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Abstract
This thesis covers studying voltage fluctuations and harmonics at the point of common connection between the grid and wind turbines at Zaafarana wind farm. Measurements were taken from the 10th of December, 2014 to the 20th of January, 2015. The study shows that Gamesa 52 is suitable for grid connection under IEC 61400-21, while the measurements taken for the Vestas 47 and Nordex 43 turbines are considered inconclusive since they do not conform to the standard conditions of measurement. To conduct the measurements, a state-of-the-art Japanese device (MR8875) was used to sample the studied turbines{u2019} instantaneous current and voltage at a rate of 2 kHz. MATLAB was then used for modeling and simulation in order to yield the results. The study also presents a comparison between its results and the results obtained by the German Institute for Wind Energy (DEWI), which tested the same Gamesa turbine in 2002. The comparison shows a difference in the values of the voltage flicker coefficients. The comparison also shows close results in switching operations tests at cut-in and rated wind speeds. As for the values of integer harmonics, interharmonics, and harmonics at high frequencies, the difference is caused by the grid forcing a certain form of current out of the tested turbine, as well as a possible difference in the used filter