| Abstract |
Wind turbines are becoming more popular in the
present energy scenario: there is a global blueprint to achieve a
12% of the world’s electricity from wind power by 2020. The
trend on Wind Energy Conversion Systems (WECS) is marked
by Multi-Megawatt variable-speed wind turbines, and the latest
prototypes glimpse to overcome the barrier of 5MW. However,
such a big amount of power is still obtained through low-voltage
drives, resulting in high currents (approximately 1kA per MW).
Medium-voltage drives, based on multilevel structures, help on
decreasing these high current values, improving efficiency,
reliability, and then, the so critical availability factor. Indeed,
multilevel converters’ features contribute to the integration of
WECS to the distribution grid, making easier the
accomplishment of the grid owner’s requirements. In this paper,
the advantages and drawbacks of using multilevel converters
inside WECS’ power circuit are discussed, and benefits with
regard to output filter size are verified through MATLAB
simulations and preliminary experimental results with a
commercial prototype. |
