Diaz, Enrique Rodriguez

PROJECT TITLE: Control and Power Architectures for Residential DC Microgrids

PhD period: 2014.12.31 – 2017.12.30 (has been prolonged till 2018.03.02)
Section: Power Electronic Systems
Research Programme: MicroGrids
Supervisor: Josep M. Guerrero
Co-Supervisor: Juan Carlos Vasquez
Contact information

Collaborator: North China Electric Power University.
Funding: DSF Sino-Danish Project “Intelligent DC Microgrid Living Lab”.


The increasing use of clean and renewable resources by the first world developed countries, has become a priority, in order to fight global warming, climate change, energy dependency, and health issues caused by local pollution. The microgrid concept appears as a solution for integrating distributed renewable energy sources. Bringing the energy production close to the consumption aims to improve the system's efficiency and power quality. Also when the microgrid is intended for specific applications as residential/office buildings, or system with sensitive loads (i.e. datacenters, hospitals), DC microgrids offer some substantial improvements compared with AC microgrids. Higher efficiency can be achieved since most of the loads in modern building are DC loads, therefore a AC/DC conversion stage can be eliminated. Sensitive loads usually require a UPS system, to ensure power supply, which are mainly based on DC devices as batteries. Suitable renewable energy generators for buildings are DC current based, as solar panel and micro wind turbines. Also due to the fact that in a DC system there is no reactive power, and a synchronization is not required, the efficiency and simplicity are intrinsically enhanced.

The project focuses on the development of future intelligent direct-current (DC) microgrids which is being deployed for highly efficient integration of distributed generation and modern electronic loads. The project is based on the collaboration between research institutes in China and Denmark, aiming to explore the different aspects of DC microgrids: design, modeling, control, coordination, communications and management. Research is carried out in DC microgrid living labs, focused on industry in China and residential applications in Denmark. A living lab focused on DC microgrids for residential applications will be established at Aalborg University. End-user appliances and smart-grid ready technologies will be used. Combination of photovoltaic systems, batteries, electrical vehicle chargers, LEDs and other nonconventional DC appliances such as DC washing machine, DC cooling fans, DC oven, DC-TV and so will be tested together. Figs 1 and 2 present the DC multibus electrical scheme and DC home, respectively.

It is expected a great development in the field, since standards are being developed by industry associations, which make easier and promotes the installation of such systems.


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