This paper firstly defines a preferable smoothing reference for a single wind turbine (WT), which is determined by the moving average of the Maximum Power Point Tracking (MPPT) curve. Subsequently, two different strategies for output power smoothing of a wind energy conversion system (WECS) with a doubly fed induction generator (DFIG) are analyzed and compared in details. The first strategy seeks to smooth the WT output power by adjusting the pitch angle of the WT blade. The second strategy reduces the wind power fluctuations by utilizing the WT rotating inertia. The second strategy distinguishes itself by minimizing the control impacts on energy harvesting and reducing the mechanical stress and fatigue of WT. A simple grid connected DFIG based WT was modeled in the DIgSILENT/PowerFactory software to demonstrate and compare the power smoothing capability of the two strategies.
['Yujun Li', 'Zhao Xu']
Power smoothing control of wind turbines using different strategies