Application of amorphous alloy to high speed motors for electric vehicles

随着汽车数量的增加，空气污染变得越来越严重，特别是在中国和印度等发展中国家。汽车对环境的影响已引起广泛关注。与主要依赖化石燃料的传统汽车相比，电动汽车（EV）是一种有效的方式，可以提供一种很好的替代方案，为更合理地使用能源，保护环境和减缓气候变化做出贡献。电动汽车用电动机不仅要高能效、高功率密度、低重量、高性价比，还要满足加速、爬坡、高速巡航等技术要求。虽然永磁同步电动机（PMSM）和感应电动机（IM）已成功地用于电动汽车，但它们都不能完全满足所有要求。近年来，电动汽车对不含稀土或减少稀土的电动机有着强烈的需求。开关磁阻电动机（SRM）已经被研究了几十年，并且已经在飞机上用作起动器/发电机以及在其他工业中使用。汽车牵引马达通常受益于高速操作。在SRM的情况下，磁芯损耗在高频率和高速度下相对较高。为了解决这一问题，近年来，人们开始关注新型磁性材料的研究。非晶合金的铁损比普通硅钢的铁损低得多。因此，将非晶材料应用于电动汽车高速开关磁阻电机是一个有趣的和当前的研究课题。本项目的目的是获得一种低成本的SRM，其功率密度和效率与PM相当。研究内容包括非晶合金磁性能的广泛测量，包括各种定子制造技术（激光切割，冲压等）的铁损。在此基础上，对开关磁阻电机的电磁设计和优化进行了研究，并制作了样机，进行了实验分析。将建立分析模型，研究电磁性能、损耗和效率、冷却行为、电机温度以及机械应力。研究将在卡尔斯鲁厄理工学院和哈尔滨工业大学同时进行。通过该计划的合作，双方可以实现良好的学术交流，促进技术和理论的发展。

With the increase of the number of automobiles, air pollution became more and more serious, particularly in developing countries such as China and India. The impact of cars on the environment has attracted extensive attention. Compared to conventional vehicles mostly depending on fossil fuels, electric vehicles (EVs) are an effective way to offer a great alternative to contribute for a more rational use of energy, environmental protection, and climate change mitigation. Electric motors for electric vehicles should not only be high energy efficient, have a high-power density, low weight and high cost effectiveness, but they also need to satisfy technical requirements such as acceleration, hill climbing and high speed cruising requirements. Although permanent magnet synchronous motors (PMSM) and induction motors (IM) have been successfully used in EVs, neither of them can full satisfy all requirements. In recent years, there are strong demands of rare-earth-free or reduced-rare- earth motors for EVs. Switched Reluctance Motors (SRM) have been investigated for decades and have been used in aircrafts as starter/generators and in other industries. Automotive traction motors generally benefit from high speed operation. In case of SRMs, core losses are relatively high at high frequencies and speeds. In order to solve this problem, researches have paid more attention to new magnetic materials in recent years. The iron losses of amorphous alloy are much lower compared to those of conventional silicon steel. Hence, the application of amorphous material to high speed SRMs for EVs is an interesting and current research topic. The purpose of this project is to obtain a low cost SRM whose power density and efficiency are comparable to PMs. The research contents include extensive measurements of the magnetic properties of amorphous alloy including iron losses for various stator manufacturing technologies (laser cutting, stamping etc.). Furthermore, the electromagnetic design and optimization of a SRM will be researched, a prototype will be manufactured and an experimental analysis will be conducted. Analytical models will be created to research electromagnetic performance, losses and efficiency, cooling behavior and motor temperature as well as mechanical stress.Research will be performed in parallel at the Karlsruhe Institute of Technology and the Harbin Institute of Technology. Through the cooperation of the programme, the two partners can achieve good academic exchanges and promote the development of technology and theory.