FCBEV operating modes
Electric driving
Fuel cell off
Power electronics
If the high-voltage battery has been charged, the
vehicle can be driven electrically. In this case, the fuel
cell does not supply any energy and does not
consume any hydrogen.
High-voltage
battery
supplies power
Electric motor runs as drive unit
lk
Electric driving and charging
Fuel cell is active
The fuel cell is activated when the charging state of
the high-voltage battery requires its power. The
electrical energy for driving and for charging the
high-voltage battery is produced from the fuelled
hydrogen with the aid of oxygen from the air.
High-voltage
battery
charging and
Electric motor runs as drive unit
supplying power
Fuel cell off
Regenerative braking
The electric motor exclusively takes care of
regenerative braking. During over-run, the electric
motor functions as an alternator. It charges the high-
voltage battery via the power electronics.
High-voltage
battery
is charged
Electric motor runs as alternator
Hydrogen for the fuel cell
The hydrogen is topped up at special filling pumps. The fuelling procedure is identical to that for natural gas. The
hydrogen is pumped into pressurised tanks under the vehicle at pressures up to 700 bar. Due to the physical
properties of hydrogen, 80 litres weigh about 6.44kg. The hydrogen reaches the fuel cell via pressure reducers. At
an operating pressure of 3 bar, it supplies a direct voltage of 250V to 450V.
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