Lvfrt - K-Factor - Fronius Galvo Serviceanleitung

LVFRT - K-Factor

The K-Factor and the upper and lower voltage limits define the voltage level at which feed-
ing in of reactive power is activated and also how high this current value should be.
When K-Factor = 0 the inverter does not feed reactive current into the grid in the event of
a voltage drop.
The K-Factor can be determined from the following graph:
Un
U
U
I
I
I
Δ U = U - U
(1)
(2)
(3)
84
-50 %
Nominal voltage
Voltage before the failure
0
Current voltage
(during the failure)
Nominal current
n
Reactive current before the failure
B0
Reactive current
B
; Δ I = I - I
0 B B
Deadband
Required additional reactive cur-
rent
Voltage drop or voltage rise
Δ I
B
(1)
-10 % 10 %
-100 %
Reactive current droop:
Typical example for set values from the
graph:
U
max
0
U
min
k = 2.0
(2)
/ I
n
20 % Δ U / U
Δ I / I
B n
k =
Δ U / U
n
= 110 %
= 90 %
(3)
n