FUEL CELL SYSTEMS WITH MAINTENANCE HYDRATION BY DISPLACEMENT OF PRIMARY POWER

摘要

Fuel cell systems that perform maintenance hydration by supplying power to satisfy at least part of an applied load from an energy-consuming assembly while a primary power source is in electrical communication with and available to supply power to the energy-consuming assembly to satisfy the portion of the applied load being satisfied by the fuel cell system. In some embodiments, a fuel cell system may determine a start time, or start condition, for maintenance of the fuel cell system. The fuel cell system then may be activated from an inactive condition according to the start time, or start condition, by initiating delivery of at least fuel, and optionally oxidant, to a fuel cell stack of the system. Power then may be supplied from the activated fuel cell system at an output voltage that is higher than a voltage at which power from the primary power source is being supplied, such that the applied load is satisfied, at least in part, by the power from the fuel cell system instead of the power from the primary power source. Upon operation of the fuel cell system for a period sufficient to rehydrate the fuel cell stack, operation of the fuel cell system may be discontinued, with the primary power source resuming supplying power to satisfy the applied load from the energy-consuming assembly.