EN 61800-2:1998

SLOVENSKI STANDARD
01-junij-2001
Adjustable speed electrical power drive systems - Part 2: General requirements -
Rating specifications for low voltage adjustable frequency a.c. power drive
systems (IEC 61800-2:1998)
Adjustable speed electrical power drive systems -- Part 2: General requirements - Rating
specifications for low voltage adjustable frequency a.c. power drive systems
Drehzahlveränderbare elektrische Antriebe -- Teil 2: Allgemeine Anforderungen -
Festlegungen für die Bemessung von Niederspannungs-Wechselstrom-
Antriebssystemen mit einstellbarer Frequenz
Entraînements électriques de puissance à vitesse variable -- Partie 2: Exigences
générales - Spécifications de dimensionnement pour systèmes d'entraînement de
puissance à fréquence variable en courant alternatif et basse tension
Ta slovenski standard je istoveten z: EN 61800-2:1998
ICS:
29.200 8VPHUQLNL3UHWYRUQLNL Rectifiers. Convertors.
6WDELOL]LUDQRHOHNWULþQR Stabilized power supply
QDSDMDQMH
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME
CEI
INTERNATIONALE
IEC
61800-2
INTERNATIONAL
Première édition
STANDARD
First edition
1998-03
Entraînements électriques de puissance
à vitesse variable –
Partie 2:
Exigences générales –
Spécifications de dimensionnement pour systèmes
d'entraînement de puissance à fréquence variable
en courant alternatif et basse tension
Adjustable speed electrical power drive systems –
Part 2:
General requirements –
Rating specifications for low voltage
adjustable frequency a.c. power drive systems
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For price, see current catalogue

61800-2 © IEC:1998 – 3 –
CONTENTS
Page
FOREWORD . 7
Clause
1 General.9
1.1 Scope and object . 9
1.2 Normative references. 9
1.3 Symbols. 13
2 Definitions.15
2.1 System. 15
2.2 Converters. 19
2.3 Drive system operating characteristics . 23
2.4 CDM, BDM and converter input parameters. 27
2.5 CDM, BDM and converter output parameters . 33
2.6 Converter circuitry and circuit elements. 35
2.7 Induction motor parameters . 37
2.8 Control systems. 39
3 Functional features. 41
3.1 Operational. 41
3.2 Fault supervision. 41
3.3 Minimum status indication required . 41
3.4 I/O devices. 41
4 Service conditions. 43
4.1 Installation and operation. 43
4.2 Storage of equipment. 51
4.3 Transportation. 53
5 Ratings.55
5.1 BDM input ratings . 55
5.2 BDM output ratings . 55
5.3 Efficiency and losses . 57
5.4 Transformers and reactors. 59
6 Performance requirements. 59
6.1 Steady state performance . 59
6.2 Dynamic performance. 63
6.3 Dynamic braking and dynamic slowdown. 63
6.4 Other performance requirements . 65

61800-2 © IEC:1998 – 5 –
Clause Page
7 Tests. 67
7.1 Classification of tests. 67
7.2 Performance of tests. 67
7.3 Items of separate device tests . 69
7.4 Items of power drive system tests . 71
7.5 Instrumentation for performance testing . 81
8 Product information. 83
8.1 Marking. 83
8.2 Information to be supplied with the PDS or CDM/BDM. 83
9 Safety and warning labels . 85
9.1 Warning labels. 85
9.2 Safety and nature of a PDS. 85
Annexes
A Motor considerations. 87
B Line-side considerations. 99
C Auxiliary equipment. 129
D Control strategies. 135
E Protection . 165
F Topologies . 173
G Monitoring features . 175

61800-2 © IEC:1998 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
ADJUSTABLE SPEED ELECTRICAL POWER DRIVE SYSTEMS –
Part 2: General requirements – Rating specifications for low voltage
adjustable frequency a.c. power drive systems
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61800-2 has been prepared by IEC technical sub-committee 22G:
Semiconductor power converters for adjustable speed electric drive systems, of IEC technical
committee 22: Power electronics.
The text of this standard is based on the following documents:
FDIS Report on voting
22G/40/FDIS 22G/44/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.
Annexes A, B, C, D, E, F, and G are for information only.

61800-2 © IEC:1998 – 9 –
ADJUSTABLE SPEED ELECTRICAL POWER DRIVE SYSTEMS –
Part 2: General requirements – Rating specifications for low voltage
adjustable frequency a.c. power drive systems
1 General
1.1 Scope and object
This part of IEC 61800 applies to general purpose adjustable speed a.c. drive systems which
include power conversion, control equipment, and also an a.c. motor or motors. Excluded are
traction and electrical vehicle drives.
It applies to systems connected to line voltages up to 1 kV a.c., 50 Hz or 60 Hz, and load side
frequency up to 600 Hz.
EMC aspects are covered in IEC 61800-3.
This part of IEC 61800 gives the characteristics of the converters and their relationship with the
complete a.c. drive system. It also states their performance requirements with respect to
ratings, normal operating conditions, overload conditions, surge withstand capabilities, stability,
protection, a.c. line earthing, and testing. Furthermore, it deals with application guidelines,
such as control strategies, diagnostics, and topologies.
This part of IEC 61800 is intended to define a complete a.c. PDS in terms of its performance
and not in terms of individual subsystem functional units.
1.2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 61800. At the time of publication, the editions indicated
were valid. All normative documents are subject to revision, and parties to agreements based
on this part of IEC 61800 are encouraged to investigate the possibility of applying the most
recent editions of the normative documents indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
IEC 60034-1:1996, Rotating electrical machines – Part 1: Rating and performance
IEC 60034-2:1972, Rotating electrical machines – Part 2: Methods for determining losses and
efficiency of rotating electrical machinery from tests (excluding machines for traction vehicles)
IEC 60034-9:1990, Rotating electrical machines – Part 9: Noise limits
IEC 60038:1983, IEC standard voltages
IEC 60050(111): International Electrotechnical Vocabulary (IEV) – Chapter 111: Physics and
chemistry
IEC 60050(151):1978, International Electrotechnical Vocabulary (IEV) – Chapter 151: Electrical
and magnetic devices
IEC 60050(441):1984, International Electrotechnical Vocabulary (IEV) – Chapter 441: Switch-
gear, control gear and fuses
61800-2 © IEC:1998 – 11 –
IEC 60050(551): International Electrotechnical Vocabulary (IEV) – Chapter 551: Power
1)
electronics
IEC 60050(601):1985, International Electrotechnical Vocabulary (IEV) – Chapter 601:
Generation, transmission and distribution of electricity – General
IEC 60076: Power transformers
IEC 60146-1-1:1991, Semiconductor convertors – General requirement and line commutated
convertors – Part 1-1: Specification of basic requirements
IEC 60146-1-2:1991, Semiconductor convertors – General requirement and line commutated
convertors – Part 1-2: Application guide
IEC 60146-1-3:1991, Semiconductor convertors – General requirement and line commutated
convertors – Part 1-3: Transformers and reactors
IEC 60204-1:1992, Electrical equipment of industrial machines – Part 1: General requirements
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60664-1:1992, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60721-3-1:1997, Classification of environmental conditions – Part 3: Classification of
groups of environmental parameters and their severities – Section 1: Storage
IEC 60721-3-2:1997, Classification of environmental conditions – Part 3: Classification of
groups of environmental parameters and their severities – Section 2: Transportation
IEC 60721-3-3:1994, Classification of environmental conditions – Part 3: Classification of
groups of environmental parameters and their severities – Section 3: Stationary use at
weatherprotected locations
IEC 60747: Semiconductor devices – Discrete devices and integrated circuits
IEC 61000-2-4:1994, Electromagnetic compatibility (EMC) – Part 2: Environment – Section 4:
Compatibility levels in industrial plants for low-frequency conducted disturbances
IEC 61000-4-7:1991, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 7: General guide on harmonics and interharmonics measurements and
instrumentation, for power supply systems and equipment connected thereto
IEC 61800-3:1996, Adjustable speed electrical power drive systems – Part 3: EMC product
standard including specific test method
IEC Guide 106:1989, Guide for specifying environmental conditions for equipment performance
rating
________
1)
Second edition, to be published.

61800-2 © IEC:1998 – 13 –
1.3 Symbols
Table 1 lists symbols defined and/or used in this part of IEC 61800.
Table 1 – Symbols
Parameter Symbol Unit Definition
Rated system voltage U V 2.4.1
LN
Rated system frequency f Hz 2.4.2
LN
Line-side converter rated a.c. voltage U V 2.4.3
VN
Line-side rated a.c. current of the CDM/BDM I A 2.4.4
LN
Rated input current of the converter I A 2.4.5
VN
Line-side harmonic content H V or A 2.4.6
L
Line-side total harmonic distortion THD % 2.4.8
L
Converter input displacement factor 2.4.9
cos ϕ
V1
Line side displacement factor ϕ 2.4.10
cos L1
Input total power factor λ 2.4.11
L
Maximum allowable a.c. system, symmetrical short-circuit current I A 2.4.13
SCM
Short-circuit ratio R 2.4.13
SC
Rated continuous output current I A 2.5.1
aN
Overload current (overload capability) I A 2.5.2
aM
Load side fundamental rated a.c. voltage U V 2.5.4
aN1
Base frequency f Hz 2.5.5
Rated fundamental output current IaN1 A 2.5.6
Efficiency of drive system η % 2.5.7
D
Efficiency of CDM % 2.5.7
η
C
Load side harmonic distortion THD % 2.5.9
a
Slip s p.u. 2.7.5
Rated slip s p.u. 2.7.6
N
Base speed N r/min 2.7.7
Maximum operating speed N r/min 2.7.8
M
Minimum operating speed N r/min 2.7.9
min
Maximum safe motor speed N r/min 2.7.10
smax
Torque M Nm
Inertia J kgm² or Nms²
61800-2 © IEC:1998 – 15 –
2 Definitions
For the purpose of this part of IEC 61800, the following definitions, as well as those given
in IEC 60050(111), IEC 60050(151), IEC 60050(441), IEC 60050(551), IEC 60050(601),
IEC 60146-1-1, IEC 60146-1-2, IEC 60146-1-3, and IEC 60147-0, apply.
2.1 System
2.1.1
a.c. power drive system (PDS)
(see figure 1) System consisting of power equipment (composed of converter section, a.c.
motor and other equipment such as, but not limited to the feeding section), and control
equipment (composed of switching control –on/off for example–, voltage, frequency, or current
control, firing system, protection, status monitoring, communication, tests, diagnostics, process
interface/port, etc.)
NOTE – Figure 1 illustrates the main functional elements of an a.c. drive system. It also includes equipment which
may be optional on many drive systems. It is intended to encompass a wide variety of a.c. drive configuration
possibilities. The converter section does not illustrate or imply a specific topology, or type of switching device, due
to the wide variety of both in current use. See annex F.
2.1.2
a.c. power drive system – hardware configuration
PDS which consists of a complete drive module (CDM) and a motor or motors with sensors
which are mechanically coupled to the motor shaft (the driven equipment is not included). See
figure 2 for hardware partition of the power drive system
NOTE – Figure 2 illustrates the parts of equipment which can be grouped and supplied as defined and shown.
2.1.2.1
basic drive module (BDM)
drive module which consists of a converter section, a control equipment for speed, torque,
current, frequency or voltage, and a power semiconductor gating system, etc.
2.1.2.2
complete drive module (CDM)
drive system, without the motor and the sensors which are mechanically coupled to the motor
shaft, consisting of, but not limited to, the BDM, and extensions such as feeding section, and
auxiliaries
2.1.2.3
installation
equipment or equipments which include at least both the PDS and the driven equipment

61800-2 © IEC:1998 – 17 –
Feeding  line
Control equipment Actual  value Power equipment

of  signalisation
Electrical
junction line
CControl  Switching ontrol switching
Input  short-circuit
I >
on / off
AC switch
a.c.  switch
on circuit-breaker
Main
≥
circuit
Transformer  :
off p >
Gas  warning
Feeding
& Auxiliaries     Gas  fault
p >
Excess.  temp.
Excessive temperature section
T >
CCapac.  overvoltage  apacitive overvoltage
Earth  fault
I >
Protection
Drive  overload
monitoring
status
Line side
≥
& 1
Converter Fan >
Converter fuses
p <
M
Over voltage
Under voltage V >
V <
Converter
DC link
d.c. Link
section
Dynamic braking
Load side
Continuous  variables
Continuous variables
Control
control
I >
Over current
Speed    Current    Gate
=
Load contactor
motor overload
I >
u
Field
f
Encoder/
Resolver /
Coupling
Tachometer
mechanical
junction line
M
Voltage
Actual Values Voltage Position Speed Current
Frequency
of the Variables frequency
Communication
test  diagnostics
Driven
equipment
Windings Temperature
Windings temperature T >
Motor vent. air flow
Motor ventilation
p <
air flow
Motor ventilation fan M
Motor vent. excess. Motor ventilation
temp.
excessive T >
Process  interface / port
temperature
and  signalisation
IEC  345/98
Figure 1 – Functional diagram of an a.c. drive system

61800-2 © IEC:1998 – 19 –
Installation or part of installation
PDS (Power Drive System)
CDM (Complete Drive Module)
System control and sequencing
BDM (Basic Drive Module)
Converter section
Control section
Feeding section
Auxiliaries
Others
Motor and sensors
Driven equipment
IEC  346/98
Figure 2 – PDS hardware configuration within an installation
2.2 Converters
2.2.1
converter, general purpose
operating unit for electronic power conversion, changing one or more electrical characteristics
and comprising one or more electronic switching devices and associated components, such as
transformers, filters, commutation aids, controls, protections and auxiliaries, if any
2.2.2
rectifying, rectification
converter action converting from a.c. to d.c. The rectifier can be uncontrolled or controlled
[IEV 551-11-06 modified]
NOTE – For the purpose of this part of IEC 61800, the line-side converter normally operates as a rectifier.

61800-2 © IEC:1998 – 21 –
2.2.3
inverting, inversion
converter action converting from d.c. to a.c. [IEV 551-11-07 modified]
NOTE – For the purpose of this part of IEC 61800, the load-side converter normally operates as an inverter.
2.2.4
converter, a.c.
converter for changing a.c. power of a given voltage, frequency, and phase number to a.c.
power in which one or more of these parameters are different
2.2.5
converter, adjustable frequency
converter for changing frequency
2.2.6
converter, indirect a.c. (converter d.c. linked)
converter with an intermediate d.c. link
NOTE – This definition is intended to include only those circuits in which the d.c. link is readily identified or explicit.
2.2.7
converter, direct a.c.
converter without an intermediate d.c. link
NOTE – These circuits have an implicit link but no single pair of conductors that can be identified as the d.c. link.
2.2.8
converter, externally commutated
converter in which the commutating voltages are supplied by the a.c. supply lines, the a.c. load,
or some other a.c. source outside the converter
2.2.9
converter, line-side commutated
converter in which the commutation voltages are supplied by the a.c. input
2.2.10
converter, self-commutated
converter in which the commutation is accomplished by components within the converter
NOTE – In this part of IEC 61800, forced commutation refers to deliberate extinction of semiconductor devices
before natural commutation can take place at zero current (natural commutation).
2.2.11
converter, load-side commutated
converter in which the commutation voltages are supplied by the a.c. load
NOTE – For purposes of this part of IEC 61800, the a.c. load is an a.c. motor.

61800-2 © IEC:1998 – 23 –
2.2.12
converter, a.c./a.c., voltage source
converter which provides an adjustable output voltage supply, essentially unaffected by the
value of the load
NOTE – The term "voltage stiff converter" having a similar physical background is used in the second edition of
IEV 551.
2.2.13
converter, a.c./a.c., current source
converter which provides an adjustable output current supply, essentially unaffected by the
value of the load
NOTE – The term "current stiff converter" having a similar physical background is used in the second edition of
IEV 551.
2.2.14
d.c. amplitude control
method of converter voltage/current control whereby the d.c. link voltage (or current) amplitude
is controlled resulting in a quasi-square wave with predictable harmonics. Harmonic content
amplitude is a function of load characteristics
2.2.15
pulse width modulation (PWM)
method of converter voltage/current control whereby a series of fixed amplitude, variable
duration output voltage/current pulses are created
2.3 Drive system operating characteristics
2.3.1
two quadrant operation
converter operation of a machine as a motor in two directions of machine rotation. It involves
operation in quadrants I and III (see figure 3)
2.3.2
four quadrant operation
converter operation of a machine as a motor or a generator in either direction of machine
rotation. It involves operation in quadrants I, II, III and IV as shown in figure 3
2.3.3
dynamic braking
process of converting the rotational energy of the rotor and connected inertial load to electrical
energy dissipated in a resistance
2.3.4
d.c. braking
process of converting the rotational energy of the rotor and connected inertial load to electrical
energy dissipated in the rotor by injection of d.c. current into the stator
2.3.5
regeneration
process of converting the mechanical energy of the system to electrical energy and transferring
it to the input supply. The motor is then working as a generator and the ratings of the motor
may be different
61800-2 © IEC:1998 – 25 –
M
M
One
Torque
quadrant
I
N
N
Speed
M
M
Two
quadrants
I
N
N
III
Four
M
M
quadrants
II I
N
N
IV
III
IEC  347/98
Figure 3 – Operating quadrants

61800-2 © IEC:1998 – 27 –
2.4 CDM, BDM and converter input parameters
Symbols defined in 2.4 are included in table 1
2.4.1
rated system voltage U
LN
RMS input line-to-line voltage at the supply terminals of the customers installation to which the
PDS will be connected
2.4.2
rated system frequency f
LN
frequency in Hertz of the power input system alternating voltage
2.4.3
line-side rated a.c. voltage U
VN
rated r.m.s. line-to-line input voltage at the a.c. terminals of the line-side converter, which has
been designated as the basis for the converter rating
NOTE – This voltage may differ from the rated system voltage (U ) due to the use of transformers and the effect of
LN
impedance. Some drives may have an input transformer with primary voltage higher than 1000 V. In this case
transformer and protective devices have to meet this standard and other relevant IEC standards. Capacitively
coupled high voltage from primary to secondary winding must be bypassed to earth (see annex B).
2.4.4
line-side rated a.c. current I
LN
maximum r.m.s. value of current on the line-side of the CDM/BDM under rated conditions. It
takes into account rated load and the most onerous combination of all other conditions within
their specified ranges, for example line voltage and frequency deviations
NOTE – This current includes currents supplied to the auxiliary circuits of the CDM/BDM. It takes into account the
effect of d.c. current ripple and circulating current, if any.
2.4.5
rated input current I
VN
maximum r.m.s. value of current on the valve side of the converter under rated conditions. It
takes into account rated load and the most onerous combination of all other conditions within
their specified ranges, for example line voltage and frequency deviations
2.4.6
line-side harmonic content
quantity obtained by subtracting, from an alternating quantity, its fundamental component
[IEV 551-17-04, applied to the line-side of the system]
NOTE – For example, for voltage (from a practical approach and with interharmonics neglected), the r.m.s. value of
the harmonic content is:
h=n
2 05,
UU=()
Hn h
∑
h=2
2.4.7
characteristic current harmonics
orders of the current harmonics produced by converter equipment in the course of normal
operation. For example, in a 6-pulse converter the characteristic current harmonics are the non
triple, odd harmonics, h = 6 k ± 1 (k any integer)
NOTE – In addition to power system frequency harmonics, there can be other harmonics resulting from interaction
with the converter load. They are called interharmonics.

61800-2 © IEC:1998 – 29 –
2.4.8
harmonic distortion
according to common practice, the total harmonic distortion coefficient is relative to the fundamental
component of the quantity which is considered. The harmonic factor is relative to the r.m.s. value of
the quantity which is considered [IEV 551-17-05 and IEV 551-17-06, modified].
The total harmonic distortion (THD) and the total harmonic factor (THF) are defined by:
2 2 2 2
− −
QQ QQ
1 1
THD = and THF =
Q Q
where
Q is the r.m.s. value of the fundamental;
Q is the total r.m.s. value;
h is the harmonic order;
Q is the r.m.s. value of harmonic component of order h;
h
Q can represent either current or voltage.
For the purpose of this standard and for clarity, limits are referred to the corresponding rated value.
Limits for THD and THF are defined by:
2 2 2 2
− −
QQ QQ
1 1
THD = and THF =
Q Q
1N N
NOTE 1 – These definitions are inaccordance with the second edition of IEV 551 and with common practice. The
network voltage waveform is much less distorted than the injected current. Therefore, application of both
definitions, total harmonic distortion coefficient THD or total harmonic factor THF, to the voltage provides the same
result while the difference is significant when current is considered.
NOTE 2 – It is important to note that these definitions include interharmonics. When interharmonics are present the
wave form is no longer periodical, which can produce more complex effects than those produced by harmonics. If
interharmonics are negligible, these equations simplify to:
h=40 h=40
2 2
Q Q
∑ h ∑ h
h=2 h=2
THD = and THF =
Q Q
1N N
where
Q is the rated r.m.s. value of the fundamental;
1N
Q is the rated total r.m.s. value.
N
The summation is extended to and includes order 40, according to IEC common practice.
NOTE 3 – For particular use, the highest frequency content of THD (order h from 14 to 40 inclusive) is named
partial harmonic distortion coefficient PHD, and the even content (where order h is only even) is named even
harmonic distortion coefficient EHD. Applied to current this gives:
h=40
h=40 2 2
∑
∑ I
I h
h he=2,ven
h=14
PHD = and EHD =
I
1N I1
N
61800-2 © IEC:1998 – 31 –
2.4.9
converter input displacement factor cos ϕϕ
V1
cosine of the phase displacement angle between the fundamental phase components of the
voltage and current on the input a.c. side of the input power converter
2.4.10
line-side displacement factor cos ϕϕ
L1
cosine of the phase displacement angle between the fundamental phase components of the
voltage and current on the input a.c. side of the CDM
2.4.11
input total power factor, λλ
L
ratio of the total power input, to the apparent power, as determined at the connection of the
CDM to the supply
Example: in a three-phase system where the voltage is considered sinusoidal.
λ = (U I 3 cos ϕ ) / (U I 3 )
L L L1 L1 L L
= (I /I ) x cos ϕ
L1 L L1
NOTE 1 – The power factor includes the effect of displacement cosϕ and of harmonics by means of the
deformation factor ν = λ / cos ϕ.
NOTE 2 – The definition applies to the converter input (subscript V) or to the CDM input line side (subscript L).
2.4.12
d.c. current I
d
average value of the current in the d.c. link over one full period of the input power system frequency
2.4.13
maximum allowable a.c. system, symmetrical short-circuit current I
SCM
maximum allowable symmetrical short-circuit current (I ), as specified on the rating plate can
SCM
be related to the fundamental component of the line-side rated a.c. current (I ) by means of
LN1
the short-circuit ratio (R )
SC
R is the ratio of the short-circuit power of the source to the fundamental apparent power on
SC
the line-side of the converter(s). (See IEC 60146-1-1)
R = S / S = I / I
SC SC LN1 SC LN1
The maximum allowable symmetrical short-circuit current (I ) is of importance in the
SCM
definition of the protection of the converter. At the point of common coupling (PCC), the relative
short-circuit power shall be considered (see 1.5.35. of IEC 60146-1-1). This R has to be
SC
limited to the following R :
SCM
R = (I ) / I
SCM SCM LN1
where I is equal to the fundamental content of I .
LN1 LN
61800-2 © IEC:1998 – 33 –
2.5 CDM, BDM and converter output parameters
Symbols defined in 2.5 are included in table 1.
2.5.1
rated continuous output current I
aN
total r.m.s. output current which can be supplied continuously without exceeding established
limitations, under prescribed operating conditions
2.5.2
overload capability I
aM
maximum output current which can be supplied, for a specified period of time, without
exceeding established limitations under prescribed operating conditions
2.5.3
operating frequency range
range of fundamental frequency over which the converter's output can be controlled
2.5.4
load-side converter a.c. rated voltage U
aN1
RMS value of the rated fundamental voltage at the a.c. terminals of the load-side converter
NOTE – This is the voltage which appears at the a.c. terminals of the load-side converter and is not necessarily the
fundamental voltage of the motor.
2.5.5
base frequency f
base frequency of an adjustable frequency drive system is the lowest frequency at which it is
capable of delivering maximum output power
2.5.6
rated fundamental output current I
aN1
RMS value of the fundamental component of the output current which can be supplied
continuously without exceeding established limits
2.5.7
efficiency of power conversion ηη , ηη
D C
η
efficiency of the drive system is the ratio of the power delivered by the motor shaft to the
D
total power drawn from the input power supply (see feeding line in figure 1), and is usually
expressed as a percentage. Efficiency of the CDM (complete drive module) η is the ratio of
C
the total output power delivered by the CDM to the motor and auxiliaries (motor ventilation fan,
etc.) to the total power drawn from the input power supply (see feeding line in figure 1), and is
usually expressed as a percentage
2.5.8
load-side harmonic content
this definition is identical to line-side harmonic content (2.4.6) but determined at the output side
of the BDM
h=n 0,5
I =()I
aHn ∑ h
h=2
NOTE – Load-side harmonic content is a function of the converter waveform and load reactance.

61800-2 © IEC:1998 – 35 –
2.5.9
load-side total harmonic distortion THD
a
the definition of harmonic distortion (2.4.8) can be applied to the output of the BDM yielding
THD
a
NOTE – Load-side voltage total harmonic distortion is expressed as THD and load side current total harmonic
Ua
distortion is expressed as THD . The difference between THD and THF is significant for both voltage and current.
Ia
2.5.10
rated load power factor
cosine of the angle between the motor phase voltage and current, at rated load, with sinusoidal
voltage applied
2.5.11
load-side displacement factor
this definition is identical to line-side displacement factor (2.4.10) but determined at the output
side of the BDM
2.5.12
quasi-square wave
stepped waveform as obtained from the difference of two phase-shifted square waves (one square
wave per half period) of equal amplitude. The wave form applies to either voltage or current
Max .
Min .
120° 60° 120° 60°
IEC  348/98
Figure 4 – Quasi-square wave
2.5.13
stepped wave
waveform obtained from the summation of any number of square waves of the same frequency,
each displaced in time from the others
2.6 Converter circuitry and circuit elements
2.6.1
commutating capacitor
capacitor which provides commutating energy for circuit-commutated thyristors in a self-
commutated converter
2.6.2
commutating inductor
inductor having one or more windings which modifies or couples the transient current produced
during commutation
2.6.3
a.c. filter network
network designed to reduce the flow of harmonic currents into the associated power system

61800-2 © IEC:1998 – 37 –
2.6.4
power factor correction network
network designed to improve the power factor of the associated power system. This network
will frequently also reduce the flow of harmonic currents
2.6.5
d.c. filter capacitor
capacitor connected across the rectifier output within a converter to reduce voltage ripple
2.6.6
d.c. filter inductor
inductor connected in series with the output of the rectifier to reduce ripple current
2.6.7
d.c. filter network
combination of d.c. filter capacitor and d.c. filter inductor applied to the d.c. link to reduce
voltage ripple and input line harmonics
2.7 Induction motor parameters
The following parameter definitions are essential to define induction motor operation with an
adjustable frequency converter. Symbols defined in 2.7 are included in table 1
2.7.1
rated motor voltage
rated a.c. input voltage as specified on the rating plate of the motor. It is the line-to-line, r.m.s.
sinusoidal, motor terminal voltage
2.7.2
rated frequency
frequency at which rated motor voltage is defined and which appears on the rating plate
2.7.3
rated motor current
a.c. r.m.s. current at rated operating conditions as specified on the rating plate
2.7.4
rated power factor
power factor under rated conditions of voltage, frequency, and load
2.7.5
slip s
per-unit, relative rotor speed difference between synchronous speed at the operating frequency
(N ) and the actual rotor speed (N), defined as:
a
(N – N)
a
s =  –––––––
N
a
2.7.6
rated slip s
N
motor slip under rated load conditions

61800-2 © IEC:1998 – 39 –
2.7.7
base speed N
motor synchronous speed at base frequency
2.7.8
maximum operating speed N
M
motor speed at maximum inverter frequency
2.7.9
minimum operating speed N
min
motor speed at minimum inverter frequency
2.7.10
maximum safe motor speed N
smax
maximum designed speed of the motor under which no permanent abnormal mechanical
deformation or weakness is introduced (see clause 21 of IEC 60034-1)
NOTE – The maximum safe speed of the driven equipment may be more restrictive.
2.7.11
equivalent circuit constants:
NOTE – For dynamic performance it is necessary to have the equivalent circuit constants of the individual motor. In
addition, for field weakened operation, the ratio between pull-out torque and rated torque at rated flux needs to be
known. See annex A for typical values.
2.7.12
rated voltage to rated frequency ratio U /f
aN aN
ratio at which rated air-gap flux exists, providing rated torque per ampere
2.7.13
torque pulsation
cyclic fluctuation of a steady state motor torque measured as a peak-to-peak variation
2.8 Control systems
2.8.1
controlled variable
system variable in the feedback control of adjustable frequency a.c. drives. Some examples of
controlled variables are voltage, stator current, frequency, speed, slip, and torque
2.8.2
service variable
specified variable, usually related to ambient conditions (e.g. temperature), for which the feedback
control system is to correct in attempting to maintain the ideal value of the controlled variable
2.8.3
operating variable
specified variable (e.g. load torque for a speed controlled drive), other than those arising from
service conditions and drift, for which the feedback control system is to correct in attempting to
maintain the ideal value of the controlled variable
2.8.4
feedback control system variables
range of service and operating variables covering the total deviations for which the feedback
system attempts to correct by means of the controlled variables. The accuracy of this control is
then defined as the width of the band of allowable deviation within which the feedback system
will regulate the controlled variable

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3 Functional features
3.1 Operational
CDM shall include specified features which may include, but are not limited to, one or more of
the following features.
– timed acceleration;
– timed deceleration;
– jog;
– adjustable current limit(s);
– dynamic braking;
– reversing;
– regeneration;
– line filtering;
– input/output data processing (analog/digital);
– automatic restart;
– boost;
– d.c. braking;
– precharge circuit.
3.2 Fault supervision
The CDM shall provide specified fault indication. This may consist of a common alarm and/or
trip signal provided via dry relay contact(s) or static relay(s). The fault indication is normally
activated by one or more of the CDM faults which may include but are not limited to the
following:
– external faults;
– output power stage fault;
– instantaneous overcurrent;
– overtemperature (converter);
– loss of cooling air;
– motor overload;
– auxiliary power supply fault;
– supply over/under voltage;
– supply phase loss;
– internal control system fault;
– regulator/power circuit diagnostics.
3.3 Minimum status indication required
The CDM shall be equipped with a status indication signal for "drive on" (whether rotating or at
standstill). The CDM may also be equipped with a status indication signal "drive ready for
operation".
3.4 I/O devices
Number and nature of I/O shall be stated by the manufacturer. Any modification shall be
agreed upon between the manufacturer and user.
NOTE – Inputs and outputs are needed for both variables and parameters. They are provided through analog or
digital inputs/outputs using voltage or current. They are communicated through serial or parallel links according to
various communications standards. Both analog and digital variables can be manually set by use of a control panel
and can be read on displays. Variables and parameters are treated in the same manner.

61800-2 © IEC:1998 – 43 –
4 Service conditions
4.1 Installation and operation
Unless modified, the equipment which is within the scope of this part of IEC 61800 shall
be capable of operation under the conditions listed in 2.2 and 2.3 of IEC 60146-1-1 and
IEC Guide 106.
4.1.1 Electrical service conditions
Unless otherwise specified, the CDM or BDM shall be designed to operate under the service
conditions specified below. The values specified include the effect of the drive system being
considered.
EMC requirements for power drive systems are s
...