Class 1
Class 2
Class 3
THD(V)
5%
8%
10%
Table 9.11 Compatibility Levels for the Total Harmonic Voltage Distortion THD(V)
9.10 IEEE Harmonics Standards
The IEEE 519 standard (Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems)
provides specific limits for harmonic voltages and currents for individual components within the supply network. The
standard also provides limits for the sum of all loads at the point of common coupling (PCC).
To determine allowable harmonic voltage levels, IEEE 519 uses a ratio between the supply short-circuit current and the
maximum current of the individual load. For allowable harmonic voltage levels for individual loads, see
. For
allowable levels for all loads connected to the PCC, see
.
I
SC
/I
L
(R
SCE
)
Allowable individual harmonic voltages
Typical areas
10
2.5–3%
Weak grid
20
2.0–2.5%
1–2 large loads
50
1.0–1.5%
A few high-output loads
100
0.5–1%
5–20 medium-output loads
1000
0.05–0.1%
Strong grid
Table 9.12 Allowable Voltage THD at the PCC for Each Individual Load
Voltage at the PCC
Allowable individual harmonic voltages
Allowable THD(V)
V
Line
≤69 kV
3%
5%
Table 9.13 Allowable Voltage THD at the PCC for all Loads
Harmonic currents must be limited to specified levels, as shown in
. IEEE 519 utilizes a ratio between the supply
short-circuit current and the maximum current consumption at the PCC, averaged over 15 minutes or 30 minutes. In certain
instances when dealing with harmonic limits containing low harmonic numbers, the IEEE 519 limits are lower than the
61000–2–4 limits. VLT
®
Parallel Drive Modules observe the total harmonic distortion as defined in IEEE 519 for all R
sce
. Each
individual harmonic current fulfills table 10–3 in IEEE 519 for R
sce
≥20.
I
SC
/I
L
(R
SCE
)
h<11
11≤h<17
17≤h<23
23≤h<35
35≤h
Total demand
distortion TDD
<20
4%
2.0%
1.5%
0.6%
0.3%
5%
20<50
7%
3.5%
2.5%
1.0%
0.5%
8%
50<100
10%
4.5%
4.0%
1.5%
0.7%
12%
100<1000
12%
5.5%
5.0%
2.0%
1.0%
15%
>1000
15%
7.0%
6.0%
2.5%
1.4%
20%
Table 9.14 Allowable Harmonic Currents at the PCC
9.11 VLT
®
Parallel Drive Modules Harmonics Compliance
The VLT
®
Parallel Drive Modules comply with the following standards:
•
IEC 61000-2-4
•
IEC 61000-3-4
•
IEEE 519
•
G5/4
EMC and Harmonics
Design Guide
MG37N102
Danfoss A/S © 6/2016 All rights reserved.
103
9
9
Summary of Contents for VLT 380-500 V
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