Optimization-Based Design Model for Electric Traction Motors Considering the Supply Risk of Critical Materials

Electric Vehicles (EVs) are considered among one of the ‘clean’ energy technologies in the transportation sector because the vehicles themselves do not generate combustion emissions. However, the substantial environmental footprint associated with the materials needed to create these technologies (extraction, manufacturing, and solid waste at end of life) calls into question their ‘clean’ label. In addition, their increasing demand adds to the existing supply risk (SR) through the requirement of critical materials. To address this, the purpose of this study is to establish a design model for electric traction motors, which are used in EVs, that will address the SR issues early in the design stage. The design model incorporates a genetic algorithm with the following objectives: minimum motor mass, minimum energy consumption, and minimum SR-equivalent. The SR-equivalent objective prioritizes the minimization of materials with high SR. Using the case study of a surface-mounted permanent magnet synchronous motor, results show how each objective is related to each other and to the parameters chosen as variables. Further analysis shows the benefits of minimizing for SR-equivalent of required materials. Future work is needed to improve the design model in terms of other important metrics such as minimizing environmental impact and cost.