8 Power Control
SMA Solar Technology AG
50
SCCP-JP-BA-A4-en-12
User Manual
8.1.1.2 Setting the Mode of Frequency-Dependent Active Power Limitation and
Associated Parameters
1. Ensure that the Sunny Central is in the operating state "Stop".
2. Log into the user interface.
3. If necessary, set the parameter
WCtlHzMod
to
CurveHys
4. Change the parameters
P-HzStr
,
P-HzStop
and
P-WGra
.
5. Confirm the parameter entry with [
Save
].
8.1.2 Frequency-Independent Active Power Limitation
8.1.2.1 Selecting the Mode with the Parameter P-WMod
You can set the active power limitation via the parameter
P-WMod
. Use this parameter to configure how the
specifications of the grid operator are to be received and implemented. The default value for this parameter is
Off
.
There are five different modes of frequency-independent active power limitation:
Procedure:
1. Ensure that the Sunny Central is in the operating state "Stop".
2. Log into the user interface.
3. Change the parameter
P
-
WMod
in the user interface (see Section 6.2, page 40).
4. Change any parameters associated with the selected mode.
Example:
A 500 kW Sunny Central is feeding 350 kW (P
cur
) into the utility grid. The frequency rises to 51.2 Hz.
The difference between the current power frequency and
P-HzStr
(51.2 Hz - 50.2 Hz) multiplied by the gradient
P-WGra
(40%/Hz) results in an active power reduction of 40% of the last available power P
cur
(350 kW). This yields
a power limitation of 140 kW and hence a maximum active power of 210 kW.
Calculation:
210 kW = 350 kW – ( (51.2 Hz – 50.2 Hz) * 40%/Hz * 350 kW )
Parameter block
The parameter
P-WMod
can only be changed in the operating state "Stop". The entry will not be accepted in any
other operating state.
Mode
Description
Off
The active power is limited to the nominal power
Pmax
of the device.
WCtlCom
The active power limitation is transmitted by means of a Modbus protocol to the
Sunny Central via the Power Reducer Box or the Power Plant Controller.
WCnst
The active power limitation is entered as an absolute value via the parameter
P-W
.
WCnstNom
The active power limitation is entered as a percentage value via the parameter
P-WNom
.
WCnstNomAnIn
The active power limitation is set via an analog signal at the input terminals for setpoint
specification.
