A method and system for controlling torsional vibration of transmission chain caused by periodic excitation

Abstract

The invention discloses a control method and system for transmission chain torsional vibration caused by periodic excitation. The method comprises the steps that A, the rotating speed of a wind wheel of a fan is measured, and a uniform pitch angle set value beta ref based on the measured rotating speed and a rotating speed set value; B, the uniform pitch angle set value is distributed to each paddle so as to obtain a pitch angle set value beta iref=Ki beta ref of the independent change of each paddle, wherein the weight coefficient Ki is determined by azimuth angle feedback of each blade; C, the input torque of a transmission chain of the fan is measured, the frequency doubling amount of the rotational frequency of the wind wheel is obtained through analysis, and a fine adjustment amount delta beta i of each pitch angle is obtained based on three times of the frequency doubling amount and six times of the frequency doubling amount; and D, the expected pitch angles of the blades are obtained according to the pitch angle set value and the pitch angle fine adjustment amount of each paddle, and each blade is controlled according to the expected pitch angles. The method and the system have the advantages that the pitch angle fine adjustment amount is added on the basis of the independent variable pitch control based on the azimuth angle feedback, and therefore the transmission chain torsional vibration caused by the periodic excitation can be better controlled.

Description

technical field [0001] The invention relates to the technical field of wind power generation, in particular to a control method for suppressing torsional vibration of a transmission chain caused by periodic excitation of a doubly-fed wind power generating set, and also relates to a system adopting the control method. Background technique [0002] With the increasing shortage of conventional energy, the development and utilization of renewable energy will undoubtedly become the main direction of energy development in the future. At present, wind power generation technology has matured, and the installed capacity of wind power has continued to expand. By the end of 2016, the installed capacity of wind power in China had exceeded 176.1GW. The focus of the wind power industry. [0003] The working environment of wind turbines is harsh, the wind speed is highly unstable, and the components of the unit are easily damaged, especially the transmission chain. In this case, the tors...

AI Technical Summary

Problems solved by technology

Unified pitch control refers to the control method of the wind turbine control system for the three blades of the wind turbine to issue the same pitch angle. This control method essentially considers that the wind speed of the entire rotation plane of the wind wheel is the same. The pitch control system has less requirements, and the control strategy is simple and easy to implement. The disadvantage is that the control output power will fluctuate, which has a great impact on the vibration of the entire unit.

In the actual situation, when the wind rotor is affected by factors such as wind shear and tower shadow effect, the wind speed at different places on the rotation plane of the wind rotor is not the same. In the case of growth, independent pitch control is the most effective way to reduce the torsional amplitude of the transmission chain caused by periodic excitation of wind turbines such as wind shear and tower shadow effect. The advantage of this control method is high control accuracy. Through Fine-tuning the pitch angle of each blade can well improve the fluctuation of the input torque of the transmission chain caused by the asymmetric load caused by the different wind speeds on the wind rotor rotation plane. The disadvantage is that the requirements for the pitch system are higher, and the control strategy complex

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