2 no q at night: off mode, 4 q at night with absolute value: varcnst mode – SMA SC 500CP-10-JP User Manual

Page 65

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SMA Solar Technology AG

8  Power Control

User Manual

SCCP-JP-BA-A4-en-12

65

7. In the parameter PwrMonErrTm configure the time lapse until recognition of the absence of setpoint specifications.
8. Confirm the parameter entry with [Save].

8.3.2 No Q at Night: Off Mode

The reactive power setpoint is limited to 0 kVAr. This setpoint cannot be controlled.

8.3.3 Q at Night with Setpoint Command via Modbus Protocol: VArCtlCom Mode

The reactive power setpoint is received via the Power Reducer Box or the Power Plant Controller. The setpoint is

transmitted as a percentage and converted to kVAr in the device.
If the Sunny Central has not received any signal for the last five minutes, the error message Q-VArModFailStt will be

displayed (see Section 8.2.2, page 63).

8.3.4 Q at Night with Absolute Value: VArCnst Mode

The reactive power setpoint is set using the parameter QoDQ-VAr. Note that the permitted range for the parameter

QoDQ-VAr is ‒QoDQmax to +QoDQmax.

8.3.5 Q at Night as a Percentage of the Nominal Power: VArCnstNom Mode

The parameter QoDQ-VArNom is used to set the reactive power setpoint in %. The parameter QoDQ-VArNom refers

to Pmax. If the calculated amount of reactive power exceeds the predefined value of QoDQmax, the power will be

limited to QoDQmax. If the calculated amount of reactive power falls below the predefined value of ‒QoDQmax,

the power will be limited to ‒QoDQmax.

8.3.6 Q at Night via Standard Signal: VArCnstNomAnIn 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 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 (see Section 8.2.2, page 63).

The analog value is converted to a setpoint for power limitation. Here, the parameter QoDQmax is the end point of the

linear characteristic curve.

PF-PFSubVal

Proxy value for the displacement power factor outside of feed-in operation

PF-PFExtSubVal

Proxy value for the excitation of the displacement power factor outside of feed-in operation

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

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

+Pmax

End point of the characteristic curve
The maximum amount of positively excited reactive power is fed in.

Parameters

Description

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