Patent ID: 8993184
Filing Date: 2015-03-31
Classification: B60L,H01M,Y02E,Y02T

Abstract:
1. A fuel cell system comprising: a fuel cell comprising a catalyst and generating electric power by promoting a reaction of hydrogen or oxygen by the catalyst; a gas supply unit for supplying at least either of oxygen and hydrogen to the fuel cell; a coolant supply unit for supplying a coolant to the fuel cell; a voltage control unit for controlling a voltage outputted from the fuel cell; a power consuming load driven by the electric power outputted from the fuel cell; and a control unit for controlling the gas supply unit, the coolant supply unit and the voltage control unit, wherein the control unit is configured to control the gas supply unit and the voltage control unit, based on a target voltage of the fuel cell calculated on the basis of required electric power and a switching voltage equal to or less than a voltage range where an oxidation-reduction reaction of the catalyst proceeds; the control unit executes a first mode of controlling the voltage control unit such that an actual voltage of the fuel cell corresponds to the target voltage, if the target voltage is equal to or less than the switching voltage; and the control unit executes a second mode of having actual electric power outputted from the fuel cell correspond to the required electric power by controlling the voltage control unit such that the actual voltage of the fuel cell is kept at the switching voltage, along with changing an actual current of the fuel cell through changing at least either of oxygen and hydrogen concentrations through controlling the gas supply unit to modify IV characteristics of the fuel cell, if the target voltage is more than the switching voltage.