Fuel cell system and method for Fluidströmungspulsation for increased stability in PEM fuel cells

Fuel cell system (10) comprising: a fuel cell stack (12); a flow control device (18, 20) that controls a supply of a fluid in a first phase flowing through the fuel cell stack (12); a controller (22) which monitors at least one parameter of the fuel cell stack (12) and the supply controlled to produce pulses of fluid when the at least one parameter crosses a threshold to An in-a second phase fluid from the fuel cell stack (12 ) to wash; and a temperature detecting system that detects a fluid temperature change across the fuel cell stack (12) and a signal to the controller (22) based on the parameter representing the temperature change provides.