面向大型浮式风电系统的柔性多体动力学建模与双重载荷控制研究

Large-scale offshore floating wind turbine had developed into one of frontier research topics in wind energy field, which can be used to deal with obstacles, such as high cost of unit power generation and construction, during the development of offshore wind resource in deep sea. However, due to the dramatic increase of the structure size, multi-degree of freedom of floating foundation support and complex and harsh operating environment, more stringent requirements are needed to ensure the reliability and stability of the whole system. To meet these technical requirements, it is planned to research on four science problems in the respect of multi-body dynamics modelling and load alleviation in the research project. Based on reduction order method of absolute nodal coordinate formulation, the wind rotor and tower which characterized by large structure deformation and large motion will be elaborated with mathematics and computational models. Then the multi-body dynamics of the whole system is modelling with generalized Hamilton principle. Take advantage of load spectrums which are calculated under different operational conditions and certification standards, the dynamic state incentives and load characteristics will be in-depth analyzed. Then a dual load control method including the semi-active and active load alleviation methods are proposed and controllers which can be used to meet the features of models are designed. From a global perspective, the coupling controller including load controllers and power controller are coordinated. Finally, a kind of system modelling theory and dual load alleviation method which characterized by accurate modelling and effective control will be presented, which can provide important theoretical and technical support during the research and development of deep-sea floating wind turbine belong to our country.

大型海上浮式风电机组作为解决深海风能资源开发中“单位发电成本高”和“建设成本高 ”等障碍的重要设计，已成为行业研究热点之一。然而因其大幅度增加的结构尺寸、多自由度的浮式基础支撑和复杂恶劣的运行环境，对系统可靠性、稳定性提出更为严苛的要求。本课题在此背景下，从系统的柔性多体动力学建模及载荷控制角度入手，开展四个方面研究：以降阶绝对坐标方法为基础，构建作大范围运动和大变形的风轮、塔架的表征方法，据此建立基于广义Hamilton原理的系统柔性多体动力学模型；结合IEC规范计算得到不同工况下的载荷谱，深入剖析其动力学性态诱因与载荷特征；进而提出含有主动和半主动方式的双重载荷控制方法并设计符合模型特征的控制算法；从全局角度协调具有耦合关联的载荷控制和功率控制的多控制系统。从而形成一套“准确建模”和“有效控制”相结合的系统建模理论与载荷控制方法，对我国深海漂浮式风电机组研发提供重支要的理论与技术支持。

我国深远海风资源丰富，开发潜力巨大，经测算30-60m深远海风电开发潜力约5亿KW，约占我国海上风电开发潜力的70%。国家“十四五明确提出：开发漂浮式风电系统，实现深远海风资源开发，掌握下一代风电装备的关键技术。但我国海上漂浮式基础及其风电机组设计技术与国外差距巨大，不具备深远海风资源开发能力，亟待开发大功率深远海漂浮式风电技术。浮式风电机组运行环境复杂，浮式支撑会产生大偏移、大幅度运动，对机组运行的安全性稳定性提出了严峻挑战。机组自身挑战巨大：叶轮气弹稳定性、叶轮-塔架耦合作用、浮体基础、系泊系统强相关；浮式基础使得风机高耸结构自由度更加复杂化：纵荡、橫荡、垂荡、横摇、纵摇、首摇；机组稳定性是保障机组安全、可靠、可持续出力的前提；亟需兼顾机组安全、降成本的创新方案：基于外部风、浪、流反馈的主动振动控制降载技术开发及抑振装置。鉴于此，本项目结合浮式基础平台的特点，选择适于我国海域深度与环境特点的半潜式海上风机作为研究对象，开展功率控制和减载控制研究，旨在为我国深海风电资源开发进行有益的探索。针对极限波浪工况下，风力机浮式平台受风浪作用而产生大幅度仰俯运动，从而导致系统故障，甚至严重倾覆。提出使用主动结构振动控制方式，通过调节阻尼器参数来调整风载荷和波浪载荷下调谐质量阻尼器中质量块的位置，进而调整作用在浮式平台上的作用力，达到风力机的减载和平稳控制。研究与实际工程紧密结合，对于大功率海上浮式风电机组高效安全稳定运行提出解决方案，可望降低风电机组故障率，提高风机工作效率，节约运维成本，加速海上浮式风电机组的推广，带来很大的经济和社会效益。