Design of a Conditioner for smoothing wind turbine output power

As a result of wind speed intermittency, highly variable wind power output can adversely impact local loads. We propose a conditioner to smooth the variable wind power by utilizing the energy of an ultracapacitor. The conditioner is based on a single phase voltage source inverter (VSI) connected between the grid interconnection point and the ultracapacitor. The shunt VSI injects or absorbs active power from the line to smooth the wind power by utilizing the short term storage capabilities of the ultracapacitor. The ultracapacitor is connected to the DC link through a DC-DC converter, which maintains the voltage of the DC link relatively constant to provide good controllability of the VSI. The control strategies for the conditioner are presented in this paper. The MATLAB simulation results show that the conditioner is efficient in smoothing the wind power. The conditioner design and control will be validated on a Skystream3.7 wind turbine installed at the Missouri University of Science & Technology.