Overview of power converter designs feasible for high voltage transformer-less wind turbine

Many leading wind turbine manufacturers are pushing forward in variable-speed wind turbines, often exceeding 5 MW. Therefore, novel designs and concepts for optimal high power wind turbines appeared. One of the most promising concepts is the high voltage (10-35 kV) transformer-less topology. High voltage design enables low power losses and elimination of bulky step-up transformer from the wind turbine system. However, new challenges appear for such topology, which have to be properly identified and successfully overcome. This paper presents possible concept for transformer-less wind turbine topology along with an overview of most promising candidates for optimal full-scale power converter design. Study is carried with proposed and justified high voltage wind turbine application along with selection of existing and most promising multilevel power converter topologies, which could be successfully proposed for transformer-less wind turbines.