High Power Density Power Electronic Converters for Large Wind Turbines

Future wind power plants will grow in rating, spurred by an increase in turbine power rating. Larger turbine power means increased power electronic converters. To deal with increased power rating and still maintain a compact yet reliable converter, it is necessary to increase the power density (MW/m3). This project aims at contributing to both academic literature and wind energy industry in terms of selection, sizing, experimenting and evaluation of power electronics converter technologies to be implemented in the multi-MW wind turbine grid connections with the utmost concerns of power density and reliability. The project involves selection, modeling, simulation, implementation and full-scale experimentation of grid side power electronic converters for large (>2.5MW) wind turbines. Three-level (3L) Voltage Source Converter (VSC) technology with Medium Voltage (MV) Insulated Gate Bipolar Transistor (IGBT) press-pack switch is chosen as a key technology. Taking power density and reliability as the main criteria, 3L-VSC topologies are investigated and their grid connection applications to large wind turbines are assessed. Finally, the most suitable topology in terms of power density and reliability is determined.