Sunny Island 4500
Installation & Operating Instructions
BWRI45-13-EE0304
- 15 -
SMA Regelsysteme GmbH
2.1 Operating Modes
The Sunny Island can be modularly combined with other power sources and must
then operate in different operating modes. Depending on the system’s structure, the
Sunny Island can be configured to toggle automatically between these operating
modes. This chapter covers both basic grid configurations and the resulting require-
ments for the Sunny Island and the other components in the island grid.
Control of voltage and frequency in the island grid
Operation of the Sunny Island is based on the following operating modes:
•
Grid forming (RUN_U), the Sunny Island keeps the voltage and the frequency of
the grid at a constant level.
•
Grid-tied (RUN_I), the Sunny Island complies with the voltage and frequency
that is defined by an additional component of the island grid that itself forms the
grid.
•
Droop-mode (special kind of RUN_U), the Sunny Island varies its battery cur-
rent depending on the grid’s frequency, and the grid’s voltage depending on its
current reactive power. It also tries to affect the grid’s frequency according to its
battery state. In case of being synchronized to a generator, the status
“RUN_UEXT” is shown in the display.