Grid Operation - SMA Sunny Island 2012 Technical Description

Connecting External Sources

13.2.4 Grid Operation

In grid operation, the stand-alone grid and main power grid are connected. The Sunny Island is
connected along with the stand-alone grid to the main power grid. Therefore, the voltage and
frequency in both grids are identical.
Information
All grid failures that occur during grid operation affect the stand-alone grid.
In grid operation, the grid monitors whether the permissible limits for voltage and frequency (see
Grid Reconnection) are maintained or whether the grid fails to assume powering the stand-alone
grid. To do this, the main power grid is disconnected (grid backup operation).
The battery is generally charged or its charge is maintained on the grid.
Charge Mode
Charge mode on the grid is indicated by energy flowing to the battery. The battery is charged until
the respective charge process (Boost, Full, Equalize) has been completed and the system transitions
into float charge (Float) (see chapter 12.4 "Charge Control" (Page 122)).
Silent Mode
In order to save energy, the silent mode can be activated using the 224.01 SilentEna" parameter
set to "enable" (default disable). In this case, the Sunny Island is set to standby mode if the charge
has been completed and the battery has been in float charge for some time
(see section 12.4.5 "Silent Mode" (Page 127)).
The silent mode is exited regularly to recharge the battery.
Grid feeding
Whether energy is fed from the stand-alone grid into the main power grid is controlled using the
"232.08 GdMod" parameter. If GridCharge (Default) is set, no energy is fed into the grid. If
GridFeed is set, energy is fed into the grid.
Information
In order to allow electricity to be fed from the battery into the grid, the battery voltage in
a charged battery (on the grid) must be increased by external DC chargers above the
nominal charging voltage.
AC feed-in generators on the stand-alone grid side (Sunny Boys) can feed their energy into the grid
through the internal transfer relay of the Sunny Island; for limitations, see section 13.2.7 "Limits and
Power Adjustment" (Page 149).
148 SI2012_2224-TEN082311
SMA Solar Technology AG
Technical Description