Effect of time step on the dynamics response of non-torque load application unit in wind turbine drivetrain test RIG

With the trend towards larger-scale and higher-power wind turbine, accurately conducting ground tests for wind turbine drivetrain has become a critical technical challenge. During ground testing of wind turbine drivetrain, the motion of non-torque load application unit (LAU) affects the loading accuracy of non-torque dynamic loads on the test rig. To accurately determine the dynamics response of the LAU, we establish its equivalent dynamics model and dynamics equation, solve them numerically using the Newmark method, and quantitatively investigate the effect of different time steps on the solution accuracy of the LAU's dynamics response. The results demonstrate that as the time step decreases, the variation magnitude of the dynamics response in the non-torque loading unit gradually diminishes. When the time step is reduced to 5×10−3s and 2×10−3s, the variation magnitude of the dynamics response stabilises. Furthermore, the proposed method provides theoretical and technical support for determining optimal time step during wind turbine drivetrain test rig loading procedures.