Patent ID: 7791915

Claim:
Electric converter for fuel cell (P) comprising current inverter means ( 2 ), a voltage step-down chopper ( 1 ) mounted between the fuel cell (P) and the current inverter means ( 2 ), and command means ( 6 ) for delivering a command signal applied to switching means ( 7 ) of the voltage step-down chopper ( 1 ) so that, under the action of the command signal: the switching means ( 7 ) of the voltage step-down chopper ( 1 ) is regularly switched from a conducting state to an off state and reciprocally, so as to lower the value of the mean voltage at the input of the current inverter means to a threshold value (Vs) in a first functioning zone (I) of the fuel cell, called cell electrode activation zone, the switching means ( 7 ) of the voltage step-down chopper ( 1 ) is maintained constantly closed, so as to maintain the value of the mean voltage at the input of the current inverter means ( 2 ) at the voltage value at the cell terminals (Vp) in a second functioning zone (II) of the fuel cell, called cell resistance zone, and when the current at the output of the current inverter means ( 2 ) reaches a maximum value (Imax), the switching means ( 7 ) of the voltage step-down chopper ( 1 ) is switched to limit the output current of the electric converter.