SMA Solar Technology AG
Sunny Boy
Technical Description
SBU2200-TEN083320
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18.2 Frequency Shift Power Control (FSPC)
This section describes the operating principles of the power adjustment via frequency "Frequency Shift
Power Control (FSPC)".
If Sunny Boys are connected in stand-alone operation, then the Sunny Backup 2200 must be capable
of limiting their output power. This kind of situation arises, for example, when the Sunny Backup 2200
battery is fully charged and the (solar) power available from the PV system exceeds the power
required by the connected loads.
To prevent the excess energy from overcharging the battery, the Sunny Backup 2200 recognizes this
situation and changes the frequency at the AC output. This frequency adjustment is analyzed by the
Sunny Boy. As soon as the grid frequency increases beyond the value specified by "Fac-Start delta"
the Sunny Boy limits its output power accordingly.
Setting older SMA inverters
It may happen that older SMA inverters cannot yet be set to "Offgrid" (stand-alone grid)
via the "Default" parameter. In this case, the values 1 - 6 in the table must be set
individually.
FSPC
The frequency shift power control only works in stand-alone grid operation!
Sunny Boy without FSPC
This function is neither supported by the SMA PV inverters SB2100TL, SB3300TL,
SB4200TL and SB5000TL, nor by older models in the SWR series. These Sunny Boys can
nevertheless be used in backup systems.
If the current battery voltage exceeds the nominal battery voltage, the above-mentioned
Sunny Boys will be disconnected from the stand-alone grid present at that time and then
reconnected only after the battery has been discharged by at least 5 %.