CONTROL DEVICE FOR HYBRID VEHICLE

摘要

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 t he vehicle is not decelerating is set to a lower value than the targetstate of charge when the vehicle is decelerating.