Fuel cell system method and apparatus employing oxygen sensor
AssigneeBallard Power Systems Inc.
InventorsRobert Kenneth Parr, Brian Wells
Life of this patent
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Abstract
A controller in a fuel cell system performs various operating parameter checks at a predefined schedule, including one or more of a stack current check; a stack voltage check; a cell voltage check; a purge cell check; an oxygen concentration check; a hydrogen concentration check; a stack temperature check; an ambient air temperature check; a fuel pressure check; and an airflow rate check; a hydrogen sensor heater check; a battery voltage check; a microcontroller self-check; and/or toggling a watchdog. The frequency of the checks are set relative to achieve an efficient control of the fuel cell system by selectively distributing the load on the microcontroller.
Claims25
A control system for a fuel cell assembly, comprising:
- an oxygen sensor;
- and
- a switch couplable to the fuel cell assembly and selectively actuatable to stop fuel cell operation in response to a high hydrogen condition indicated by an oxygen reading from the oxygen sensor.
A control system for a fuel cell assembly comprising:
- an oxygen sensor;
- a hydrogen sensor;
- a temperature sensor;
- and
- a switch couplable to the fuel cell assembly and selectively actuatable to stop fuel cell operation in response to at least one of a low oxygen condition indicated by an oxygen reading from the oxygen sensor, a high hydrogen condition indicated by a hydrogen reading from the hydrogen sensor, and a high temperature condition indicated by a temperature reading from the temperature sensor.
A fuel cell system for use in a habitable environment, comprising:
- at least one fuel cell;
- an oxygen sensor;
- a hydrogen sensor;
- and
- a first switch selectively actuatable to stop fuel cell operation in response to at least one of a high hydrogen condition indicated by at least one of a hydrogen reading from the hydrogen sensor and an oxygen reading from the oxygen sensor wherein in the first switch comprises a controller that compares the oxygen reading to a low oxygen threshold value corresponding to a first hydrogen concentration, and further comprising a second switch, comprising a second controller that compares the hydrogen reading to a high hydrogen threshold value corresponding to a second hydrogen concentration equal to or less than the first hydrogen concentration.
A fuel cell system for use in a habitable environment, comprising:
- at least one fuel cell;
- an oxygen sensor;
- a hydrogen sensor;
- and
- a first switch selectively actuatable to stop fuel cell operation in response to at least one of a high hydrogen condition indicated by at least one of a hydrogen reading from the hydrogen sensor and an oxygen reading from the oxygen sensor wherein in the first switch comprises a controller that compares the oxygen reading to a low oxygen threshold value corresponding to a first hydrogen concentration and that compares the hydrogen reading to a high hydrogen threshold value corresponding to a second hydrogen concentration not greater than the first hydrogen concentration.
A method of operating a fuel cell assembly, comprising:
- determining a concentration of oxygen proximate the fuel cell;
- and
- providing fuel to the fuel cell if the determined concentration of oxygen proximate the fuel cell is greater than an oxygen threshold value.
A computer-readable media containing instructions to cause a processor to control operation of a fuel cell assembly, by:
- determining a concentration of oxygen proximate the fuel cell assembly;
- and
- providing fuel to the fuel cell if the concentration of oxygen proximate the fuel cell assembly is greater than an oxygen threshold value.
Dependencies are inferred from the claim text.