Energy flow management in hybrid vehicle power output apparatus

摘要

The present invention prevents a decrease in efficiency due to energy circulation in a power transmission path in a power output apparatus having an engine and a motor as power source. In the power output apparatus, a planetary gear 120 has a sun gear shaft linked with a generator MG1, a ring gear shaft linked with a motor MG2, and a planetary carrier linked with an output shaft of an engine 150. The power output apparatus carries out a control procedure to avoid energy circulation, which goes through the planetary gear 120, the motor MG2, and generator MG1, and the planetary gear 120, and thereby prevent a decrease in efficiency. The energy circulation occurs when the motor MG2 converts the power output from the engine 150 to electric power and the generator MG1 carries out power operation with the regenerated electric power. The control procedure monitors a torque command value of the motor MG2 and shifts a driving point of the engine 150 to another driving point of higher revolving speed when the torque command value is not greater than a threshold value Tref.