基于外转子横向磁通发电机的再生制动式永磁缓速器的研究

Retarder has become the essential device for the automotive braking system, especially for heavy vehicles. Permanent magnet retarder is a new auxiliary braking device developed in recent years and it is the most competitive retarder for the future. Currently, the main problem that restricts the development of permanent magnet retarder is that its braking torque density is too small. So, this project aims to adopt external rotor transverse flux generator to solve this problem. Adopting the structure can significantly improve the regenerative braking capability and torque density of permanent magnet retarder. This will help to accelerate the practical realization of permanent magnet retarder..The external rotor transverse flux machine operating as a regenerative retarder is a special kind of generator application. The main scientific problems of the project include the following two aspects. Firstly, coupled mechanical, electrical, magnetic and thermal model of the external rotor transverse flux generator will be investigated under vehicle braking condition. Its design and analysis methods will be established. Secondly, a new structure of the retarder or improved structure will be proposed and the control circuit and corresponding regenerative strategies will be given. These will help to construct regenerative retarder system, form energy feedback methods and carry out multi objective optimization. Through the research of this project, the currently problems of permanent magnet retarder will be effectively solved. It helps to the energy saving and safety improving for automobiles and it has great application potential.

缓速器已经成为汽车制动系统，尤其是重型汽车的必备装置。永磁缓速器是近年发展起来的新型辅助制动装置，是最具竞争力的未来缓速器。目前制约永磁缓速器发展的最主要问题是其制动力矩密度偏小，本项目拟采用外转子横向磁通发电机结构来解决这一问题。采用该结构可以显著提高永磁缓速器的再生制动能力和转矩密度，这将有助于加快实现永磁缓速器的更大规模实用化。.外转子横向磁通发电机作为再生制动缓速器，是一种特殊的发电机应用。项目拟就其主要科学问题开展深入研究，包括以下两方面：一是研究车辆制动工况下外转子横向磁通发电机的机、电、磁、热多领域耦合模型，建立其设计及分析方法；二是提出缓速器本体的新结构或改进结构，给出再生制动式缓速器的控制电路与策略，构建再生制动式缓速器系统并研究其能量回馈方法。并在此基础上，进行多目标综合优化。通过本项目的研究将有效解决目前永磁缓速器存在的问题，有利于汽车节能和安全性提升，应用潜力巨大。

本项目实现了研究目标，即：提出了外转子横向磁通发电机的新结构，或者对现有外转子横向磁通发电机的结构进行改进，使其适合再生制动缓速器的应用；实现了能够在重型车辆上实际应用的再生制动永磁缓速器系统，利用外转子横向磁通发电机在转矩密度上的优势和能量回馈后的节能效果，实现了材料和制造成本低于现有的液力缓速器或电涡流缓速器产品。.本项目提出的发电机新结构具有以下特点。采用了横向磁场磁通反向结构，在横向磁场电机能实现较高电负荷和磁负荷基础上，通过定子侧铁心内装有永磁体，使得气隙磁场双极性变化，磁通变化率更大，能够进一步提升发电机转矩密度；永磁体固定在定子铁心内，转子侧仅由铁心组成，发电机散热性能良好，机械强度高，可靠性高。定子铁心、转子铁心无论采用硅钢片叠成，还是采用软磁复合材料直接成型，制造工艺简单，发电机适合于大规模批量生产。由于本项目提出的发电机新结构具有低速大力矩的特点，因此也适合风能和海洋能（潮汐能或波浪能）的发电应用。