Hybrid vehicle, control device for hybrid vehicle and control method for hybrid vehicle

A control device for a hybrid vehicle,

• the hybrid vehicle including:
• an engine;
• a first motor;
• a planetary gear mechanism including three rotational elements connected to the engine, the first motor and a drive shaft linked to an axle;
• a second motor configured to exchange driving power with the drive shaft;
• a first inverter configured to drive the first motor;
• a second inverter configured to drive the second motor, the second inverter including a positive bus-bar and a negative bus-bar in common with the first inverter,
• an electric storage device including a negative electrode terminal connected to the negative bus-bar;
• a boost converter including a first transistor, a first diode, a second transistor, a second diode and a reactor, the first transistor connected to the positive bus-bar and serving as an upper arm, the first diode connected in parallel to the first transistor in an inverse direction, the second transistor connected to the first transistor and the negative bus-bar and serving as a lower arm, the second diode connected in parallel to the second transistor in an inverse direction, the reactor connected to a positive electrode terminal of the electric storage device and a connection point between the first transistor and the second transistor, the boost converter configured to adjust a voltage on a side of the first inverter and the second inverter to equal to or higher than a voltage on a side of the electric storage device;
• and
• a smoothing capacitor connected to the positive bus-bar and the negative bus-bar,
• the control device comprising an electronic control unit,
• the electronic control unit configured to execute a battery-less traveling when the electronic control unit determines that the boost converter has an abnormality, the battery-less traveling being a traveling in which the hybrid vehicle travels while the boost converter is shut off and the first motor and the second motor are driven such that a voltage of the capacitor is higher than the voltage of the electric storage device,
• the electronic control unit configured to determine that the upper arm of the boost converter has been short-circuited, when the electronic control unit makes at least one of a determination that the electric storage device has been charged and a determination that the voltage of the capacitor has approached the voltage of the electric storage device, while the electronic control unit is executing the battery-less traveling.

A control method for a hybrid vehicle,

• the hybrid vehicle including:
• an engine;
• a first motor;
• a planetary gear mechanism including three rotational elements connected to the engine, the first motor and a drive shaft linked to an axle;
• a second motor configured to exchange driving power with the drive shaft;
• a first inverter configured to drive the first motor;
• a second inverter configured to drive the second motor, the second inverter including a positive bus-bar and a negative bus-bar in common with the first inverter;
• an electric storage device including a negative electrode terminal connected to the negative bus-bar;
• a boost converter including a first transistor, a first diode, a second transistor, a second diode and a reactor, the first transistor connected to the positive bus-bar and serving as an upper arm, the first diode connected in parallel to the first transistor in an inverse direction, the second transistor connected to the first transistor and the negative bus-bar and serving as a lower arm, the second diode connected in parallel to the second transistor in an inverse direction, the reactor connected to a positive electrode terminal of the electric storage device and a connection point between the first transistor and the second transistor, the boost converter configured to adjust a voltage on a side of the first inverter and the second inverter to equal to or higher than a voltage on a side of the electric storage device;
• a smoothing capacitor connected to the positive bus-bar and the negative bus-bar;
• and
• an electronic control unit,
• the control method comprising:
• executing, by the electronic control unit, a battery-less traveling when the electronic control unit determines that the boost converter has an abnormality, the battery-less traveling being a traveling in which the hybrid vehicle travels while the boost converter is shut off and the first motor and the second motor are driven such that a voltage of the capacitor is higher than the voltage of the electric storage device;
• and
• determining, by the electronic control unit, that the upper arm of the boost converter has been short-circuited, when the electronic control unit makes at least one of a determination that the electric storage device is being charged and a determination that the voltage of the capacitor is close to the voltage of the electric storage device, while the electronic control unit is executing the battery-less traveling.