Grid
SMA Solar Technology AG
120
SBU2200-TEN083320
Technical Description
15 Grid
The backup systems are designed to provide seamless backup power for operation on the public grid.
Here, a distinction is made between two main states:
• Public grid present
• Grid failure (stand-alone grid operation)
The status of the grid determines the operating mode of the Sunny Backup 2200. If the public grid is
available, the loads in the main power grid are supplied with electricity while the Sunny Backup 2200
charges its batteries or keeps them fully charged. The PV system feeds into the public grid via a
dedicated meter.
In the event of grid failure, the Sunny Backup System S disconnects the public grid from the loads in
less than 50 ms and then powers these loads with grid-quality voltage. The Sunny Backup 2200 is
responsible for powering the loads while the grid is down (stand-alone grid operation).
The Automatic Switch Box S switches the PV system to the load side. The electricity from the PV system
is then fed into the stand-alone grid. If the PV system is generating more PV energy than needed, the
surplus power is stored in the battery. If more energy is being consumed than the PV system can
generate, the extra energy required is taken from the battery.
15.1 Conditions
The standard applicable at the installation location (e.g. for Germany: DIN VDE 0126-1-1) and the
voltage and frequency threshold values as stipulated by the standard must be continuously monitored
for operation on the public grid. If these thresholds are breached, the Sunny Backup System S will
disconnect from the grid in less than 200 ms.
Switching times during grid failure
During these 200 ms, the loads continue to be powered, as although the grid voltage or
frequency breaches the thresholds, there is still sufficient voltage and frequency available.
If the voltage fails completely, the backup system will be disconnected from the grid within
50 ms.
Adjusting specified limit value
In certain cases it may be necessary to adjust the voltage and frequency limits to the grid
situation in order to prevent grid disconnections from occurring too frequently. In such
instances it is imperative that you consult your energy supply company. To adjust these
limits in the "232# Grid Control" menu, you must first enter your personal SMA grid guard
password (see section 12.2.3 „Setting the Installer Identification“ (108)).
