Drive device, method for controlling the same, and transport apparatus

A drive device comprising:

• a first energy storage having a first power weight density and a first energy weight density;
• a second energy storage having a second power weight density higher than the first power weight density and a second energy weight density lower than the first weight density;
• a voltage converter to convert a voltage output from the second energy storage;
• a driver to be driven with power supplied from at least one of the first energy storage and the second energy storage;
• and
• circuitry configured to
• interrupt current from the driver or from the second energy storage to the first energy storage;
• and
• control the voltage converter based on a power of the first energy storage and a required driving force for the driver in such a manner as to allow power to be supplied to the driver from both the first energy storage and the second energy storage in a case where an optimum voltage, with which a driving efficiency of the driver according to a required driving force for the driver is greater than or equal to a threshold value, is less than or equal to the voltage of the first energy storage and where a relationship between a voltage output by the first energy storage and a voltage output by the second energy storage satisfies all of a first condition, a second condition, and a third condition, the voltage of the first energy storage being less than or equal to a withstand voltage limit of the driver in the first condition, the voltage of the first energy storage being less than or equal to a first value and the voltage converter converting the voltage of the second energy storage with a maximum conversion rate so as to obtain the first value in the second condition, the voltage of the first energy storage being greater than or equal to a second value and the voltage converter converting the voltage of the second energy storage with a minimum conversion rate so as to obtain the second value in the third condition.

A drive device comprising:

• a first energy storage having a first power weight density and a first energy weight density;
• a second energy storage having a second power weight density higher than the first power weight density and a second energy weight density lower than the first weight density;
• a voltage converter to convert a voltage output from the second energy storage;
• a driver to be driven with power supplied from at least one of the first energy storage and the second energy storage;
• and
• circuitry configured to interrupt current from the driver or from the second energy storage to the first energy storage;
• and
• control the voltage converter so that the first energy storage and the second energy storage interchange power with each other, without voltage conversion by the voltage converter, in such a manner that the first energy storage and the second energy storage are connected to each other via an interrupter in a case where a relationship between a voltage output by the first energy storage and a voltage output by the second energy storage does not satisfy all of a first condition, a second condition, and a third condition, the voltage of the first energy storage being less than or equal to a withstand voltage limit of the driver in the first condition, the voltage of the first energy storage being less than or equal to a first value and the voltage converter converting the voltage of the second energy storage with a maximum conversion rate so as to obtain the first value in the second condition, the voltage of the first energy storage being greater than or equal to a second value and the voltage converter converting the voltage of the second energy storage with a minimum conversion rate so as to obtain the second value in the third condition.

A method for controlling a drive device, comprising:

• interrupting current from a driver or from a second energy storage to a first energy storage;
• and
• controlling a voltage converter based on a power of the first energy storage and a required driving force for the driver in such a manner as to allow power to be supplied to the driver from both the first energy storage and the second energy storage in a case where an optimum voltage, with which a driving efficiency of the driver according to a required driving force for the driver is greater than or equal to a threshold value, is less than or equal to the voltage of the first energy storage and where a relationship between a voltage output by the first energy storage and a voltage output by the second energy storage satisfies all of a first condition, a second condition, and a third condition, the voltage of the first energy storage being less than or equal to a withstand voltage limit of the driver in the first condition, the voltage of the first energy storage being less than or equal to a first value and the voltage converter converting the voltage of the second energy storage with a maximum conversion rate so as to obtain the first value in the second condition, the voltage of the first energy storage being greater than or equal to a second value and the voltage converter converting the voltage of the second energy storage with a minimum conversion rate so as to obtain the second value in the third condition.