Pitch control method of variable-speed constant-frequency wind driven power generator at rated revolution speed stage

Abstract

The invention relates to a pitch control method of a variable-speed constant-frequency wind driven power generator at a rated revolution speed stage. The pitch control method comprises the following steps: A. solving Cp-Lambda curves of the wind driven power generator corresponding to different pitch angles; B. finding out the maximal outer envelope line Cpmax-Lambda of a Cp-Lambda curve family and blade pitch angles corresponding to different blade tip speed ratios; C. solving the blade tip speed ratio for the operation of the wind driven power generator according to the incoming wind speed at the rated revolution speed stage; and D. adjusting the blade pitch angle according to the blade tip speed ratio, thus the wind driven power generator operates on the outer envelope line of the Cp-Lambda curve family. According to the invention, optimal power can be ensured for the variable-speed constant-frequency wind driven power generator at the rated revolution speed stage, thus more wind energy can be converted; under the low altitude, the power generation amount can be improved to a certain extent; and under the high altitude, the electricity generation power is improved greatly, the wind wheel load can be reduced greatly, the safety and reliability for the operation of the wind driven power generator are improved, and the variable-speed constant-frequency wind driven power generator at the rated revolution speed stage has important engineering significance.

Description

technical field [0001] The invention relates to an operation control method of wind power generation equipment, in particular to a pitch control method of a variable speed constant frequency wind power generator at the rated speed stage. Background technique [0002] Wind power is an important clean energy, and its development and utilization have been paid more and more attention. At present, the variable pitch technology has been widely used in large-scale wind turbines. A proper pitch control strategy can make the wind turbine blades in a better flow state to obtain more wind energy, and thus obtain a considerable increase in power generation. Pitch variable benefits; on the other hand, it can also effectively reduce the aerodynamic loads such as wind rotor thrust and blade root bending moment, thereby reducing the strength and fatigue requirements of wind turbine design and increasing the reliability of wind turbine operation. Therefore, the pitch control technology has...

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Problems solved by technology

In these four stages, different pitch control strategies will make the wind turbine run on different Cp-λ curves. Usually, the pitch angle of the blades is kept at z

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