Capacity estimation method and capacity estimation system for power storage device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsRyota Tajima, Toshiyuki Isa, Akihiro Chida
Life of this patent
Estimating the term…
Abstract
It is difficult to know the remaining amount and the degradation state of a power storage device, and it is also difficult to estimate how long the power storage device can be used. Data obtained through midway discharge and mid-to-full charge is used as the learning data to calculate the degradation state and the capacity. In other words, the learning data includes both a discharge curve of midway discharge and a charge curve of mid-to-full charge, and neural network processing is performed with the use of the learned data.
Claims8
A capacity estimation method for a power storage device comprising a plurality of lithium-ion secondary batteries, comprising:
- performing self-discharging of a secondary battery with an SOC of 100% over time during a first period;
- charging the secondary battery from an SOC of a self-discharged state to a fully charged state during a second period;
- discharging the secondary battery to SOC 80% using a discharging circuit during a third period;
- charging the secondary battery to a fully charged state using a charging circuit during a fourth period;
- obtaining a first charge-discharge data during the third period and the fourth period;
- and
- calculating a degradation state from the first charge-discharge data by neural network processing.
A capacity estimation system for a power storage device comprising a plurality of lithium-ion secondary batteries connected in series, comprising:
- performing self-discharging of a secondary battery with an SOC of 100% with a constant load during a first period;
- charging the secondary battery from an SOC of a self-discharged state to a fully charged state during a second period;
- discharging the secondary battery to SOC 80% using a discharging circuit during a third period;
- charging the secondary battery to a fully charged state using a charging circuit during a fourth period to obtain a first charge data;
- and
- calculating a degradation state from the first charge data by neural network processing.
A capacity estimation method for a power storage device, comprising:
- preparing a first secondary battery as a test cell;
- performing self-discharging of the first secondary battery with an SOC of 100% with a constant load during a first period;
- charging the first secondary battery from an SOC of a self-discharged state to a fully charged state during a second period;
- discharging the first secondary battery to SOC 80% during a third period;
- charging the first secondary battery to a fully charged state during a fourth period;
- obtaining learning data comprising the charge data during the fourth period;
- learning the learning data in a neural network portion;
- charging a second secondary battery from SOC 80% to a fully charged state;
- and
- calculating a degradation state of the second secondary battery by the neural network portion after learning.
Dependencies are inferred from the claim text.