Carbon footprint minimization of electric powertrains by multi-objective design optimization

The reduction of greenhouse gas emissions is a central motivation for electrification of road traffic. Although electric vehicles (EVs) do not produce local greenhouse gas emissions during operation, their production and the generation of electrical energy required for operation might still result in a relevant carbon footprint. Accordingly, it is important to incorporate considerations regarding greenhouse gas emissions in the design process of new EVs and that way aim to minimize their carbon footprint. In the present work, this is achieved by consideration of both production emissions and in-use emissions in a design optimization method for electric axle drives (e-drives). Accordingly, the carbon footprint of an e‑drive can be directly minimized alongside the optimization of other design objectives, e.g., production cost, energy efficiency and package integration. The optimization result is represented as Pareto front of various optimal design solutions for specified e‑drive requirements. The proposed method is applied to a case study, which involves the optimization of an e‑drive for a passenger vehicle. The obtained Pareto front and found trade-offs between carbon footprint, cost and energy efficiency are discussed. Furthermore, a promising design solution from the Pareto front is selected to guide subsequent development phases.