Megawatt wind driven generator set as well as control method and control system thereof

Abstract

The invention discloses a control method and a control system of a megawatt wind driven generator as well as the megawatt wind driven generator set. In the control method, the power of the current status of a wind driven generator is firstly detected; only when the controller judges that the power of the current status of the wind driven generator is more than a preset limit power value and the continuous working time of the wind driven generator under the status that the power of the current status of the wind driven generator is more than the preset limit power value is more than preset time, the control method of the wind driven generator is transformed into a variable-pitch control method from a torque control method. In addition, the torque control method with quicker response is always adopted for controlling. With the method, the control requirement of the wind driven generator under the certain working condition can be satisfied, the phenomenon that two control methods are frequently transformed under the working conditions that the wind speed is fluctuated at the rated wind speed and the fluctuation is small can be effectively solved, the fatigue strength of a variable-pitch system is reduced, the service life of each component of the wind driven generator set is prolonged, and the problems of wind wheel overspeed and large limit load can be solved for the working condition of extreme lifting gust.

Description

technical field [0001] The invention relates to the technical field of wind power generation, in particular to a method for controlling a megawatt wind power unit. In addition, the present invention also relates to a control system including the above-mentioned control method and a megawatt wind turbine. Background technique [0002] In recent years, with the increase of wind power installed capacity, the unit performance and power generation quality have attracted much attention, which puts forward higher requirements for the design and control of large wind power units. [0003] The control method of the wind turbine in the prior art mainly adopts the control method combining the torque control and the variable pitch control. When the wind speed is relatively small and the power of the wind turbine is less than the rated speed stage, the generator mainly adopts the torque control. Torque control can adjust the speed of the wind turbine to follow the change of wind speed, ...

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Problems solved by technology

[0006] like figure 1 As shown, the rising and falling speed of the extreme lifting gust is very fast, and the time for the power of the wind turbine to suddenly rise above the rated power is relatively short. If the problem of wind speed change is not addressed, it will cause overspeed failure of the wind turbine, resulting in the shutdown of the fan and the emergence of a large ultimate load. A large ultimate load means an increase in the weight and cost of the fan.

[0007] In addition, for the working conditions where the wind speed is constantly changing above and below the rated wind speed, using the existing control method, due to the continuous change of the wind speed, the wind turbine will frequently switch between the two control methods of torque control and pitch control. Switching, reducing the service life of each component of the wind turbine

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