CIRCUTOR AFQ Series - Manual (Page 35)

AFQ-4W
Instruction Manual 35
4.1.3.- MOST COMMON HARMONICS
Table 5 lists the most common harmonic generator loads and the wave shape of
the current they consume, as well as their harmonic spectrum.
Type of load Wave shape Harmonic spectrum THD(I)
6-pulse transducers:
-
Speed drives
- UPS
- Three-phase rectifiers
- Transducers for
electrolysis and baths
- Discharge lamps
- Single-phase transducers
- Lighting lines
- Computer lines
- Sound and image units
Table 5: Most common harmonics.
4.1.4.- HARMONIC COMPENSATION
Active filters are units 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 distortion. ( Figure 31 ).
Figure 31: General connection diagram of an active filter