SMA SC 500CP-US-10 600V - Manual (Page 67)

SMA America, LLC 8 Reactive Power Control
Operating Manual SCCP-US-BE-US_en-52 67
The analog measured values must be between 4 mA and 19 mA. If the analog signal is less than 2 mA, the error
message will be displayed in the instantaneous value Q-VArModFailStt.
The analog value is converted to a setpoint for power limitation. Here, the parameter QoDQmax is the end point of the
linear characteristic curve.
Figure 29: Limitation of the parameter Pmax to the parameter QoDQmax
If the value of Pmax exceeds the value of QoDQmax, the characteristic curve will be limited to QoDQmax at the value
Q
QoDmax
and the reactive power value will remain constant at QoDQmax in the range from +Q
QoDmax
to +P
max
.
If the value of ‒Pmax falls below the value of ‒QoDQmax, the characteristic curve will be limited to ‒QoDQmax at
the value ‒Q
QoDmax
and the reactive power value will remain constant at ‒QoDQmax in the range from ‒P
max
to
‒Q
QoDmax
.
Signal Power limit Description
< 2 mA Last valid value or 0 kVAr
after restart
Signal is in the invalid range.
2 mA to 4 mA − Pmax The maximum amount of negatively excited reactive power is fed in.
4 mA − Pmax Starting point of the characteristic curve
The maximum amount of negatively excited reactive power is fed in.
11.5 mA 0 kVAr Zero-crossing of the characteristic curve
No reactive power is fed in.
> 19 mA +Pmax End point of the characteristic curve
The maximum amount of positively excited reactive power is fed in.
Parameters used none