Frequency scanning for power system property Determination-applied to a wind power grid

This paper presents an investigation of a method for determining the dynamic properties of a power system. The investigation is based on the injection of perturbations in the supply voltage magnitude and the analysis of the resulting active and reactive power responses. A large dc/ac converter (HVDC-Light installation) has been used to generate the perturbations. The frequency range of the perturbations was from 0.03 to 20 Hz. The method is experimentally verified on a small 10-kV grid with 5 MW of wind power, subjected to the above perturbations. Both theoretical and experimental results indicate that a large concentration of wind turbines does not cause any power quality disturbances or serious oscillations, although the grid is fairly weak.