Analysis and choice of representative drive cycles for light duty vehicles – case study for electric vehicles

Abstract

Since the homologation drive cycles are not all entirely representative of real everyday driving conditions, additional cycles must be used to properly quantify the energy consumption of electric vehicles. Three methodologies have been developed to objectively determine a limited number of additional drive cycles. The first methodology is based upon a simple comparison of velocity profiles expressed on the same time scale. The second is based on a correlation analysis of various statistical criteria defined for each cycle. Finally, the third methodology is based on an automatic clustering technique (K-means algorithm). These three methodologies have been used to analyse 18 drive cycles including official homologation cycles used in Europe (NEDC), Japan (JC08) and in the US (FTP72), and transient non-official cycles representing real world driving patterns (Artemis, Hyzem and Eurev cycles). When applied to these cycles, all these approaches allow the identification of a reduced number of five representative cycles enabling an efficient characterization in terms of the performance of electric vehicles in urban, extra-urban and highway conditions.