Improving Post Assembly Magnetization Performance Through High-Temperature Magnetization

With the increasing demand for electric vehicles, the use of Permanent Magnet Synchronous Motors (PMSM) which have characteristics such as high efficiency and high energy density has been expanding. For mass production of PMSM, the Post Assembly Magnetization process, where unmagnetized permanent magnets are inserted into the rotor and then magnetized using a magnetization yoke, is used widely. However, for products with a smaller outer diameter rotor than the magnetizer`s inner diameter that does not fit the dedicated magnetization yoke for recycling the magnetizing system, applying the same magnetic field can show results less magnetizing ratio causing increasing leakage flux with the long air gap. Therefore, this paper proposes optimizing the temperature of permanent magnets by heating them to reduce magnet coercivity, achieving the same magnetization performance with the existing magnetizer without increasing the capacity of the magnetization power supply or redesigning the magnetization yoke. This research is expected to enable the use of a universal magnetizer for rotors of different sizes, thereby reducing production costs. The analysis will be conducted using ANSYS Electronics Desktop 2019 R3. Copyright © The Korean Institute of Electrical Engineers.