基于永磁材料改性的高速永磁电机热设计和热管理研究

High-speed permanent-magnet synchronous machine system are the core unit technology and widely used in high power equipment applications because of their advantages including high-power density , high efficiency and large speed range. However, high-power density results in a high loss density and limited heat dissipation, which make the cooling of the high-speed permanent-magnet synchronous machine difficult, especially rotor cooling is a very challenging. The key novelty in this project is increasing resistivity of the Nd-Fe-B magnets to decrease eddy current loss and the circulating cooling in stator and rotor, the objective is to propose thermal design and management schemes for high-speed permanent-magnet synchronous machine. The effect of various factors on eddy current losses, the characteristics of magnet performance and electrical resistivity based on internally segmented sintered magnets , and multi-objective optimization as well as the integral self-cooperating thermal management of high-speed permanent-magnet synchronous machine will be researched. The suitable characteristics of internally segmented sintered magnets will be obtained based on testing and analyzing to type samples. The coupling relationships between the electro-magnetic losses, temperature, speed and liquid flow will be analyzed, which couples finite element method considering the electro-magnetic, fluid and thermal. The thermal design will be performed using a layered multi-objective optimization method, which couples field-circuit coupled FEM, and thermal management schemes will be executed using integral self-cooperating circulating cooling in stator and rotor. The reliability including internally segmented sintered magnets ,thermal design method and thermal management schemes will be experimentally validated. The research results will provide fundamental basis and technical support for the industrialization and practical application of high-speed permanent-magnet synchronous machine.

高速永磁电机具有功率密度高、效率高、转速范围大等优点，必将成为引领新一代高端动力装备的“芯片”单元技术，但其热问题是制约高速永磁电机可靠运行的瓶颈问题，特别是转子散热则更是困难。本项目提出永磁材料掺杂降低转子涡流损耗和定转子一体化自循环冷却的新方法，为高速永磁电机热设计和热管理提供全面的解决方案。拟研究多因素对高速永磁电机涡流损耗的影响、永磁材料掺杂对其磁特性及电阻特性影响、高速永磁电机系统分层多目标优化设计、基于多场耦合的高速永磁电机一体化自协调热管理等；揭示基于掺杂的永磁材料磁特性与电阻率变化规律;提出基于损耗最小的高速永磁电机系统分层多目标优化设计方法;揭示多场耦合的多参量耦合机制，查明电磁、温度、速度及流量之间的耦合关系。最后，搭建基于硬件的实时仿真和实验平台，验证永磁材料改性、一体化自循环冷却方法的有效性，为高速永磁电机的产品化、实用化提供理论基础和技术支撑。

高速永磁电机具有功率密度高、效率高、转速范围大等优点，必将成为引领新一代高端动力装备的关键技术。然而其热问题是制约高速永磁电机可靠运行的瓶颈问题。目前国内外对高速永磁电机的热问题研究主要集中在损耗分析、温度场计算和热分析、电机转子保护套设计等方面。对于高性能永磁材料掺杂、基于系统损耗最低的优化设计及定转子整体散热技术等方面的研究较少。.本项目针对多因素对高速永磁电机涡流损耗的影响、永磁材料掺杂对其磁特性及电阻特性影响、高速永磁电机系统分层多目标优化设计、基于多场耦合的高速永磁电机一体化自协调热管理等多方面进行研究， 取得了如下一些重要成果：.建立了一种定子铁心损耗和绕组损耗的全域计算方法，同时考虑高速永磁电机涡流损耗的影响，建立高速永磁电机系统场路耦合模型；建立了现有牌号的永磁材料的性能数据库，对永磁材料掺杂对其磁特性及电阻特性影响进行总结，分析永磁体改性后性能变化；建立高速永磁电机的电磁-温度-流体耦合分析模型，利用多物理场耦合分析方法开展高速永磁电机系统的综合分析，对高速永磁电机系统进行了分层多目标优化设计；建立了定转子一体化冷却方案的电磁-温度-流体耦合分析模型，完成了定转子一体化冷却方案；制造了一台带有导流叶片的高速永磁电机的样机，搭建高速永磁电机系统硬件实时仿真和实验验证平台，对基于多场耦合的高速永磁电机一体化自协调热管理进行验证。.本项目的研究成果为高速永磁电机热设计和热管理提供全面的解决方案。为进一步的工程应用提供理论支持和实验依据，为未来高速永磁电机在新领域的发展和应用提供新的思路。