沈阳工业大学鞠孝伟等：面向可靠性的SiC逆变器驱动电动汽车牵引电机发夹绕组设计

电动汽车驱动电机不断向高频高压化发展，结合扁线绕组和碳化硅逆变器已成为主要技术方案之一，导致扁线绕组槽内匝间电压应力和温度不断升高，增加了局部放电的风险，对绝缘安全性提出了很大挑战。因此，本文针对这一问题提出了基于可靠性导向车用驱动电机扁线绕组设计方法。首先，本文基于一台8极48槽6层扁线绕组驱动电机，结合扁线绕组层间换位特点，分析了匝间电压应力和温度的不均匀分布规律。其次，建立了该电机的高频等效电路模型，基于场路耦合有限元方法计算得到匝间电压应力最大值及其分布位置，仿真与实验误差仅为5.7%，验证了所提模型的准确性。然后，提出了一种改进的扁线绕组连接方案，使最大电压应力降低了29.3%。并通过分析扁线绕组槽内匝间的温度分布情况，探讨了温度对绕组绝缘局部放电的影响。最后，考虑电压应力和温度耦合作用下，计算并实验验证了匝间绝缘的局部放电起始电压。本文提出了一种面向可靠性导向的车用驱动电机扁线绕组设计方法和流程，实现在电机设计阶段扁线绕组电机绝缘无局部放电设计。 

With the development of high-frequency and high-voltage traction machines (TM) incorporating hairpin windings (HW) and SiC inverters for electric vehicles (EV), both the interturn voltage stress and temperature within HW are rising, increasing the risk of partial discharge (PD), and presenting significant challenges to insulation safety. Therefore, this paper addresses this issue and proposes potential solutions. Firstly, the paper examines an 8-pole, 48-slot, 6-layer HW TM to highlight the unique characteristics of this winding structure, and explains the uneven distribution of interturn voltage stress and temperature. Subsequently, a high-frequency equivalent circuit model of the HW TM prototype is developed. The error of simulation and experiment is only 5.7 %, which proves the accuracy of the model. Then, an improved HW scheme is proposed to lower the maximum voltage stress by 29.3 %. Furthermore, the temperature distribution of HW TM is analyzed to facilitate a detailed examination of the impact of temperature on insulation PD. Finally, the partial discharge inception voltage (PDIV) of interturn insulation, considering temperature effects, is calculated and verified through experiment. The paper proposes a reliability-oriented design method and process for HW TM. It demonstrates that the reliability-oriented design can achieve PD-free performance in the design stage of HW.