fractional order pid control of air feed system in a proton exchange membrane fuel cell

Proton exchange membrane fuel cell (pemfc) converts chemical energy liberated during the electrochemical reaction of hydrogen and oxygen to electrical energy and has huge potential in transport, stationary and portable applications. it is an open loop stable system but it does not settle in the given set point. hence controllers are required to make the system to settle at the set point and also to prevent the pemfc from oxygen starvation. a simulative approach of controlling pemfc with proportional integral derivative (pid) controller and fractional order pid (fopid) controller is investigated in this paper. fopid controller is tuned using two approaches namely kc auto tuning and oustaloup approximation. the performances of the two fopid controllers are compared with pid controller. the use of fopid controller results in better closed loop time domain characteristics than pid controller and is shown with simulations in matlab.