In many industrial applications the self-starting capability of electric motors is still an important requirement enabling to simplify the drive architecture and increase the system's reliability. The efficiency improvement of this motor topology has been targeted by various national and international regulatory authorities with ad-hoc policies. Indeed, a lower energy consumption leads to the twofold benefits of reducing the operational costs and the CO2 emissions. The adoption of a copper cage has been successfully proven to reduce the motor losses. However, this could affect other performance indexes, such as the starting torque. In this paper, the advantages and drawbacks of adopting a copper cage are analysed in depth by comparing the motors performance at different operating conditions, with respect to the more common aluminium cage. Starting from a set of induction machines optimized with an aluminium cage, the effect of the direct material cage substitution is analysed both in terms of electromagnetic and thermal aspects. The overall performance are also compared against machines specifically optimized with a copper cage. With the presented performance comparison exercise, general design guidelines are outlined aimed at improving the efficiency without deteriorating other performance metrics.

中文翻译：

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鼠笼感应电机：铝笼和铜笼之间基于设计的比较


在许多工业应用中，电动机的自启动能力仍然是一个重要的要求，能够简化驱动架构并提高系统的可靠性。各个国家和国际监管机构都以提高这种电机拓扑的效率为目标，并制定了特别政策。事实上，较低的能源消耗可以带来降低运营成本和二氧化碳排放的双重好处。事实证明，采用铜笼可以降低电机损耗。然而，这可能会影响其他性能指标，例如启动扭矩。本文通过比较不同工况下的电机性能，相对于更常见的铝保持架，深入分析了采用铜保持架的优缺点。从一组采用铝保持架优化的感应电机开始，从电磁和热方面分析了直接材料保持架替代的效果。整体性能还与专门使用铜笼优化的机器进行了比较。通过所提出的性能比较练习，概述了一般设计指南，旨在提高效率而不恶化其他性能指标。