A wind energy power conversion system includes a gearbox, a generator, an AC to DC power converter, a DC link, and a DC to AC power converter, and at least one ultracapacitor module connected in parallel on the DC link. A method of reducing stress on a wind turbine gearbox can be performed by obtaining an unwanted frequency of the wind energy power conversion system gearbox; determining an input torque value on the input shaft of the gearbox as a function of time; determining a frequency of the input torque value; and adjusting a torque on the output shaft of the gearbox based on the unwanted frequency.
FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
This invention was made with government support under grant no. 09EE0001386 awarded by the U.S. Department of Energy, and under grant no. 0925709 awarded by the National Science Foundation. The government has certain rights in the invention.