基于混杂切换系统的风电磁悬浮偏航系统建模与控制

Currently, the large and medium-scale horizontal axis wind turbines adopt generally the gear-driven yaw system which has the drawback such as complicated structure, periodic lubrication, inconvenient maintenance and high maintenance cost etc. This project intends to apply maglev technique into the yaw system of wind turbine. A novel yaw system based on maglev technique combining "regenerative-braking-type" passive yaw with "wind-auxiliary-type" active yaw during the stable suspension of nacelle is proposed in this project. It has the notable advantages such as higher precision to the wind, no lubrication needed, simple structure, easy maintenance, short downtime and much low maintenance cost. The multimodal modeling maglev yaw system by using hybrid switched system theory is done in this project, as well as the analysis of the stability and optimal control for multi-mode switching. A three-layer control strategy including operational mode decision of modal unit collaborative optimization, dynamic coordination of mode switching and mode optimal control will be researched. The axial- and radial- magnetic field decoupling method based on the stator flux-oriented control strategy is put forward to realize that the suspension and yaw of the nacelle can be controlled independently. The suspension control system also includes the suspension starting and landing which dynamic process' impact on the performance of suspension (nacelle) will be studied. An experimental platform will be established to verify the validity of the proposed mathematical mode and control algorithm. The expected results of this project can not only promote the development of hybrid switched system optimization control theory, but also have important theoretical value and practical significance to break through the key bottlenecks technology in the process of the industrialization of large-scale wind turbines.

目前大中型水平轴风电机组均采用齿轮驱动的偏航系统，存在结构复杂、维护费用高等缺陷。本项目拟将磁悬浮技术应用于风机偏航系统，提出基于机舱稳定悬浮下的"再生制动式"被动偏航和"风力辅助式"主动偏航相结合的新型风电磁悬浮偏航系统，具有对风精度高、无需润滑、结构简单、维护方便、停电时间短、运行维护费用低等显著优点。采用混杂切换系统理论对磁悬浮偏航系统进行多模态建模，分析模态切换稳定性及优化控制问题，提出含模态单元协同优化的工作模态决策、模态切换动态协调、各模态优化控制等三层控制策略。提出基于定子磁链定向的轴径向磁场解耦方法，实现机舱悬浮和偏航完全独立控制；将悬浮起动和悬浮降落纳入到悬浮控制体系中，研究其动态过程对悬浮体（风机）性能影响。搭建实验平台验证所提理论和技术的有效性。本项目不仅促进混杂切换系统优化控制理论的发展，而且对突破大型风电机组产业化进程中的关键瓶颈技术具有重要的理论价值和指导意义。

为了解决目前水平轴风电机组齿轮驱动偏航系统存在的结构复杂、偏航摩擦损耗大、维护费用高等缺陷，本项目研究一种新型的风电磁悬浮偏航系统及其控制策略，具体研究：采用混杂切换系统理论对磁悬浮偏航系统进行多模态建模；对模态切换稳定性及优化控制问题进行了分析，提出了含模态单元协同优化的工作模态决策、模态切换动态协调、各模态优化控制等三层控制策略；研究并提出了基于转子磁链定向的轴径向磁场解耦方法，实现了机舱悬浮和偏航独立控制；深入开展了基于PID控制、模型预测控制（MPC）、滑模控制、自适应控制、神经网络等控制策略的机舱磁悬浮控制方面的研究；设计并制作了风电磁悬浮偏航装置试验样机，建立了一套全新的风电磁悬浮偏航系统实验测试平台，为本项目提出的优化控制策略与相关算法提供了综合验证平台，为各种控制器的研发提供新方法和新手段，理论上较系统地探索解决了具有非线性混杂切换系统优化控制问题和含悬浮启动和降落的机舱悬浮系统控制问题，成功实现了重达484kg悬浮物的稳定悬浮及0.3rpm的超低速稳定旋转，悬浮起动无超调，悬浮降落无机械冲击，悬浮气隙稳态误差仅为0.15mm，实现了机舱悬浮和偏航的柔性切换，切换所致悬浮气隙波动仅为0.25mm，偏航转速稳态误差为0.05rpm，可快速实现偏航转速的调向控制，同时具有较强的抗干扰能力，其中轴向干扰力可达悬浮物重量的20%，倾覆干扰力可达悬浮物重量的10%，证明了系统具有极强的鲁棒性。. 本项目创新性地提出一种全新的风电磁悬浮偏航系统，具有对风精度高、无需润滑、结构简单、维护方便、停电时间短、发电效率高、运行维护费用低等显著优点，其研究成果不仅促进混杂切换系统优化控制理论的发展，而且对突破大型风电机组产业化进程中的关键瓶颈技术具有重要的理论价值和指导意义。