A STUDY OF REGENERATIVE BRAKING SYSTEM (RBS) INVOLVING MODIFIED BRAKE PEDAL FOR RETROFIT CONVERSION OF HYBRID ELECTRIC VEHICLE (HEV)

Regenerative braking system has always been a very important feature in all hybrid and full electric vehicles since it helps to improve on fuel economy, as well as conserve energy efficiency. Unlike conventional vehicles which apply the friction brake system and contribute to the loss of the kinetic energy in the form of heat energy and friction, regenerative braking can conserve the energy lost during braking. Issue is addressed as to why this project is carried out. There is a lack of regenerative braking performance study for a bench-testing prototyping stage in retrofit conversion of hybrid electric vehicles. Also, the current solution to implement a regenerative braking system in existing vehicle part is costly. In this project, alternatives are first, explored to design brake pedal assembly to detect brake pedal movement for regenerative braking. In order to achieve this, a linear potentiometer is selected. This is followed with the design of a voltage follower circuit to produce stable output voltage to the motor controller. Then, configuration of the circuitry to the motor controller is learnt and set-up. Last part of the step covers the monitoring and experimentation of the performance for regenerative current by using the lab equipment. The bench-testing is done in free or zero-load condition. Results obtained showed a very little regenerative current being fed back into the battery when the brake pedal is exerted at its maximum, with respect to different motor speed run. Further work can be carried out to test the actual regenerative performance when the prototype is fully mounted into the vehicle.