BATTERY SOC ESTIMATION DEVICE

• US 20130297243A1
• Filed: 12/01/2011
• Published: 11/07/2013
• Est. Priority Date: 01/18/2011
• Status: Active Grant

• Current Assignee: Calsonic Kansei Corporation, KEIO University
• Original Assignee: Calsonic Kansei Corporation, KEIO University
• Inventors: Baba, Atsushi, Adachi, Shuichi
• Granted Patent: US 9,329,240 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• 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: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H02J 7/00716 in response to integrated charge or discharge current
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• 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 SoC estimation device includes a discharge-and charge current detection means 1, a terminal-voltage detection means 2, a current-integration SoC estimation means 3, an open-circuit-voltage SoC estimation means 4, an error estimation means 6, and an SoC calculating means 7. The estimation means 3 estimates a current-integration-method SoC (SoC_i), calculating variance of current-integration-method SoC based on information on detection accuracy of the detection means 1. The estimation means 4 estimates an open-circuit-voltage-method SoC (SoC_v) corresponding to an open circuit voltage value estimated based on a discharge-and-charge current value and a terminal voltage value, using a battery equivalent circuit model. The estimation means 6 estimates an estimate error n_i of the current-integration-method SoC based on a difference between the SoC_v and the SoC_i, variance of the SoC_i, and variance of the SoC_v. The calculating means 7 calculates SoC of a battery based on the SoC_i and the n_i.

Claims

1. A battery State-of-Charge estimation device comprising:

a discharge-and-charge current detection means that detects a discharge-and-charge current value of a battery;

a terminal voltage detection means that detects a terminal voltage value of the battery,

a current-integration-method State-of-Charge estimation means that estimates a current-integration-method State-of-Charge based on a State-of-Charge obtained by integrating the discharge-and-charge current value inputted from the discharge-and-charge current detection means and a State-of-Charge obtained at previous time, calculating a variance of the current-integration-method State-of-Charge based on information on a detection accuracy of the discharge-and-charge current detection means;

an open-circuit-voltage method State-of-Charge estimation means that estimates an open-circuit-voltage State-of-Charge based on the discharge-and-charge current value inputted from the discharge-and-charge current detection means and the terminal voltage value inputted from the terminal voltage detection means, using a battery equivalent circuit model, the open-circuit-voltage method State-of-Charge estimation means calculating a variance of the open-circuit-voltage method State-of-Charge based on information of detection accuracy of the discharge-and-charge current detection means and the terminal voltage detection means;

an error estimation means that estimates an estimate error of the current-integration-method State-of-Charge based on a difference between the open-circuit-voltage method State-of-Charge and the current-integration-method State-of-Charge, the variance open-circuit-voltage method State-of-Charge of current-integration-method State-of-Charge, and the variance of; and

a State-of-Charge calculating means that calculates a State-of-Charge of the battery based on the current-integration-method State-of-Charge and the estimate error estimated by the error estimation means.

2. The battery State-of-Charge estimation means according to claim 1, wherein

the open-circuit-voltage-method State-of-Charge estimation means and the error estimation means use a Kalman filter, respectively.

3. The battery State-of-Charge estimation means according to claim 1, wherein

the current-integration-method State-of-Charge estimation means estimates the current-integration-method State-of-Charge, using the State-of-Charge that is previously obtained by the State-of-Charge calculating means.

4. The battery State-of-Charge estimation means according to claim 2, wherein

the current-integration-method State-of-Charge estimation means estimates the current-integration-method State-of-Charge, using the State-of-Charge that is previously obtained by the State-of-Charge calculating means.