Uniform and independent variable pitch hybrid control method for megawatt wind turbine based on master control

Abstract

The invention discloses a uniform and independent variable pitch hybrid control method for a megawatt horizontal axis wind turbine based on master control, namely, when the rotation speed deviation of a power generator is larger, a uniform variable pitch control manner is adopted; and when the rotation speed deviation is smaller, an independent variable pitch control manner is adopted to drive anelectrical servo variable pitch mechanism to drive a blade to finish a variable pitch action. During the uniform variable pitch control, a variable pitch command sent by a wind turbine master controlis a variable pitch preset command for each blade; and during the independent variable pitch control, model transformation is performed on the variable pitch command sent by the wind turbine master control to obtain a corresponding average wind speed, calculation and control are performed through a shimmy load and waving load model in combination with respective space position of each blade to obtain the respective variable pitch command for each blade. Both a uniform variable pitch controller and an independent variable pitch controller take the variable pitch command sent by the wind turbine master control as an input value of the controller, so that good compatibility and generality of the overall wind turbine are guaranteed, the advantages of quick response of the uniform variable pitch control and high precision of the independent variable pitch control are integrated, and the purposes of stabilizing output, optimizing power, reducing and balancing blade load, reducing spindle vibration, improving the dynamic stability of the wind turbine and prolonging the service life of the wind turbine are achieved.

Description

technical field [0001] The present invention relates to a control method of wind power generation, in particular, it is a control method based on master control for the unified and independent pitch mixing of a megawatt-level horizontal axis wind turbine. Background technique [0002] Wind energy is a kind of renewable energy. In recent years, the development and utilization of wind energy has been widely and highly valued. Generally, variable speed and pitch adjustment are the two main power adjustment methods for wind energy collection and conversion of megawatt horizontal axis wind turbines. When the wind speed is lower than the rated wind speed, the variable speed adjustment method is mainly adopted, that is, the maximum wind energy conversion power is obtained by adjusting the rotor speed of the generator; when the wind speed is higher than the rated wind speed, the pitch adjustment method is adopted, that is, by adjusting the pitch angle , so that the output power of ...

AI Technical Summary

Problems solved by technology

Although the independent pitch control method mentioned in this article has weakened the load in the flailing direction, there are problems. First, what factors need to be considered for the flailing direction load and how to calculate it is not clearly given. Second, the control system is formed. Ring, cannot guarantee the security and stability of the system

This method is very difficult to apply. This is because after considering factors such as wind shear and tower shadow effects, the wind speed of the entire wind rotor surface is different. How to measure and how many points to measure to form sample data is very complicated. In addition, through It is not an ideal method to predict the incoming flow angle to obtain the pitch angle, because the incoming flow angle is determined when the wind speed and the rotor speed are determined.

For the blade, the wind speed along the span direction is different, so the angle of flow at each point is different, but for a certain blade, the pitch angle changes without considering the twist angle of the blade shape are the same size, which means that it is necessary to determine the power angles of different sizes at each point of the blade, or to determine the variation of the pitch angle at each point, which also requires a large amount of sample data

Images