Patent ID: 7473479

Claim:
A current limiting system for fuel cells, which limits electric current generated by a fuel cell stack, the fuel cell stack including a plurality of single cells generating electricity by a chemical reaction between fuel gas and oxidant, the current limiting system comprising: a cell voltage detector which detects a lowest cell voltage amongst the plurality of single cells; a current detector which detects a current generated by the fuel cell stack; an input device through which are inputted the lowest cell voltage detected by the cell voltage detector and the generated current detected by the current detector; a target current limit value setting device which calculates a target current limit value for limiting the current generated by the fuel cell stack in accordance with the lowest cell voltage; a current limit value setting device which sets a current limit value to the target current limit value when a difference between the current limit value and the generated current becomes smaller than a first predetermined value; and an output device which outputs the current limit value either to a current limiter for limiting the current generated by the fuel cell stack in accordance with the current limit value or to an electric power consumption controller for controlling electric power consumption of loads that consume the generated current, wherein limiting the current generated by the fuel cell stack is released when the lowest cell voltage becomes greater than a second predetermined value, wherein the current limit value is gradually changed based on the current generated by the fuel cell stack when limiting the current generated by the fuel cell stack is released.