Method for monitoring the operational state of a fuel cell stack
AssigneeAVL List GmbH
InventorErich Ramschak
Life of this patent
Estimating the term…
Abstract
The invention relates to a method for monitoring the operational state of a fuel cell stack comprising a plurality of series-connected single cells. In order to significantly reduce measuring costs and apparatus a low-frequency current or voltage signal is impressed on the fuel cell stack and the resulting current or voltage signal is measured. From at least one change of the harmonic content of the signal the operational state of individual cells of the fuel cell stack is inferred.
Claims20
A method for monitoring the operational state of a fuel cell stack comprising a plurality of individual cells connected in series, comprising the steps of:
- impressing a low-frequency current or voltage signal on the fuel cell stack,
- measuring the resulting current or voltage signal, and
- inferring the operational state of individual cells of the fuel cell stack from at least one change in the harmonic content of said current or voltage signal.
A method according to claim .1, wherein by analysis of harmonics, using an impressed low-THD load signal spread over the whole load range, a field of current/voltage curves with corresponding dispersion band is obtained.
Dependencies are inferred from the claim text.