Current control for parallel fuel cell stacks
AssigneeGeneral Motors Corporation
InventorsJohn S Wheat, Clark Hochgraf, Daryl Chapman
Life of this patent
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Abstract
A fuel cell system includes fuel cell stacks electrically connected in parallel and supplying a gross current to a load. A controller determines the gross load current, and produces a desired current through the load by adjusting, based on the gross load current, at least one parameter affecting at least one of the inputs to and outputs from the system. This system allows a stack design and its voltage output to be kept constant while stacks are added for increased power.
Claims38
A fuel cell system comprising:
- a plurality of fuel cell stacks connected in parallel, each of said stacks supplying one of a plurality of currents for a load;
- a plurality of inputs to and a plurality of outputs from each of said stacks that affect respective ones of said plurality of currents;
- and
- a controller that produces a desired current through said load by adjusting ones of said currents in a predetermined sequence,
- wherein said controller adjusts said currents by adjusting at least one parameter affecting at least one of said inputs and outputs.
A fuel cell system comprising:
- a plurality of fuel cell stacks electrically connected in parallel, each of said stacks supplying one of a plurality of currents, which collectively supply a gross load current to a load, each stack comprising a plurality of inputs and outputs that are affected by a plurality of parameters;
- and
- a controller that produces a desired current through said load by adjusting selected ones of said currents in a predetermined sequence until each of said currents is less than an upper threshold and greater than a lower threshold.
A method for controlling current to a load supplied by a plurality of fuel cells, comprising:
- combining the fuel cells to provide a plurality of fuel cell stacks, each fuel cell stack providing one of a plurality of currents to a load;
- connecting the stacks in parallel;
- and
- adjusting ones of said currents in a predetermined sequence until each of said currents is less than an upper threshold and greater than a lower threshold,
- wherein said adjusting comprises adjusting at least one parameter affecting said ones of said currents.
A method for controlling current to a load supplied by a plurality of fuel cells, comprising:
- combining the fuel cells to provide a plurality of fuel cell stacks, each of said stacks having a standard number of cells;
- electrically connecting said stacks in parallel to provide a standard voltage range across each of said stacks;
- obtaining desired set-points for current from each of said stacks;
- and
- providing a desired current through said load by adjusting ones of said currents in a predetermined sequence until each of said currents reach a respective set-point;
- said obtaining and regulating performed by controlling at least one of a plurality of parameters affecting at least one of an input to and an output from at least one said stack.
A method for controlling current to a load supplied by a plurality of fuel cells, comprising:
- combining the fuel cells to provide a plurality of fuel cell stacks;
- electrically connecting said stacks in parallel;
- determining a gross current to the load;
- and
- balancing currents produced by said stacks in a predetermined sequence and based on said gross load current to provide a desired load current,
- said balancing performed by adjusting one or more parameters affecting at least one of an input to and an output from at least one of said stacks for each of the stacks individually.
A fuel cell system comprising:
- N fuel cell stacks connected in parallel, each of said N stacks supplying a current for a load;
- a plurality of inputs and outputs that are associated with each of said N stacks;
- and
- a controller that produces a desired current through said load by sequentially selecting M ones of said N stacks based on a predetermined sequence and adjusting at least one parameter affecting at least one of said inputs and outputs associated with said selected ones of said N stacks,
- wherein N and M are integers greater than one and M is less than or equal to N.
Dependencies are inferred from the claim text.