A diagnosis method for identification of the defected cell(s) in the PEM fuel cells

Incorrect controlling of the pressure, temperature, flow rate and humidity levels of reactant gases can inflict severe and sometimes irreversible damages on the PEM fuel cells. Most important damage is leakage between the two sides of cathode and anode that may lead to physical defects in the stack. Usage of neutral gas method only reveals the overall leakage and does not show the exact location of the defected cell in the stack. This research seeks to determine the exact location of the defective cell using a method that is based on the data received from the voltage–time graphs of the stack under hydrogen sudden stop condition when the stacks are operating in the open circuit voltage condition. This method has been used with respect to two fuel cell stacks with different powers in different working conditions. Also the stack voltage drop due to leakage has been considered theoretically.