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US 8,541,141 B2Granted
Fuel cell system
AssigneeNissan Motor Co., Ltd.
InventorsKenji Yonekura, Hitoshi Igarashi, Tetsuya Kamihara
Life of this patent
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Abstract
A fuel cell system and method of controlling a fuel cell system capable of preventing deterioration in performance when the system reinitiates a normal operation from an idle stop state. For a predetermined time after reinitiating the supply of fuel gas and oxidant gas from the idle stop state, discharge of off-gas occurs and the cessation of fuel gas and oxidant gas supply is prohibited.
Claims24
A fuel cell system, comprising:
- a fuel cell having a fuel electrode to which a fuel gas is supplied and an oxidant electrode to which an oxidant gas is supplied, the fuel cell configured to generate electricity via a reaction between the fuel gas and the oxidant gas during a normal generation mode;
- a gas discharge unit for discharging a discharge gas from the fuel electrode of the fuel cell;
- an external load for receiving power from the fuel cell;
- and
- a controller unit operable configured to:
- while the fuel cell is operating in the normal generation mode, stop supply of the fuel gas and the oxidant gas to the fuel cell to enter a first idle stop mode from the normal generation mode responsive only to a condition that a driving power does not need to be supplied to the external load from the fuel cell;
- and
- each time the driving power needs to be supplied to the external load from the fuel cell while operating in an idle stop mode including the first idle stop mode:
- restart the supply of the fuel gas and the oxidant gas to the fuel cell to end the idle stop mode and return to the normal generation mode;
- calculate a length of an idle stop prohibition period, the length having a maximum time value dependent on a duration of the idle stop mode;
- begin the idle stop prohibition period upon the return to the normal generation mode;
- upon the return to the normal generation mode, re-enter into the idle stop mode responsive to the condition that the driving power does not need to be supplied to the external load from the fuel cell only if the idle stop prohibition period has lapsed;
- and
- calculate a correction time value that is dependent on at least one operating parameter of the fuel cell system after restarting the supply of the fuel gas and the oxidant gas, wherein the length of the idle stop prohibition period is a difference between the maximum time value and the correction time value.
11 more elements
A fuel cell system including a fuel cell and a secondary cell, comprising:
- means for stopping supply of a fuel gas and an oxidant gas to the fuel cell to enter a first idle stop mode while the fuel cell is operating in a normal generation mode responsive only to a condition that a driving power does not need to be supplied to an external load from the fuel cell;
- means for restarting the supply of the fuel gas and the oxidant gas to the fuel cell to end an idle stop mode including the first idle stop mode and return to the normal generation mode each time the driving power needs to be supplied to the external load from the fuel cell while operating in the idle stop mode;
- means for calculating a length of an idle stop prohibition period each time the driving power needs to be supplied to the external load from the fuel cell while operating in the idle stop mode, the length having a maximum time value dependent on a duration of the idle stop mode;
- means for beginning the idle stop prohibition period when restarting the supply of the fuel gas and the oxidant gas to end the idle stop mode and return to the normal generation mode;
- means for, upon the return to the normal generation mode, re-entering into the idle stop mode responsive to the condition that the driving power does not need to be supplied to the external load from the fuel cell only if the idle stop prohibition period has lapsed;
- and
- means for calculating a correction time value that is dependent on at least one operating parameter of the fuel cell system after restarting the supply of the fuel gas and the oxidant gas, wherein the length of the idle stop prohibition period is a difference between the maximum time value and the correction time value.
4 more elements
A method of controlling a fuel cell system including a fuel cell, comprising:
- stopping, using a controller, supply of a fuel gas and an oxidant gas to the fuel cell to enter a first idle stop mode while the fuel cell is operating in a normal generation mode responsive only to a condition that a driving power does not need to be supplied to an external load from the fuel cell, the fuel cell having a fuel electrode to which the fuel gas is supplied and an oxidant electrode to which the oxidant gas is supplied and the fuel cell configured to generate electricity via a reaction between the fuel gas and the oxidant gas during the normal generation mode and the fuel cell system including a gas discharge unit for discharging a discharge gas from the fuel electrode of the fuel cell and an external load for receiving power from the fuel cell;
- and
- each time the driving power needs to be supplied to the external load from the fuel cell while operating in an idle stop mode including the first idle stop mode:
- restarting the supply of the fuel gas and the oxidant gas to the fuel cell using the controller to end the idle stop mode and return to the normal generation mode;
- calculating, using the controller, a length of an idle stop prohibition period, the length having a maximum time value dependent on a duration of the idle stop mode;
- beginning the idle stop prohibition period when restarting the supply of the fuel gas and the oxidant gas upon the return to the normal generation mode;
- upon the return to the normal generation mode, re-enter into the idle stop mode responsive to the condition that the driving power does not need to be supplied to the external load from the fuel cell only if the idle stop prohibition period has lapsed;
- and
- calculating a correction time value that is dependent on at least one operating parameter of the fuel cell system after restarting the supply of the fuel gas and the oxidant gas, wherein the length of the idle stop prohibition period is a difference between the maximum time value and the correction time value.
6 more elements
Dependencies are inferred from the claim text.