BATTERY CONTROL DEVICE

• US 20150357852A1
• Filed: 01/27/2014
• Published: 12/10/2015
• Est. Priority Date: 03/29/2013
• Status: Active Grant

• Current Assignee: Vehicle Energy Japan, Inc. (Nissan Motor Co., Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: OHKAWA, Keiichiro, IGARASHI, Naoyuki, NAKAO, Ryouhei, IMAI, Shinji, SOMA, Takahiro
• Granted Patent: US 9,685,807 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• 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: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• 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: 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 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 Detection of state of health [SOH]
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• 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

Provided is a battery control device that can accurately detect a state of charge even if characteristics relating to the state of charge change as a result of battery degradation. This battery control device is provided with map data describing the correspondence relationship between an open-circuit voltage and a state of charge of the battery and outputs different state-of-charge values for the same open-circuit voltage according to the amount of elapsed time.

Claims

1. A battery control device comprising:

a controller that outputs, using a SOC-OCV characteristic indicating a relationship between open circuit voltage and state of charge of battery, information about a state of charge of a battery or of an assembled battery according to a voltage of the battery or to a voltage of the assembled battery, the assembled battery being configured by electrically connecting a plurality of the batteries,

wherein the controller acquires a plurality of pairs of;

an amount of state of the battery or of the assembled battery calculated on the basis of one or both of a voltage of the battery or a voltage of the assembled battery and an electric current flowing through the battery; and

an open circuit voltage of the battery or of the assembled battery that is calculated corresponding to the amount of state,

wherein the controller corrects the SOC-OCV characteristic according to the acquired plurality of pairs and according to a characteristic that indicates a relationship between amount of state of the battery or of the assembled battery and open circuit voltage,

and wherein the controller outputs different states of charge depending on progress of time even if the voltage of the battery or the voltage of the assembled battery is same.

3. The battery control device according to claim 1, further comprising:

a OCV calculator that calculates open circuit voltage of the battery;

a SOC-OCV characteristic storage unit that stores the SOC-OCV characteristic;

a residual capacity calculator that calculates a residual capacity of the battery as the amount of state by integrating an electric current flowing through the battery;

a Q-OCV characteristic storage unit that stores Q-OCV characteristic indicating a relationship between residual capacity of the battery and open circuit voltage of the battery; and

a corrector that acquires a plurality of pairs of the residual capacity and an open circuit voltage of the battery that is calculated corresponding to the residual capacity, and that corrects the SOC-OCV characteristic to accommodate with state of health of the battery according to a relationship between the acquired plurality of pairs and the Q-OCV characteristic.

4. The battery control device according to claim 1, the controller further comprising:

a OCV calculator that calculates open circuit voltage of the battery;

a SOC-OCV characteristic storage unit that stores the SOC-OCV characteristic;

an internal resistance calculator that calculates an internal resistance of the battery as the amount of state according to a voltage of the battery and according to an electric current flowing through the battery;

a R-OCV characteristic storage unit that stores R-OCV characteristic indicating a relationship between internal resistance of the battery and open circuit voltage of the battery, and

a corrector that acquires a plurality of pairs of the internal resistance and an open circuit voltage of the battery that is calculated corresponding to the internal resistance, and that corrects the SOC-OCV characteristic to accommodate with state of health of the battery according to a relationship between the acquired plurality of pairs and the R-OCV characteristic.

5. The battery control device according to claim 3,

wherein the controller further comprises a battery charger controller that controls operation of a battery charger that charges the battery,

and wherein the corrector acquires the plurality of pairs during a period when the battery charger controller is causing the battery charger to charge the battery.

6. The battery control device according to claim 4,

wherein the controller further comprises a battery charger controller that controls operation of a battery charger that charges the battery,

and wherein the corrector acquires the plurality of pairs during a period when the battery charger controller is causing the battery charger to charge the battery.

7. The battery control device according to claim 5,

wherein the battery charger controller controls the operation of the battery charger to repeat a charging operation and temporarily suspending the charging operation during a period when causing the battery charger to charge the battery,

and wherein the corrector acquires the pair at a time when the battery charger controller causes the battery charger to temporarily suspend the charge operation.

8. The battery control device according to claim 7,

wherein the battery charger controller further comprises a mode determinator that determines whether state of health of the battery has reached a predetermined degree,

wherein if the mode determinator determines that state of health of the battery has reached the predetermined degree before the battery charger controller causes the battery charger to charge the battery, the battery charger controller controls the operation of the battery charger to repeat the charging operation and temporarily suspending the charging operation.

9. The battery control device according to claim 8,

wherein if the mode determinator determines that state of health of the battery has not reached the predetermined degree, the battery charger controller does not cause the battery charger to temporarily suspend the charging operation.

10. The battery control device according to claim 3,

wherein a plurality of the SOC-OCV characteristics is provided corresponding to deterioration characteristics of the battery,

and wherein the corrector selects one of the SOC-OCV characteristics corresponding to sate of health of the battery.

11. The battery control device according to claim 3,

wherein the corrector corrects the SOC-OCV characteristic by a predetermined amount according to state of health of the battery.

2. (canceled)