Power storage control apparatus, direct-current power system, and controlling method thereof

A controlling method of a direct-current power system including a direct-current power source that generates power, a power conditioner that performs a maximum power point tracking and converts power outputted from the direct-current power source, and a power line connecting the direct-current power source and the power conditioner to each other, the power storage control apparatus, comprising:

• measuring a first voltage value of the power line;
• obtaining a power charge or discharge command value indicating an amount of power to charge the battery or an amount of power to be discharged from the battery;
• and
• controlling a bidirectional DC-DC converter circuit electrically connected to the power line interface, comprising a primary winding electrically connected to the power line interface and a secondary winding electrically connected to the battery based on the first voltage value and the power charge or discharge command value to approximate a voltage value of a direct current flowing through the power line to a prescribed voltage value, and to approximate a current value of a direct current flowing between the bidirectional DC-DC converter circuit and the power line to a prescribed current value.

A direct-current power system, comprising:

• a direct-current power source that generates power;
• a power conditioner that performs maximum power point tracking and converts power outputted from the direct-current power source;
• a power line connecting the direct-current power source and the power conditioner to each other;
• a power line interface electrically connected to the power line;
• a voltage sensor that measures a first voltage value of direct current flowing through the power line;
• a bidirectional DC-DC convertor circuit electrically connected to the power line interface, comprising a primary winding electrically connected to the power line interface and a secondary winding electrically connected to a battery;
• the battery;
• and
• a controller that receives the first voltage value measured by the voltage sensor and a power charge or discharge command value indicating an amount of power to charge the battery or an amount of power to be discharged from the battery, and controls the bidirectional DC-DC converter circuit based on the first voltage value and the power charge or discharge command value, wherein
• the bidirectional DC-DC convertor circuit controls the first voltage value to approximate to a prescribed voltage value, and a current value of a direct current flowing between the bidirectional DC-DC converter circuit and the power line to approximate to a prescribed current value.