Circutor AFQm, Instruction Manual, Page: 154 / 230

154
AFQm
Instruction Manual
ENGLISH
Table 18: Most common harmonics.
Type of load Wave shape
Harmonic spectrum
THD(I)
6-pulse converters
Variable speed drives
UPS
Three-phase rectifiers
Converters for electrolysis and baths
Discharge lamps
Single-phase converters
Lighting lines
Computer lines
Sound and image devices
4.1.3.- HARMONIC COMPENSATION
Active filters are devices responsible for the compensation of harmonic currents.
Compensation is achieved by injecting harmonic currents equal to those in the installation in counter
phase.
This means that upstream of the filter connection point, the signal shows virtually no harmonic distor-
tion (
Figure 33
).
L1
L2
L3
S1 S2
P1
P2
S1 S2
P1 P2
CARGAS / LOADS
RED / MAIN
N
S1
S2
P1
P2
I
F
I
C
I
R
AFQm
Figure 33: General connection diagram of an active filter.