Power generation system and method of operating the same

A power generation system comprising:

• a fuel cell system including a fuel cell configured to generate electric power using a fuel gas and an oxidizing gas, a case configured to house the fuel cell, and a ventilator;
• a controller;
• a combustion device including a combustion air supply unit configured to supply combustion air;
• an air intake passage configured to supply air to the case;
• and
• a discharge passage formed to connect the case and an exhaust port of the combustion device and configured to discharge an exhaust gas from the fuel cell system and an exhaust gas from the combustion device to an atmosphere through an opening of the discharge passage, the opening being open to the atmosphere, wherein:
• the ventilator is configured to discharge a gas in the case to the discharge passage to ventilate an inside of the case;
• and
• in a case where the controller determines that the combustion device has operated when the ventilator is operating, the controller increases an operation amount of the ventilator.