Fuel cell system and method for controlling fuel cell system

A fuel cell system incorporated in a vehicle, the fuel cell system comprising:

• a fuel cell that uses a reaction gas to generate electric power;
• and
• a controller that controls an electric power generation performed by the fuel cell, wherein when output restriction that restricts the electric power output by the fuel cell is performed,
• (a) the controller does not store in a memory of the controller a content of the performed output restriction as a history in a case where:
• (i) a throttle opening of a throttle is smaller than an opening threshold, (ii) an output request is smaller than an output threshold, or (iii) both the throttle opening of the throttle is smaller than the opening threshold and the output request is smaller than the output threshold, the throttle accepting an instruction of adjusting a speed of the vehicle, the output request being issued to the fuel cell and set in accordance with the throttle opening, and
• (b) the controller stores in the memory the content of the performed output restriction as the history in a case where a condition specified in advance is satisfied while the throttle opening is greater than the opening threshold and the output request is greater than the output threshold.