An Investigation into the Performance of Magnetically Geared Devices for Marine Hydrokinetic and Wind Applications

风能和旋转式海洋动能转换装置通常依靠机械变速箱来提高速度，以满足电磁发电机的要求。然而，机械变速箱造成了可靠性问题，而变速箱的维护可能会显著增加能源的水平成本。替代方法，如使用直接驱动发电机，由于其固有的低单位体积扭矩能力，在较高功率水平下变得不切实际。这项研究将调查使用磁齿轮发电装置的理论和实际性能。与传统的机械变速箱相比，磁力变速箱具有许多优势，因为磁力变速箱无需任何物理接触即可实现变速，不需要齿轮润滑，并且具有固有的过载扭矩限制能力。通过将磁性齿轮箱连接到发电机上，发电机系统的可靠性可以大大提高，其体积大小可能与其机械齿轮相当。通过提高可靠性，磁齿轮式发电机可以降低风力和海洋发电转换的水平成本。这可以提高可再生能源的利用率，从而有助于减少与化石燃料燃烧有关的空气污染物的排放。这项研究的主要目标是(1)开发建模工具，以了解轴向磁齿轮和径向磁齿轮拓扑的比例和成本/性能权衡。(2)建造并试验了定子驱动的无级变速磁力齿轮和轴向驱动的直驱式磁齿轮发电机。(3)对所提出的磁力传动装置在较宽的转速和扭矩范围内的效率进行了实验评估。在使用铁氧体和稀土磁体时，轴向和径向磁通聚焦磁齿轮设计之间的实际性能权衡将在成本的背景下确定。潮流、效率和功率因数特性将根据现有技术进行表征。这项研究将有助于更好地理解使用磁力齿轮、无级变速磁力齿轮和磁力齿轮直驱电机时的能量转换过程。使用磁通聚焦磁齿轮拓扑时，将仔细定义获得非常高的质量和体积扭矩密度所需的技术。文中将推导出将无级变磁齿轮并入电网时的潮流和控制方程。本科生和研究生都将协助这项研究。代表不足的学生将积极参与这项研究。将为当地高中生举办外展活动和年度暑期研究体验。研究成果将在领先的期刊、会议和研讨会上传播，以造福于科学界和工业界。

Wind and rotary based marine hydrokinetic energy conversion devices often rely on a mechanical gearbox to increase their speed so as to match the requirements of the electromagnetic generator. However, mechanical gearboxes are creating reliability concerns and the maintenance of the gearbox can significantly add to the levelized cost of energy. Alternative approaches such as using a direct-drive generator become impractical at higher power levels due to their inherently low torque-per-volume capability. This research will investigate the theoretical and practical performance capabilities of using magnetically geared generation devices. A magnetic gearbox offers a number of advantages over traditional mechanical gearboxes in that a magnetic gearbox creates speed change without any physical contact, it does not require gear lubrication and has an inherent overload torque limiting capability. By coupling a magnetic gearbox to a generator the reliability of the generator system can be significantly improved and the volumetric size could potentially be comparable to its mechanically geared equivalent. By improving reliability a magnetically geared generator could reduce the levelized cost of wind and ocean power conversion. This could increase the utilization of renewable energy resources and consequently help reduce the emission of airborne pollutants associated with the combustion of fossil fuels. The primary goals of this research are to (1) develop modeling tools to understand the scaling and cost/performance trade-offs of axial magnetic gears and radial magnetic gear topologies. (2) Construct and test a stator driven continuously variable magnetic gear and an axially driven direct-drive magnetically geared generator. (3) Experimentally assess the efficiency of the proposed magnetic gear devices over a wide speed and torque range. The practical performance trade-offs between axial and radial flux-focusing magnetic gear designs when using ferrite and rare-earth magnets will be determined in the context of cost. The power flow, efficiency and power factor characteristics will be characterized with respect to existing technology. This research will lead to a greater understanding of the energy conversion process when using magnetic gears, continuously variable magnetic gears and magnetically geared direct-drive electrical machines. The techniques required to achieve very high mass and volumetric torque densities when using flux focusing magnetic gear topologies will be carefully defined. The power flow and control equations for the integration of a continuously variable magnetic gear into the grid will be derived. Both undergraduate and graduate students will assist with this research. Underrepresented students will be actively involved in this research. Outreach activities and yearly summer research experiences for local high-school students will take place. The research results will be disseminated in leading journals, conferences, and workshops in order to benefit the scientific and industrial community.