Fronius IG 300 Bedienungsanleitung Seite 181

Q specified value:
abs
Change gradient:
Reserved data must always be 0x00.
Response:
Start Length Device / Op-
tion
variable 0x00
Remote Ctrl Data
- The Q specified value indicates the reactive power provided by the inverter while
abs
feeding energy into the grid as an absolute value.
- A Q specified value of 0 var means live operation while feeding energy into the grid
abs
(reactive components may occur due to the integrated EMI filter if filter compensation
is not activated).
- The change gradient indicates the speed at which the inverter will change from the
present Q specified value to the new Q
abs
be used to avoid erratic changes between entered values.
The sign of the Q specified value defines whether the inverter behaves like an over- or
abs
under-excited synchronous machine. The inverter always acts like a generator regarding
the flow direction of the active energy:
Sign of Q specified value
abs
Negative
Positive
Example of the calculation of the maximum reactive power of an inverter with a power of
60 kW and a maximum reactive power range of 0.85 (cos phi
- S = 60000 VA
max
- Cos phi = 0.85
max
- Phi = 31.7883°
max
- Q (100%) = S x sin(Phi
max max
var
The reactive power available for each feed-in operating point also depends on the present
effective power output due to the limited maximum cos phi.
For this reason, the reactive power specified value is only used as a maximum value when
sufficient effective power is being output and thus the power factor remains within the de-
fined limits.
big endian | signed int | resolution: 1 LsB = 1 [var] |
Value range -32768d to +32767d
Value range limitation for Fronius IG Plus and Fronius CL:
The values entered may not exceed the +Q
the respective inverter
big endian | unsigned int | resolution: 1 LsB = 1 [var] / sec |
Value range 1-6553d / Special value: 0xFFFF is defined as
"as fast as possible"
Example: Change from -1000 var to +1000 var corresponds
to a Delta of 2000. A change gradient of 1000 entails a
change from -1000 var to +1000 var in 2 seconds (calcula-
tion: Delta/Change gradient = 2000/1000 = 2 seconds)
Number Com-
mand
0x00 0x9F 0x04
Inverter number Check-
specified value. The change gradient can
abs
Meaning
over-excited
under-excited
) = 60000 x sin(31.7883) = 60000 x 0.5267 = 31600
max
to -Q
max
Remote Ctrl Separator
CMD ID
0x7F
sum
):
max
of
max
179