SMA Sunny Island 2012 Technical Description page 203

SMA Solar Technology AG
Glossary
Automatic Switch Box
Switching unit which switches the Sunny Backup System between grid and off-grid operation. In grid
operation, a PV plant in the Sunny Backup System is operated via an automatic disconnection
device at its own feed-in counter. If the grid drops out it is switched to the stand-alone grid separated
from the public grid. The box can optionally integrate a diesel generator into the Sunny Backup
System.
Backup system
So-called backup systems are power supply systems which provide an extra level of security for
standard power supply systems. The public grid is usually the standard power supply system, which
is backed up by an additional stand-alone grid system in case of a power outage. In addition to the
backup systems, diesel generators in PV battery systems are also described as backup generators.
Here they perform the same task as a backup system does for the public grid.
Battery
A battery is an electrochemical storage device which can release previously stored chemical energy
as electrical energy. A distinction is made between non-rechargeable primary elements (often used
in consumer markets, for example) and rechargeable secondary elements (accumulators). In so-
called stand-alone grid systems, the batteries used as rechargeable secondary elements are almost
exclusively lead acid batteries and, very rarely, nickel/cadmium batteries.
Battery Bank
See Battery System.
Battery Charging Mode
A battery inverter operating mode, in which the inverter takes energy from the AC grid to recharge
the battery in a controlled fashion. In this operating mode, the battery inverter is primarily
responsible for correctly charging the battery, and acts as an independent battery charger.
Battery Inverter
See Battery Power Converter.
Battery Management
The battery management is responsible for optimal battery charging and reliable protection against
deep discharge. This is the only way of ensuring that the battery service life reflects the
manufacturer's specifications.
Battery Power Converter
A bidirectional power converter which can regulate voltage and frequency in a stand-alone grid
and is also responsible for correct battery charging.
Battery System
Series connection and possibly also parallel connection of several identical batteries. Battery banks
of 12 V, 24 V, 48 V and 60 V are typical.
Technical Description SI2012_2224-TEN082311 203