Tine Vandoorn
Supervisor(s): Lieven Vandevelde I. I NTRODUCTION The electrical system is traditionally fed by large centralized power plants connected to the power transmission network. Recently, because of environmental considerations, technological developments and tax incentives for renewables, the grid architecture is changing from centralized to decentralized energy supply with distributed generators (DGs) connected to the utility grid. The DG technology may include microturbines, fuel cells, wind, photovoltaics (PV), internal combustion engines, etc. Because of the small size of the emerging DG, the generators can be positioned near the consumers, which reduces the amount of energy lost in the power transfer across the transmission lines. DG can also lead to improved reactive power support and voltage profile, removal of transmission bottlenecks, usage of environmental friendly resources (by private-owned, low-voltage connected on-site generation) and postponement of investments in new transmission systems and large-scale generators. As DGs are increasingly being connected to the utility grid, their task is changing from back-up elements to primary energy resources. One of the advantages of distributed generation, the increase of reliability of the electrical energy supply, can be realized by the introduction of the microgrid concept. A microgrid is a cluster of supply, storage and load elements connected to the low-voltage distribution sys—————————————————–
T.L. Vandoorn is with the Department of Electrical Energy, Systems & Automation, Ghent University (UGent), Gent, Belgium. E-mail: Tine.Vandoorn@UGent.be.
DG (e.g. PV panel) DG (e.g. wind turbine) stand-alone mode CHP Fuel cell
utility grid
grid-connected energy storage mode (power-electronically interfaced) PCC distributed loads
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power-electronic converter
Figure 1. Microgrid with (power-electronically interfaced)