A Novel Non‐Torque Dynamic Load Decoupling Method for Large Wind Turbine Nacelle Test Bench

ABSTRACT Accurate reproduction of non‐torque dynamic loads is a key challenge for full‐scale wind turbine nacelle test benches, where the nacelle‐level drivetrain is validated under controlled multi‐degree‐of‐freedom mechanical loading. This study focuses on the shaft‐conjugate load application unit (LAU) adopted in the 25‐MW‐class full‐scale wind turbine nacelle test bench at China's National Offshore Wind Power Research and Test Base. Under dynamic conditions, the inertial and damping forces of the LAU can significantly affect load application accuracy. To address this issue, this study proposes a non‐torque dynamic load decoupling method that explicitly accounts for these forces. A rigid‐flexible coupled dynamic model of the LAU is established, and an iterative solution algorithm is developed to obtain the actuator load curves required for accurate dynamic load reproduction. Numerical examples involving two types of dynamic loads are used to validate the proposed method. The results show that the method converges rapidly, reproduces the target dynamic loads with maximum relative errors below 10 −6 , and yields accurate load curves for all six actuators. In contrast, neglecting inertial and damping forces leads to noticeable deviations in the actuator load curves, with a maximum relative deviation of 9.03%. The proposed method may offer useful guidance for dynamic load reproduction in similar complex mechanical test systems.