CN-114909257-B - Control method of hydraulic pitch system of wind turbine generator

CN114909257BCN 114909257 BCN114909257 BCN 114909257BCN-114909257-B

Abstract

A control method of a hydraulic pitch system of a wind turbine comprises the following steps of S1, S2, building a hydraulic cylinder piston position formula according to the relevant parameters in S1, S3, building a piston thrust formula according to the relevant parameters in S1 and the hydraulic cylinder piston position formula in S2, S4, building a pitch torque formula according to the relevant parameters in S1 and the piston thrust formula in S3, calculating pitch torque, S5, building a proportional valve control signal formula according to the relevant parameters in S1 and the hydraulic cylinder piston position formula in S2, calculating to obtain a proportional valve control signal, and S6, controlling the hydraulic pitch system according to the pitch torque and the proportional valve control signal. The invention realizes that the current mature electric pitch control algorithm is indirectly transplanted to the hydraulic pitch control, and solves the problems of subsequent technical improvement upgrading and technical optimization after manufacturers of orphan units adopting the hydraulic pitch system abroad exit from the China market.

Inventors

LIU LIMING
ZHOU MINQIANG
ZHUANG JIANYU
ZHU CHANGJIANG
SONG XIAOYANG
LIN ZHOUQUAN

Assignees

浙江运达风电股份有限公司

Dates

Publication Date: 20260508
Application Date: 20220412

Claims (6)

1. A control method of a hydraulic pitch system of a wind turbine generator is characterized in that a mathematical control model is established according to the stroke of a hydraulic cylinder piston and a corresponding pitch angle through dynamic stress analysis of the hydraulic cylinder piston during normal operation; the method comprises the following steps: S1, acquiring relevant parameters of a hydraulic cylinder, wherein the relevant parameters comprise the length from a fixed fulcrum of the hydraulic cylinder to a rotation center of a hub, a torque arm of a hydraulic pitch-changing actuating mechanism when a blade feathers, an included angle between the fixed fulcrum of the hydraulic cylinder and a connecting line of the rotation center of the hub, a pitch-changing angle, an area parameter, a cylinder cavity pressure, an actual pitch angle and a reference pitch angle; S2, constructing a hydraulic cylinder piston position formula according to the length from a hydraulic cylinder fixed fulcrum to a hub rotation center and an included angle between a torque arm of a hydraulic variable pitch actuating mechanism and a connecting line of the hydraulic cylinder fixed fulcrum to the hub rotation center when a blade feathers, and expressing a nonlinear relation between the linear motion of a piston of the hydraulic cylinder and the circular motion of the blade; s3, establishing a piston thrust formula according to the cylinder cavity pressure and the area parameters of the hydraulic cylinder and the hydraulic cylinder piston position formula in S2; s4, establishing a variable pitch torque formula according to the variable pitch torque and the variable pitch angle and the piston thrust formula in S3, and calculating the variable pitch torque; S5, establishing a proportional valve control signal formula according to the actual pitch angle and the reference pitch angle, and calculating to obtain a proportional valve control signal formula, wherein the relation between the proportional valve control signal and the piston stroke of the hydraulic cylinder and the corresponding pitch angle is the proportional valve control signal formula; and S6, controlling the hydraulic pitch system according to the pitch torque and the proportional valve control signal.
2. The control method of the hydraulic pitch system of the wind turbine generator set is characterized in that the control signal of the proportional valve is a 4-20 mA current signal or a 0-10V voltage signal.
3. The control method of the hydraulic pitch system of the wind turbine generator according to claim 1, wherein the hydraulic cylinder piston position formula is specifically as follows: Wherein L is the length of extension of a piston of the hydraulic cylinder, θ is the pitch angle, alpha 0 is the included angle between a connecting line of a fixed fulcrum of the hydraulic cylinder and a rotation center of the hub, L is the length of the fixed fulcrum of the hydraulic cylinder and the rotation center of the hub, and r is the torque arm of the hydraulic pitch actuating mechanism during feathering.
4. The control method of a hydraulic pitch system of a wind turbine generator according to claim 1, wherein the piston thrust formula specifically comprises: Wherein eta is the viscous damping coefficient on the hydraulic cylinder piston, P a and P b are the cylinder cavity pressures, S a and S b are the area parameters, Is the derivative of the cylinder piston position x.
5. The control method of a hydraulic pitch system of a wind turbine generator according to claim 1, wherein the pitch torque formula specifically comprises: Wherein, the Is a function related to piston thrust, r is a torque arm of a hydraulic pitch actuator when blades feathering, F is piston thrust, eta is a viscous damping coefficient on a hydraulic cylinder piston, P a and P b are cylinder cavity pressures, S a and S b are area parameters, Is the derivative of the cylinder piston position x.
6. The control method of a hydraulic pitch system of a wind turbine according to claim 1 or 2 or 3 or 4 or 5, wherein the proportional valve control signal formula specifically comprises: Where k is the proportional gain, θ Actual practice is that of is the actual pitch angle, θ Reference to is the reference pitch angle, x (θ Reference to ) is the reference cylinder piston position relative to the reference pitch angle, and x (θ Actual practice is that of ) is the actual cylinder piston position relative to the actual pitch angle.

Description

Control method of hydraulic pitch system of wind turbine generator Technical Field The invention relates to the field of wind turbine generator control, in particular to a control method of a hydraulic pitch system of a wind turbine generator. Background The hydraulic pitch system has the characteristics of large driving torque, light weight, accurate positioning, high dynamic response speed of an actuating mechanism and the like, and both Vestas and Gemesa of the main stream fan manufacturers abroad adopt the hydraulic pitch system. The main actuating mechanism of the hydraulic pitch system is a mechanical link mechanism and a hydraulic cylinder, the main actuating mechanism of the electric pitch system is a pitch motor and a driver, and the two are greatly different in structural design, so that the electric pitch system is a nearly impossible task for replacing the original hydraulic pitch system. After the foreign main stream fan manufacturer continuously exits from the Chinese market, the hydraulic variable pitch system is adopted in China due to the intellectual property protection of the foreign fan manufacturer and the huge difference of the hydraulic variable pitch system and the electric variable pitch system in structural design and control route, so that the problem of subsequent upgrading and optimizing of the machine set is solved in the current wind power market. Disclosure of Invention The invention provides a control method of a hydraulic pitch system of a wind turbine, which aims to solve the problem that the prior art is difficult to upgrade and optimize a hydraulic pitch system of an orphan machine set in China. In order to achieve the above purpose, the present invention adopts the following technical scheme: A control method of a hydraulic pitch system of a wind turbine comprises the following steps of S1, S2, building a hydraulic cylinder piston position formula according to the relevant parameters in S1, S3, building a piston thrust formula according to the relevant parameters in S1 and the hydraulic cylinder piston position formula in S2, S4, building a pitch torque formula according to the relevant parameters in S1 and the piston thrust formula in S3, calculating pitch torque, S5, building a proportional valve control signal formula according to the relevant parameters in S1 and the hydraulic cylinder piston position formula in S2, calculating to obtain a proportional valve control signal, and S6, controlling the hydraulic pitch system according to the pitch torque and the proportional valve control signal. The dynamic geometrical analysis of the actuating mechanism of the variable-pitch hydraulic cylinder is used for expressing the nonlinear relation between the linear motion of the piston of the hydraulic cylinder and the circular motion of the blade by a mathematical formula according to related parameters, and the dynamic stress analysis of the piston of the hydraulic cylinder during normal operation is used for establishing a mathematical control model for controlling a proportional valve control signal, the stroke of the piston of the hydraulic cylinder and the corresponding variable-pitch angle by the related parameters, so that the current mature electric variable-pitch control algorithm is indirectly transplanted to the control of the hydraulic variable-pitch, and the problems of upgrading and technical optimization of subsequent technical improvement after manufacturers of orphan units adopting the hydraulic variable-pitch system abroad exit from the market of China are solved. As a preferable scheme of the invention, the related parameters comprise the length L from a fixed fulcrum of the hydraulic cylinder to the rotation center of the hub, a torque arm r of a hydraulic pitch actuator during feathering of the blade, an included angle alpha 0 between the fixed fulcrum of the hydraulic cylinder and the connecting line of the rotation center of the hub, a pitch angle theta, area parameters S a and S b, cylinder cavity pressures P a and P b, an actual pitch angle theta Actual practice is that of and a reference pitch angle theta Reference to . As a preferable scheme of the invention, the hydraulic cylinder piston position formula is specifically as follows: Wherein L is the length of extension of a piston of the hydraulic cylinder, θ is the pitch angle, alpha 0 is the included angle between a connecting line of a fixed fulcrum of the hydraulic cylinder and a rotation center of the hub, L is the length of the fixed fulcrum of the hydraulic cylinder and the rotation center of the hub, and r is the torque arm of the hydraulic pitch actuating mechanism during feathering. As a preferable scheme of the invention, the piston thrust formula specifically comprises: Wherein eta is the viscous damping coefficient on the hydraulic cylinder piston, P a and P b are the cylinder cavity pressures, S a and S b are the area parameters, Is the derivative of the cylinder piston position x.