Secondary battery pack connection control method for controlling connection of input and output terminals in power storage system comprising plurality of secondary battery packs

• US 9,819,201 B2
• Filed: 03/15/2016
• Issued: 11/14/2017
• Est. Priority Date: 08/02/2010
• Status: Active Grant

• Current Assignee: NEC Energy Devices, Ltd. (Envision Group /TX/)
• Original Assignee: NEC Energy Devices, Ltd. (Envision Group /TX/)
• Inventors: Suzuki, Shin
• Primary Examiner(s): Levin, Naum B
• Application Number:
  US15/070,856
• Publication Number:
  US 20160197497A1
• Time in Patent Office: 609 Days
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/007182 in response to battery 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 power storage system has a plurality of secondary battery packs and a host device. The secondary battery packs each have: secondary batteries; a charge switch means that turns a charging path to the secondary batteries ON and OFF; a discharge switch means that turns a discharging path from the secondary battery ON and OFF; and a current-limiting means that causes the secondary battery to discharge while limiting the current to, or below, a fixed value. When switching from the secondary battery pack connected to the input/output terminals of the system to a first secondary battery pack in which voltage is higher than in the second secondary battery pack, the host device causes the charge switch means of the second secondary battery pack to turn OFF the charging path while in a state in which the current limiting means of the first secondary battery pack will cause a discharge operation to begin while limiting the flow of current.

Claims

1. A secondary battery pack connection control method for controlling connection of the input and output terminals of a secondary battery pack system in a power storage system provided with a plurality of secondary battery packs connected in parallel, said method comprising:

when connecting a first secondary battery pack to the power storage system and disconnecting a second secondary battery pack from the power storage system,

starting discharge while controlling current to a fixed value or lower from said first secondary battery pack; and

then

turning OFF the charging path of said second secondary battery pack in which voltage is lower than in said first secondary battery pack.

2. The secondary battery pack connection control method as set forth in claim 1, wherein:

the discharging path of said first secondary battery pack is turned ON at the same time as the charging path of said second secondary battery pack is turned OFF, and the current limit of the discharge current is canceled; and

then

the discharging path of said second secondary battery pack is turned OFF.