Frequency-separation-based energy management control strategy of power flows within electric vehicles using ultracapacitors

This paper deals with a frequency-based energy sharing method between batteries and ultracapacitors (UC) as power sources within an electric vehicle (EV). A frequency splitter is used for routing the low-frequency content of power demand into the battery and its high frequencies into the UC system, taking profit from the UC as a peak power unit. The autonomy may thus be increased while also preserving the battery life. Real-time experiments on a dedicated test rig validate the proposed energy management approach.