REGENERATIVE BRAKING CHARACTERISATION - PART 4

This is the final article in a four-part series on regenerative braking characterisation by Marco Victorero, Test Engineer, Braking Systems in Applus IDIADA.

- Marco Victorero

The objective of this article is to present new advanced testing procedures for regenerative braking. The two first parts of the article introduced the work and presented the methodology –test procedure, instrumentation, post-processing formulae, etc.– for the vehicles whose regenerative system was characterized in terms of durability and performance testing. The 3rd part focused on the results for the brake durabilities: Vehicle 1 completed a short Los Angeles City Traffic (LACT) test, while Vehicle 2 data was gathered across a Mojácar durability.

This 4th and last part, on the other hand, will present the main results for Vehicles 3 and 4, that were tested in IDIADA HQ's proving ground.

1. Performance Testing

1. Vehicle 3

The regenerative behaviour of the vehicle is highly tuneable due to the different selectable levels available through paddles behind the steering wheel Level 0 (no regeneration), Level 1, Level 2, Level 3 and i-Pedal (Single Pedal).

Brake blending is available in all levels except for the neutral gear and Level O which have the same strategy - no regeneration at all.

Coastdown deceleration (no brake pedal application) levels vary from 0,8m/ s2 of Level 1 to 2,3m/s2 of the i-Pedal mode.

The vehicle is not capable of controlling the wheel slip with the electric motors, hence the regeneration is always disconnected when a panic brake application is performed. Nevertheless, this disconnection is performed with a certain slope and keeping a certain amount of small regeneration in the "background" throughout the stop.