Switched Control Strategies. Application to Renewable Energy Conversion Systems and their Interaction with Power Grid

TitleSwitched Control Strategies. Application to Renewable Energy Conversion Systems and their Interaction with Power Grid
Publication TypeThesis
Year of Publication2014
AuthorsInthamoussou FA
Date Published12/2014
UniversityUniversidad Nacional de La Plata
CityLa Plata, Buenos Aires, Argentina
Thesis TypePhD thesis

This thesis analyzes and proposes robust and flexible control strategies for renewable energy conversion systems in the distributed generation framework. It mainly deals with wind and photovoltaic energy conversion, and also with a storage and recovery energy system. Particular attention is given to the control of the micro source power supply in order to accomplish requirements for the connection to a distributed grid or a microgrid. The analysis of these power systems is out of the scope of this work. For photovoltaic energy systems, strategies for maximization of the resource extraction and control of the active power delivered by the micro source are proposed. A stability analysis for classical dc-dc converters is realized. Furthermore, these concepts are extended to the control of the electronic converter of fuel cell based micro sources. As for the storage and recovery energy system, a strategy capable of starting the system, exchanging energy with the grid, protecting the energy storage device and shutting down the system in a automatic way is proposed. The stability analysis of all operating modes and the combination among them for a global stable operation is performed. As for wind energy conversion systems, the operation of the wind turbine over the entire operating wind speed range is investigated. The operating region is extended to deal with active output power control which enables new operating modes like power generation with reserve for the contribution to frequency stability. The control of the electric interfaces is addressed in the sliding mode framework, whereas the H∞ optimal control and the linear parameter varying (LPV) approach are used for the control of the mechanical actuators of wind turbines. Additionally, for PV, fuel cell and storage systems, simulation and experimental results are presented. As for wind turbine systems, simulation results with a high order model (FAST) developed by the National Renewable Energy Laboratory (NREL) are presented. The obtained results confirms the performance and feasibility of the proposed strategies predicted by the theoretical analysis.

Full Text

Full text in Spanish is available through UNLP repository (link)

Research Line: 
Control of renewable energy systems
Control of hybrid renewable systems and their integration to the grid
Control de sistemas híbridos de energías renovables y su integración a la red
Control of wind turbines and their integration to the grid
Control de turbinas eólicas y su integración a la red