An Accessible Pre-design Calculation Tool to Support the Definition of EV Components

The new freedoms in design that electric powertrains offer lead to a wide variety of configurations to consider when developing an electric vehicle (EV) from scratch. Furthermore, the strong relation of the battery size with vehicle weight, range and performances leads to a set of interrelated dependencies that can result in many design loops to fulfil the targets and regulations simultaneously. The paper presents a tool that integrates the main relations regarding vehicle targets, market and regulations constraints and plots them as restrictions for vehicle development. As a result, the tool depicts a set of feasible vehicle configurations that could fulfil the targets. Furthermore, to better assist selection, it also provides a sensitivity analysis of the performances and the user can introduce a cost function depending on vehicle weight and battery size. The tool is aimed at providing an overview of specifications for component selection avoiding detailed vehicle modelling in the early pre-design phase in which vehicle characteristics and even powertrain architecture are unknown. Finally, the tool is evaluated by modelling one of its solutions for passenger car for three different architectures in the simulation software vemSim. Furthermore, for one of the architectures, two control strategies were simulated, leading to a total of four simulations. The results of the simulations are compared to the solution of the pre-design tool to evaluate the level of fidelity and the deviations in the final result that can appear depending on the architecture, components and control strategy.