SMA SC 500CP-10-JP User Manual

Page 56

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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 (see Section 8.2.2, page 63).

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.

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