Reduction of Harmonics from MW-class Wind Turbines by Interlaced Active Front-Ends

With the request of renewable energy also the size of the wind turbines is growing. The converters used to connect them to the grid have to transfer a big amount of captured power. Since they handle high power, the switching devices work with a low switching frequency. This results in a high harmonic distortion of the injected currents and the need of big passive filters on ac side. In order to improve the power quality of the transferred wind energy, an inverter system made up of interlaced active front-ends is proposed. Its mathematical model is also developed in order to analyze harmonic distortion. It can be introduced in the existing models of wind turbines and grid. The numerical results prove the benefits of the proposed system.