Design and Analysis of Interior Permanent Magnet Motor for Electric Vehicle Application Considering Irreversible Demagnetization

The design of permanent magnet motors for the battery-powered electric vehicle has different aspects. In this study, the conceptual design process of an electric machine for Sedan Low car is presented. Based on the vehicle requirements, an interior permanent magnet motor with a maximum power of 120 kW with different slot/pole combinations is designed. To obtain the best slot/pole combination, The New European Driving Cycle in terms of crucial performance characteristics is compared. Given the importance of irreversible demagnetization phenomenon to an electric vehicle application, an accurate approach to determine the irreversible demagnetization rate is first introduced. Design tips are then proposed to reduce the probability of the irreversible demagnetization. Finally, fault-tolerant design in case of irreversible demagnetization withstand capability is carried out using a two-level Taguchi optimization approach. The results obtained from this study indicated that the proposed approach is effective in the fault-tolerant design of the permanent magnet machine for electric vehicle applications.