Abstract
The study of changing combination of motor/generator and transmission is actively conducted to improve the specific electric consumption of BEV. In this study, OpenModelica model provided by TRAMI was used to predict the specific electric consumption in both steady run and WLTC cycle with changing maximum motor speed, transmission system, and number of gear speed. Sensitivity analysis was also conducted to examine the factors that affect the efficiency improvement of electric vehicles. As a result, it was quantitatively found that i) WLTC ranking does not necessarily accord with steady one, ii) the ring gear output is good when using planetary gear system and iii) CVT shows high mechanical efficiency by keeping low input speed and wide ratio-coverage and the optimization of shift map will be required, and iv) a combination of 2 motor and multi-speed is the best in specific electric consumption.