Control of maximum output current of fuel-cell stack e.g. for domestic AC loads, involves initially setting the fuel flow through the fuel-cell stack in order to generate current

摘要

Fuel-cell stacks forming part of a fuel-cell system can often function in fuel depletion supply mode, as a result of an insufficient supply of hydrogen until the reformer overcomes its traditionally sluggish response and finally 'kicks in' to provide the correct level of hydrogen. This sort of operation can lead to damage of the fuel cells in the stack. Operation of the fuel-cell stack now requires initially setting the flow of fuel through the fuel cell stack (32) so as to generate a current, and then the cell voltages of the fuel cell stack are sampled so as to determine the minimum cell voltage. A minimum threshold value for the current is then set and is at least partly based on the minimum cell voltage.