To enhance the torque of short‐time duty permanent magnet (PM) dual‐redundancy brushless DC motors (DR‐BLDCM) and avoid the motor overheating under a fixed outer diameter and length, a design method based on the optimization of split ratio and stator magnetic density (B_m) considering thermal limitations is presented. The global thermal limitation of DR‐BLDCM is set by limiting loss density. The local thermal limitation of the winding is set by limiting current density. The thermal limitations are taken as the boundary of torque enhancement design optimization. Both the cold backup and hot backup DR‐BLDCM are studied in this paper. By researching the relationship between torque, split ratio, and B_m, the optimal combination of split ratio and B_m are calculated analytically. The influences of thermal limitations on the maximum torque and the optimal combination are analyzed, and the principle to determine the optimal combination is obtained. The analytically calculated results are verified by finite element simulation, and the error is less than 6.82%. A prototype is manufactured based on analytical design results. The error between the calculated and measured copper loss is 6.96%. The verification results show that the proposed optimization method can fully enhance the torque of DR‐BLDCM under the condition of fixed overall dimension and thermal limitations. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

中文翻译：

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双冗余永磁无刷直流电动机的设计优化，以增强扭矩

为了提高短时负荷永磁（PM）双冗余无刷直流电动机（DR-BLDCM）的转矩并避免电动机在固定的外径和长度下过热，一种基于分流比和定子优化的设计方法提出了考虑到热限制的磁密度（B _m）。DR‐BLDCM的全局热限制是通过限制损耗密度来设置的。通过限制电流密度来设置绕组的局部热限制。热限制被视为扭矩增强设计优化的边界。本文同时研究了冷备份和热备份DR-BLDCM。通过研究扭矩，分流比，和之间的关系乙_米，的分流比和最优组合乙_m是解析计算的。分析了热限制对最大转矩和最佳组合的影响，得出了确定最佳组合的原理。分析计算结果通过有限元仿真验证，误差小于6.82％。根据分析设计结果制造原型。计算和测量的铜损之间的误差为6.96％。验证结果表明，所提出的优化方法可以在固定总尺寸和热限制条件下充分提高DR‐BLDCM的扭矩。©2020日本电气工程师学会。由Wiley Periodicals LLC发布。