Hybrid vehicle and method for controlling the same

A hybrid vehicle mounted with a motor for generating power to drive the vehicle and an internal combustion engine configured to be capable of outputting power to drive the vehicle independently of said motor,

• said hybrid vehicle comprising:
• a main power storage device;
• an electric power feeding line for supplying electric power to an inverter that controls and drives said motor;
• a first voltage converter provided between said electric power feeding line and said main power storage device and configured to convert voltage bidirectionally;
• a plurality of sub power storage devices provided in parallel to each other;
• a second voltage converter provided between said plurality of sub power storage devices and said electric power feeding line and configured to convert voltage between one of said plurality of sub power storage devices and said electric power feeding line bidirectionally;
• a connection unit provided between said plurality of sub power storage devices and said second voltage converter and configured to selectively connect a selected sub power storage device among said plurality of sub power storage devices to said second voltage converter;
• and
• a switching control device configured to control selective connection between said plurality of sub power storage devices and said second voltage converter,
• said switching control device including:
• a switching determination unit for determining, based on a state of charge of a residual capacity of said selected sub power storage device being used, whether generation of a request to switch said selected sub power storage device is necessary;
• and
• prohibition means for instructing said switching determination unit not to generate the request to switch said selected sub power storage device, while a process for starting or a process for stopping said internal combustion engine is being performed.

A method for controlling a hybrid vehicle,

• said hybrid vehicle including:
• a motor for generating power to drive the vehicle;
• an internal combustion engine configured to be capable of outputting power to drive the vehicle independently of said motor;
• a main power storage device;
• an electric power feeding line for supplying electric power to an inverter that controls and drives said motor;
• a first voltage converter provided between said electric power feeding line and said main power storage device and configured to convert voltage bidirectionally;
• a plurality of sub power storage devices provided in parallel to each other;
• a second voltage converter provided between said plurality of sub power storage devices and said electric power feeding line and configured to convert voltage between one of said plurality of sub power storage devices and said electric power feeding line bidirectionally;
• a connection unit provided between said plurality of sub power storage devices and said second voltage converter and configured to selectively connect a selected sub power storage device among said plurality of sub power storage devices to said second voltage converter;
• a switching control device configured to control selective connection between said plurality of sub power storage devices and said second voltage converter;
• and
• a traveling control unit for dividing and thus assigning a total required power for said hybrid vehicle to power output from said motor and power output from said internal combustion engine,
• said method comprising the steps of:
• determining whether a process for switching connection between said plurality of sub power storage devices and said second voltage converter is being performed;
• and
• prohibiting a process for starting said internal combustion engine which is being stopped and a process for stopping said internal combustion engine which is being operated, while said process for switching is being performed.

A method for controlling a hybrid vehicle,

• said hybrid vehicle including:
• a motor for generating power to drive the vehicle;
• an internal combustion engine configured to be capable of outputting power to drive the vehicle independently of said motor;
• a main power storage device;
• an electric power feeding line for supplying electric power to an inverter that controls and drives said motor;
• a first voltage converter provided between said electric power feeding line and said main power storage device and configured to convert voltage bidirectionally;
• a plurality of sub power storage devices provided in parallel to each other;
• a second voltage converter provided between said plurality of sub power storage devices and said electric power feeding line and configured to convert voltage between one of said plurality of sub power storage devices and said electric power feeding line bidirectionally;
• a connection unit provided between said plurality of sub power storage devices and said second voltage converter and configured to selectively connect a selected sub power storage device among said plurality of sub power storage devices to said second voltage converter;
• a switching control device configured to control selective connection between said plurality of sub power storage devices and said second voltage converter;
• a traveling control unit for dividing and thus assigning a total required power for said hybrid vehicle to power output from said motor and power output from said internal combustion engine;
• a rotary element having a speed of rotation varied according to change in output of said internal combustion engine;
• and
• a protection control unit for generating one of a request to start said internal combustion engine and a request to stop said internal combustion engine for preventing excessive rotation of said rotary element,
• said method comprising the steps of:
• determining whether a process for switching connection between said plurality of sub power storage devices and said second voltage converter is being performed;
• prohibiting a process for starting said internal combustion engine which is being stopped and a process for stopping said internal combustion engine which is being operated, while said process for switching is being performed, and
• permitting one of said process for starting said internal combustion engine and said process for stopping said internal combustion engine, regardless of whether said process for switching connection is being performed, when said protection control unit generates one of said request to start said internal combustion engine and said request to stop said internal combustion engine.

A method for controlling a hybrid vehicle,

• said hybrid vehicle including:
• a motor for generating power to drive the vehicle;
• an internal combustion engine configured to be capable of outputting power to drive the vehicle independently of said motor;
• a main power storage device;
• an electric power feeding line for supplying electric power to an inverter that controls and drives said motor;
• a first voltage converter provided between said electric power feeding line and said main power storage device and configured to convert voltage bidirectionally;
• a plurality of sub power storage devices provided in parallel to each other;
• a second voltage converter provided between said plurality of sub power storage devices and said electric power feeding line and configured to convert voltage between one of said plurality of sub power storage devices and said electric power feeding line bidirectionally;
• a connection unit provided between said plurality of sub power storage devices and said second voltage converter and configured to selectively connect a selected sub power storage device among said plurality of sub power storage devices to said second voltage converter;
• and
• a switching control device configured to control selective connection between said plurality of sub power storage devices and said second voltage converter,
• said method comprising the steps of:
• determining, based on a state of charge of a residual capacity of the selected sub power storage device being used, whether generation of a request to switch said selected sub power storage device is necessary;
• and
• issuing an instruction not to generate said request to switch, regardless of the state of charge of said selected sub power storage device, while a process for starting or a process for stopping said internal combustion engine is being performed.