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US 12,537,209 B2Granted
Method for diagnosing deterioration of fuel cell and method and system for preventing deterioration of fuel cell using the same
AssigneesHyundai Motor Company, Kia Corporation
InventorHyun Seung Lee
Life of this patent
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Abstract
A fuel cell deterioration prevention system includes a cell voltage stability determination unit determining cell voltage stability according to a preset operating condition, a fuel cell deterioration diagnosing unit diagnosing deterioration of a fuel cell by changing and controlling a control variable pre-selected according to an operating condition and monitoring a resultant change in the cell voltage of the fuel cell, and a deterioration avoidance operation control unit performing a deterioration avoidance operation based on a diagnosis result of the fuel cell deterioration diagnosing unit.
Claims18
A method of diagnosing deterioration of a fuel cell, the method comprising:
- determining whether a fuel cell system has entered a preset operating condition;
- determining cell voltage stability for the preset operating condition;
- and
- when it is determined that a cell voltage is not stable, diagnosing the deterioration of the fuel cell by changing and controlling a control variable selected according to the operating condition selected from among a control variable group including a supply air recirculation amount, a cathode target stoichiometry ratio (SR), humidifier target temperature, and supply air pressure, and monitoring a resultant change in the cell voltage of the fuel cell;
- wherein the determining of the cell voltage stability comprises at least one of:
- (i) determining the cell voltage stability from a difference between an average cell voltage and a minimum cell voltage at a time point at which a first current density is reached within a first reference time after starting the fuel cell system;
- (ii) when the fuel cell system is operated above a first reference output for more than a second reference time, calculating a current average cell voltage in a corresponding section, and determining the cell voltage stability from a difference between the calculated current average cell voltage and an average cell voltage in an identical section during a previous operation;
- and
- (iii) when the fuel cell system is repeatedly operated to increase from a second current density to a third current density and decrease from the third current density to the second current density within a third reference time, determining the cell voltage stability from a difference between a minimum cell voltage at a fourth current density when a current density decreases and a minimum cell voltage at the fourth current density when the current density increases.
6 more elements
A method of preventing deterioration of a fuel cell, the method comprising:
- determining whether a fuel cell system has entered a preset operating condition;
- determining cell voltage stability for the preset operating condition;
- when it is determined that a cell voltage is not stable, diagnosing the deterioration of the fuel cell by changing and controlling a control variable selected according to the operating condition selected from among a control variable group including a supply air recirculation amount, a cathode target stoichiometry ratio (SR), humidifier target temperature, and supply air pressure, and monitoring a resultant change in the cell voltage of the fuel cell;
- and
- performing a deterioration avoidance operation according to a result of the diagnosing of the deterioration of the fuel cell;
- wherein the determining of the cell voltage stability comprises at least one of:
- (i) determining the cell voltage stability from a difference between an average cell voltage and a minimum cell voltage at a time point at which a first current density is reached within a first reference time after starting the fuel cell system;
- (ii) when the fuel cell system is operated above a first reference output for more than a second reference time, calculating a current average cell voltage in a corresponding section, and determining the cell voltage stability from a difference between the calculated current average cell voltage and an average cell voltage in an identical section during a previous operation;
- and
- (iii) when the fuel cell system is repeatedly operated to increase from a second current density to a third current density and decrease from the third current density to the second current density within a third reference time, determining the cell voltage stability from a difference between a minimum cell voltage at a fourth current density when a current density decreases and a minimum cell voltage at the fourth current density when the current density increases.
7 more elements
A fuel cell deterioration prevention system comprising:
- a cell voltage stability determination unit determining cell voltage stability according to a preset operating condition;
- a fuel cell deterioration diagnosing unit including information on control variables to be changed and controlled when a cell voltage is unstable according to an operating condition selected among a control variable group including a supply air recirculation amount, a cathode target SR, humidifier target temperature, and supply air pressure, and diagnosing deterioration of a fuel cell by changing and controlling a control variable pre-selected according to an operating condition when the cell voltage stability determination unit determines that the cell voltage is unstable, and monitoring a resultant change in the cell voltage of the fuel cell;
- and
- a deterioration avoidance operation control unit configured to perform a deterioration avoidance operation based on a diagnosis result of the fuel cell deterioration diagnosing unit;
- wherein the determining of the cell voltage stability comprises at least one of:
- (i) determining the cell voltage stability from a difference between an average cell voltage and a minimum cell voltage at a time point at which a first current density is reached within a first reference time after starting the fuel cell system;
- (ii) when the fuel cell system is operated above a first reference output for more than a second reference time, calculating a current average cell voltage in a corresponding section, and determining the cell voltage stability from a difference between the calculated current average cell voltage and an average cell voltage in an identical section during a previous operation;
- and
- (iii) when the fuel cell system is repeatedly operated to increase from a second current density to a third current density and decrease from the third current density to the second current density within a third reference time, determining the cell voltage stability from a difference between a minimum cell voltage at a fourth current density when a current density decreases and a minimum cell voltage at the fourth current density when the current density increases.
6 more elements
Dependencies are inferred from the claim text.