Direct fuel cell-supercapacitor hybrid power source for personal suburban transport

In view to proposing an alternative to oversized energy sources currently installed in electric vehicles for suburban transport, a direct hybrid fuel cell (FC)-supercapacitors (SC) source has been designed and tested on a test bench. The rated 15.6 kW source-with an air-cooled 5.6 kW FC and a 165 F SC storage device-was shown perfectly suited to traction of a 520 kg vehicle along the NEDC cycle, then validating the previously developed concept of a one-ton car propelled by a 10 kW FC in the rated 30 kW hybrid source for this cycle. In comparison with a FC used alone, hybridization was shown to allow the power demand for the cell to vary in quite a narrower range, as formerly observed. Moreover, the rates of fuel cell voltage and current generated in the driving cycle, were shown to be reduced by one order of magnitude by the direct hybridization which is to contribute to the FC durability. Two operating parameters were shown to have a significant effect on the hybrid source efficiency, namely the capacity of the SC at 110 or 165 F, and the recovery of deceleration power-emulated by an external power supply-which can decrease by 25% the fuel consumption in NEDC cycle conditions, as predicted by the model.