Vehicle and control method for vehicle

A vehicle that travels by rotating an output shaft coupled to a drive wheel using power of at least one of an engine and a motor, comprising:

• a generator that generates electric power using power of the engine;
• a battery that is configured to be connectable to the motor and the generator;
• and
• a transmission that is provided between the motor and the output shaft, wherein the controller is configured to change the limit value on the basis of a speed ratio of the transmission;
• wherein
• the transmission establishes any one of a low-speed gear and a high-speed gear that is smaller in speed ratio than the low-speed gear, and
• a controller that is configured to drive the motor in pulse width modulation control when a vehicle speed is lower than a threshold, and that is configured to drive the motor in rectangular control, which has an improved output but poor controllability as compared with the pulse width modulation, when the vehicle speed exceeds the threshold, wherein
• at the time of an abnormality of the battery, the controller is configured to execute battery-less travel control in which the battery is isolated from the motor and the generator, the generator is caused to generate electric power by generating a torque, corresponding to at least any one of an accelerator operation amount and a vehicle required torque, from the generator, and the motor is driven by using the electric power generated by the generator, and
• at the time of executing the battery-less travel control, when the vehicle speed exceeds a limit value corresponding to the threshold, the controller is configured to execute at least one of a first process of limiting a rate of variation in the accelerator operation amount, a second process of limiting a rate of variation in the vehicle required torque and a third process of limiting a torque of the generator to thereby suppress losing a balance of input and output electric powers between the generator and the motor;
• and
• the controller is configured to increase the threshold and the limit value when the high-speed gear is established as compared with when the low-speed gear is established.

A control method for a vehicle that travels by rotating an output shaft coupled to a drive wheel using power of at least one of an engine and a motor, wherein the vehicle includes:

• a generator that generates electric power using power of the engine;
• a battery that is configured to be connectable to the motor and the generator;
• and a controller that is configured to control the motor and the generator, the control method comprising:
• driving the motor in pulse width modulation control when a vehicle speed is lower than a threshold;
• driving the motor in rectangular control that has an improved output but poor controllability as compared with the pulse width modulation control when the vehicle speed exceeds the threshold;
• determining an abnormality of the battery;
• executing, if the battery is determined to be abnormal, a battery-less travel control in which the battery is isolated from the motor and the generator, the generator is caused to generate electric power by generating a torque, corresponding to at least any one of an accelerator operation amount and a vehicle required torque, from the generator, and the motor is driven by using the electric power generated by the generator;
• determining, if the battery-less travel control is executed, if the vehicle speed exceeds the threshold;
• and
• executing, if the vehicle speed is determined to exceed the threshold, at least one of a first process, a second process, and a third process to thereby suppress losing a balance of input and output electric powers between the generator and the motor, wherein the control method further comprises:
• in the first process, limiting a rate of variation in the accelerator operation amount,
• in the second process, limiting rate of variation in the vehicle required torque, and
• in the third process, controlling the torque of the generator to not decrease below a predetermined lower limit.