Power supply system, transportation device, and power transmission method

A power transmission method for performing power transmission among an electric load, a first energy storage, and a second energy storage, the power transmission method comprising:

• acquiring at least one of a request supply amount of electric power to be supplied to the electric load or a request output amount of regenerative electric power output from the electric load, the electric load being an electric motor or an electric actuator;
• calculating a first input or output target amount of electric power for the first energy storage and a second input or output target amount of electric power for the second energy storage in accordance with at least one state quantity including the at least one of the request supply amount or the request output amount, the first energy storage being a battery, the second energy storage being a battery or a capacitor;
• controlling electric power transmission so that the first input or output target amount and the second input or output target amount are satisfied;
• and
• controlling the electric power transmission so that a change in an amount of the electric power transmission decreases even though changes in the first input or output target amount and the second input or output target amount are discontinuous,
• wherein the electric power transmission is further controlled so that at least one of:
• a rate of increase in an actual input or output of one of the first energy storage and the second energy storage when the first input or output target amount and the second input or output target amount discontinuously increases is different in magnitude from a rate of decrease in the actual input or output of the one of the first energy storage and the second energy storage when the first input or output target amount and the second input or output target amount discontinuously decreases;
• a magnitude of the rate of increase in the actual input or output of the first energy storage when the first input or output target amount discontinuously increases is less than a magnitude of the rate of decrease in the actual input or output of the first energy storage when the first input or output target amount discontinuously decreases;
• or
• a magnitude of a rate of decrease in an actual output of the first energy storage when the first output target amount discontinuously decreases is less than a magnitude of a rate of decrease in an actual input of the first energy storage when the first input target amount discontinuously decreases.

A power supply system comprising:

• a first energy storage to supply electric power to an electric load and to be charged by the electric load, the first energy storage being a battery, the electric load being an electric motor or an electric actuator;
• a second energy storage to supply electric power to the electric load and to be charged by the electric load, the second energy storage being a battery or a capacitor;
• a power transmission circuit via which the electric load is connected to the first energy storage and to the second energy storage;
• and
• circuitry configured to
• acquire at least one of a request supply amount of electric power to be supplied to the electric load or a request output amount of regenerative electric power output from the electric load;
• calculate a first input or output target amount of electric power for the first energy storage and a second input or output target amount of electric power for the second energy storage in accordance with at least one state quantity including the at least one of the request supply amount or the request output amount;
• control the power transmission circuit to control electric power transmission so that the first input or output target amount and the second input or output target amount are satisfied;
• and
• control the power transmission circuit so that a change in an amount of the electric power transmission decreases even though changes in the first input or output target amount and the second input or output target amount are discontinuous,
• wherein the circuitry is configured to control the power transmission circuit so that a rate of increase in an actual input or output of one of the first energy storage and the second energy storage when the first input or output target amount and the second input or output target amount discontinuously increases is different in magnitude from a rate of decrease in the actual input or output of the one of the first energy storage and the second energy storage when the first input or output target amount and the second input or output target amount discontinuously decreases.