| Due to the development of offshore wind farms,wind turbines need larger output power and blade size.With the increase of blade size,the traditional methods of fatigue loading are undergoing severe challenges: The loading force required to reach the resonant amplitude of the blade is increasing.In order to solve the problem of insufficient driving force,a dual-actuatordriven fatigue loading scheme was proposed in this paper,which is driven by two actuators synchronously.However,under the influence of internal factors and external disturbances,the output of the two actuators is difficult to achieve full synchronization,so an additional torque will be generated in the blade loading point,which makes the blade torsional,reduces the accuracy of the test,and even damages the blade when it is serious.Therefore,it is of great scientific significance to study the synchronous driving mechanism and develop the dualactuator synchronous excitation algorithm of dual-actuator fatigue loading system to improve the performance of fatigue loading system.The main research results of this paper are as follows:Firstly,a dual-actuator fatigue loading scheme is proposed according to the fatigue loading requirements of wind turbine blades.Based on this,the vibration characteristics of blades and actuators are analyzed,and the mathematical model of dual-actuator fatigue loading system considering blade stiffness and rotation angle is established.Then the dual-actuator fatigue loading system without using control algorithm is simulated based on MATLAB/SIMULINK,and the simulation results are analyzed.Secondly,a cross-coupling control strategy based on auto-disturbance rejection control algorithm is proposed combining the characteristics of the dual-actuator fatigue loading control system and the synchronous control structure;a set of active disturbance rejection controller is designed by using the optimal control function based on arranging the transition process,tracking and estimating the system state and perturbation,error feedback and disturbance compensation.Furthermore,the auto disturbance rejection control algorithm and the PID control algorithm are combined with the mathematical model of the AC permanent magnet servo motor respectively,and the simulation and comparison are carried out.The results show that the following control precision of the auto disturbance rejection control algorithm is obviously higher than the following control precision of the PID control algorithm;the cross-coupling control strategy based on the auto-disturbance-rejection control algorithm is combined with the system model to simulate,demonstrating the superiority of this control strategy in the dual-actuator synchronous excitation system.Thirdly,According to the control requirements and monitoring requirements,the control system is developed,including:(1)the upper computer and lower computer functions were assigned;(2)the upper computer is developed based on Lab VIEW software,including manual operation,automatic search frequency,intel igent control amplitude,data acquisition,data recording,fault alarm,etc.(3)The lower machine control logic and the movement realization method were designed according to the actuator operation requirements.Finally,in order to fundamentally verify the feasibility of the fatigue loading scheme and the effectiveness of the cross-coupling strategy based on the auto-disturbance rejection control algorithm,a wind turbine blade double-actuator fatigue loading test platform was built,and the fatigue loading of the LZ 5.0-62 model blade is carried out.Fatigue loading.The experimental results show that the cross-coupled synchronous control strategy based on the auto-disturbance rejection control algorithm can ensure the speed synchronism and displacement synchronism of the actuator better,and the system is less affected by the wind load,and the system is robust. |
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