The impact of BoBC in off-shore wind energy conversion system

Abstract

Offshore windfarms is an emerging technology in the wind energy conversion system. For onshore wind farms high voltage overhead lines are used for transmitting power from the wind farm to the grid. However this option is not possible in the case of an offshore windfarm as large part of the distance to connection point must be covered by submarine cables. The application of high voltage dc (HVDC) transmission for integrating large scale and/or off-shore wind generation systems with the electric grid is attractive in comparison to extra high voltage (EHV) ac transmission due to a variety of reasons like efficiency, economics etc. In the case of HVDC transmission a converter is connected between the wind farm and the utility grid. Even though CSC's and VSC's are widely used for the realization of large HVDC systems, as an alternative approach Bridge of Bridge converter (BoBC) is introduced recently. In this work the performance of the VSC and BoBC are compared and analyzed. The simulation is done using PSCAD/EMTDC software. Compared with the onshore wind farms, the offshore wind farms have access to significantly better wind energy resources and hence offer larger energy generating capability. Therefore offshore wind farms are gaining importance and the BoBC proves to be better than the VSC for similar applications.