SMA Solar Technology AG
4 Q on Demand 24/7
Technical Information
IPC_STP-TI-en-14
11
4 Q on Demand 24/7
The "Q on Demand 24/7" function keeps the inverter on the utility grid over night. It is powered by the grid in order to
provide reactive power (III)* . Additionally, in feed-in operation, the inverter can provide up to 100% of its apparent
power as reactive power (II) over and above its normal operating range (I).
Figure 8: Extension of the operating range and limits of the Sunny Tripower by using the "Q on Demand 24/7" function
Parameters for Q on Demand 24/7
With the parameter
Oper.st.vol.maint.at Q on Dem., st.vol.maint.conf. (Q-VArModDmd)
, you can activate only
the function "Q on Demand 24/7".
The general setting of the grid management service (e.g. cos(phi) setpoint or Q(V) characteristic curve) can be set
independently of function "Q on Demand 24/7" using the relevant parameters.
* If the inverter is disconnected from the utility grid during the night (e.g. under fault conditions), it cannot connect to the utility grid again until
the next morning if there is sufficient PV power. Until then, the function "Q on Demand 24/7" is inactive.
Parameter name
Description
Oper.st.vol.maint.at Q on Dem.,
st.vol.maint.conf.
(Q-VArModDmd)
1 = default setting
Limitation of reactive power Q depending on the active power P is switched
on.
0 = Limitation of reactive power Q depending on the active power P is
switched off. When using the "Q on Demand 24/7" function, set this
parameter to 0.
P
max
P
P
Q
(I)
(II)
(III)
Q
Q
max
= 0.5 x P
max
