Fuel cell system failure diagnosis method, failure diagnosis device using same, and fuel cell system
First Claim
1. A failure diagnosis method of a fuel cell system, which includes a step for computing an impedance in a prescribed portion of a fuel cell of a fuel cell system from a signal obtained by superposing an alternating current on a direct current generated from the fuel cell system under a certain operation condition, wherein when in comparison of the impedance with an impedance as computed under a previously determined standard operation condition, an abnormality is present in the prescribed portion of the fuel cell, whether a cause of the abnormality of the prescribed portion resides in any one or plural prescribed sites constituting the fuel cell system is determined by using the comparison result;
- and the determination is to separate whether the cause of the abnormality of the prescribed portion resides in the fuel cell per se which the fuel cell system has or the prescribed sites other than the fuel cell.
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Accused Products
Abstract
It was difficult to specify a portion which is a cause of a power generation abnormality of a fuel cell which performs the power generation by feeding an oxygen-containing oxidizer gas into a cathode and feeding a hydrogen-containing fuel gas into an anode. A failure diagnosis method of a fuel cell system, which includes a step for computing an impedance in a prescribed portion of a fuel cell of a fuel cell system from a signal obtained by superposing an alternating current on a direct current as generated from the fuel cell system under a certain operation condition, wherein when in comparison of the impedance with an impedance as computed under a previously determined standard operation condition, an abnormality is present in the prescribed portion of the fuel cell, whether a cause of the abnormality of the prescribed portion resides in any one or plural prescribed sites constituting the fuel cell system is determined by using the comparison result.
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Citations
19 Claims
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1. A failure diagnosis method of a fuel cell system, which includes a step for computing an impedance in a prescribed portion of a fuel cell of a fuel cell system from a signal obtained by superposing an alternating current on a direct current generated from the fuel cell system under a certain operation condition, wherein
when in comparison of the impedance with an impedance as computed under a previously determined standard operation condition, an abnormality is present in the prescribed portion of the fuel cell, whether a cause of the abnormality of the prescribed portion resides in any one or plural prescribed sites constituting the fuel cell system is determined by using the comparison result; - and
the determination is to separate whether the cause of the abnormality of the prescribed portion resides in the fuel cell per se which the fuel cell system has or the prescribed sites other than the fuel cell. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 19)
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2. (canceled)
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10. A failure diagnosis device of a fuel cell system including
an alternating current source for feeding a frequency variable alternating current which is superposed on a direct current generated from a fuel cell of a fuel cell system, an impedance computation instrument for computing an impedance corresponding to a prescribed portion of the fuel cell of the fuel cell system from a signal obtained by superposing the alternating current on the direct current, and a diagnosis instrument in which when in comparison of the impedance with an impedance as computed under a previously determined standard operation condition, an abnormality is present in the prescribed portion of the fuel cell, whether a cause of the abnormality of the prescribed portion resides in any one or plural prescribed sites constituting the fuel cell system is determined by using the comparison result, wherein the diagnosis instrument achieves the determination by using a corresponding relation between an operation condition of each prescribed site of the fuel cell system and an impedance of each prescribed portion of the fuel cell under the standard operation condition as a characteristic profile, as the certain operation condition, changing the operation condition of the prescribed site more greatly than the standard operation condition and comparing a diagnosis impedance as measured corresponding to the change with an impedance of the characteristic profile, and making the judgment such that when a change of the diagnosis impedance from the impedance of the characteristic profile can be judged on the basis of the characteristic profile, its cause resides in that prescribed site, whereas when the change cannot be judged, its cause does not reside in that prescribed site.
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11. (canceled)
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17. (canceled)
Specification