SMA SC 400HE - Manual (Page 51)

SMA Solar Technology AG 4 Sunny Central Control
Operating Manual SC4-63HE-BE-BEN103280 51
If the value of "P
max
" exceeds the value of "Qmax", the characteristic curve for the value "Qmax" is
limited to "Qmax" and has a linear progression from -Pmax to -Qmax and from +Qmax to +Pmax.
4.8.8 "PFCnst" Procedure
The reactive power setpoint is set using the "PF-PF" and "PF-PFExt" parameters. The "PF-PF" parameters
indicate the displacment power factor cos φ and the "PF-PFExt" parameter indicates the degree of
excitation.
4.8.9 "PFCnstAnIn" Procedure
The reactive power target value is set at the input terminals using an analog signal for specifying the
target value (see enclosed installation manual). This is usually accomplished by using a radio ripple
control receiver.
The analog value is converted into a power factor. The current of the connected signal determines the
target value.
The analog measured values must be between 4 mA … 19 mA. If the analog signal is smaller than
2 mA, the error message "Q-VArModFailStt" is displayed.
The analog value is converted to the power factor target value. Here, the "PFAbsMin" parameter is
the start and end point of the linear characteristic curve.
Used parameters none
Used parameters PF-PF
PF-PFExt
Signal Power limit Description
< 2 mA Last valid value, or 1 after reboot Signal is in the invalid range
2 mA … 4 mA PFAbsMin / underexcited The maximum amount of
negatively excited reactive
power is fed in.
4 mA PFAbsMin / underexcited Starting point of the curve
Maximum amount of negatively
excited reactive power is fed in.
11.5 mA 1 Zero-crossing of the curve No
reactive power is fed in.
> 19 mA PFAbsMin / overexcited End point of the curve
Maximum amount of positively
excited reactive power is fed in.
Used parameters none