Applications of Reconfigurable Windings for Traction Motors and Drives

目标是设计一种具有商业和技术吸引力的定子绕组重构系统。众所周知，根据电机工作点重新配置定子绕组的概念可以为给定质量的稀土磁体提供电机效率和转矩密度方面的性能优势。从夏季项目中开展的工作也表明，电力电子产品的规格有降低的潜力。在感应电机启动的工业应用中，在星形和德尔塔运行模式之间重新配置绕组是一种常见的做法，然而，由于成本和包装的限制，这种用于牵引应用的系统几乎不存在商业实施。这项研究的目的是开发和展示这样一种在汽车牵引电机应用中可能具有商业相关性的系统，并评估其有效性。该项目将基于机械切换机制来开发概念，因为我们相信这是实现成本要求并使这项技术与主流汽车应用具有商业相关性的唯一现实途径。以前的工作详细介绍了基于半导体的开关系统，但如果不考虑控制电路或冷却，单靠电力电子设备很难实现200欧元以下的成本。相比之下，机械开关解决方案使用大量可用的材料和廉价的制造技术，因此具有极大的成本优化潜力。为了实现这一概念的全部好处，人们希望将其集成到电机包装中。这将确保整个封装针对体积和质量进行优化，并且比集成在变频器中更可取，因为它避免了连接电机和变频器的12根电缆。尽管在这一领域有多项专利，但尚未有商业产品进入市场，这突显了实现实际解决方案的难度。我们认为，生产实用设计的关键因素之一是减少开关数量，或者更准确地说，减少电接触面的数量，因为这些是最终限制封装容量的因素。建议的解决方案提高技术水平的一个关键领域是通过最大限度地使用双掷开关来减少电接触面的数量。作为工作的一部分，将对可能的开关机制进行全面审查，包括电气原理图和驱动机制，以期将成本和体积降至最低。这项工作最终将分析这类系统，目的是建立一种可应用于一般情况的设计方法，从分析上权衡数量和性能，确保项目产出得到广泛应用。

The objective is to design a stator winding reconfiguration system which is commercially and technically attractive. The concept of reconfiguring the stator windings depending on the motor operating point is widely known to offer performance advantages in terms of motor efficiency and torque density for a given mass of rare earth magnets. From work carried out in the summer project it is also shown that there is potential to reduce the specification of power electronics. Reconfiguration of windings between star and delta modes of operation is a common practice in industrial applications for start-up of induction machines, however commercial implementation of such systems for traction applications is almost non-existent owing to cost and packaging constraints. The objective of this research is to develop and demonstrate such a system which could be commercially relevant in automotive traction motor applications, and to evaluate its efficacy.The concept which will be developed within this project is based around a mechanical switching mechanism, as we believe this offers the only realistic route to achieve the cost requirement and make this technology commercially relevant for mainstream automotive applications. Previous work details semiconductor-based switching systems but are difficult to realise for under 200 euro for the power electronics alone, not considering control circuitry or cooling. In contrast, the mechanical switching solution uses abundantly available materials and inexpensive manufacturing techniques and so has excellent potential for cost optimisation. To realise the full benefits of this concept, it is desired to be integrated into the motor packaging. This will ensure that the total package is optimised for volume and mass and is preferable to integration within the inverter because it avoids the need for 12 cables connecting the motor and inverter. Despite multiple patents in this area no commercial product has yet reached the market, highlighting the difficulty of achieving a practical solution. We believe one of the key factors in producing a practical design is reducing the number of switches, or more precisely the number of electrical contact faces, since these are ultimately what limits the package volume. A key area in which the proposed solution progresses the state-of-the-art is in reducing the number of electrical contact faces by making maximum use of double-throw switches. A full review of possible switching mechanisms will be conducted as part of the work, including electrical schematics and actuation mechanisms, with a view to minimising cost and volume. This work will ultimately analyse such systems with the aim of establishing a design methodology which can be applied to the general case, to analytically trade off volume with performance, ensuring the project outputs are widely applicable.