Storage-battery evaluation device, energy storage system, and storage-battery evaluation method

A storage-battery evaluation device comprising:

• a storage battery comprising at least one battery board including a plurality module each including a plurality of cells;
• a charge/discharge controlling circuit to receiver a plurality of charge/discharge command values instructing charge/discharge of electric power for an energy storage device and perform charge/discharge control for the storage battery in accordance with the plurality of charge/discharge command values;
• a first circuit configured to:
• receive voltage values measured at the storage battery at a time of execution of the plurality of charge/discharge command values, and
• generate corresponding data including voltages values and charge amounts of the storage battery based on the received voltage values;
• and
• a second circuit configured to:
• specify first charge/discharge command values of the plurality of charge/discharge command values, wherein execution of the first charge/discharge command values results in the charge amounts of the energy storage device falling within a first charge-amount range, and the first charge-amount range corresponds to part of a charge-amount range of the energy storage device,
• obtain information indicating whether a first distribution of a relation between charge/discharge command values and frequencies based on the first charge/discharge command values satisfies a predetermined condition regarding a frequency of charge/discharge command values,
• specify, if the predetermined condition is satisfied, voltage values corresponding to charge amounts belonging to the first charge-amount range, based on the corresponding data, and
• specify a deterioration state of the energy storage device using a second distribution of a relation between voltage values and frequencies based on the specified voltage values.

A storage-battery evaluation method comprising:

• receiving a plurality of charge/discharge command values instructing charge/discharge of electric power for an energy storage device,
• receive voltage values measured at the energy storage device subjected to charge/discharge at a time of execution of the plurality of charge/discharge command values;
• generating corresponding data including voltages values and charge amounts of the energy storage device based on the received voltage values;
• specifying first charge/discharge command values of the plurality of charge/discharge command values, wherein execution of the first charge/discharge command values results in the charge amounts of the energy storage device falling within a first charge-amount range, and the first charge-amount range corresponds to part of a charge-amount range of the energy storage device:
• obtaining information indicating whether a first distribution of a relation between charge/discharge command values and frequencies based on the first charge/discharge command values satisfies a predetermined condition regarding a frequency of charge/discharge command values;
• specifying, if the predetermined condition is satisfied, voltage values corresponding to charge amounts belonging to the first charge-amount range, based on the corresponding data;
• and
• specifying a deterioration state of the energy storage device using a second distribution of a relation between voltage values and frequencies based on the specified voltage values.