Fuel cell system and control method therefor

A fuel cell system that includes a fuel cell, and a cell-side passage for a cooling medium, the cell-side passage having a first cell-side passage and a second cell-side passage that are disposed on a surface of the fuel cell, the fuel cell system comprising:

• a fuel cell activation portion that starts electricity generation of the fuel cell;
• a first cooling medium passage in which a first pump is disposed, the first cooling medium passage being provided for passing the cooling medium through the first cell-side passage;
• a second cooling medium passage in which a second pump is disposed, the second cooling medium passage being provided for passing the cooling medium through the second cell-side passage;
• and
• a pump control portion programmed to stop the first pump and the second pump for a predetermined period, after a start of the electricity generation caused by the fuel cell activation portion, at a time when a temperature of the fuel cell is lower than or equal to a predetermined value,
• wherein the pump control portion is programmed to, after the predetermined period elapses, alternately switch, according to an elapsed time, a direction of a flow of the cooling medium in the first cell-side passage and the second cell-side passage between a first state and a second state by controlling operation of the first pump and the second pump;
• wherein in the first state the flow of the cooling medium in the first cooling medium passage is stopped and the cooling medium in the second cooling medium passage is caused to flow in a first direction along the surface of the fuel cell, and in the second state the cooling medium in the first cooling medium passage is caused to flow in a second direction that opposes the first direction and the flow of the cooling medium in the second cooling medium passage is stopped.