepared by IEC technical committee 33: Power
capacitors.
The text of this standard is based on the following documents:
FDIS Report on voting
33/432/FDIS 33/433/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
61071 © IEC:2007 – 9 –
The committee has decided that the contents of this publication will remain unchanged until the
maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
61071 © IEC:2007 – 11 –
CAPACITORS FOR POWER ELECTRONICS
1 Scope
This International Standard applies to capacitors for power electronics applications.
The operating frequency of the systems in which these capacitors are used is usually up to
15kHz, while the pulse frequencies may be up to 5 to 10 times the operating frequency.
The standard distinguishes between a.c. and d.c. capacitors which are considered as
components when mounted in enclosures.
This standard covers an extremely wide range of capacitor technologies for numerous
applications, e.g. overvoltage protection, d.c. and a.c. filtering, switching circuits, d.c. energy
storage, auxiliary inverters, etc.
The following are excluded from this standard:
– capacitors for induction heat-generating plants operating at frequencies between 40 Hz and
24 000 Hz (see IEC 60110-1 and IEC 60110-2);
– capacitors for motor applications and the like (see IEC 60252-1 and IEC 60252 -2);
– capacitors to be used in circuits for blocking one or more harmonics in power supply
networks;
– small a.c. capacitors as used for fluorescent and discharge lamps (see IEC 61048 and
IEC 61049);
– capacitors for suppression of radio interference (see IEC 60384-14);
– shunt capacitors for a.c. power systems having a rated voltage above 1 000 V (see
IEC 60871-1 and IEC 60871-2);
– shunt power capacitors of the self-healing type for a.c. systems having a rated voltage up to
and including 1 000 V (see IEC 60831-1 and IEC 60831-2);
– shunt power capacitor of the non-self-healing type for a.c. systems having a rated voltage
up to and including 1 000 V (see IEC 60931-1 and IEC 60931-2);
– electronic capacitors not used in power circuits;
– series capacitors for power systems (see IEC 60143);
– coupling capacitors and capacitors dividers (see IEC 60358);
– capacitors for microwave ovens (see IEC 61270-1);
– capacitors for railway applications (see IEC 61881).
Examples of applications are given in Clause 9.1.
61071 © IEC:2007 – 13 –
2 Normative references
The following referenced documents are indispensable for the application 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 60068-2-6, Environmental testing – Part 2: Tests. Test Fc: Vibration (sinusoidal)
IEC 60068-2-14, Environmental testing – Part 2: Tests. Test N: Change of temperature
IEC 60068-2-20, Environmental testing – Part 2: Tests. Test T: Soldering
IEC 60068-2-21, Environmental testing – Part 2: Tests. Test U: Robustness of terminations and
integral mounting devices
IEC 60068-2-78, Environmental testing – Part 2: Tests. Test Cab: Damp heat, steady state
IEC 60071-1, Insulation coordination – Part 1: Definitions, principle and rules
IEC 60071-2, Insulation coordination – Part 2: Application guide
IEC 60269-1, Low-voltage fuses – Part 1: General requirements
IEC 60664-1, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60695-2-11, Fire hazard testing – Part 2-11: Glowing/hotwire based test methods, Glow-
wire flammability test method for end-products
IEC 60695-2-12, Fire hazard testing – Part 2-12: Glowing/hotwire based test methods, Glow-
wire flammability test method for materials
IEC 60947-1, Low-voltage switchgear and controlgear – Part 1: General rules
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
capacitor element (or element)
a device consisting essentially of two electrodes separated by a dielectric
[IEV 436-01-03]
3.2
capacitor unit (or unit)
assembly of one or more capacitor elements in the same container with terminals brought out
[IEV 436-01-04]
3.3
capacitor bank
number of capacitor units connected so as to act together
[IEV 436-01-06]
61071 © IEC:2007 – 15 –
3.4
capacitor
general term used when it is not necessary to state whether reference is made to an element, a
unit or a capacitor bank
3.5
capacitor equipment
assembly of capacitor units and their accessories intended for connection in power electronic
equipment
3.6
capacitor for power electronics
power capacitor intended to be used in power electronic equipment and capable of operating
continuously under sinusoidal and non-sinusoidal current and voltage
3.7
metal-foil capacitor (non-self-healing)
capacitor in which the electrodes usually consist of metal foils separated by a dielectric
NOTE In the event of a breakdown of the dielectric, the capacitor does not restore itself.
3.8
self-healing metallized dielectric capacitor
capacitor, of which at least one electrode consists of a metallic deposit on the dielectric
NOTE In the event of local breakdown of the dielectric, the electric properties of the capacitor are rapidly and
essentially self-restored.
3.9
a.c. capacitor
capacitor essentially designed for operation with alternating voltage
NOTE AC capacitors may be used with d.c. voltage up to the rated voltage only when authorized by the capacitor
manufacturer.
3.10
d.c. capacitor
capacitor essentially designed for operation with direct voltage
NOTE DC capacitors may be used with a specified a.c. voltage only where authorized by the capacitor
manufacturer.
3.11
model capacitor
unit which simulates a complete unit or element in an electrical test, without reducing the
severity of the electrical, thermal or mechanical conditions
NOTE 1 The model unit may be of a different size from the complete unit.
NOTE 2 The combined sum of stresses should always be considered, for instance the sum of temperature and
mechanical conditions as well as electrical stresses.
3.12
internal (element) fuse
fuse connected inside a capacitor unit, in series with an element or a group of elements
[IEV 436-03-16]
61071 © IEC:2007 – 17 –
3.13
safety devices
3.13.1
overpressure disconnector
disconnecting device inside a capacitor, designed to interrupt the current path in case of
abnormal increase of internal overpressure
3.13.2
overpressure detector
device designed to detect abnormal increase of the internal pressure, usually used to operate
an electrical switch and indirectly interrupt the current path
3.13.3
segmented metallization design
design of the metal layer over the dielectric shaped in a way to allow a small part of it to be
isolated in case of local short circuit or breakdown, in order to restore the full functionality of
the unit with a negligible loss of capacitance
3.13.4
special unsegmented metallization design
design of the metal layer over the dielectric shaped in a way that safe self-healing features
operating at a voltage up to U guarantee the full functionality of the unit with a negligible loss
s
of capacitance.
3.14
discharge device of a capacitor
a device which may be incorporated in a capacitor, capable of reducing the voltage between
the terminals practically to zero, within a given time, after the capacitor has been disconnected
from a network
[IEV 436-03-15 modified]
3.15
rated a.c. voltage
U
N
maximum operating peak recurrent voltage of either polarity of a reversing type waveform for
which the capacitor has been designed
NOTE 1 The waveform can have many shapes. Examples are given in Annex A.
NOTE 2 The mean value of the waveform may be positive or negative.
NOTE 3 It is important to note that the rated a.c. voltage is not an r.m.s. value.
3.16
rated d.c. voltage
U
NDC
maximum operating peak voltage of either polarity but of a non-reversing type waveform, for
which the capacitor has been designed, for continuous operation
NOTE 1 Damping capacitors, for gate turn-off thyristor (GTO) can be regarded as d.c. capacitors with a ripple
voltage equal to the rated d.c. voltage U = U .
NDC r
In the case of reversal voltage (U ), the use should be agreed between user and manufacturer.
rev
NOTE 2 If the reversal voltage is small (less than 10 %), the voltage waveform can be considered to be non-
reversing. For test purposes, U and U should be increased by U , the reversal voltage.
NDC r rev
3.17
ripple voltage
U
r
peak-to-peak alternating component of the unidirectional voltage
61071 © IEC:2007 – 19 –
3.18
non-recurrent surge voltage
U
s
peak voltage induced by a switching or any other disturbance of the system which is allowed for
a limited number of times and for durations shorter than the basic period
3.19
insulation voltage
U
i
r.m.s. value of the sine wave voltage designed for the insulation between terminals of
capacitors to case or earth
3.20
maximum peak current
Î
maximum repetitive peak current that can occur during continuous operation
3.21
maximum current
I
max
maximum r.m.s. current for continuous operation
3.22
maximum surge current
Î
s
peak non-repetitive current induced by switching or any other disturbance of the system which
is allowed for a limited number of times, for durations shorter than the basic period
3.23
pulse frequency
f
p
repetition rate of periodic current pulses
3.24
current pulse width
τ
time of current flow during charging or discharging from one voltage value to another, of the
capacitor
NOTE Pulse current waveform examples are shown in Annex A.
3.25
resonance frequency
f
r
lowest frequency at which the impedance of the capacitor becomes minimum
3.26
duty cycle
3.26.1
continuous duty
operation time such that a capacitor is at thermal equilibrium for most of the time
3.26.2
intermittent duty
discontinuous working or operation with variable loads which should be described in terms of
ON/OFF or HIGH/LOW periods with their durations
61071 © IEC:2007 – 21 –
3.27
highest operating temperature
temperature of the hottest point on the case of the capacitor when in thermal equilibrium
3.28
lowest operating temperature
θ
min
lowest temperature of the dielectric at which the capacitor may be energized
3.29
container temperature rise
Δθ
case
difference between the temperature of the hottest point of the container and the temperature of
the cooling air
3.30
cooling-air temperature
θ
amb
temperature of the cooling air measured at the hottest position of the capacitor, under steady-
state conditions, midway between two units
NOTE If only one unit is involved, it is the temperature measured at a point approximately 0,1 m away from the
capacitor container and at two-thirds of the height from its base.
3.30.1
outlet fluid temperature for forced-cooled capacitors
temperature of the cooling fluid as it leaves the capacitor, measured at the hottest point
3.30.2
inlet fluid temperature for forced-cooled capacitors
temperature of the cooling fluid measured in the middle of the inlet fluid channel at a point not
influenced by the heat dissipation of the capacitor
3.31
maximum operating temperature
θ
max
highest temperature of the case at which the capacitor may be operated
3.32
steady-state conditions
thermal equilibrium attained by the capacitor at constant output and at constant cooling-air
temperature
3.33
capacitor losses
active power dissipated in the capacitor
[IEV 436-04-10]
NOTE Unless otherwise stated, the capacitor losses are understood to include losses in fuses and discharge
resistors forming an integral part of the capacitor. At high frequency, the capacitor losses are predominantly due to
losses in connections, contacts and electrodes.
3.34
tangent of the loss angle of a capacitor
tan δ
ratio between the equivalent series resistance and the capacitive reactance of a capacitor at a
specified sinusoidal alternating voltage, frequency and temperature
[IEV 436-04-11]
61071 © IEC:2007 – 23 –
tan δ = R ωC = tan + R ωC
esr d s
tan = dielectric loss factor
d
3.35
equivalent series resistance of a capacitor
R
esr
effective resistance which, if connected in series with an ideal capacitor of capacitance value
equal to that of the capacitor in question, would have a power loss equal to active power
dissipated in that capacitor under specified operating conditions
3.36
series resistance
R
s
effective ohmic resistance of the conductors of a capacitor under specified operating conditions
3.37
maximum power loss
P
max
maximum power loss at which the capacitor may be operated at the maximum case
temperature
3.38
maximum frequency for maximum power loss and maximum current
f
frequency at which the maximum current (I ) produces the maximum power loss (P ) in
max max
the capacitor
NOTE For explanation of f , see Annexe B.
4 Service conditions
4.1 Normal service conditions
This standard gives requirements for capacitors intended for use in the following conditions.
4.1.1 Altitude
Altitude shall not exceed 1 000 m unless the effects on cooling and external insulation are
taken into account.
NOTE The effect of altitude on convection cooling and external insulation should be taken into consideration, if the
altitude exceeds 1 000 m.
4.1.2 Operating temperature (θ )
max
θ at which the capacitor may be operated, shall
The upper limit of the case temperature
max
normally be chosen from the values 45 °C, 55 °C, 70 °C and 85 °C. A different maximum
operating temperature shall be subject to agreement between manufacturer and user.
4.1.3 Operating temperature with forced cooling
If capacitors are intended for use with forced cooling using a fluid medium, the operating
temperature conditions specified in 4.1.2 shall be observed.
61071 © IEC:2007 – 25 –
The lowest inlet temperature for the cooling fluid should be defined, taking into account the
viscosity of the fluid.
There are two methods for specifying the upper temperature limit of the cooling medium, using
either the inlet or the outlet cooling fluid temperature.
Unless otherwise agreed, the choice of method shall be left to the capacitor manufacturer.
For the inlet method, the flow of cooling medium shall be specified.
4.2 Unusual service conditions
This standard does not apply to capacitors, whose service conditions are such as to be in
general incompatible with its requirements, unless otherwise agreed between the manufacturer
and the user.
Unusual service conditions require additional measurements, which ensure that the conditions
of this standard are complied with even under such unusual service conditions.
If such unusual service conditions exist then they must be notified to the manufacturer of
the capacitor.
Unusual service conditions can include:
– unusual mechanical shocks and vibrations.
– cooling water with corrosive or obstructing particles (sea water, very hard water).
– corrosive and abrasive particles in the cooling air.
– dust in the cooling air, particularly if conductive.
– explosive dust or gas.
– oil or water vapour or corrosive substances.
– nuclear radiation.
– unusual storage or transport temperature.
– unusual humidity (tropical or subtropical region).
– excessive and rapid changes of temperature (more than 5 °C/h) or of humidity (more than
5 %/h).
– service areas higher than 1 000 m above sea level.
– superimposed electromagnetic fields.
– excessive overvoltages, as far as they exceed the limits given in Clause 6.
5 Quality requirements and tests
5.1 Test requirements
5.1.1 General
This subclause gives the test requirements for capacitor units.
5.1.2 Test conditions
Unless otherwise specified for a particular test or measurement, the temperature of the
capacitor dielectric shall be in the range of +5 °C to +35 °C
61071 © IEC:2007 – 27 –
If corrections are necessary, the reference temperature shall be +20 °C, unless otherwise
agreed between the manufacturer and the user.
NOTE It is assumed that the dielectric temperature is the same as the ambient temperature, provided that the
capacitor has been left in an unenergized state, in a constant ambient temperature, for an adequate period of time
in order to reach thermal equilibrium.
The a.c. tests and measurements shall be carried out with a substantially sinusoidal voltage at
a frequency specified by the manufacturer.
5.2 Classification of tests
The tests are classified as routine tests and type tests.
5.2.1 Routine tests
a) Sealing test (5.8).
b) External inspection (5.14.2).
c) Voltage test between terminals (5.5.2).
d) Voltage test between terminals and case (5.6.1).
e) Capacitance and tan δ measurements (5.3).
f) Test of internal discharge device (5.7).
Routine tests shall be carried out by the manufacturer on every capacitor before delivery.
At his request, the user shall be supplied with a certificate detailing the results of such tests.
The sequence of the tests is as indicated above.
5.2.2 Type tests
a) Mechanical tests (5.14).
b) Voltage test between terminals (5.5.3).
c) Voltage test between terminals and case (5.6.2).
d) Surge discharge test (5.9).
e) Self-healing test (5.11).
f) Environmental testing (5.13).
g) Measurement of the tangent of the loss angle (tan δ) (5.4).
h) Thermal stability test (5.10).
i) Test of internal discharge device (5.7).
j) Resonance frequency measurement (5.12).
k) Endurance test between terminals (5.15).
l) Disconnection test on fuses (5.17).
m) Destruction test (5.16).
61071 © IEC:2007 – 29 –
Type tests are intended to prove the soundness of the design of the capacitor and its suitability
for operation under the considerations detailed in this standard.
The type tests shall be carried out by the manufacturer, and the user shall, on request, be
supplied with a certificate, detailing the results of such tests.
Unless otherwise specified, every capacitor sample to which it is intended to apply the type test
shall first have withstood satisfactorily the application of all the routine tests.
These tests shall be made upon a capacitor of a design identical to that of the capacitor under
contract, or on a capacitor of a design that gives during the test the same or more severe test
conditions.
It is not essential that all type tests be carried out on the same capacitor sample.
5.3 Capacitance and tan δ measurements (routine test)
5.3.1 Measuring procedure
The capacitance and tan δ shall be measured at a voltage and a frequency chosen by the
manufacturer.
The method used shall not include errors due to harmonics or to accessories external to the
capacitor to be measured, such as reactors and blocking circuits in the measuring circuit.
The accuracy of the measuring method shall be given and shall be better than 0,2 % for
capacitance and 10 % for tan δ.
NOTE For capacitors in the millifarad range a lower accuracy may be appropriate
The capacitance measurement shall be carried out after the voltage test between terminals
(see 5.5).
For capacitors with internal fuses, capacitance measurement shall also be made before the
voltage tests.
5.3.2 Capacitance tolerances
If not otherwise specified, the capacitance measured shall not differ from the rated capacitance
by more than –10 % to +10 %.
5.3.3 Loss requirements (tan δ)
The requirements regarding capacitor losses may be agreed upon between the manufacturer
and the user.
5.4 Measurement of the tangent of the loss angle (tan δ) of a capacitor (type test)
5.4.1 Measurements
The following measurements shall be made.
5.4.1.1 AC capacitors
The capacitor losses (tan δ) shall be measured at the end of the thermal stability test (see
5.10). The measuring voltage and frequency may be agreed upon between the manufacturer
and the user.
61071 © IEC:2007 – 31 –
5.4.1.2 DC capacitors
The measurement shall be carried out at the end of thermal stability test at an a.c. voltage
appropriate to capacitor rating, subject to this voltage being a maximum of U divided by 2 2.
r
5.4.2 Loss requirements
The value of tan δ measured in accordance with 5.4.1 shall not exceed the value declared by
the manufacturer, or the value agreed upon between the manufacturer and the user.
5.5 Voltage test between terminals
5.5.1 General
Tests shall be carried out according to the following Table 1.
Table 1 – Test voltage between terminals
AC capacitors DC capacitors
All types Non-self-healing Self-healing
AC test voltage r.m.s. value 1,5 U – –
N
DC test voltage
2,15 U 2 U 1,5 U
N NDC NDC
The test voltage indicated in Table 1 can be reduced if capacitors are intended for intermittent
duty (see 3.27) or for short service duration; the new values shall be agreed upon between the
manufacturer and the user.
NOTE The a.c. test voltage may be at a frequency of 50 Hz or 60 Hz.
5.5.2 Routine test
Every capacitor shall be subjected for 10 s to either test of 5.5.1 at ambient temperature. The
choice is left to the manufacturer. During the test, neither puncture nor flashover shall occur.
Self-healing breakdowns are permitted.
The duration may be reduced to 2 s provided the voltage is increased by 10 %.
In the case of units with all elements in parallel, operation of internal element fuse(s) is
permitted, provided the capacitance tolerances are still met.
NOTE The routine test is intended to be applied once. If repeated it should be carried out at 90 % of the original
value unless agreed differently otherwise by the manufacturer.
5.5.3 Type test
The capacitor shall be subjected for 1 min to either test of 5.5.1.
The choice is left to the manufacturer.
After the voltage test between terminals the capacitance and tan δ shall be measured.
61071 © IEC:2007 – 33 –
5.6 AC voltage test between terminals and case
5.6.1 Routine test
Units having all terminals insulated from the container shall be subjected for 10 s to a voltage
applied between the terminals (joined together) and the container.
The test voltage values are the following:
U = 2 U + 1 000 V or 2 000 V whichever is the highest value,
t- case i
where U is the insulation voltage.
i
The duration may be reduced to 2s provided the voltage is increased by 10 %.
The insulating voltage of the capacitor shall be specified by the user. The insulation voltage is
2 , unless otherwise specified.
equal to the rated voltage of the capacitor, divided by
During the test, neither puncture nor flashover shall occur. The test shall be performed even if
one of the terminals is intended to be connected to the container in service.
Units having one terminal permanently connected to the container shall not be subjected to this
test.
Units having insulated containers shall not be subjected to this test.
NOTE 1 If the capacitor (with metal container) is equipped with an external overpressure detector, the terminals of
the detector should be joined together and connected to the container.
NOTE 2 The voltage test between the overpressure detector and the container should be agreed between user
and manufacturer.
NOTE 3 This test can be carried out a maximum of two times on the same capacitor.
5.6.2 Type test
Units having all terminals insulated from the container shall be subjected to a test according to
5.6.1 with the same voltage value, but with a duration of 1 min. Capacitors with insulating
container shall have a metal foil tightly wrapped all around them during the test. The foil shall
be connected to one terminal of the test supply.
5.7 Test of internal discharge device
The resistance of
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