Renewable Energy Source Integration by MicroGrids in Smart Cities02/24/2017
Electric Grids are currently migrating from fully controllable and predictable fossil based systems, to intermittent, rather unpredictable, with large shares of renewable energy sources. In the same time, electricity consumption has much increased, and is expected to further increase with the arrival of electrical vehicles. Current systems are not able to deal with all these changes, but new technologies in control, computers and communications have allowed the possibility of SmartGrids who can cope with this new reality.
These new SmartGrids can greatly benefit from the transformation cities are going through. Distributed Generation from solar panels, urban wind turbines, combined heat and power have greatly changed cities from consumers to alternating consumers and producers, also known as prosumers. This new production scheme comes in at the same time as new intermittent, and sometimes controllable, loads represented by electric vehicles and Smart Buildings. This multiplication of time-varying sources and loads has brought the electric system to extreme strain, and the stabilization of such systems may be a very tough problem. Mostly for this reason, it is being considered to split urban power grids into cluster of loads and microsources operating as a single controllable system that provides power to its local area. To attain this goal, it is necessary to also consider energy storage to match this strict power balance.
But even there, the task is still very complicated. Power sources, loads and storage work in different time scales. Furthermore, most of new elements are connected to the grid by power electronic converters, which are nonlinear. This means that the considered system is represented by networked nonlinear systems with different time scales. It is then proposed to acknowledge the fact that many components of MicroGrids like solar panels, batteries, fuel cells, supercapacitors and electric cars are in Direct Current (DC), in contrast to the standard Alternative Current (AC). The MicroGrid is then considered as a Mixed AC/DC grid, where nonlinear techniques are used to stabilize the DC side, and provide stable power to the AC one. Furthermore, it is necessary to consider a multi-layered control scheme to cope with the different time scales present in such systems. In the lower control layer, nonlinear control techniques have been utilized in order to correctly feed the loads and to respect grid voltage stability around a desired equilibrium point. A secondary higher level controller is designed using Model Predictive Control techniques to steer the whole system to assure energy fulfilment, and if possible, optimality in respect to an objective function.
Gilney Damm is Associate Professor at the Paris-Saclay University, France. He received his /Habilitation à Diriger des Recherches/in 2010 and Ph.D. in 2001 at Paris-Saclay University; his M.Sc. in automatic control in 1997 and his Bachelor in Electronic Engineer in 1995 at the COPPE - Rio de Janeiro Federal University. His research interests concern nonlinear and adaptive control and observers applied to power systems (SmartGrids, SuperGrid, MicroGrids). His main applications are in the field of large scale renewable energy integration; Multi-Terminal DC systems; Mixed AC/DC MicroGrids; energy integration in SmartCities; Variable Speed Pumped Storage Plants; Control of power generators (transient stabilization, frequency and voltage stability); synchronization of power networks.
He has a large experience as coordinator or Work-Package Leader in several European and French research projects as the European Network of Excellence on Highly Complex and Networked Control Systems - HYCON2, the Smart Energy Summer School and the European Virtual Smart Grid Lab from the KIC EIT Digital (former ICT LABS), and the French project WINPOWER. In the same way, he is co-leader of the French research forum on SmartGrids, and was co-leader of the Research Initiative Large Scale Systems and SmartGrids from the Institute for Control and Decision of Paris Saclay – iCODE.
Currently his main research activities are connected to the Institutes for Energy Transition SuperGrid (on large scale high voltage electrical grids) and Efficacity (on MicroGrids and power grids in SmartCities).
He has received the French research excellence grant (Prime d'Excellence Scientifique) since 2008, and is member of the IFAC Technical Committee TC 6.3 Power and Energy Systems since 2015. He is Associate Editor from the European Journal of Control since 2010.
Marie-Minerve.Louerat (at) nullLip6.fr