초록 ▼

A part of cell stack portions constituting a part of a fuel cell stack is used as a voltage detection portion, the size of a frequency component belonging to a predetermined specific frequency range is extracted from a voltage signal detected and the existence/absence of abnormality of a fuel cell s

A part of cell stack portions constituting a part of a fuel cell stack is used as a voltage detection portion, the size of a frequency component belonging to a predetermined specific frequency range is extracted from a voltage signal detected and the existence/absence of abnormality of a fuel cell system is diagnosed on the basis of the frequency component extracted.

대표청구항 ▼

The invention claimed is: 1. A fuel cell system including a fuel cell stack, said system comprising: voltage detection means for detecting a voltage of a portion of said fuel cell stack by using a voltage detection portion; signal processing means for extracting a frequency component within a prede

The invention claimed is: 1. A fuel cell system including a fuel cell stack, said system comprising: voltage detection means for detecting a voltage of a portion of said fuel cell stack by using a voltage detection portion; signal processing means for extracting a frequency component within a predetermined frequency range corresponding to a specific abnormality in said fuel cell system from said voltage detected by said voltage detection means, and for diagnosing the existence/absence of a periodical abnormality of said fuel cell stack or said system containing said fuel cell stack from the size of said extracted frequency component; and power conditioning means which receives a result of said diagnosis of a periodical abnormality which is executed by the said signal processing means, and controls the current of said fuel stack based on the result of said diagnosis of a periodical abnormality. 2. A fuel cell system according to claim 1, wherein said diagnosis means: extracts frequency components of at least two predetermined frequency ranges from the voltage detected by said voltage detection means; and diagnoses the existence/absence of abnormality of said fuel cell stack or said system containing said fuel cell stack from the sizes of said extracted frequency components of said at least two predetermined frequency ranges. 3. A fuel cell system according to claim 2, wherein said diagnosis means: diagnoses abnormality of said fuel cell stack from at least one extracted frequency component; and diagnoses abnormality of a hydrogen production apparatus from at least one other extracted frequency component. 4. A fuel cell system according to claim 1, wherein for a predetermined period of time, said diagnosis means overlaps said extracted frequency component with at least one control signal associated with at least one of fuel feed means of said fuel cell system, a reformer, control means of said reformer, said fuel cell stack, a heat recovery system, control means of said heat recovery system and a power conditioner; diagnoses the existence/absence of abnormality of said fuel cell stack or said system containing said fuel cell stack on the basis of said overlap of said extracted frequency component and said control signal. 5. A fuel cell power generation system for home use that uses said fuel cell system according to claim 1. 6. A fuel cell system according to claim 1, wherein said voltage detection portion is situated at an end portion of the fuel cell stack. 7. A fuel cell system according to claim 1, wherein said voltage detection portion comprises no more than twenty cells. 8. A fuel cell system according to claim 7, wherein said voltage detection portion further comprises two voltage detection terminals and at least two separators to separate each cell from any other cell and from the voltage detection terminals. 9. A fuel cell system according to claim 8, wherein a cell comprises an integrated membrane-electrode assembly (MEA). 10. A fuel cell system according to claim 1, wherein said fuel cell stack comprises a plurality, of voltage detection portions. 11. A fuel cell system according to claim 10, wherein said voltage detection portion comprises no more than twenty cells. 12. A fuel cell system according to claim 10, wherein said voltage detection portions are situated at intermediate portions of the fuel cell stack. 13. A fuel cell system including a fuel cell stack, the system comprising: a voltage detection portion that detects a voltage of a portion of the fuel cell stack; a signal processing portion that extracts a frequency component within a predetermined frequency range corresponding to a specific abnormality in the fuel cell system from the voltage detected by the voltage detection portion, and diagnoses the existence/absence of a periodical abnormality of the fuel cell stack or the system containing the fuel cell stack in accordance with a size of the extracted frequency component; and a power conditioning portion which receives a result of the diagnosis of a periodical abnormality which is executed by the signal processing portion, and controls the current of the fuel stack based on the result of the diagnosis of a periodical abnormality. 14. A fuel cell system according to claim 13, wherein the voltage detection portion is situated at an end portion of the fuel cell stack. 15. A fuel cell system according to claim 13, wherein said voltage detection portion comprises no more than twenty cells. 16. A fuel cell system according to claim 15, wherein the voltage detection portion further comprises two voltage detection terminals and at least two separators to separate each cell from any other cell and from the voltage detection terminals. 17. A fuel cell system according to claim 16, wherein a cell comprises an integrated membrane-electrode assembly (MEA). 18. A fuel cell system according to claim 13, wherein the fuel cell stack comprises a plurality of voltage detection portions. 19. A fuel cell system according to claim 18, wherein said voltage detection portion comprises no more than twenty cells. 20. A fuel cell system according to claim 18, wherein the voltage detection portions are situated at intermediate portions of the fuel cell stack. 21. The fuel cell system according to claim 1, wherein the predetermined frequency range includes a range of several millihertz to several decades of millihertz. 22. The fuel cell system according to claim 13, wherein the predetermined frequency range includes a range of several millihertz to several decades of millihertz.