Application of amorphous alloy to high speed motors for electric vehicles

• Applicant: Professor Dr.-Ing. Martin Doppelbauer
• Subject Area: Electrical Energy Systems, Power Management, Power Electronics, Electrical Machines and Drives
• Term: from 2018 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 392021023

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.

• DFG Programme: Research Grants
• International Connection: China
• Partner Organisation: National Natural Science Foundation of China
• Cooperation Partner: Professorin Dr.-Ing. Feng Chai