Abstract:
This thesis presents a hybrid AC and DC micro grid as a solution for efficient and
sustainable power system. The system directly integrates DC/AC renewable sources and
loads to DC/AC links respectively. The disadvantage of AC grids for connection of DC
inherent sources and loads as well as AC loads with DC links is that additional DC/AC or
AC/DC converters are required, which may result in efficiency loss from the reverse
conversion. Also in DC grids AC sources have to be converted into DC before connected
to a DC grid and DC/AC inverters are required for conventional AC loads. This
conversion again will result in power loss. And this conversion loss is presented as a
main problem in this thesis
Therefore to avoid this reverse conversion in a single grid, coexistence of both AC and
DC grid is proposed as a solution. The hybrid grid eliminates multiple DC-AC-DC and
AC-DC-AC conversions in an individual AC and DC grid. The grid model is introduced;
control and operation of renewable sources, energy storages and loads were analyzed.
From the result of the analysis the efficiency improvement in using AC and DC Micro
hybrid grid is from 85.61 %to 92.35 %, that is 7.24%.