Harmonic order (h)
Class 1 (V
h
%)
Class 2 (V
h
%)
Class 3 (V
h
%)
5
3
6
8
7
3
5
7
11
3
3.5
5
13
3
3
4.5
17
2
2
4
17
˂
h≤49
2.27 x (17/h) – 0.27
2.27 x (17/h) – 0.27
4.5 x (17/h) – 0.5
Table 10.45 Compatibility Levels for Harmonics
Class 1
Class 2
Class 3
THDv
5%
8%
10%
Table 10.46 Compatibility Levels for the Total Harmonic Voltage Distortion THDv
10.16.4 Harmonic Compliance
Danfoss drives comply with the following standards:
•
IEC61000-2-4
•
IEC61000-3-4
•
G5/4
10.16.5 Harmonic Mitigation
In cases where extra harmonic suppression is required, Danfoss offers the following mitigation equipment:
•
VLT
®
12-pulse Drives
•
VLT
®
Low Harmonic Drives
•
VLT
®
Advanced Harmonic Filters
•
VLT
®
Advanced Active Filters
Selecting the right solution depends on several factors:
•
The grid (background distortion, mains unbalance, resonance, and type of supply (transformer/generator).
•
Application (load profile, number of loads, and load size).
•
Local/national requirements/regulations (such as IEEE 519, IEC, and G5/4).
•
Total cost of ownership (initial cost, efficiency, and maintenance).
10.16.6 Harmonic Calculation
Use the free Danfoss MCT 31 calculation software to determine the degree of voltage pollution on the grid and needed
precaution. The
VLT
®
Harmonic Calculation MCT 31
is available at
.
Electrical Installation Con...
VLT® AutomationDrive FC 302
174
Danfoss A/S © 01/2018 All rights reserved.
MG38C202
10
10
