1,646 research outputs found
The Comparison Study of Short-Term Prediction Methods to Enhance the Model Predictive Controller Applied to Microgrid Energy Management
Electricity load forecasting, optimal power system operation and energy management play key roles that can bring significant operational advantages to microgrids. This paper studies how methods based on time series and neural networks can be used to predict energy demand and production, allowing them to be combined with model predictive control. Comparisons of different prediction methods and different optimum energy distribution scenarios are provided, permitting us to determine when short-term energy prediction models should be used. The proposed prediction models in addition to the model predictive control strategy appear as a promising solution to energy management in microgrids. The controller has the task of performing the management of electricity purchase and sale to the power grid, maximizing the use of renewable energy sources and managing the use of the energy storage system. Simulations were performed with different weather conditions of solar irradiation. The obtained results are encouraging for future practical implementation
Plug-and-play and coordinated control for bus-connected AC islanded microgrids
This paper presents a distributed control architecture for voltage and
frequency stabilization in AC islanded microgrids. In the primary control
layer, each generation unit is equipped with a local controller acting on the
corresponding voltage-source converter. Following the plug-and-play design
approach previously proposed by some of the authors, whenever the
addition/removal of a distributed generation unit is required, feasibility of
the operation is automatically checked by designing local controllers through
convex optimization. The update of the voltage-control layer, when units plug
-in/-out, is therefore automatized and stability of the microgrid is always
preserved. Moreover, local control design is based only on the knowledge of
parameters of power lines and it does not require to store a global microgrid
model. In this work, we focus on bus-connected microgrid topologies and enhance
the primary plug-and-play layer with local virtual impedance loops and
secondary coordinated controllers ensuring bus voltage tracking and reactive
power sharing. In particular, the secondary control architecture is
distributed, hence mirroring the modularity of the primary control layer. We
validate primary and secondary controllers by performing experiments with
balanced, unbalanced and nonlinear loads, on a setup composed of three
bus-connected distributed generation units. Most importantly, the stability of
the microgrid after the addition/removal of distributed generation units is
assessed. Overall, the experimental results show the feasibility of the
proposed modular control design framework, where generation units can be
added/removed on the fly, thus enabling the deployment of virtual power plants
that can be resized over time
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