Abstract: A fuel cell system that has a fuel cell stack with a plurality of laminated cells, each of the laminated cells includes an electrolyte membrane interposed between a fuel electrode receiving a supply of fuel gas and an oxidizing agent electrode receiving a supply of oxidizing agent gas. A fuel gas supply device supplies a fuel gas to the fuel electrode. An oxidizing agent gas supply device supplies an oxidizing agent gas to the oxidizing agent electrode. A fuel electrode side discharge system discharges a discharge gas from the fuel electrode to an external. A circulation device re-circulates the discharge gas discharged from the fuel electrode into an upstream side of the fuel electrode. A voltage limit device limits a voltage across the fuel cell stack by drawing a current from the fuel cell stack at a time of an activation of the fuel cell system.

Abstract: A fuel cell system which prevents the deterioration of the fuel cell stack when feeding of the oxidant gas is paused under a load to perform a fuel conservation operation. Controller shuts down oxidant gas compressor and cooling water circulating pump to execute fuel conservation operation at a low fuel cell system load. The controller gives a current draw instruction to electric power controller. In the fuel conservation operation, electric power controller draws a current larger than zero from fuel cell stack, and keeps the total charge drawn per unit time constant or substantially constant.

Abstract: A fuel cell system has a purge valve that adjusts the amount of nitrogen in a hydrogen circulation channel and a fuel electrode to be discharged through a discharge channel. A purge rate correcting unit variably sets a target control value of the nitrogen content in the hydrogen circulation channel and the fuel electrode by taking into account whether a driving mode is set in a normal power generation mode or an idle mode. An opening of the purge valve is controlled on the basis of the target control value.

Abstract: A fuel cell system can be initiated in shorter time while minimizing the deterioration of a fuel cell. The fuel cell system includes a fuel cell stack having a fuel electrode, an oxidizer electrode and an electrolyte membrane disposed there between, the fuel cell producing electricity by an electrochemical reaction of a fuel gas and an oxidizer gas, which are supplied to the fuel electrode and the oxidizer electrode, respectively; a fuel gas supplying device for supplying the fuel gas to the fuel cell stack; an oxidizer gas supplying device for supplying the oxidizer gas to the fuel cell stack; a current controlling device for extracting a current from the fuel cell stack; and a voltage sensor disposed in at least two of the fuel cell stacks.

Abstract: A fuel cell system including: a fuel cell supplied with a fuel gas to a fuel electrode thereof and air to an air electrode thereof; a fuel gas supplying device which supplies the fuel gas to the fuel electrode; an air supplying device which supplies air to the air electrode; a fuel gas pressure regulator which regulates fuel gas pressure at the fuel electrode; a purge valve which discharges exhaust fuel gas from the fuel electrode to the outside; and a controller. The controller continues power generation of the fuel cell, controlling the fuel gas pressure regulator to lower the fuel gas pressure at the fuel electrode, having the air supplying device continuing supplying air to the air electrode with the purge valve closed; and after the fuel gas pressure at the fuel electrode becomes equal to or lower than the atmospheric pressure, stops power generation of the fuel cell.

Abstract: A fuel cell has an anode, a cathode, and a proton-exchange membrane disposed between the anode and cathode. An exhaust anode gas exhausted from an outlet of the anode is directed back to an inlet of the anode. Hydrogen is added to the exhaust anode gas before the exhaust anode gas reaches the inlet.

Abstract: A fuel cell system that has a fuel cell stack with a plurality of laminated cells, each of the laminated cells includes an electrolyte membrane interposed between a fuel electrode receiving a supply of fuel gas and an oxidizing agent electrode receiving a supply of oxidizing agent gas. A fuel gas supply device supplies a fuel gas to the fuel electrode. An oxidizing agent gas supply device supplies an oxidizing agent gas to the oxidizing agent electrode. A fuel electrode side discharge system discharges a discharge gas from the fuel electrode to an external. A circulation device re-circulates the discharge gas discharged from the fuel electrode into an upstream side of the fuel electrode. A voltage limit device limits a voltage across the fuel cell stack by drawing a current from the fuel cell stack at a time of an activation of the fuel cell system.