Evaluation device, evaluation method and evaluation system for energy storage device

Patent metadata

Field	Value
Publication number	US-2020233037-A1
Application number	US-201916567786-A
Country	US
Kind code	A1
Filing date	Sep 11, 2019
Priority date	Jan 22, 2019
Publication date	Jul 23, 2020
Grant date	—

Abstract

According to one embodiment, an evaluation device for an energy storage device includes first processing circuitry and second processing circuitry. The first processing circuitry acquires data items including an amount of charge and a voltage value measured in a measurement period from the energy storage device, the energy storage device being charge-discharge-controlled according to charge-discharge command values. The second processing circuitry generates a representative data item of voltage values for amounts of charge, based on the data items acquired for the measurement period; and evaluates a degradation state of the energy storage device, based on a relative change between a plurality of the representative data items corresponding to a plurality of the measurement periods.

First claim

1 . An evaluation device for an energy storage device, comprising:
first processing circuitry configured to acquire data items including an amount of charge and a voltage value measured in a measurement period from an energy storage device, the energy storage device being charge-discharge-controlled according to charge-discharge command values; second processing circuitry configured to
generate a representative data item of voltage values for amounts of charge, based on the data items acquired for the measurement period; and
evaluate a degradation state of the energy storage device, based on a relative change between a plurality of the representative data items corresponding to a plurality of the measurement periods.

2 . The evaluation device according to claim 1 ,
wherein the second processing circuitry sorts the data items in an order of the amounts of charge, and wherein the second processing circuitry generates a moving average data item of the voltages value for the amounts of charge, as the representative data item, based on the sorted data items.

3 . The evaluation device according to claim 2 ,
wherein the second processing circuitry identifies the amount of charge corresponding to a threshold of a voltage value, in a plurality of the moving average data items, and wherein the second processing circuitry evaluates the degradation state of the energy storage device, based on a relative change between the identified amounts of charge.

4 . The evaluation device according to claim 3 ,
wherein the threshold is a minimum value among maximum voltages in the plurality of the moving average data items.

5 . The evaluation device according to claim 3 ,
wherein a first moving average data item among the plurality of the moving average data items corresponds to a first measurement period among the plurality of the measurement periods, wherein a second moving average data item among the plurality of the moving average data items corresponds to a second measurement period among the plurality of the measurement periods, and wherein the second processing circuitry evaluates the degradation state of the energy storage device in the second measurement period, based on a ratio between the amount of charge at the threshold in the second moving average data item and the amount of charge at the threshold in the first moving average data item.

6 . The evaluation device according to claim 2 , wherein
the second processing circuitry: applies a window frame for the sorted data items, a size of the window frame being smaller than a number of the sorted data items, calculates an average of the voltage values based on the data items belonging to the window frame; and repeats movement of the window frame and calculation of the average to generate the moving average data item.

7 . The evaluation device according to claim 6 ,
wherein the second processing circuitry calculates a first distribution of the charge-discharge command values in the measurement period, and a second distribution of the charge-discharge command values in a partial period corresponding to the window frame applied in the measurement period, wherein the second processing circuitry determines whether the second distribution is equivalent to the first distribution or not, and if the second distribution is not equivalent to the first distribution, performs a trimming process of the charge-discharge command values in the partial period resulting in that the second distribution is equivalent to the first distribution, wherein the second processing circuitry calculates the average, based on data corresponding to the charge-discharge command values in the partial period after the trimming process when the second distribution becomes equivalent to the first distribution.

8 . The evaluation device according to claim 6 ,
wherein the second processing circuitry calculates a first distribution of the charge-discharge command values in the measurement period, and a second distribution of the charge-discharge command values in a partial period corresponding to the window frame set in the measurement period, wherein the second processing circuitry determines whether the second distribution is equivalent to the first distribution or not, wherein the second processing circuitry generates the moving average data item without using the average of the voltage values belonging to the window frame if the second distribution is not equivalent to the first distribution.

9 . The evaluation device according to claim 1 ,
wherein the first processing circuitry acquires temperature information on the energy storage device, from the energy storage device, wherein the second processing circuitry calculates a representative temperature of the energy storage device in the measurement period based on the temperature information, and wherein the second processing circuitry performs degradation evaluation of the energy storage device in an order of a first to third measurement periods, and wherein if the representative temperature in the second measurement period is changed from the representative temperature in the first measurement period, the second processing circuitry determines the degradation state in the second measurement period to be identical to the degradation state in the first measurement period, and evaluates the degradation state in the third measurement period with reference to the representative data in the second measurement period.

10 . A evaluation method for an energy storage device, comprising:
acquiring data items including an amount of charge and a voltage value measured in a measurement period from the energy storage device, the energy storage device being charge-discharge-controlled according to charge-discharge command values; generating a representative data item of voltage values for amounts of charge, based on the data items acquired for the measurement period; and evaluating a degradation state of the energy storage device, based on a relative change between a plurality of the representative data items corresponding to a plurality of the measurement periods.

11 . An evaluation system, comprising:
an energy storage device configured to be charge-discharge-controlled according to charge-discharge command values; and an evaluation device for the energy storage device, the evaluation device comprising: first processing circuitry configured to acquire data items including an amount of charge and a voltage value measured in a measurement period from an energy storage device; second processing circuitry configured to
generate a representative data item of voltage values for amounts of charge, based on the data items acquired for the measurement period; and
evaluate a degradation state of the energy storage device, based on a relative change between a plurality of the representative data items corresponding to a plurality of the measurement periods.

Assignees

• Toshiba Kk
• Toshiba Energy Systems & Solutions Corp

Inventors

• Yamamoto Takahiro
• Tatano Hisaaki
• Fujiwara Kenichi
• Sakuma Masatake
• Koiwa Kaoru
• Ogura Yasuhiro
• Kobayashi Takenori
• Mitsumoto Kenji

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• G01R31/367

  Software therefor, e.g. for battery testing using modelling or look-up tables · CPC title

• G01R31/392 Primary

  Determining battery ageing or deterioration, e.g. state of health · CPC title

• G01R31/3648

  comprising digital calculation means, e.g. for performing an algorithm · CPC title