Danfoss AHF 010, Design Manual

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Number of
standard Title Scope Comments
IEC
61000-3-2 Limits for harmonic current
emissions (equipment
input current
≤
16 A per
phase).
Equipment connected to the
public low-voltage distri-
bution system having an
input current up to and
including 16 A per phase. Danfoss frequency converters are in Class A.
There are no limits for professional equipment with a total
rated power >1 kW.
IEC
61000-3-12 Limits for harmonic
currents produced by
equipment connected to
public low-voltage systems
with input current >16 A
and
≤
75 A.
Equipment connected to the
public low-voltage distri-
bution system having an
input current >16 A and
≤
75 A.
The emission limits are currently only for 230/400 V 50 Hz
systems.
There are requirements for individual harmonics (5
th
, 7
th
, 11
th
,
and 13
th
) and for THD
1)
and PWHD
2)
.
All frequency converters listed in chapter 1.3 Intended Use
comply with these limits without extra filtering.
IEC
61000-3-4 Limits, limitation of
emission of harmonic
currents in low-voltage
supply systems for
equipment with rated
current >16 A. Equipment with rated current
>75 A connected to the
public low-voltage distri-
bution system. A 3-stage assessment procedure is described for the connection
of equipment to the public supply. Equipment >75 A is limited
to stage 3
Connection based on the load's agreed power .
The supply authority may accept the connection of the
equipment based on the agreed active power of the load's
installation and local requirements of the supply authority
apply.
The manufacturer shall provide individual harmonics and the
values for THD and PWHD.
IEC
61000-2-2/
IEC
61000-2-4 Compatibility levels for
low-frequency conducted
disturbances. Stipulation of compatibility
levels for low-frequency
conducted disturbances in
public low-voltage supply
systems (IEC 61000-2-2) and
industrial plants (IEC
61000-2-4). Low-frequency disturbances include but are not limited to
harmonics.
Consider the values prescribed in the standards when planning
installations.
IEEE 519 IEEE-recommended
practices and requirements
for harmonic control in
electrical power systems. Control of the voltage
distortion at the PCC to a
TDD of 5% and limitation of
the maximum individual
frequency voltage harmonic
to 3%. Establishment of goals for the design of electrical systems that
include both linear and non-linear loads. Waveform distortion
goals are established, and the interface between sources and
loads is described as point of common coupling (PCC).
The current distortion limits depend on the ratio I
SC
/I
L
where I
SC
is the short circuit current at the utility PCC and I
L
is the
maximum demand load current. The limits are given for
individual harmonics up to the 35
th and total demand
distortion (TDD).
The most effective way to meet the harmonic distortion
requirements is to mitigate at the individual loads and measure
at the PCC.
G5/4 Engineering recommen-
dation, planning levels for
harmonic voltage
distortion, and the
connection of non-linear
equipment to transmission
systems and distribution
networks in the United
Kingdom. Setting planning levels for
harmonic voltage distortion
to be used in the process of
connecting non-linear
equipment. A process for
establishing individual
customer emission limits
based on these planning
levels is described. G5/4 is a system level standard.
For 400 V, the voltage THD planning level is 5% at the PCC.
Limits for odd and even harmonics in 400 V systems are given
in Table 2 in the standard.
The standard describes a 3-stage assessment procedure for the
connection of non-linear equipment. The procedure aims at
balancing the level of detail required by the assessment process
with the degree of risk that the connection of particular
equipment results in unacceptable voltage harmonic distortion.
Compliance of a system containing VLT
®
frequency converters
depends on the specific topology and population of non-linear
loads. To meet the requirements of G5/4, employ VLT
®
Advanced Harmonic Filters AHF 005/AHF 010.
Table 2.1 Harmonics Mitigation Standards
Introduction to Harmonics a... Design Guide
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