Fuel cell system
First Claim
1. A fuel cell system built as a system in which a fuel cell and an electric storage device are provided in parallel, the fuel cell system comprising:
- the fuel cell;
a fuel feeder;
the electric storage device; and
a DC/DC converter, wherein the fuel feeder feeds the fuel cell with fuel, wherein the DC/DC converter converts an output voltage of the electric storage device into a predetermined voltage and then outputs the predetermined voltage, and wherein the predetermined voltage is equal to or higher than an output voltage of the fuel cell as obtained when the fuel cell is outputting a maximum output electric power.
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Accused Products
Abstract
A fuel cell system of the invention is built as a system in which a fuel cell stack and an electric storage device are provided in parallel, and includes, in addition to the fuel cell stack and the electric storage device, a fuel feeder and a DC/DC converter. The fuel feeder feeds the fuel cell stack with fuel. The DC/DC converter converts the output voltage of the electric storage device into a predetermined voltage and outputs it. This predetermined voltage is equal to or higher than the output voltage of the fuel cell stack as obtained when it is outputting the maximum output electric power. The fuel cell system of the invention is free from shortening of the lifetime of the fuel cell.
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Citations
11 Claims
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1. A fuel cell system built as a system in which a fuel cell and an electric storage device are provided in parallel, the fuel cell system comprising:
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the fuel cell;
a fuel feeder;
the electric storage device; and
a DC/DC converter, wherein the fuel feeder feeds the fuel cell with fuel, wherein the DC/DC converter converts an output voltage of the electric storage device into a predetermined voltage and then outputs the predetermined voltage, and wherein the predetermined voltage is equal to or higher than an output voltage of the fuel cell as obtained when the fuel cell is outputting a maximum output electric power. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A fuel cell system built as a system in which a fuel cell and an electric storage device are provided in parallel, the fuel cell system comprising:
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the fuel cell;
the electric storage device; and
a fuel cell current limiter, wherein the fuel cell current limiter controls an output current of the fuel cell at a limit value or below, and wherein the limit value is equal to or smaller than a value of the output current of the fuel cell as obtained when the fuel cell is outputting a maximum output electric power in a stably operating state after having been used in the stably operating state for a predetermined duration until an output of the fuel cell exhibits a drop as compared with the output in an initial state.
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9. A fuel cell system built as a system in which a fuel cell and an electric storage device are provided in parallel, the fuel cell system comprising:
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the fuel cell;
the electric storage device; and
a fuel cell voltage limiter, wherein the fuel cell voltage limiter controls an output voltage of the fuel cell at a limit value or above, and wherein the limit value is equal to or larger than a value of the output voltage of the fuel cell as obtained when the fuel cell is outputting a maximum output electric power in a stably operating state.
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10. A fuel cell system built as a system in which a fuel cell and an electric storage device are provided in parallel, the fuel cell system comprising:
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the fuel cell;
the electric storage device;
a fuel cell current limiter; and
a fuel cell voltage limiter, wherein the fuel cell current limiter controls an output current of the fuel cell at a first limit value or below, wherein the fuel cell voltage limiter controls an output voltage of the fuel cell at a second limit value or above, wherein the first limit value is equal to or smaller than a value of the output current of the fuel cell as obtained when the fuel cell is outputting a maximum output electric power in a stably operating state after having been used in the stably operating state for a predetermined duration until an output of the fuel cell exhibits a drop as compared with the output in an initial state, and wherein the second limit value is equal to or larger than a value of the output voltage of the fuel cell as obtained when the fuel cell is outputting the maximum output electric power in the stably operating state.
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11. A fuel cell system built as a system in which a fuel cell and an electric storage device are provided in parallel, the fuel cell system comprising:
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the fuel cell;
the electric storage device;
a DC/DC converter;
a charge circuit; and
a controller, wherein the DC/DC converter converts an output voltage of the electric storage device;
wherein the charge circuit charges the electric storage device by using an output of the fuel cell, and wherein the controller controls electric power passed through the DC/DC converter and through the charge circuit in such a way that the fuel cell operates at a maximum output electric power operating point thereof.
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Specification