SMA MEDIUM VOLTAGE POWER STATION 500SC-JP - Reactive Power Setpoint Via Standard Signal: Varcnstnomanin Mode; Reactive Power Setpoint Via Displacement Power Factor Cos Φ: Pfcnst Mode

13.3.3.6 Reactive Power Setpoint via Standard Signal: VArCnstNomAnIn Mode
The reactive power setpoint is set at the input terminals for the setpoints via an analog signal. This is usually
implemented by a ripple control signal. The analog value is converted into a reactive power setpoint. 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 mean value or 0kVAr after
restart
Signal is in the invalid range.
2 mA to 4 mA
Qmax / underexcited
The maximum amount of negatively excited reactive
power is fed in.
4mA
Qmax / underexcited
Start 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
Qmax / overexcited
End point of the characteristic curve
The maximum amount of positively excited reactive
power is fed in.
The analog value is converted to a setpoint for power limitation. Here, the parameter Qmax forms the end point of the
linear characteristic curve.
Figure 68: Limitation of the reactive power to the parameter Qmax
13.3.3.7 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.
13 Function Description
SMA Solar Technology AG
System Manual 193MVPS22JP-SH-en-11