Abstract—This
paper presents an improved full-bridge threelevel (IFBTL) dc/dc converter for a
wind turbine in a dc grid by inserting a passive filter into the dc/dc
converter to improve the performance of the converter. The passive filter can
effectively reduce the voltage stress of the medium frequency transformer in
the IFBTL dc/dc converter. A modulation strategy, including two operation
modes, is proposed for the IFBTL dc/dc converter. Then, a voltage balancing
control strategy is proposed for the IFBTL dc/dc converter. Furthermore, the
control of thewind turbine based on the IFBTL dc/dc converter in a dc-grid
system is presented. Finally, a small-scale IFBTL dc/dc converter prototype was
built and tested in the laboratory, and the results verify the theoretical
analysis.
(Index
Terms—DC/DC converter, dc grid, full-bridge three-level (FBTL), permanentmagnet
synchronous generator, wind turbines.)
