Battery state estimating apparatus

• US 10,507,734 B2
• Filed: 02/05/2018
• Issued: 12/17/2019
• Est. Priority Date: 02/09/2017
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Oguma, Yasumasa, Osaka, Tetsuya, Tsuda, Shingo, Utsumi, Kazuaki, Yokoshima, Tokihiko, Mukoyama, Daikichi
• Primary Examiner(s): Williams, Arun C
• Application Number:
  US15/888,323
• Publication Number:
  US 20180222344A1
• Time in Patent Office: 680 Days
• Field of Search: 320134
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A battery state estimating apparatus is provided with: an acquirer configured to obtain a complex impedance of a battery; a calculator configured to calculate a ratio of a variation of a predetermined feature amount regarding the complex impedance; and an estimator configured to estimate a charge amount of the battery on the basis of the ratio of the variation of the predetermined feature amount with respect to an integrated current value, which is an integrated value of an electric current flowing through the battery.

Claims

1. A battery state estimating apparatus comprising:

an acquirer configured to obtain a complex impedance of a battery;

a calculator configured to calculate a ratio of a variation of a predetermined feature amount from the complex impedance; and

an estimator configured to estimate a charge amount of the battery on the basis of the ratio of the variation of the predetermined feature amount with respect to an integrated current value, which is an integrated value of an electric current flowing through the battery, wherein

said calculator is configured to calculate the ratio of the variation of the predetermined feature amount by using, for the predetermined feature amount,

(i) a real component of the complex impedance,

(ii) an imaginary component of the complex impedance,

(iii) an absolute value of the complex impedance, and

(iv) a slope of a straight line connecting an origin on a complex plane and a value of the complex impedance at a first predetermined frequency, the complex plane having an axis that is a real component of the complex impedance and an axis that is an imaginary component of the complex impedance.

2. A battery state estimating apparatus comprising:

an acquirer configured to obtain a complex impedance of a battery;

a calculator configured to calculate a ratio of a variation of a predetermined feature amount from the complex impedance; and

an estimator configured to estimate a charge amount of the battery on the basis of the ratio of the variation of the predetermined feature amount with respect to an integrated current value, which is an integrated value of an electric current flowing through the battery, wherein;

said acquirer is configured to obtain a plurality of complex impedances at a plurality of different temperatures, and

said calculator is configured to calculate the ratio of the variation of the predetermined feature amount by using, for the predetermined feature amount, a slope of a straight line connecting values of the obtained plurality of complex impedances at a second predetermined frequency on a complex plane having an axis that is a real component of the complex impedance and an axis that is an imaginary component of the complex impedance.

3. The battery state estimating apparatus according to claim 2, further comprising:

a determinator configured to determine an intersection of a straight line connecting values of the obtained plurality of complex impedances at a third predetermined frequency and the axis that is the real component, to be a reference point; and

a corrector configured to correct the predetermined feature amount calculated on said calculator, to a slope of a straight line connecting the reference point and the values of the obtained plurality of complex impedances at the second predetermined frequency.

4. The battery state estimating apparatus according to claim 3, wherein

said determinator is configured to calculate a plurality of intersections by changing the third predetermined frequency and is configured to determine a point corresponding to a convergence value on which a distribution of the calculated plurality of intersections converges, to be the reference point.