A hybrid automobile runs by transmitting a power from an engine and a power
from a motor-generator MG2, and can store a part of the power from the
engine and an electric power generated by a motor-generator MG1. In this
hybrid automobile, a power requirement Pr* of a drive shaft is set based
on an accelerator opening, and a battery charge electric power Pbi is set
based on SOC, and the sum of the power requirement Pr* and the battery
charge electric power Pbi are set as an engine target power Pe*. When the
engine target power Pe* is less than a predetermined minimum value Plow,
the engine target power Pe* is changed to the minimum value Plow. Further,
in accordance with this change, the battery charge electric power Pbi is
also changed, and the engine and the motor-generators MG1, MG2 are
operated. Since the minimum value Plow is set to be a value such that the
efficiency with respect to the output of the engine becomes optimal, it is
possible to prevent the engine from being operated in a low output region
where the efficiency is low.
