Operation Together With Sunny Boys - SMA Sunny Island 5048 Installation Instructions Manual

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14.2.8 Operation Together With Sunny Boys

Since electricity is fed into the grid through the relay of the Sunny Island 5048, they
must be prevented from overloading. For this reason, reverse power monitoring is used
that, if required, establishes the connection to the main power grid if the reverse power
limit is exceeded or an excessive load is applied to the relay.
If the current flowing through the relay exceeds the maximum permissible
current, the grid is disconnected (relay protection). The quantity of PV
output installed in the stand-alone grid must not exceed the maximum
quantity allowed by the AC input (see section 20 "Technical Data" (Page
155)).
If the battery is fully charged, the frequency limits the power output of the AC feed-in
generators (Sunny Boys) in the stand-alone grid. If the grid is now reconnected, the
frequency would be lowered, if required, as the Sunny Island 5048 is synchronized
with the grid. The AC feed-in generators (Sunny Boys) would then feed additional
energy into the system and possibly overload the batteries. In order to prevent this
during such conditions, the stand-alone grid frequency is temporarily increased
("#230.04 AcSrcFrqDel" parameter), in line with the synchronization, until the AC feed-
in generators (Sunny Boys) are disconnected from the stand-alone grid as a result of the
grid limits being exceeded.
Technical Description SI5048-11:EE4206 Page 113