Full Envelope Wind Turbine Control Systems Design

风力涡轮机是提供清洁、安全和丰富能源的一种手段。对环境的影响有限，运营成本低。另一方面，***风力涡轮机的初始资本成本很高。因此，长寿命和可预测的操作模式是可取的。该提案旨在通过全面的包络控制来提高风力涡轮机的寿命和运行的可预测性。风力涡轮机在两种状态下运行：中等风速，其目标是提取最大的功率；较高的风速，其功率被调节到接近容量。在中等和较高风速之间的过渡中，系统应该有效和安全地在不同的状态之间移动。大多数大型风力涡轮机都是变速、变螺距配置，其中使用两种驱动：发电机定子的励磁，作为制动力来控制旋转；而桨距，会影响气动升力和阻力并产生力。***为了降低运营成本，尽可能避免叶片的俯仰，因为这涉及到需要润滑的机械部件和有限寿命的轴承。因此，在中等***风速下，仅使用场激励，而在功率调节模式下，同时使用桨叶俯仰和***场激励。从一种状态过渡到另一种状态涉及到执行器数量的变化，以及控制系统目标和动态特性的变化。在***过渡区域，涡轮机的超速可能导致***轴承和叶片和塔结构中的扭矩和力超过额定条件。所有这些问题都会大大降低预期寿命并增加维护成本。***有前途的风力发电机反馈控制方法包括线性参数变化概念、优化扰动抑制方法和模型预测控制。此外，切换系统将允许更灵活地处理不同的目标、执行器数量和不同的动态。这里的工作将考虑这些方法的外推，以处理过渡区域控制和涡轮机的全包线运行。政权之间的过渡会引起速度和扭矩的振荡，也会增加俯仰致动器的磨损。智能选择控制策略以避免非线性振荡将有利于实际实现。找到峰值功率充满了困难。由于叶片磨损和损坏导致的动态变化，不确定的功率曲线数据，以及涡轮机之间和与环境的复杂相互作用，都可能导致估计最大功率提取参数的错误。采用本方案所述的先进的反馈控制技术可以提高效率，最大限度地提取功率，提高涡轮机的寿命。

Wind turbines are a means of providing clean, safe and abundant energy. There is limited***environmental impact and the operating costs are low. On the other hand, initial capital costs for***wind turbines are high. As such, long life and predictable operating patterns are desirable. This***proposal aims to improve the life and predictability of operation of wind turbines through full***envelope control. Wind turbines operate in two regimes: moderate wind speeds where the goal is to***extract maximum power and higher wind speeds where power is regulated near capacity. In the***transition between moderate and higher wind speeds the system should efficiently and safely move***between regimes. Most large wind turbines are of a variable speed, variable pitch configuration***where two actuations are used: field excitation of the generator stator, governing rotation as a***braking force; and blade pitch, which affects the aerodynamic lift and drag and generated forces.***For lower operating costs, pitching of the blades is avoided as much as possible as this involves***mechanical components requiring lubrication and bearings with finite lifespans. Thus, at moderate***wind speeds only field excitation is used, while in power regulation mode, both blade pitching and***field excitation are employed. Transitioning from one regime to the other involves a change in the***number of actuators, along with changes in control system goals and in dynamic characteristics. In***the transition region, overspeeding of the turbine can result in exceeding rated conditions for***bearings and torques and forces in the blades and tower structure. All of these issues can greatly***reduce the life expectancy and increase maintenance costs.***Promising methods for feedback control of wind turbines include linear parameter varying concepts,***optimized disturbance rejection methods and model predictive control. Further, switched systems***will allow more flexibility in dealing with varying objectives, number of actuators, and varying***dynamics. Work here will consider the extrapolation of these methods to handle transition region***control and full envelope operation of the turbine. Transition between regimes can induce***oscillations in speed and torques and also increase wear on the pitch actuators. Intelligent choices of***control strategy to avoid nonlinear oscillations would be of benefit to practical implementation.***Finding peak power is fraught with difficulty. Varying dynamics due to blade wear and damage,***uncertain power curve data, and complex interaction between turbines and with the environment***can cause errors in estimating parameters for maximum power extraction. Employment of advanced***feedback control techniques as described in this proposal can improve the efficiency, maximum***power extraction and improve life of the turbine.