SMA Solar Technology AG
Connecting External Sources
Technical Description
SI5048-TEN093630
121
14.2.8 Limits and Power Adjustment
The Sunny Island charges the public grid during each phase using the current specified via the
"232.03 GdCurNom" parameter. The power that is not directly used by the loads flows into the
battery for charging. At the same time, the limits for the AC charging current limit
("210.02 InvChrgCurMax" parameter) on the Sunny Island and the DC charging current limit
("222.01 BatChrgCurMax" parameter) are active. If the battery voltage reaches the charging voltage
nominal value, it is also reduced (see section 13.4 ”Charge control” (page 94)).
If the current set using the "232.03 GdCurNom" parameter is not sufficient for powering the loads,
the battery provides support.
14.2.9 Operation in Conjunction with PV Inverters
Since electricity is fed into the grid through the relay of the Sunny Island, 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 battery is fully charged, the frequency limits the power output of the AC feed-in generators
(PV inverters) in the stand-alone grid. If the grid is now reconnected, the frequency would be lowered,
if required, as the Sunny Island is synchronized with the grid. The AC feed-in generators would then
feed additional energy into the system and possibly overload the batteries. In order to prevent this, in
this case the stand-alone grid frequency is temporarily increased, in line with the synchronization, until
the AC feed-in generators (Sunny Boy) are disconnected from the stand-alone grid as a result of the
grid limits being exceeded.
14.3 Generator and Grid
In addition to the public grid, a generator can also be integrated into an off-grid system as a
secondary protective measure. This is particularly useful in case of long-term grid failures, even if the
battery size is no longer sufficient to bridge the failure after a period of time.
Silent Mode Active
When silent mode is activated, the grid cannot be supported!
A short grid outage can occur. This way, the voltage fed to the loads will be interrupted for
a short time.
NOTICE!
Damage to the Sunny Island due to high currents.
If the current flowing through the relay exceeds the maximum permissible current, the grid
is disconnected (relay protection).
• Do not install more PV in the stand-alone grid than the maximum quantity allowed by
Summary of Contents for SI 5048
Page 2: ......
Page 10: ...Table of Contents SMA Solar Technology AG 10 SI5048 TEN093630 Technical Description...
Page 43: ...SMA Solar Technology AG Electrical Connection Technical Description SI5048 TEN093630 43...
Page 209: ......
Page 210: ......
Page 212: ...4 4PMBS 5FDIOPMPHZ XXX 4 EF...
