摘要 |
A PEM-fuel-cell-stack backup electric generator comprising: a fuel-cell stack, formed by a plurality of stacked PEM fuel cells electrically connected in series for supplying electrical energy to an electrical load; a cell-voltage monitor for measuring the voltage supplied by each fuel cell; an electrical-energy management and conditioning unit, connected between the fuel-cell stack and the electrical load; a blower for supplying the amount of air necessary for the chemical reactions that occur in the fuel cells; a hydrogen recirculator for recirculating hydrogen between the outlet and the inlet of the fuel-cell stack; a hydrogen-purging device for carrying out a primary purging of hydrogen at a lower flow rate, and a secondary purging of hydrogen at a higher flow rate; and a controller, programmed for managing operation of the electric generator differently at start-up, at shut-down, and during normal operation thereof. |