Toyota Jidosha Kabushiki Kaisha

Tatsuki Saito

Shigeki Kinomura

Shoichi Sasaki

Yoshimitsu Takahashi

Hiroyuki Azuma

A hybrid vehicle includes: an engine; a motor; a drive system battery connected to a drive system power line; an auxiliary system battery connected to an auxiliary system power line; a bidirectional power converter configured to step down power on the drive system power line to supply the stepped-down power to the auxiliary system power line, and configured to boost power on the auxiliary system power line to supply the boosted power to the drive system power line; and a control device. The control device is configured to, upon a cold start in which the engine is started, control the engine, the motor, and the bidirectional power converter to cause the motor to crank the engine while causing the bidirectional power converter to boost the power on the auxiliary system power line to supply the boosted power to the drive system power line.

Hybrid vehicle and method for controlling hybrid vehicle

In a state of reverse driving with load operation of an engine, an upper limit torque Temax of the engine is set to cause a total torque of a torque demand Tr* and a cancellation torque for cancelling a torque applied to a driveshaft accompanied with load operation of the engine to be output from a second motor to the driveshaft. A product of the upper limit torque Temax of the engine and an upper limit rotation speed Nemax of the engine is set to an upper limit power Pemax. A target power Pe* of the engine is then set in a range of not greater than the upper limit power Pemax. The engine, a first motor and the second motor are then controlled such as to cause the target power Pe* to be output from the engine and such as to output the torque demand Tr* to the driveshaft.

Hybrid vehicle

When the temperature of coolant in an engine is greater than or equal to a half-warm-up determination value, an engine cooling control section opens a valve to mix the coolant in two coolant circuits. Accordingly, even if the temperature of the coolant in the engine fluctuates due to mixing coolants at different temperatures, such fluctuation occurs in a temperature range lower than the determination value for the warm-up completion of the engine. This prevents a control procedure for the time before the warm-up completion and a control procedure for the time after such completion from being performed in a repeating, alternating manner. As a result, when the coolant circulating in the first coolant circuit and the coolant circulating in the second coolant circuit are mixed together, control that should be performed based on the coolant temperature in the engine is carried out without hindrance.

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Nagoya, Japan

Tatsuki Saito