A DC wind turbine with integrated storage

Abstract

The dc series and series-parallel wind farms have been recently proposed as alternatives to ac for offshore applications. A dc wind turbine for use in dc series and series-parallel wind farms has been proposed in this paper. The operation of the dc series and series-parallel wind farm results in continuous variation of the output voltage with possibility of losing maximum power point tracking capability (MPPT). A wind turbine (WT) design with back-to-back connection of voltage source converter (VSC) and dual active bridge (DAB) dc-dc converter is proposed. An integrated storage connected to internal dc bus of the turbine with a DAB is also proposed. Simulation results show that the proposed design ensure maximum energy capture during undervoltage and overvoltage operating conditions. The output voltage variation is limited to a range of 0.7 to 1.5 p.u.