Hybrid vehicle control method and control device

A hybrid vehicle control device for a hybrid vehicle in which a first motor/generator provided as a travel drive source is connected to a drive wheel via a deceleration gear train, and in which an engine and a second motor/generator are directly connected via a gear train having a plurality of gears that are engaged with each other, and in which a battery electrically is connected to the first motor/generator and the second motor/generator, and in which an outside air temperature sensor is configured to detect an outside air temperature, the hybrid vehicle control device comprising:

• a controller programmed to control a requested torque of the second motor/generator, and the controller being further programmed to:
• repeat a power generation operation for rotating the second motor/generator using the engine and a motoring operation for rotating the engine using the second motor/generator in accordance with a rise and fall of a charge capacity of the battery upon determining a combustion request has occurred;
• continuously apply a prescribed negative torque to the second motor/generator while in the power generation operation such that a transmission torque of the gear train does not continuously fluctuate above and below zero torque;
• continuously apply a prescribed positive torque to the second motor/generator while in the motoring operation such that the transmission torque of the gear train does not continuously fluctuate above and below zero torque;
• and
• set a motoring rotational speed and a power generation rotational speed of the engine higher upon detecting the outside air temperature is less than a preset temperature as compared to when the outside air temperature is detected as being greater than or equal to the preset temperature while the power generation operation and the motoring operation are repeated.