8 Power Control
SMA Solar Technology AG
56
SCCP-JP-BA-A4-en-12
User Manual
Figure 19: Limitation of the parameter
Pmax
to the parameter
Qmax
If the value of
Pmax
exceeds the value of
Qmax
, the characteristic curve will be limited to Qmax at the value Q
max
and
the reactive power value will remain constant at Qmax in the range from +Qmax to +Pmax.
If the value of ‒
Pmax
falls below the value of ‒
Qmax
, the characteristic curve will be limited to ‒Qmax at the value
‒Q
max
and the reactive power value will remain constant at ‒Qmax in the range from ‒Pmax to ‒Qmax.
8.2.1.8 Reactive Power Setpoint via Displacement Power Factor cos φ: PFCnst Mode
The reactive power setpoint is set via the parameters
PF
-
PF
and
PF
-
PFExt
. The parameter
PF-PF
indicates the
displacement power factor cos φ and the parameter
PF-PFExt
indicates the degree of overexcitation or underexcitation.
8.2.1.9 Displacement Power Factor cos φ via Standard Signal: PFCnstAnIn Mode
The reactive power setpoint is set via an analog signal at the input terminals for setpoint specification (see Sunny Central
installation manual). This is usually implemented by a ripple control signal.
The analog value is converted into a displacement power factor cos φ. The electrical current strength of the connected
signal determines the setpoint.
The analog measured values must be between 4 mA and 19 mA. If the analog signal is less than 2 mA, an error message
will be displayed in the instantaneous value
Q
-
VArModFailStt
Signal
Power limit
Description
< 2 mA
Last valid value or 1 after
restart
Signal is in the invalid range.
2 mA to 4 mA
PFAbsMin
/
underexcited
The maximum amount of negatively excited reactive power is fed in.
4 mA
PFAbsMin
/
underexcited
Start point of the characteristic curve
Maximum amount of negatively excited reactive power is fed in.
11.5 mA
1
Zero-crossing of the characteristic curve
No reactive power is fed in.
