This study investigates the gradeability performance of an L7e-class electric
micro truck from both vehicle dynamics and thermal perspectives. A 1D simulation
model (Amesim) was developed and validated with multiple test results. Using
inputs such as motor characteristics, drivetrain configuration, and vehicle
mass, the model analyzed vehicle performance on a 20% gradient, calculating the
required torque, achievable motor speed, and corresponding vehicle speed.
Furthermore, gradeability limits were evaluated, and the effects of gear ratio
and airflow rate around the air-cooled motor on both gradeability and thermal
behavior were examined. The findings provide practical insights for improving
the powertrain and cooling system design of lightweight electric vehicles. The
results showed that selecting an appropriate gear ratio can enable the motor to
operate more efficiently under demanding driving conditions. A 20% increase in
the gear ratio was found to delay motor heating by up to 10%. However, its
effect was observed to be negative under driving conditions such as WLTP, which
require variable RPM demand.