Sun, Bo

Project title: Control Strategies for Hybridized Energy Storage Systems in MicroGrid Applications

PhD period: 2013.12.01 – 2016.11.30.
Section: Power Electronic Systems
Research Programme: Microgrids
Supervisor: Josep M. Guerrero
Co-Supervisors: Tomislav Dragicevic & Juan Carlos Vasquez
Contact information

Collaborator: China Scholarship Counsil.
Funding: China Scholarship Counsil and scholarship from the Dept. of Energy Technology.



Growing environmental awareness and strong political impetus have resulted in plug-in hybrid electric vehicles (PHEV) 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 PHEV fleets, which is recognized in smart grid (SG) objectives. The prevailing concern in that sense is the combined impact of a large number of randomly connected PHEVs in the distribution network.

Up to date, industry has defined three PHEV battery recharging rates: 1) Regular household single-phase AC plug that supports power of up to 2 kW 2) Dedicated AC plug that supports power from 6.6 up to 19.2 kW, and 3) Dedicated DC plug with built-in charger that has virtually no limit on charging power, with currently available products ranging up to 100 kW. The last one represents the most attractive option for public installations, as it is able to recharge any commercial PHEV in less than half an hour. Moreover, 80% of nominal state of charge can be reached in 10 minutes in some cases, which is a time comparable to refueling at conventional public gas stations.

The proposed PhD project will support a smart grid strategy that could be termed CS2G(Charging Station to Grid). It will explore the possibility of using a dedicated energy storage system (ESS) within the charging station to alleviate grid and market conditions but not compromise the PHEV’s battery charging algorithms or place the daily routine of the PHEV owners in jeopardy. Management of this introduces additional non-technical considerations as traffic and recharging needs will vary according to day and season. Hence a dual set of needs need to be balanced, those of the grid and those of the road. This can be done per unit CS or as a portfolio oriented service including more than one ESS equipped CS.


Publications in journals and conference papers may be found at VBN.