Wind energy power conversion system reducing gearbox stress and improving power stability

摘要

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.

主权项

1. A method of controlling power output from a wind energy power conversion system, the wind energy power conversion system comprising a generator coupled to a wind turbine rotor via a gearbox, the generator being coupled to an AC to DC power converter, the AC to DC power converter being coupled via a DC link to a DC to AC power converter, the DC link comprising at least one ultracapacitor connected in parallel directly to the DC link to absorb and release a charge in order to buffer and isolate variations in generator power output from the output of the DC/AC converter, the method comprising
varying a voltage level of the DC link to control the power output of the DC to AC power converter, wherein varying a voltage level of the DC link to control the power output of the DC to AC power converter comprises at least one of (i) lowering a voltage level of the DC link to release a charge and increase the power output of the DC to AC power converter and (ii) raising a voltage level of the DC link to absorb a charge and decrease the power output of the DC to AC power converter; outputting power from the DC to AC power converter at a different rate than a rate of power input to the AC to DC power converter; and increasing power output from the DC to AC power converter at a rate that is slower than a rate of increase of power input to the AC to DC power converter.