Model development of electric vehicles based on test data analysis

Abstract

Performances of electrified vehicles, such as Hybrid Electric Vehicles (HEVs), Plug-in Hybrid Electric Vehicles (PHEVs), and Battery Electric Vehicles (BEVs) are highly depending on not only the performance of the battery used in the powertrain system but also the utilization of the battery for the driving. By using simulation models of the battery, it is possible to save the effort and the time to evaluate the impact of the battery technology in the electrified vehicle. However, developing a good simulation model is not an easy task because it is difficult to obtain the parameters used in the simulation model. In this study, a process to estimate the parameters of the battery model based on data obtained from bench dynamometer tests is introduced, and it shows that a good battery model is able to be developed by using vehicle test results, although the battery is not taken apart from the powertrain system. The simulation models are evaluated in various test driving cycles, and 70% of simulations produce the output voltage within 1% of RMS error, compared to the test data. This parameter estimation process would not be possible to fully replace previous model development process for batteries, but it could be a feasible solution to analyze the performance of the batteries and build appropriate simulation models for the electric vehicles. Copyright © 2018 Society of Automotive Engineers of Japan, Inc. All rights reserved