Abstract: The present invention provides a technique for controlling creep torque to prevent a vehicle from rolling backward on an upward slope. In particular, a gradient of a road is calculated in real time from a detection value of a sensor and vehicle acceleration. A maximum creep torque for preventing roll-back caused by gravity according to the gradient is calculated using the gradient and vehicle information. A first creep torque reference is calculated based on the maximum creep torque and the vehicle speed. A second creep torque reference is calculated based on the maximum creep torque and the vehicle acceleration. A torque command value according to an operation state of a brake is calculated based on the first creep torque reference value and the second creep torque reference value and the gradient. In response, a torque output of a driving motor is controlled according to the calculated torque command value.

Abstract: The present invention provides a technique for controlling creep torque to prevent a vehicle from rolling backward on an upward slope. In particular, a gradient of a road is calculated in real time from a detection value of a sensor and vehicle acceleration. A maximum creep torque for preventing roll-back caused by gravity according to the gradient is calculated using the gradient and vehicle information. A first creep torque reference is calculated based on the maximum creep torque and the vehicle speed. A second creep torque reference is calculated based on the maximum creep torque and the vehicle acceleration. A torque command value according to an operation state of a brake is calculated based on the first creep torque reference value and the second creep torque reference value and the gradient. In response, a torque output of a driving motor is controlled according to the calculated torque command value.

Abstract: A power-down control method of a fuel cell hybrid vehicle includes determining an operation mode when a key-off command is input. If the mode is a fuel cell mode, the method includes: converting a low voltage DC-DC converter connected to an auxiliary battery to a boost mode; maintaining a driving state of a high voltage part, powered by voltage from the auxiliary battery and boosted by the low voltage DC-DC converter; subsequently stopping operation of a fuel cell stack and turning off the high voltage part; and subsequently turning off the low voltage DC-DC converter. If the mode is a hybrid mode, the method includes: maintaining a driving state of the high voltage part, powered by voltage from a super capacitor; subsequently stopping operation of the fuel cell stack and turning off the high voltage part; subsequently turning off the DC-DC converters; and subsequently cutting power of the super capacitor.

Abstract: A regenerative braking system includes a capacitor which is electrically connected to a stack and is charged by the stack, a traction motor, a motor control unit which control electric power input to the traction motor and electric power output from the traction motor, a chopper which is connected to the capacitor so as to be ON and OFF switched thereby limiting charging voltage of the capacitor, a braking resistor which consumes regenerative energy so as to serve as an auxiliary brake, and a hybrid control unit which turns on the chopper in case that a charging voltage limit of capacitor is exceeded so as to control overcharge of the capacitor and turns off the chopper in case that charging voltage of the capacitor descends. The capacitor is preferably a super capacitor.

Abstract: A power-down control method of a fuel cell hybrid vehicle includes determining an operation mode when a key-off command is input. If the mode is a fuel cell mode, the method includes: converting a low voltage DC-DC converter connected to an auxiliary battery to a boost mode; maintaining a driving state of a high voltage part, powered by voltage from the auxiliary battery and boosted by the low voltage DC-DC converter; subsequently stopping operation of a fuel cell stack and turning off the high voltage part; and subsequently turning off the low voltage DC-DC converter. If the mode is a hybrid mode, the method includes: maintaining a driving state of the high voltage part, powered by voltage from a super capacitor; subsequently stopping operation of the fuel cell stack and turning off the high voltage part; subsequently turning off the DC-DC converters; and subsequently cutting power of the super capacitor.

Abstract: A regenerative braking system includes a capacitor which is electrically connected to a stack and is charged by the stack, a traction motor, a motor control unit which control electric power input to the traction motor and electric power output from the traction motor, a chopper which is connected to the capacitor so as to be ON and OFF switched thereby limiting charging voltage of the capacitor, a braking resistor which consumes regenerative energy so as to serve as an auxiliary brake, and a hybrid control unit which turns on the chopper in case that a charging voltage limit of capacitor is exceeded so as to control overcharge of the capacitor and turns off the chopper in case that charging voltage of the capacitor descends. The capacitor is preferably a super capacitor.