Electricity Storage System and Method for Controlling Electricity Storage System

• US 20170187202A1
• Filed: 12/27/2016
• Published: 06/29/2017
• Est. Priority Date: 12/28/2015
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: SHIN, Seogchul, HONKURA, Kohei, KAMIJOH, Takashi, NAGASHIMA, Yuuji
• Granted Patent: US 10,418,827 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence

Abstract

An electricity storage system includes: a plurality of rechargeable batteries connected in parallel; and a control unit that controls the rechargeable batteries. The control unit detects a deactivation target rechargeable battery of which charge or discharge need to be deactivated, of the rechargeable batteries, electrically separates and deactivates the deactivation target rechargeable battery from a load in a case where a charging rate of the deactivation target rechargeable battery is lower than a predetermined charging rate, and performs control such that a temperature of the deactivated rechargeable battery is within a predetermined temperature range. In this manner, it is possible to disperse ions inside a battery such that it is possible to recover performance of the battery.

Claims

1. An electricity storage system comprising:

a plurality of rechargeable batteries connected in parallel; and

a control unit that controls the rechargeable batteries,

wherein the control unit

detects a deactivation target rechargeable battery of which charge or discharge need to be deactivated, of the rechargeable batteries,

electrically separates and deactivates the deactivation target rechargeable battery from a load in a case where a charging rate of the deactivation target rechargeable battery is lower than a predetermined charging rate, and

performs control such that a temperature of the deactivated rechargeable battery is within a predetermined temperature range.

2. The electricity storage system according to claim 1,

wherein the control unit detects, as the deactivation target rechargeable battery, a rechargeable battery having a temperature higher than an average temperature of the other rechargeable batteries of the rechargeable batteries.

3. The electricity storage system according to claim 2,

wherein the predetermined charging rate is 60%.

4. The electricity storage system according to claim 3,

wherein the predetermined temperature range is a range of 25°

C. to 40°

C.

5. The electricity storage system according to claim 4,

wherein the control unit deactivates the deactivation target rechargeable battery in a case where the activation rate indicating a percentage of rechargeable batteries, in which charge or discharge is performed, to the rechargeable batteries is higher than the predetermined activation ratio.

6. The electricity storage system according to claim 1,

wherein the control unit performs control by using a temperature of a predetermined rechargeable battery of the rechargeable batteries such that the temperature of the deactivated rechargeable battery is within the predetermined temperature range.

7. The electricity storage system according to claim 6,

wherein the predetermined rechargeable battery is another rechargeable battery apart from the deactivated rechargeable battery.

8. The electricity storage system according to claim 1,

wherein the rechargeable batteries are provided with temperature control units that control temperatures individually, respectively, and

wherein the control unit performs control such that the temperature of the deactivated rechargeable battery is within the predetermined temperature range via the temperature control unit provided to the deactivated rechargeable battery.

9. The electricity storage system according to claim 1,

wherein the control unit detects direct current resistances of the rechargeable batteries and detects, as the deactivation target rechargeable battery, a rechargeable battery having a direct current resistance higher than a predetermined direct current resistance.

10. The electricity storage system according to claim 1,

wherein the rechargeable batteries are lithium-ion batteries.

11. A method for controlling an electricity storage system that includes

a plurality of rechargeable batteries connected in parallel, and

a control unit that controls the rechargeable batteries,

the method comprising:

detecting, by the control unit, a deactivation target rechargeable battery of which charge or discharge need to be deactivated, of the rechargeable batteries,

electrically separating and deactivating the deactivation target rechargeable battery from a load in a case where a charging rate of the deactivation target rechargeable battery is lower than a predetermined charging rate, and

performing control such that a temperature of the deactivated rechargeable battery is within a predetermined temperature range.