| Wind turbine simulator based on motor towing system is an important tool for dynamic characteristic simulation experiment of wind turbines.It can simulate the mechanical dynamics and grid connection of the actual wind turbine in the laboratory,which greatly facilitates the development and testing of wind turbines.However,because the real rotational of inertia of the wind turbine simulator is much smaller than the actual wind turbine,the use of the rotational inertia compensation strategy is the key to realizing the mechanical dynamic simulation of the actual wind turbine.However,the existing wind turbine simulator based on the rotational inertia compensation strategy of high order filter is applied to simulate the abnormal speed fluctuation phenomenon of wind turbines with large rotational inertia in turbulent wind.It is found in this paper that the abnormal fluctuation of speed is mainly caused by system delay.Specifically,the existing rotational inertia compensation strategy sets the compensation torque according to the observed acceleration value,but the system delay leads to the lag of compensation,resulting in the torque deviation component.Existing strategies suppress the influence of torque deviation components by setting high-order filters.However,due to the delay in the suppression process,the deviation component has not been completely eliminated,resulting in abnormal fluctuation of simulator speed.To solve this problem,this paper conducts discrete modeling analysis on the wind turbine simulator using the existing rotational inertia compensation strategy and constructs a discrete mathematical model of the wind turbine simulator considering the system delay,and carries out the time-domain analysis.On this basis,a torque compensation strategy based on feedforward torque deviation suppression for wind turbine simulator was proposed.According to the existing torque deviation components,the torque deviation suppressor is designed at the input end of the simulator transmission chain by using the feedforward method,and the unbalanced torque is reduced before the torque instruction is issued,to offset the influence of the torque deviation components generated in the torque compensation loop.In this way,the torque deviation induced by system delay can be suppressed accurately,and the wind turbine simulator with the small rotational of inertia can accurately simulate the slow mechanical dynamic characteristics of the wind turbine with the large rotational of inertia in turbulent wind.Finally,the effectiveness of the proposed strategy is verified by simulation and experiment. |
