Dynamic modeling and analysis of wind turbine drivetrain considering platform motion

Abstract For floating offshore wind turbines, platform motion is large under the impact of waves and currents leading to increasing system vibration and should be analyzed in the design phase to improve the survivability of wind turbine. However, most of the wind turbine drivetrain models lack the attention to the dynamic response caused by platform motions. In this work, a novel dynamic modeling method considering platform motion is proposed, which is suitable for any combinations of the planetary and parallel gear stages. A dynamic model of the drivetrain with platform motions is developed, which includes the concentrated mass components (CMCs) with the fixed-shaft and orbital revolution motions, the flexible gear meshes and bearings as well as the flexible shafts. The vibration modes of the drivetrain are investigated. Three kinds of platform motions are determined and applied to the drivetrain. The effects of these platform motions on the dynamic behaviors of the drivetrain are studied in-depth. The simulation results indicate that the platform motions not only introduce additional excitation frequencies to the drivetrain and increase system vibration but also increase the risk of the resonance. The proposed method can be utilized to guide the modeling and design of an offshore wind turbine drivetrain.