Battery controller

• US 9,952,288 B2
• Filed: 02/05/2013
• Issued: 04/24/2018
• Est. Priority Date: 02/05/2013
• Status: Active Grant

• Current Assignee: Vehicle Energy Japan, Inc.
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Nakao, Ryohei, Kawahara, Yohei, Kudou, Akihiko, Ookawa, Keiichiro, Igarashi, Naoyuki
• Primary Examiner(s): Bui, Bryan
• Application Number:
  US14/765,741
• Publication Number:
  US 20150369873A1
• Time in Patent Office: 1,904 Days
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery

Abstract

Provided is a battery control device which can verify a probability of a state of charge or a state of health of a battery. A battery controller according to the invention calculates a measurement parameter of the battery using the state of charge or the state of health of the battery, and the probability of the state of charge or the state of health is diagnosed by comparing the measurement results (see FIGS. 9(a) and 9(b)).

Claims

1. A battery control system, comprising:

a voltage sensor that measures a both-end voltage of a battery;

a current sensor that measures a current flowing in the battery; and

a battery controller communicatively coupled to the voltage sensor and the current sensor;

wherein the battery controller;

calculates a state of charge and a state of health of the battery;

calculates a modeled both-end voltage based on the current flowing in the battery, the state of charge and the state of health of the battery; and

determines a probability of the state of charge and the state of health of the battery by comparing the both-end voltage of the battery and the modeled both-end voltage,

outputs a diagnosis result based on the probability of the state of charge;

wherein;

when the battery is discharging, the state of health of the battery is calculated to be small in a case where the modeled both-end voltage of the battery is larger than the both-end voltage of the battery detected by a predetermined threshold or more, and

when the battery is discharging, the state of health of the battery is calculated to be large in a case where the modeled both-end voltage is smaller than the both-end voltage by the predetermined threshold or more, and

when the battery is charging, the state of health of the battery is calculated to be large in a case where the modeled both-end voltage is larger than the both-end voltage by the predetermined threshold or more, and

when the battery is charging, the state of health of the battery is calculated to be small in a case where the modeled both-end voltage of the battery is smaller than the both-end voltage by the predetermined threshold or more.

2. The battery control system according to claim 1, further comprising:

wherein the battery controller further determines the probability of the state of charge and the state of health of the battery calculated by comparing a resultant both-end voltage of the battery in a case where an allowable charge current or an allowable discharge current flows in the battery with the both-end voltage in a case where the allowable charge current or the allowable discharge current flows in the battery.

3. The battery control system according to claim 2,

wherein:

the state of health of the battery is calculated to be small in a case where a variation amount of the both-end voltage of the battery exceeds a variation amount of the modeled both-end voltage by a predetermined threshold and

the state of health of the battery is calculated to be large in a case where the variation amount of the both-end voltage of the battery is lower than the variation amount of the modeled both-end voltage.

4. The battery control system according to claim 1,

wherein:

the state of health of the battery is calculated to be small in a case where the modeled both-end voltage is smaller than the both-end voltage when the battery is charged or discharged.

5. The battery control system controller according to claim 1,

wherein the battery controllers

determine the probability of the state of charge of the battery in a case where the current does not flow in the battery, or the current flowing in the battery is equal to or less than a predetermined threshold so as to be considered as no current flowing in the battery, and

determines the probability of the state of health of the battery in a case where the battery is charged or discharged.

6. The battery controller according to claim 1, further comprising a temperature sensor that measures an internal temperature of the battery,

wherein the battery controller further:

calculates a modeled internal temperature of the battery using the state of charge and the state of health of the battery, and

determines the probability of the state of charge or the state of health of the battery by comparing the modeled internal temperature of the battery with the internal temperature of the battery.

7. The battery control system according to claim 6,

wherein:

the state of health of the battery is calculated to be large in a case where the modeled internal temperature is larger than the internal temperature by a predetermined threshold or more, and

the state of health of the battery is calculated to be small in a case where the modeled internal temperature of the battery calculated is smaller than the internal temperature by the predetermined threshold or more.

8. The battery control system according to claim 1,

wherein the battery controller further

in a case where the state of charge or the state of health of the battery is not correct,

acquires a first magnitude relation indicating a larger one of the modeled both-end voltage and an open circuit voltage of the battery, and a second magnitude relation indicating a larger one of the both-end voltage of the battery and the open circuit voltage of the battery, and

determines that the state of charge or the state of health of the battery is incorrect based on a displacement between a detection timing of the current sensor and a detection timing of the voltage sensor in a case where the magnitude relation indicated by the first magnitude relation is inverted to the magnitude relation indicated by the second magnitude relation.