3 research outputs found
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Model-based decentralized optimal control of a microgrid
Power networks have experienced dramatic changes with the growth of renewable energy and `smart' grids. To accommodate the challenges posed to traditional power system control architectures, the microgrid concept has gained traction. Microgrids are small-scale power networks that can disconnect from the main grid and operate autonomously if necessary. These systems add robustness and facilitate the incorporation of renewable power, but they face control challenges of their own due to the lack of significant inertial generation. Without the main grid to provide balance, the high proportion of electrically-interfaced power resources can cause significant deterioration in microgrid stability.
This dissertation proposes designs to improve decentralized control in microgrids; model based information is incorporated into controllers and estimators to more optimally guide control signals, while still only using local data for real-time computation.
We outline the role that microgrid topology can have on stability, and how judicious power injection can mitigate instabilities. These results are extended to a decentralized H-infinity control design for microgrid frequency; even with limited model-based information and controller distribution, the design offers significant improvements over traditional controllers.
Building upon the idea of microgrid stabilization, we also present a control method by which a wind turbine can be coordinated for microgrid support. The wind turbine is used as a controllable power source by utilizing the rotational energy stored in its rotor; this design incorporates an aerodynamic wind turbine model and a novel optimal blade pitch angle controller to ensure stable turbine operation. This allows for rapid power injection for grid support.
This theme concludes with a decentralized estimation scheme to facilitate coordinated control across a microgrid using only local data.
We leverage the frequency synchronization and load-sharing intrinsic to the microgrid so that local measurements can provide insight about grid-wide conditions. This allows for effective implementation of optimal filtering techniques so that remote conditions can be estimated using only local data; this allows for grid-wide coordination and optimization. Together these ideas represent the concept that the microgrid model, even in a limited and inaccurate sense, can be manipulated to provide significant benefits for decentralized control across the network.Mechanical Engineerin
SMARAD - Centre of Excellence in Smart Radios and Wireless Research - Activity Report 2011 - 2013
Centre of Excellence in Smart Radios and Wireless Research (SMARAD), originally established with the name Smart and Novel Radios Research Unit, is aiming at world-class research and education in Future radio and antenna systems, Cognitive radio, Millimetre wave and THz techniques, Sensors, and Materials and energy, using its expertise in RF, microwave and millimeter wave engineering, in integrated circuit design for multi-standard radios as well as in wireless communications.
SMARAD has the Centre of Excellence in Research status from the Academy of Finland since 2002 (2002-2007 and 2008-2013). Currently SMARAD consists of five research groups from three departments, namely the Department of Radio Science and Engineering, Department of Micro and Nanosciences, and Department of Signal Processing and Acoustics, all within the Aalto University School of Electrical Engineering. The total number of employees within the research unit is about 100 including 8 professors, about 30 senior scientists and about 40 graduate students and several undergraduate students working on their Master thesis.
The relevance of SMARAD to the Finnish society is very high considering the high national income from exports of telecommunications and electronics products. The unit conducts basic research but at the same time maintains close co-operation with industry. Novel ideas are applied in design of new communication circuits and platforms, transmission techniques and antenna structures. SMARAD has a well-established network of co-operating partners in industry, research institutes and academia worldwide. It coordinates a few EU projects. The funding sources of SMARAD are diverse including the Academy of Finland, EU, ESA, Tekes, and Finnish and foreign telecommunications and semiconductor industry. As a by-product of this research SMARAD provides highest-level education and supervision to graduate students in the areas of radio engineering, circuit design and communications through Aalto University and Finnish graduate schools.
During years 2011 – 2013, 18 doctor degrees were awarded to the students of SMARAD. In the same period, the SMARAD researchers published 197 refereed journal articles and 360 conference papers