Experimental study on power curtailment of three in-line turbines

Abstract

A dataset of wind tunnel power and wake flow measurements on a setup of three aligned model wind turbines is presented. The power outputs of the three turbines are in good agreement with measurements from a full-scale wind farm of similar inter-turbine spacing. A comparison of the wake flow behind the first row and the second row shows a significantly higher mean velocity loss behind the second row justifying a further power drop from the second to the third row turbine. Curtailing the front row turbine to smaller than rated tip speed ratios resulted in insignificant total power gains below 1%. Curtailments of both the first and second row turbine indicate that the best combined array power results are achieved for slightly lower than rated tip speed ratios. Although power curtailment is observed to have a rather small potential for power optimization of a wind farm, it could be an effective method for load distribution at constant farm power.