Fuel cell system start-up using voltage profile control

A vehicle comprising:

• a fuel cell stack having a plurality of fuel cells and a stack voltage;
• a direct current-direct current (DC-DC) boost converter;
• a battery pack electrically connected to the fuel cell stack and having a DC output voltage;
• a power inverter module (PIM) electrically connected to the battery pack and configured to convert the DC output voltage to an alternating current (AC) voltage;
• an electric machine electrically connected to the PIM and energized via the AC voltage to produce an output torque;
• a drive wheel connected to the electric machine and driven via the output torque from the electric machine to propel the vehicle;
• and
• a controller operable for regulating the stack voltage via the DC-DC boost converter during start-up of the fuel cell stack, and programmed with a plurality of calibrated voltage profiles each having a corresponding magnitude and rate of change, wherein the controller is configured to detect an air start of the fuel cell stack in response to a requested start-up of the fuel cell stack, and responsive to the detected air start, to enforce a predetermined voltage profile of the stack voltage during an actual start-up of the fuel cell stack via regulation of the DC-DC boost converter using the plurality of calibrated voltage profiles.

A method for use with a fuel cell stack having a plurality of fuel cells and a stack voltage, the method comprising:

• detecting an air start of the fuel cell stack via a controller in response to a requested start-up of the fuel cell stack, wherein the controller is programmed with a plurality of calibrated voltage profiles each having a corresponding magnitude and rate of change;
• and
• responsive to the detected air start, enforcing a predetermined voltage profile of the stack voltage via the controller during an actual start-up of the fuel cell stack, including regulating operation of a direct current-direct current (DC-DC) boost converter using the plurality of calibrated voltage profiles;
• wherein the calibrated voltage profiles include a first voltage profile corresponding to an anode pressurization stage and a second voltage profile corresponding to a cathode fill stage, with the second voltage profile having a rate of change that is less than that of the first voltage profile.