The objective of this Project is the viability analysis of the marine energy transmission systems using direct current submarine cable for distances below 50 km. Currently, this distance is the economically viable limit for the use of direct current in energy transmission. The most relevant points are the elimination of the offshore AC-DC conversion station, the use of direct current in medium voltages and the availability of direct current protection equipment in medium voltage range from 4 kV to 33 kV and currents below 200 A. Different alternatives for direct connection of wind turbines to the medium voltage range (from 4 kV to 33 kV) direct current bus will be studied and simulated. Moreover, it is proposed to build a reduced scale prototype.