Fuel cell system

A fuel cell system that warms up a fuel cell by carrying out a low-efficiency operation with a low power generation efficiency compared with a normal operation, comprising:

• a voltage control unit programmed to, when a setting condition is not satisfied, shift the operation from the low-efficiency operation to the normal operation by performing a ΔV control, in which an output voltage of the fuel cell is controlled to achieve system required power while considering charge/discharge amounts with respect to a capacitance component of the fuel cell, whereas when the setting condition is satisfied, the operation is automatically shifted from the low-efficiency operation, not through the AV control, to the normal operation;
• a supply oxidant gas control unit for increasing an oxidant gas supplied to the fuel cell by a predetermined amount when shifting the operation from the low-efficiency operation to the normal operation;
• a derivation unit programmed to derive an output power deviation of the fuel cell by detecting output power of the fuel cell before and after the increase of the oxidant gas;
• and
• a judgment unit programmed to make a judgment on whether or not the setting condition is satisfied when shifting an operation from the low-efficiency operation to the normal operation,
• wherein, when the derived output power deviation of the fuel cell is below a set power threshold, the judgment unit is programmed to judge that the setting condition is satisfied.