Parameters
vacon • 179
Local contacts: https://www.danfoss.com/en/contact-us/contacts-list/
Correction can be up to +/- 150 V.
The correction term is determined by ”perturb-and-observe” logic (P&O).
P3.22.2.8 P&O
UPDATE
TIME
P3.22.2.9 P&O
VOLTAGE
STEP
DC voltage reference is periodically (at intervals defined by P3.22.2.8) increased or decreased by a
small value (P3.22.2.9). If the variation brings a higher motor power, next variation will follow the
same direction, otherwise it will be reversed.
A short perturb period (P3.22.2.8) makes the regulation faster, assuming that the PI gains are not
too low (power variation has to complete within the period).
The correction term can be monitored (V2.2), to help the tuning of reference feed-forward. When
the panels temperature is close to standard, 25 °C, the correction term should result small (+/- 20
to 30 V).
The correction decreases towards negative maximum as temperature increases.
The correction term increases towards positive maximum in case of low temperature.
If something different is observed, feed-forward values should be improved.
P3.22.2.10 P&O
POWER
VARIATION
P3.22.2.10 determines the variation in motor power, above which iteration of voltage reference
change continues in the same direction.
Small value leads to a regulation very close to the maximum of the panel curve, with possible in-
stability. Higher values lead to a more stable point, but with lower efficiency.
