US Patent 10532732 Hybrid vehicle and control method therefor

When an accelerator is turned on in a braking state in which the accelerator is turned off during predetermined traveling and a braking torque is output from a first motor to a drive shaft via a planetary gear set with negative rotation of the first motor and with a counter electromotive voltage of the first motor higher than a voltage of power lines on a high voltage side, a step-up and step-down converter and an engine are controlled such that a voltage of the power lines on the high voltage side increases and a rotation speed of the first motor increases in comparison with a case in which the accelerator is turned off.