Microgrid - Siemens SINAMICS S120 System Manual

Grid types

3.3 Microgrid

3.3 Microgrid
A micro grid represents a locally constrained electrical system with several power generating
units, loads and possibly energy storage systems. This can be connected to a large power
grid – or can also be independently operated (i.e. an island grid with one or several power
generating units).
Figure 3-3 Microgrid
Requirements
If the micro grid is separated from the power grid, then the same requirements apply as for
an island grid. When running up, the power generating units must also be synchronized to
the actual grid frequency and voltage. In addition, the energy mix must be controlled, i.e. the
percentage participation of the individual power generating units to reliably supply the
connected loads ("load sharing").
However, if it is coupled with the power grid, then the same requirements apply as for a
power generating unit, which feeds into the power grid.
Further, the transition between the two operating modes must be able to be reliably handled.
Function modules for a micro grid
A micro grid can form an island grid, but can also be connected to a power grid. This means
that all of the requirements specified in the two previous chapters must be fulfilled.
Correspondingly, all of the previously mentioned function modules must be activated in the
Active Line Module.
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System Manual, 04/2015, A5E03347436A
Grid infeed