In this paper, a microgrid organization has been studied in
order to define the roles and the required control systems for
the integration of dispersed PV generators and DER units in the
electrical system. The main problem is that the output power
from most REBGs fluctuates depending on weather conditions
when the power quality of the grid may decrease. Experiences
currently show that the maximum penetration ratio of these
passive PV generators in European island networks is 30%.
One way to increase the penetration ratio is to upgrade actual
PV generators in order to transform them into controllable
generators. These active generators are new flexibilities for the
grid system operator. In this paper, a solution has been proposed
to promote and coordinate large dispersed small PV-based
generators and a gas microturbine in the plan to lower energy
costs for customers, achieve energy independence, and reduce
greenhouse gas emissions. This work falls into the framework
of smart grids since the solution relies on an enhanced EMS
and a communication network. Cases with complex systems,
including more active PV-based generators and gas turbines, are
subject to future works.
A determinist operational power planning has been proposed
to perform the day-ahead power scheduling for the conventional
and PV generators. The presented scheme relies on PV power
predictions and load forecasting. The scheme also sets out plans
for the use of the distributed battery storage. Power references
are communicated to customers. An open local controller inside
an E-box has been developed and presented in order to satisfy
grid operator requirements according the local state of the
sources (state of the batteries’ charge, solar radiation, etc.). At
the customer side, two storage technologies are used to enable
grid demand management and renewable energy integration.
Batteries are used to ensure an energy reserve for the grid operator.
Supercapacitors are used to balance fast power variations
coming from the PV generator and from the primary frequency
control. A strategy has been presented to drive them according
to the solar energy resources and grid requirements. Experimental
results of the proposed smart grid solution for planning
and operating the microgrid are presented. Currently, further
research is aimed at hypothetical business cases associated with
smart grids and distributed resource integration to provide more
value to the microgrid management.