海上浮式风机多体系统耦合动力模型研究

Coupled dynamic model of multi⁃body system of floating offshore wind turbine

海上浮式风机是近年来随着海上风电的快速发展,为了捕获深海更丰富、更持久的风能而提出的一种风力发电装置,已成为当今风能开发的主要方向。作为一种多体系统,由于海上浮式风机结构特殊,加上环境复杂,对其进行准确的计算和分析尤为重要。本文对海上浮式风机的耦合动力模型进行了研究,建立了复杂工况下Spar型海上浮式风机改进的14-DOF耦合动力模型,包括气动力模块、水动力模块和结构分析模块等,用于扩展其适用范围和准确计算风机的动力响应,并通过数值仿真对所建模型进行了分析和验证。主要的改进有:不对平台和塔架的转动角度作小量近似,扩展其适用范围;考虑角速度和欧拉角速度的换算关系,不作等化处理。此外,所建模型考虑风机叶片扭转角对叶片变形的影响,得到了较为准确的叶片面内外响应。同时采用线性势流理论对水动力进行计算,较之Morison方程适用性更广。仿真分析表明,本文所建模型可以更准确地计算海上浮式风机系统的动力响应,且具有更广的适用范围。

With the rapid development of offshore wind power in recent years,the floating offshore wind turbine is proposed to cap-ture more abundant and lasting wind energy in the deep sea,which has become the main direction of wind energy development.Due to the special structures and complex environment,the accurate calculation and analysis of floating offshore wind turbines will be particularly important for a multi-body system.In this paper,the coupling dynamic model of a floating offshore wind turbine is deeply studied.The improved 14-DOF coupling dynamic model of spar floating offshore wind turbine under complex working con-ditions is established,including an aerodynamic model,hydrodynamic model and structural analysis model,which can accurately calculate its dynamic response and verified by numerical simulation.The main improvements are as follows:expanding its scope of application without using small approximation of the angle in the coordinate rotation matrix;considering the conversion relationship between angular velocity and Euler angular velocity,the motion equation of floating offshore wind turbine with wider application range and more accuracy is derived.Besides,considering the influence of fan blade torsion angle on blade deformation,the accurate in-plane and out-of-plane response of the blade is obtained.Meanwhile,the potential flow theory is used to calculate the hydrody-namic force in order to solve the limitations of the traditional Morison equation algorithm.The simulation analysis shows that the model proposed in this paper can calculate the dynamic response of floating offshore wind turbine system more accurately with wid-er applicability.