More electric aircraft is a promising solution to the problems of fuel consumption, emissions, and noise faced by the aviation industry. Electrical machines with high power density are essential to improve the overall performance of more electric aircraft. The huge difference between the maximum and the rated output of electrical machines shows that the performance does not reach the present limit of the electromagnetic design. Improving thermal designs is an important and effective way to increase power density at the present stage, as the temperature rise limit of materials is the main obstacle to restricting the performance of electrical machines. In this article, a variety of thermal designs are comprehensively reviewed and critically discussed according to different cooling positions. Next, an analysis of suitable thermal designs for different applications of electrical machines in more electric aircraft is presented. Subsequently, cooling capacity and additional mass of the thermal designs, which are the two key determinants of improving power density, are estimated and compared. Moreover, the reliability and cost of the thermal designs are discussed in depth. This work contributes to a thorough understanding of thermal designs in improving the power density of electrical machines and guides their future designs and applications in more electric aircraft.

中文翻译：

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提高电机功率密度的热设计综述


更多电动飞机是解决航空业面临的燃油消耗、排放和噪音问题的有希望的解决方案。具有高功率密度的电机对于提高更多电动飞机的整体性能至关重要。电机的最大输出与额定输出之间的巨大差异表明其性能未达到现有电磁设计的极限。改善热设计是现阶段提高功率密度的重要而有效的途径，因为材料的温升极限是制约电机性能的主要障碍。本文根据不同的冷却位置对各种热设计进行了全面的回顾和批判性的讨论。接下来，对多电动飞机中电机的不同应用的合适热设计进行了分析。随后，对热设计的冷却能力和附加质量（提高功率密度的两个关键决定因素）进行了估计和比较。此外，还深入讨论了热设计的可靠性和成本。这项工作有助于全面了解提高电机功率密度的热设计，并指导它们在更多电动飞机中的未来设计和应用。