US Patent 10093166 Power generation control system for hybrid vehicle

A hybrid vehicle has a first motor/generator mechanically coupled to a drive wheel, a second motor/generator mechanically coupled to an internal combustion engine and a high-power battery that is electrically coupled to the motor/generators. The second motor/generator has a smaller electrical power generation capability than the first motor/generator. While starting the vehicle at a time of insufficient battery capacity required for the EV start, the power generation controller disconnects the first electric motor from the drive wheel, connects the first electric motor to the internal combustion engine, and carries out MG1 idle power generation in which the first electric motor generates power by receiving torque from the internal combustion engine. When the vehicle is stopped at a time of sufficient battery capacity, the power generation controller does not carry out the MG1 idle power generation and keeps the first electric motor mechanically coupled to the drive wheel.