SMA SC 500CP XT - Manual (Page 113)

The dynamic grid support function is activated via the parameter FRTEna. The inverter behavior can be controlled via
the parameter FRTMod. The level of reactive current provided with full dynamic grid support is determined via the
parameter FRTArGraNom. The grid limits and deactivation delays vary depending on the country.
10.5.2.2 Grid Support in Case of Untervoltage (LVRT)
The inverter can support the utility grid during a brief grid-voltage dip. The behavior of the inverter depends on the
percentage ratio of grid voltage V
grid
to nominal voltage V.
Figure 40: Maximum duration of a voltage dip that the inverter can work through without disconnecting from the utility grid
Ratio V
grid
/V Inverter behavior
90% to 100% The ratio of grid voltage V
grid
to nominal voltage V is in the normal range and the inverter
feeds in without any problems.
20% to 90% The ratio of grid voltage V
grid
to nominal voltage V is in the critical range. There is a distur-
bance in the utility grid.
While this disturbance remains present, the inverter supports the utility grid with reactive cur-
rent.
The inverter can bridge disturbances of up to five seconds without disconnecting from the util-
ity grid.
If the set grid monitoring time is exceeded during this period, the inverter disconnects from
the utility grid.
0% to 20% The ratio of grid voltage V
grid
to nominal voltage V is in the critical range. There is a distur-
bance in the utility grid. While this disturbance remains present, the inverter supports the util-
ity grid with reactive current. The inverter can bridge disturbances of up to 1.2 seconds with-
out disconnecting from the utility grid. The requirement is that the ratio V
grid
/V was at least
90% before the error occurred.
If the set grid monitoring time is exceeded during this period, the inverter disconnects from
the utility grid.
10 Function Description SMA Solar Technology AG
User Manual 113 SCCPXT-BA-E4-en-54