Regenerative Braking Experimental Tests and Results for Formula Student Car ()
ABSTRACT
In this
paper, the tuning process of a regenerative braking system for a full electric
Formula Student car is reported. Experimental results will be discussed and
recovered energy will be measured. In order to obtain the best tuning some
preliminary requirements have been decided: no-slip
motion of traction wheels during braking phase, no over current and over voltage
of Li-ion cells and the best feeling from the braking pedal for the driver. The
main target of the regenerative braking system is to obtain the maximum recovered
energy during the Endurance event in a typical Formula Student Competition (FS
Germany, Hockenheim ring). First, an accurate estimation of the admissible
braking torques with the tires used was carried out, starting from the magic
formula of Pacejka of the tires. The maximum electric braking torque that the
installed engine can provide at various speeds was then estimated, compatibly
with the charging currents allowed by the storage system. Subsequently, a
mechanical regulating device for regenerative braking was designed and
described here, installed directly on the gear lever system that connects the
brake pedal to the brake pumps. The proposed system is able to appropriately
delay the entry into action of the hydraulic brake pumps and this delay is
mechanically adjustable by acting on threaded pins. In this way, the interval
of actuation of the brake pedal which activates only the electric braking can
be adjusted and tuned. Finally, the overall project was tested on the track, in
order to validate the hypotheses previously calculated and determine the
setting capable of optimizing the energy recovered during a test equivalent to
the Endurance event, compatibly with the constraints of the installed systems
on board.
Share and Cite:
Martellucci, L. and Giannini, M. (2021) Regenerative Braking Experimental Tests and Results for Formula Student Car.
Journal of Transportation Technologies,
11, 78-89. doi:
10.4236/jtts.2021.111005.