PROBLEM TO BE SOLVED: To restrict discharge quantity of a battery and to previously prevent extreme capacity lowering of the battery by controlling total output torque of an internal combustion engine and an electric motor within a small region of rotating speed in comparison with the time when residual capacity is large at the time when the residual capacity of the battery shows a small value by furnishing a residual capacity monitoring means of the battery. SOLUTION: Residual quantity of a battery 3 is judged by incorporating output of a residual capacity monitoring means 14 in a program control means 10 at the time when an automobile furnished with a hybrid power plant travels. Hereby, an inverter 4 is controlled by selecting a first output torque characteristic of a control map 13 at the time when residual capacity of the battery 3 is judged large. In the meantime, the inverter 4 is controlled by selecting a second output torque characteristic of the control map 13 at the time when the residual capacity of the battery 3 is judged small. In this case, torque which is made comparatively small to maintain rotational speed of an internal combustion engine 1 in the middle of travelling at 5 speed as 1200 rpm and 70 km/h as car speed is given to the internal combustion engine 1 by an electric motor 2.
【課題】 補助動力用の電動機に電流を供給する電池の 残存容量が低下したときには、運転者の自然な体感によ る運転操作にしたがって補助動力の分担割合を小さくで きるようにする。
【解決手段】 電池の残存容量監視手段の出力に得られ る残存容量が小さい値を示すとき、電池の残存容量の大 きいときに比べて内燃機関およびこの内燃機関に補助ト ルクを与える電動機の総合出力トルクを制御マップにし たがって回転速度の小さい領域で小さく制御する。