US 2002/0157882 A1 · Control device for hybrid vehicle

Abstract

A hybrid vehicle is provided with an internal combustion engine as a power source and an electric motor. The electric motor is used to charge the high-voltage battery. Charge/discharge control of the high-voltage battery and an idle-stop control can be performed, taking into account battery deterioration. For this purpose, the internal resistance R is detected as a degree of deterioration in the high-voltage battery. When the internal resistance R is less than a predetermined resistance R1, a threshold value of a state of charge (SOC) of the high-voltage battery, SOCa above which the idle stop operation permitted is set, fitted to an initial condition wherein the high-voltage battery has not undergone deterioration. On the other hand, when the internal resistance R is greater than or equal to the predetermined value R1, the threshold value tSOCa is varied to higher value. Further, a target SOC of the high-voltage battery is varied in response to the degree of deterioration of the battery. In order to regenerate sufficient inertial energy during deceleration, the target SOC for the high-voltage battery when the vehicle is not decelerating is set to a lower value than the target state of charge when the vehicle is decelerating.

Claims20

Dependent claims

A control device for a hybrid vehicle which comprises an engine (1) as a power source for running the vehicle and a motor/generator (2), comprising:

a high-voltage battery (11) which functions as a power source for the motor/generator (2);
a low-voltage battery (14) for vehicle-mounted electrical loads which has a lower voltage than the high-voltage battery (11);
an inverter (12) for controlling the motor/generator (2);
a sensor (18,19) which detects a condition of the high-voltage battery (11);
and
a microprocessor (16) which is programmed to:
compute a state of charge (SOC) of the high-voltage battery (11) based on the condition of the high-voltage battery (11);
compute a degree of deterioration of the high-voltage battery (11) based on the condition of the high-voltage battery (11);
control a current generated by the motor/generator (2) so that the SOC of the high-voltage battery (11) coincides with a target SOC;
and
vary the target SOC according to the degree of deterioration of the high-voltage battery (11).

8 more elements

A control device for a hybrid vehicle which comprises an engine (1) as a power source for running the vehicle and a motor/generator (2), comprising;

a high-voltage battery (11) which functions as a power source of the motor/generator (2);
a low-voltage battery (14) for vehicle-mounted electrical loads which has a lower voltage than the high-voltage battery (11);
an inverter (12) for controlling the motor/generator (2);
a sensor (18,19) which detects a condition of the high-voltage battery (11);
a sensor (31) which detects a rotation speed of the engine (1);
a sensor (34) which detects a vehicle speed;
a sensor (35) which detects depression of an accelerator pedal;
a sensor (36) which detects depression of a brake pedal;
and
a microprocessor (16) programmed to:
compute a state of charge (SOC) of the high-voltage battery (11) based on the condition of the high-voltage battery (11);
determine whether or not the vehicle is brought to a temporary halt with the engine running at idle speed, based on the rotation speed of the engine, the vehicle speed, the depression of the accelerator pedal, and the depression of the brake pedal;
and
stop the engine (1) when the SOC of the high-voltage battery (11) is greater than or equal to a threshold value and when the vehicle is brought to the temporary halt with the engine running at the idle speed.

11 more elements

Dependencies are inferred from the claim text.

Control device for hybrid vehicle

Life of this patent

Control device for hybrid vehicle

Life of this patent

Abstract

Claims20