Abstract:
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Peak oil, climate change and the achievement of energy independence have set the world
into a new energy transition seeking to decarbonize both the power generation and
transportation sectors. The convergence and synergy between both sectors, an electrified
transportation powered by renewable energy, holds true potential to significantly reduce
the world’s dependence on fossil fuels and the consequent emission of greenhouse gases.
Nonetheless the integration of electric vehicles on the power system is not a minor issue
and its associated impacts need to be carefully analyzed and addressed.
In this context the main objective of this thesis is to develop a smart charging solution to
safely integrate Plug-in Electric Vehicles into low voltage distribution networks while
mitigating their corresponding impacts. This is done by designing a control algorithm
capable to simultaneously meet both voltage and thermal network constrains by
managing the vehicle’s charging process in real-time, while at the same time being
respectful to current charging standards, computationally light and implementable in
any current radial distribution grid.
The proposed charging algorithm is built under a “Multi-Agent System” architecture
combining a local decentralized voltage management with a centralized thermal control
conceived to minimize user impact under three alternative optimization techniques. The
architecture is fully implemented and tested on a realistic environment using Simulink
by modeling key elements such as the charging stations, the vehicles themselves, and
the different dwellings. An extensive analysis of the algorithm’s performance is
completed testing it under multiple relevant scenarios. Finally the control algorithm is
transferred to a real-time simulator (dSPACE MicroLabBox) to be validated and further
evaluate its behavior through hardware-in-the-loop (HIL) simulations using both real
charging stations and Plug-in Electric Vehicles available in the laboratory
A satisfactory validation of the algorithm’s execution under and compatibility with real
hardware is revealed by the HIL tests. At the same time a successful management of the
considered network voltage and thermal constrains is obtained under all
implementations, causing a minimal impact over the participating users and effectively
peak shaving their total aggregated demand. For a full vehicle penetration scenario, the
proposed control successfully prevents over 200 voltage limit violations and achieves so
while significantly reducing the total transformer loading deviation, almost halving it
when compared to an equivalent unrestricted charging case, and ensuring a net zero
impact to 95% of participating users under its most effective thermal implementation.
The study also reveals that a full participation of all vehicle owners is not critical factor
to ensure a proper grid operation under the designed algorithm, as satisfactory results
are also obtained when only half of them are actively involved in network management.
Finally an economic assessment covering the application of the designed control over
conventional network reinforcements further demonstrates the advantages of such an
active management approach reporting additional economic benefits to the DSO. |