Battery state-of-charge calculation device

• US 8,994,334 B2
• Filed: 06/03/2009
• Issued: 03/31/2015
• Est. Priority Date: 06/03/2009
• Status: Active Grant

• Current Assignee: Kyushu Electric Power Company Incorporated, Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Kyushu Electric Power Company Incorporated, Mitsubishi Heavy Industries, Ltd.
• Inventors: Shigemizu, Tetsuro, Iida, Masami, Nishida, Takehiko, Ohishi, Masazumi, Adachi, Kazuyuki, Murakami, Shinji, Wada, Yoshihiro
• Primary Examiner(s): Tso, Edward
• Assistant Examiner(s): BOATENG, ALEXIS ASIEDUA
• Application Number:
  US13/375,642
• Publication Number:
  US 20120086405A1
• Time in Patent Office: 2,127 Days
• Field of Search: 320/132, 320/134, 320/107, 320/136, 320/116, 320/129, 320/150, 320/161, 320/103, 320/106, 320/112, 324/426, 324/430, 324/429, 324/433, 324/441
• US Class Current: 320/134
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/3828 using current integration
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The battery state-of-charge calculation device (100) is provided with a SOCV calculation unit (5) which outputs a first state of charge calculated based on voltage data, a SOCI calculation unit (6) which outputs a second state of charge calculated based on current data, an estimated impedance voltage calculation unit (12) which calculates an impedance voltage value based on an effective state of charge and the current data, a static determination unit (7) which determines that the impedance voltage value remains static for a predetermined time or longer in a range identified by a predetermined threshold value and outputs the determination result; and a SOC decision unit (20) which, based on the determination result, outputs the first state of charge as the effective state of charge where the impedance voltage value is static and outputs the second state of charge as the effective state of charge where the impedance voltage value is not static.

Claims

1. A battery state-of-charge calculation device, comprising:

a first state-of-charge calculation unit which outputs a first state of charge calculated on the basis of voltage data;

a second state-of-charge calculation unit which outputs a second state of charge calculated on the basis of current data;

an impedance voltage calculation unit which calculates an impedance voltage value on the basis of an effective state of charge and the current data;

a static determination unit which obtains the impedance voltage value at a predetermined cycle, thereby measuring a period of time during which the impedance voltage value is within a range identified by a predetermined threshold value, and determines that the impedance voltage value is static where a static time is equal to or longer than a predetermined time in the range identified by the predetermined threshold value and outputs the determination result; and

a state-of-charge decision unit which, on the basis of the determination result, outputs the first state of charge as the effective state of charge where the impedance voltage value is static and outputs the second state of charge as the effective state of charge where the impedance voltage value is not static.

2. The battery state-of-charge calculation device according to claim 1, wherein the second state-of-charge calculation unit integrates the current data, with the first state of charge given as an initial value or with the effective state of charge in which a former value is held given as an initial value, thereby calculating the second state of charge.

3. The battery state-of-charge calculation device according to claim 1, wherein

the first state-of-charge calculation unit calculates the first state of charge from a no-load voltage value based on the voltage data and the impedance voltage value.

4. The battery state-of-charge calculation device according to claim 1, wherein the state-of-charge decision unit outputs the first state of charge as the effective state of charge where a difference between the first state of charge and the second state of charge is equal to or more than a predetermined threshold value.

5. The battery state-of-charge calculation device according to claim 1, wherein the impedance voltage calculation unit calculates an impedance voltage value on the basis of the effective state of charge, the current data and the temperature data.