Development of a Methodology for Virtual Efficiency Evaluation of Electric Drive Modules

This study focuses on the development of a virtual methodology for the evaluation of the efficiency of an EDM (Electric Drive Module), with a focus on the mechanical characteristics, i.e, the loss that arises in the reduction unit needed to adapt the Electric Motor (EM) characteristics to the vehicle requirements that are commonly split into load losses and non-load losses, depending on their variability with the applied torque. Two units, a test reducer and the EDM of the Fiat 500 Battery-Electric Vehicle (BEV), are modelled with different levels of complexity by using three simulation software tools available in the market (MASTA, AVL Excite and Romax). The simulations are performed in steady-state conditions to replicate the testing activity. The project starts with a review of the analytical and theoretical loss models implemented, the modelling techniques and the testing methodology, and concludes with the simulation and comparison of results with the data coming from the laboratory tests. The results show that analytical formulations still lack on accuracy in the prediction of non load losses, while the models for load losses perform better in terms of percentage error