Multi-Objective System Design Synthesis for Electric Powertrain Development

The design process of automotive electric power-trains, considering electric machine, gearbox and power electronics, is influenced by manifold requirements regarding performance, efficiency, package and costs. The high variability of component design parameters and packaging-related aspects leads to a complex problem in the design process. In the present work, an innovative system design optimization method is introduced, holistically considering all components and requirements in a multi-objective manner. In this way, the system design synthesis is based on component-specific Pareto optimal designs to handle performance, efficiency, package and costs for given system requirements. The results are displayed as Pareto fronts of electric powertrain system designs variants, from which decision makers are able to choose the best suitable trade-off. The new approach is exemplarily demonstrated on an electric axle drive application with a permanent magnet synchronous machine and a single-speed, two-stage helical gearbox with an integrated differential drive, representing a common topology for electric axle drives in passenger cars.