Efficient braking energy recovery using bidirectional step up converter in fuel cell and battery electric vehicles

Düşmez S., VURAL B., UZUNOĞLU M., BOYNUEĞRİ A. R., Zhihao L.

International Journal of Powertrains, vol.4, no.2, pp.89, 2015 (Peer-Reviewed Journal)


The topology of the power conditioning unit (PCU) that is used with energy storage system (ESS), has a vital role especially in braking energy recovery. In recent studies, conventional bidirectional half-bridge topology is widely used as a PCU for ESSs. Due to its structure, it does not have the capability of capturing braking energy when the voltage across the motor terminals is lower than ESS voltage. This study investigates the feasibility of utilising a PCU with stepping up capability in regenerative braking operation mode, focusing on the additional braking energy that can be captured in comparison with that of the conventional half-bridge buck/boost converter. In order to verify the advantageous of the proposed approach in braking energy recovery, two 1 kW prototypes, a conventional half-bridge buck-boost and cascaded buck-boost converters are designed and tested for three different drive cycles including normalised version of ECE-15.