| CPC B60W 20/13 (2016.01) [F01N 3/2013 (2013.01); B60W 2510/068 (2013.01); B60W 2510/244 (2013.01)] | 5 Claims |
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1. A method for a hybrid vehicle including an engine in which an electrically heated type catalyst device that is heated with supply of electric power is provided in an exhaust gas passage and a motor that generates power with supply of electric power from a battery as traveling power sources and having a first travel mode in which only the motor is used as the traveling power source and a second travel mode in which at least the engine is used as the traveling power source as travel modes, the method comprising:
a switching process of switching the travel mode to the second travel mode when a state of charge of the battery is equal to or less than a predetermined mode-switching state of charge while the hybrid vehicle is traveling in the first travel mode;
a pre-heating process of starting supply of electric power to the catalyst device when the state of charge of the battery is equal to or less than an optimal power-supply state of charge greater than the mode-switching state of charge, the pre-heating process being a process of performing electric heating of the catalyst device while the hybrid vehicle is traveling in the first travel mode;
a calculation process of calculating a first value SOP1 of the optimal power-supply state of charge at a start of supplying electric power to the catalyst device according to equation SOP1=SHV+W1×HT, wherein SOP1 is the first value of the optimal power-supply state of charge, SHV represents the predetermined mode-switching state of charge, W1 represents a travel load of the hybrid vehicle, and HT represents a predetermined time during which the electric power is supplied to the catalyst device until a catalyst temperature reaches a catalyst activation temperature; and
a correction process of:
calculating a second value SOP2 of the optimal power-supply state of charge after the supply of the electric power to the catalyst device has been started according to equation SOP2=SHV+W2×HT, wherein SOP2 is the second value of the optimal power-supply state of charge, SHV represents the predetermined mode-switching state of charge, W2 represents a travel load of the hybrid vehicle after the supply of the electric power to the catalyst device has been started, and HT represents a predetermined time during which the electric power is supplied to the catalyst device until a catalyst temperature reaches a catalyst activation temperature,
calculating a decreased input electric power according to
E=E0×(SOP1−SOP2)/(SOP1−SHV), wherein E is the decreased input electric power, and E0 is an initial input electric power, and
decreasing input electric power of the catalyst device based on the decreased input electric power.
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