Lvfrt - K-Factor - Fronius SnapINverter 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 current is activated and also how high this current value should be.
When the K-Factor = 0, the inverter does not feed any additional reactive current into the
grid in the event of a voltage drop.
The K-Factor can be determined from the following graph:
Un
U
0
U
I
n
I
B0
I
B
Δ U = U - U
(1)
(2)
(3)
(4)
-50 %
Nominal voltage
Voltage before the failure
Current voltage
(during the failure)
Nominal current
Reactive current before the failure
Reactive current
; Δ I = I - I
0 B B 0
DeadBand Low
DeadBand High
Required additional reactive cur-
rent
Voltage drop or voltage rise
(3)
Δ I / I
B n
(1) (2)
-10 % 10 % 20 %
-100 %
Reactive current droop:
k =
Typical example for set values from the
graph:
U = 110 %
max
U = 90 %
min
k = 2.0
Δ U / U (4)
n
Δ I / I
B n
Δ U / U
n
97