Analysis of a DC collector-based power converter topology for an offshore wind farm

摘要

The conventional collection grids for offshore wind farmconsist of internal AC link comprising of series-parallel connectionsof identical wind energy conversion units (WECUs). Each WECUincludes a 60- or 50-Hz power transformer. The power transformersare replaced by the power converters in this article. The weightof a power converter is much lower compared to that of a powertransformer of similar characteristics, thus reducing the weight ofthe offshore wind farm. Most of the studies being done to designDC collection grids use the conventional full-bridge voltage sourceconverter as the topology of power converter. The efficiency of thewind farm is low due to the switching losses. In this article a cascadeconnection of a diode rectifier and an interleaved DC-DC boost converteris used for the converter topology. The switches duty cycle isreduced, thus improving the efficiency of the wind farm. The dynamicmodel of the proposed power converter is derived, including its controlschemes. Power Simulator (The Powersim, Rockville, USA) andMATLAB Software (The MathWorks, Natick, Massachusetts, USA)are used to test the performances of the proposed converter model.