The invention provides a vehicle-mounted fuel
cell system and a start operation control method thereof, belongs to the technical field of
fuel cells, and solves the problem that a coordination control method for a fuel
cell and a DC-
DC converter within a wide step-up ratio range in the process of switching from
cold start to normal operation does not exist in the prior art. The
system comprises a galvanic
pile, a DC-
DC converter,
hydrogen equipment, air equipment and a controller. The
hydrogen inlet of the electric
pile is connected with the output end of the
hydrogen equipment, the air inlet is connected with the output end of the air equipment, and the power supply end is connected with the DC-
DC converter. And during low-temperature starting, the controller controls the DC-DC converter to be in a low
switching frequency, the air equipment and the hydrogen equipment are started, and the stoichiometric ratio and the current of air entering the
pile are adjusted, so that the pile outputs target
voltage. And in the switching process, after the controller controls the output current of the electric pile to be reduced to a calibration value, the in-pile air stoichiometric ratio is adjusted to a target stoichiometric ratio. And during high-temperature operation, the controller controls the DC-DC converter to convert high
switching frequency, and then the parameters of the fuel
cell are adjusted in real time.