Research and Development of the Utility Scale, Tocardo T4 Tidal Turbine

QED海军和Tocardo涡轮机成功地部署了一个小规模的潮汐能装置。他们的Gen 01 Subhub设备有三个发电机，专为社区规模的项目而设计（150千瓦- 300千瓦总），但野心是发展工业规模（300 kW - 1.25 MW）和公用事业规模（总共2 MW - 4 MW）。公用事业规模设备预期具有多个发电机，Tocardo在永磁同步电机（PMSM）领域拥有丰富的经验，能够满足风能和潮汐发电行业的广泛需求。这些机器通常是直接驱动的，因此需要开发高扭矩（所谓的扭矩发动机）。鉴于永磁同步电机的转矩与定子绕组中的电流有关，热极限通常是电机中转矩极限的原因。因此，一台能够提供更高热性能的机器将能够产生更高的最大扭矩，这对于该应用来说可能能够在更高流速下在磁场减弱之前改善能量捕获。因此，Tocardo已经为所谓的“开芯机舱”拓扑结构做了初步设计工作，见图1。这将取代坚实的转子轴与管道，让海水自由流过涡轮机。这将创造一个额外的冷却表面，提高热性能，而不需要淹没机舱，或安装主动冷却的组件。后者都提出了操作上的挑战，这在潮汐领域是要避免的。因此，本项目的目的是评估这种拓扑结构中电机的设计，并通过使用热建模来评估开芯机舱拓扑结构的有效性。目的是在项目结束时，将创建MW级潮汐涡轮机的设计。根据建模的结果，这种设计可能采用开放式核心机舱概念，也可能是针对潮汐环境优化的更传统的PMSM。最后，在项目设计过程中，将评估设计工具和流程，以提高Tocardo的设计能力。

QED Naval and Tocardo turbines have successfully deployed a small scale tidal energy device. Their Gen 01Subhub device has three generators and is designed for community scale projects (150 kW - 300 kW total), butthe ambition is to develop industrial scale (300 kW - 1.25 MW total), and utility scale (2 MW - 4 MW total).The utility scale device is expected to have multiple generators, each with a rated power of approximately 1 MW.This project concerns the development of this generator.Tocardo's experience is in Permanent Magnet Synchronous Machines (PMSMs), which matches the wideralignment of the wind and tidal industry. These machines are typically directly driven, and as such need todevelop high torques (so-called torque engines). Given the torque of a PMSM is linked to the current in statorwindings, thermal limits are usually the cause of torque limits in an electrical machine. As such, a machine thatcould deliver greater thermal performance would be able to develop a higher maximum torque, which for thisapplication may be able to improve energy capture before field weakening at higher flow rates.As such Tocardo has done preliminary design work for a so-called "open-core nacelle" topology, see Fig. 1. Thiswould replace the solid rotor shaft with a pipe, allowing sea water to flow freely through the turbine. This wouldcreate an extra surface for cooling, improving the thermal performance without the need for flooding the nacelle,or the installation of active cooling of the components. Both of the latter present operational challenges, whichin the tidal sector is something to be avoided.As such, the aim of this project is to assess the design of the electrical machine within such a topology, and toassess the effectiveness of the open-core nacelle topology through the use of thermal modelling. The aim is thatat the conclusion of the project a design for a MW scale tidal turbine will have been created. Depending on theoutcomes of the modelling this design may feature the open-core nacelle concept or may be a more conventionalPMSM optimised for the tidal environment. Finally, over the course of the project design tools and processeswill be assessed with the aim of improving Tocardo's design capabilities.