Impact of Rolling Resistance Modeling on Energy Consumption for a Low Voltage Battery Electric Vehicle

A promising form of transportation, particularly in cities, is the use of compact and lightweight passenger cars with low-voltage electric traction system drives. Energy efficiency is a key factor for these applications to enhance performance and extend range. Energy-efficient control techniques and optimal design methodology can be used to minimize the vehicle's power losses in different operating conditions. These methods rely on the electric drive module model and the estimation of power losses at the vehicle level. A representative model of energy losses at tire ground contact is essential for an accurate prediction of energy consumption. Most of the existing literature about energy management on hybrid and electric vehicles accounts for rolling resistance as a constant or speed-dependent term. The present work proposes a modeling approach of the rolling resistance as a function of tire slip and longitudinal vehicle speed. Several vehicle simulations have been performed using a forward model of the retained 52 V battery electric vehicle (BEV). To demonstrate the contribution of dissipation due to tire slip, the effect of rolling resistance losses on energy consumption is assessed in urban driving cycles.

I. Introduction

Nowadays, the automotive industry is facing a substantial shift towards electrification and new forms of transportation to meet sustainability goals and more stringent CO2 regulations [1]. The interest in new ways of urban mobility is increasing, such as micro-mobility solutions, e-bikes, and e-scooter [2]. In the context of micro-mobility, the market of light quadricycles (L6) and heavy quadricycles (L7) [3] is rapidly increasing as a promising mobility form, especially in urban areas. These vehicles (for example Citroen AMI or XEV Yoyo) feature a mass lower than 500 kg, low voltage traction systems (lower than 60 V [4]), and limited range and performance. The maximum rated power of an L-category vehicle is limited to 15 kW, thus it is not sufficient to cover extra-urban driving missions. Furthermore, these vehicles are not subjected to all the passive and active safety requirements of vehicles classified as M (Euro NCAP).