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

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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
< 2 mA Last valid mean value or 0 kVAr after
restart
2 mA to 4 mA Qmax / underexcited
4 mA Qmax / underexcited
11.5 mA 0 kVAr
> 19 mA Qmax / overexcited
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.
System Manual
Description
Signal is in the invalid range.
The maximum amount of negatively excited reactive
power is fed in.
Start point of the characteristic curve
The maximum amount of negatively excited reactive
power is fed in.
Zero-crossing of the characteristic curve
No reactive power is fed in.
End point of the characteristic curve
The maximum amount of positively excited reactive
power is fed in.
MVPS22JP-SH-en-11
13 Function Description
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