SMA STP 50-40 - Configuring the Active Power Mode; Configuring Q on Demand 24;7

8 Operation
SMA Solar Technology AG
Operating manual STP50-4x-BE-en-23 79
8.16 Configuring the Active Power Mode
Starting the installation assistant
1. Open the user interface (see Section8.2, page61).
2. Log in as Installer.
3. Start the installation assistant (see Section8.7, page72).
4. Select [Save and continue] after each step up until the step Grid management service.
5. Make the settings as described in the following.
Make the settings for systems with external setpoint
1. In the tab Active power mode set the switch Active power setpoint to [On].
2. In the drop-down list Operating mode active power setpoint, select the entry External
setpoint.
3. In the drop-down list Fallback behavior, select the entry Apply fallback values.
4. In the field Fallback value of the maximum active power enter the value to which the
inverter is to limit its nominal power in case of a communication failure to the higher control
unit at the end of the timeout time.
5. In the field Timeout, enter the time that the inverter is to wait before it limits its nominal power
to the set fallback value.
6. If, in the event of a 0% or 0W specification, the inverter is not permitted to feed small amounts
of active power into the utility grid, select the entry Yes in the drop-down list Grid
disconnection for 0% active power setpoint. This ensures that in the event of a 0% or 0W
specification, the inverter disconnects from the utility grid and does not feed in active power.
Make the settings for systems with manual setpoint
1. In the tab Active power mode set the switch Active power setpoint to [On].
2. In the Operating mode active power setting drop-down list, select Manual setting in %
or Manual setting in W for the manual preset and enter the respective default value.
8.17 Configuring QonDemand24/7
With the "QonDemand 24/7" function, the inverter remains connected to the utility grid overnight
and is supplied with power via the utility grid in order that it can provide reactive power. When
connected overnight, the inverter only draws an insignificant amount of active power from the utility
grid to supply its internal assemblies. The inverter can provide up to 100% of its power as reactive
power. The provision of reactive power during feed-in operation leads to a reduction of the feed-in
power. This means that at 100% reactive power, the feed-in power is 0%.
The general setting of the grid management services (e.g. cos phi setpoint or Q(V) characteristic
curve) can not be fully set independently of the "QonDemand 24/7" function via the relevant
parameters - "Q on Demand 24/7" only permits Q specifications. It is to be noted here that certain
settings can have an influence on other grid-support settings and functions.