With the fast development of tidal turbines for sustainable energy generations, reliable and efficient tidal pitch systems are highly demanded. This paper presents a systematic design for a novel tidal pitch system based on hydraulic servo and bevel geared transmission. This system holds the characteristics of compact and triangular structure, making it easy to be installed in a narrow turbine hub. The pitch system dynamics are modeled by taking account of model uncertainties and external disturbances. An uncertainty and disturbance estimator (UDE)-based robust pitch control algorithm is developed to achieve effective pitch angle regulation, disturbance rejection, and generator power smoothing. The UDE controller is designed in a composite hierarchical manner that includes an upper level power smoothing controller and a low-level pitch angle tracking controller. The performance of the proposed pitch system and the UDE control is demonstrated through extensive simulation studies based on a 600-kW tidal turbine under varying tidal speeds. Compared with the conventional controller, the UDE-based pitch controller can achieve more reliable power smoothing and pitch angle tracking with higher accuracy.

中文翻译：

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基于不确定性和扰动估计器的潮汐机复合分级桨距角控制


随着用于可持续能源发电的潮汐涡轮机的快速发展，人们对可靠、高效的潮汐变桨系统提出了很高的要求。本文提出了一种基于液压伺服和锥齿轮传动的新型潮汐变桨系统的系统设计。该系统具有紧凑、三角形结构的特点，易于安装在狭窄的涡轮轮毂中。通过考虑模型不确定性和外部干扰来对变桨系统动力学进行建模。开发了基于不确定性和干扰估计器（UDE）的鲁棒桨距控制算法，以实现有效的桨距角调节、干扰抑制和发电机功率平滑。 UDE控制器采用复合分层方式设计，包括上层功率平滑控制器和下层俯仰角跟踪控制器。通过基于 600 kW 潮汐涡轮机在不同潮汐速度下的广泛模拟研究，证明了所提出的变桨系统和 UDE 控制的性能。与传统控制器相比，基于UDE的桨距控制器可以实现更可靠的功率平滑和精度更高的桨距角跟踪。