Electric Vehicle Simulation for Design Optimization

摘要

Currently available electric passenger vehicles have revealed a lack of design sophistication that has highlighted the need for an accurate method of forecasting performance. An electric vehicle computer simulation program was developed to satisfy that need. The approach was to establish a very comprehensive and flexible vehicle model and simulate its operation on a realisitc driving cycle. The driving cycle selected was the Federal Urban Driving Sequence. A thorough vehicle model was established that incorporates aerodynamic drag, rolling resistance, both rotational and translational inertial effects, and component by component dynamic power train efficiencies. Battery discharge performance is tracked by a fractional-utilization algorithm with corrections for short-term discharge effects. The simulation compares required power obtained from the driving cycle speed schedule and vehicle model characteristics with the available power at the motor for each time increment of the driving cycle to compute battery fraction used and deviation from the speed schedule when available power is insufficient. These results of the simulation can be used to evaluate an existing vehicle's performance, or, if desired, to develop vehicle parameters to obtain a specified performance level.