PhD defence by Bo Sun on Control of Flywheel Energy Storage Systems in Electrical Vehicle Charging Stations
09.12.2016 kl. 13.00 - 16.00
Bo Sun, Department of Energy Technology, will defend the thesis "Control of Flywheel Energy Storage Systems in Electrical Vehicle Charging Stations".
Control of Flywheel Energy Storage Systems in Electrical Vehicle Charging Stations
Professor Josep M. Guerrero
Associate Professor Sanjay Chaudhary
Associate Professor Dezso Sera, Dept. of Energy Technology, Aalborg University Esbjerg (Chairman)
Lecturer Antonio Griffo, The University of Sheffield, UK
Associate Professor Sergio Busquets-Monge, Technical University of Catalonia (UPC), Barcelona, Spain
Growing environmental awareness and strong political impetus have resulted in plug-in electric vehicles (PEV) becoming ever more attractive means of transportation. They are expected to have a significant impact to the overall loading of future distribution networks. Thus, current distribution grids need to be updated in order to accommodate PEV fleets, which are recognized in smart grid (SG) objective. The prevailing concern in that sense is the combined impact of a large number of randomly connected PEVs in the distribution network. On the other hand, continually growing PEVs are likely to impose more specific and acute challenges in short term, it is also expected to expect that grid operators will impose strict demand-response requirements for the operation of charging stations (CS)s.
Accordingly, this PhD project proposed a fast charging station structure which is combined with flywheel energy storage system (FESS). The proposed PhD project supports a corresponding smart control strategy that could be termed “charging station to grid (CS2G)”. First, for the purpose of control optimization and parameter tuning of the primary layer, detailed modeling of grid ac/dc and FESS converters is built and analyzed. Aiming at alleviating the unexpected conditions in grid-side and providing ancillary services to distributed network, multi-functional controller in secondary control layer which enables four-quadrate operation ability is proposed to cope with different scenarios, such as PEV sudden connection and disconnection, active power compensation (load shifting), reactive power compensation, loss of grid power.
Furthermore, stability issues are discussed and analyzed based on proposed control algorithm feature. First, small-signaling model of each component are built to study the dynamic stability of system operating at different stages in details. Due to the switching modes existing in the system, stability of switching system is studied based on common Lyapunov function method when the system switches its operation behavior between two modes. In addition, due to the bidirectional operation feature and interaction behavior between multi power electronics converters, impedance model of the system is built to study the impedance based stability for the purpose of further optimizing the control and design of system.
Finally, a downscaled FCS prototype with FESS is built in in the intelligent MG lab, and experiments and hardware-in-loop simulation results are conducted to verify the effectiveness and feasibility with the proposed FCS concept, control schemes, modeling and stability analysis.
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ALL ARE WELCOME. THE DEFENCE WILL BE IN ENGLISH.
AFTER THE DEFENCE THERE WILL BE AN INFORMAL RECEPTION AT PONTOPPIDANSTRAEDE 111 IN TNE COFFEE ROOM.
Department of Energy Technology
Pontoppidanstræde 111, auditorium