Failure diagnostic method and failure diagnostic device of solar cell string
AssigneeMitsubishi Electric Corporation
InventorsShinsuke Yura, Mutsumi Tsuda, Hidetada Tokioka
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Abstract
A technique that ensures proper failure diagnosis of a solar cell string. A failure diagnostic method and a failure diagnostic device of the solar cell string include an impedance measure, an analyzer, and a determination processor. The analyzer obtains the inductance of the solar cell string based on a relational expression containing an impedance, an inductance, and a frequency in a predetermined equivalent circuit of the solar cell string, and the frequency characteristic of the first impedance measured by the impedance measure. The determination processor conducts failure diagnose for the solar cell string based on the inductance obtained by the analyzer.
Claims7
A failure diagnostic method of a solar cell string, wherein
- the solar cell string includes a plurality of solar cell modules each having a photovoltaic power generator and an electro-conductive frame, a plurality of photovoltaic power generators of the plurality of solar cell modules being electrically connected in series by an output cable, a plurality of frames of the plurality of solar cell modules being electrically connected in common, the method comprising the steps of:
- (a) measuring frequency characteristic of a first impedance between one end of the output cable electrically connecting the plurality of solar cell modules in series and the plurality of frames electrically connected in common by an impedance measurer;
- (b) obtaining an inductance of the solar cell string based on a relational expression containing an impedance, an inductance, and a frequency in a predetermined equivalent circuit of the solar cell string and the frequency characteristic of the first impedance measured in the step (a);
- and
- (c) conducting failure diagnosis for the solar cell string based on the inductance obtained in the step (b).
A failure diagnostic device of solar cell string, wherein
- the solar cell string includes a plurality of solar cell modules each having a photovoltaic power generator and an electro-conductive frame, a plurality of the photovoltaic power generators of the plurality of solar cell modules being electrically connected in series by an output cable, a plurality of the frames of the plurality of solar cell modules being electrically connected in common, the failure diagnostic device comprising:
- an impedance measurer configured to measure frequency characteristic of a first impedance between one end of the output cable electrically connecting the plurality of solar cell modules in series and the plurality of frames electrically connected in common;
- an analyzer configured to obtain an inductance of the solar cell string based on a relational expression containing an impedance, an inductance, and a frequency in a predetermined equivalent circuit of the solar cell string and the frequency characteristic of the first impedance measured by the impedance measurer;
- and
- a determination processor configured to conduct failure diagnosis for the solar cell string based on the inductance obtained by the analyzer.
Dependencies are inferred from the claim text.