Application of Supercapacitor for Braking Energy Recovery in Electric Bicycles

Author: Enrico Catahan

Catahan, Enrico, 2024 Application of Supercapacitor for Braking Energy Recovery in Electric Bicycles, Flinders University, College of Science and Engineering

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Abstract

In a generation where the consequences of climate change have become more apparent, environmental awareness has been rapidly gaining momentum. There has been more conscious effort to promote sustainability and reduce carbon footprints. The transportation sector is one of the major culprits of CO2 emissions worldwide. The development of green transportation has been crucial to sustainable mobility as operating one does not produce carbon emissions. Electric bicycles, whose popularity worldwide continues to rise, requires minimal space, and contributes to reducing traffic. But comparing to electric vehicles (EVs), e-bikes have much smaller batteries, which translates to a significantly shorter driving range. While battery technology continues to develop, it still generally suffers from a limited lifespan. Regenerative braking, which converts kinetic energy produced by a moving body to electrical energy, is almost synonymous to EVs. Due to the significant difference in weight and driving speed limitations, e-bikes have much less kinetic energy potential compared to EVs. This study proposes a regenerative braking system for e-bikes that utilises the high power density of supercapacitors to more efficiently store energy recovered during braking. The improvement in the motor drive range compared to a conventional e-bike was investigated using simulation models developed in MATLAB/Simulink. Charging and discharging characteristics of the supercapacitor were measured with changes to the road inclination and braking behaviour and a drive cycle representing an actual bicycle route in South Australia was derived to obtain a practical representation of the improvement in performance. The results of the study showed the potential of regenerative braking in e-bikes using supercapacitors and discusses the conditions that need to be met for effective energy recovery during braking. Future plans suggest the next steps in the study, including which factors to focus on to maximize energy recovery.

Keywords: BLDC motor, drive cycle, e-bike, electric bicycle, pedelec, regenerative braking, supercapacitors

Subject: Engineering thesis

Thesis type: Masters
Completed: 2024
School: College of Science and Engineering
Supervisor: Dr. Amin Mahmoudi