Key achievements related to
microgrid solutions include:
• Islanded
and non-interconnected territories:
EDF has designed the electricity systems of the French overseas
territories, which represent several million customers. Islands such
as Martinique, Guadeloupe, La Réunion, Saint Pierre et Miquelon
are operated on permanent islanded modes. Corsica and Guyana
are operated on temporary islanded modes. In such territories,
conventional generation as well as Transmission and Distribution
(T&D) grids are able to be operated without the stabilization resulting from a connection to a large power system, while coping with
the intermittency of a large share of power coming from renewable generation (up to 30% of the power injected). EDF is able to
ensure the resilience of the electricity grid by optimizing management of energy reserves, deploying energy storage including fastresponse storage, and employing demand side management.
• Islanded
distribution grids: EDF is currently developing solutions for operating portions of electricity distribution grids
in islanded modes (microgrid mode) so as to maintain service
during a disconnection from the main substation or from the
transmission grid. This requires maintaining the generation/load
balance at the local level by controlling distributed generation (e.g.,
solar, small hydro), energy storage (e.g., batteries) and demand side
management devices. Adapted grid protection schemes are also
necessary to ensure that microgrids will be able to respond to an
electric fault.
• Islanded
transmission grids: the “Defense Plan” of
the French transmission grid also demonstrates the ability of EDF
to use islanded modes to maintain service in degraded situations,
for instance when the disconnection of major transmission lines
in a region hamper the stability of the locally connected generation units. To avoid spreading of the situation to the entire grid
(which may take only seconds), the EDF group has done extensive
studies and used sophisticated dynamic models to design a
plan to island the affected region while maintaining a balance
between local generation and load.
• Nuclear
power stations: French nuclear plants
(900-1300 MW) are capable of operating in full islanded mode,
for instance in the case of a severe transmission grid outage.
The stringent security and safety constraints of nuclear plants
have led EDF to carefully design the transitions between full
connection and islanded mode, and later on the re-connection
to the main grid. Managing these transitions demonstrates EDF’s
comprehensive expertise in electricity grids under constrained
situations and especially electric transients, technical transitions,
management, and design of plant’s electrical equipment, etc.
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