ELECTRIC ENERGY STORAGE SYSTEM WITH BALANCING CIRCUIT

• US 20120194138A1
• Filed: 03/02/2012
• Published: 08/02/2012
• Est. Priority Date: 09/02/2009
• Status: Active Grant

• Current Assignee: Japan Aerospace Exploration Agency, Japan Capacitor Industrial Co., Ltd.
• Original Assignee: Japan Aerospace Exploration Agency, Japan Capacitor Industrial Co., Ltd.
• Inventors: Ito, Kazushige, Uno, Masatoshi, Kukita, Akio, Sekido, Tsutomu
• Granted Patent: US 9,318,779 B2
• Time in Patent Office: Days
• US Class Current: 320/119
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An electric energy storage system is designed to equally utilize electric energy storage banks during charging/discharging, and keep fluctuation of an input voltage from a charger or an output voltage to a load, within an arbitrary range, while equally utilizing the electric energy storage banks during charging/discharging. The electric energy storage system comprises an electric energy storage module, a charger, a balancing circuit, a voltage detection section, taps led out, respectively, from one of opposite terminals of the electric energy storage module and/or the other terminal of the electric energy storage module and/or one or more of series-connection points between the electric energy storage units, through respective switches, and a switch control section for switching the switches such that one of the taps is connected to one of opposite terminals of the charger. The switch control section is operable to sequentially switch the switches according to progress of the charging.

Claims

1. An electric energy storage system comprising:

an electric energy storage module having a plurality of electric energy storage units connected in series, each of the plurality of electric energy storage units having one electric energy storage bank or a plurality of electric energy storage banks connected in series;

a charger for charging at least one of the electric energy storage banks;

a balancing circuit connected to the electric energy storage module to correct a variation in charged/discharged state between the electric energy storage banks;

a voltage detection section for detecting a voltage across or across each of one or more of the electric energy storage banks, or a voltage across the charger;

a plurality of taps led out, respectively, from one of opposite terminals of the electric energy storage module and/or one or more of a plurality of series-connection points between the electric energy storage units, through respective switches; and

a switch control section for switching the switches such that one of the plurality of taps is connected to one of opposite terminals of the charger, the switch control section being operable, during a charging period, to sequentially switch the switches according to progress of the charging, based on a detection result from the voltage detection section, so as to control the number of at least one of the plurality of electric energy storage units which is to be charged not via the balancing circuit but directly from the charger.

2. The electric energy storage system as defined in claim 1,

wherein the plurality of taps are led out, respectively, from one of opposite terminals of the electric energy storage module and/or the other terminal of the electric energy storage module and/or one or more of a plurality of series-connection points between the electric energy storage units, through respective switches, and

wherein the switch control section for switching the switches such that one of the plurality of taps is connected to one of opposite terminals of the charger and another of the plurality of taps is connected to the other terminal of the charger.

3. The electric energy storage system as defined in claim 2, wherein the switch control section is operable, after switching the switches predetermined times, with respect to each of a plurality of groups set by grouping the plurality of electric energy storage units, to subsequently sequentially switch the switches according to progress of the charging, based on a detection result from the voltage detection section and in a time division manner, so as to control the number of at least one of the plurality of electric energy storage units which is to be charged not via the balancing circuit but directly from the charger.

4. The electric energy storage system as defined in claim 2, wherein the switch control section is operable, with respect to each of a plurality of groups set by grouping the plurality of electric energy storage units, to sequentially switch the switches according to progress of the charging, based on a detection result from the voltage detection section and in a time division manner, so as to control the number of at least one of the plurality of electric energy storage units which is to be charged not via the balancing circuit but directly from the charger.

5. The electric energy storage system as defined in claim 3, wherein the switch control section is further operable to perform one or more times, after switching the switches predetermined times, with respect to each of groups set by re-grouping the plurality of electric energy storage units such that the number of the group set by the re-grouping is greater than the number of the group after switching the switches predetermined times, subsequent sequential switching of the switch according to progress of the charging, based on a detection result from the voltage detection section and in a time division manner, so as to control the number of at least one of the plurality of electric energy storage units which is to be charged not via the balancing circuit but directly from the charger.

6. The electric energy storage system as defined in claim 4, wherein the switch control section is further operable to perform one or more times, after switching the switches predetermined times, with respect to each of groups set by re-grouping the plurality of electric energy storage units such that the number of the group set by the re-grouping is greater than the number of the group after switching the switches predetermined times, subsequent sequential switching of the switch according to progress of the charging, based on a detection result from the voltage detection section and in a time division manner, so as to control the number of at least one of the plurality of electric energy storage units which is to be charged not via the balancing circuit but directly from the charger.

7. An electric energy storage system comprising:

an electric energy storage module having a plurality of electric energy storage units connected in series, each of the plurality of electric energy storage units having one electric energy storage bank or a plurality of electric energy storage banks connected in series;

a load to which electric energy is to be supplied from at least one of the electric energy storage banks;

a balancing circuit connected to the electric energy storage module to correct a variation in charged/discharged state between the electric energy storage banks;

a voltage detection section for detecting a voltage across or across each of one or more of the electric energy storage banks, or a discharging voltage from the electric energy storage banks to the load;

a plurality of taps led out, respectively, from one of opposite terminals of the electric energy storage module and/or one or more of a plurality of series-connection points between the electric energy storage units, through respective switches; and

a switch control section for switching the switches such that one of the plurality of taps is connected to one of opposite terminals of the load, the switch control section being operable, during a discharging period, to sequentially switch the switches according to the discharged state, based on a detection result from the voltage detection section, so as to control the number of at least one of the plurality of electric energy storage units which is to be discharged from at least one of the electric energy storage units not via the balancing circuit but directly to the load.

8. The electric energy storage system as defined in claim 7,

wherein the plurality of taps are led out, respectively, from one of opposite terminals of the electric energy storage module and/or the other terminal of the electric energy storage module and/or one or more of a plurality of series-connection points between the electric energy storage units, through respective switches, and

wherein the switch control section for switching the switches such that one of the plurality of taps is connected to one of opposite terminals of the load and another of the plurality of taps is connected to the other terminal of the load.

9. The electric energy storage system as defined in claim 8, wherein the switch control section is operable, with respect to each of a plurality of groups set by grouping the plurality of electric energy storage units, to sequentially switch the switches according to the discharged state, based on a detection result from the voltage detection section and in a time division manner, so as to control the number of at least one of the plurality of electric energy storage units which is to be discharged from at least one of the electric energy storage units not via the balancing circuit but directly to the load.

10. The electric energy storage system as defined in claim 9, wherein the switch control section is further operable to perform one or more times, after switching the switches predetermined times, with respect to each of at least one group set by re-grouping the plurality of electric energy storage units such that the number of the at least one group set by the re-grouping is less than the number of the groups after switching the switches predetermined times, at least one subsequent sequential switching of the switches according to the discharged state, based on a detection result from the voltage detection section and in a time division manner, so as to control the number of at least one of the plurality of electric energy storage units which is to be discharged from at least one of the electric energy storage units not via the balancing circuit but directly to the load.

11. An electric energy storage system comprising:

an electric energy storage module having a plurality of electric energy storage units connected in series, each of the plurality of electric energy storage units having one electric energy storage bank or a plurality of electric energy storage banks connected in series;

a charger for charging at least one of the electric energy storage banks;

a balancing circuit connected to the electric energy storage module to correct a variation in charged/discharged state between the electric energy storage banks;

a voltage detection section for detecting a voltage across or across each of one or more of the electric energy storage banks, or a voltage across the charger;

a plurality of taps led out, respectively, from one of opposite terminals of the electric energy storage module and/or the other terminal of the electric energy storage module and/or one or more of a plurality of series-connection points between the electric energy storage units, through respective switches; and

a switch control section for switching the switches such that one of the plurality of taps is connected to one of opposite terminals of the charger and another of the plurality of taps is connected to the other terminal of the charger, the switch control section being operable, with respect to each of a plurality of groups set by grouping the plurality of electric energy storage units, to sequentially switch the switches so as to repeatedly charge the same at least one electric energy storage unit not via the balancing circuit but directly from the charger, in a time division manner.

12. An electric energy storage system comprising:

an electric energy storage module having a plurality of electric energy storage units connected in series, each of the plurality of electric energy storage units having one electric energy storage bank or a plurality of electric energy storage banks connected in series;

a load to which electric energy is to be supplied from at least one of the electric energy storage banks;

a balancing circuit connected to the electric energy storage module to correct a variation in charged/discharged state between the electric energy storage banks;

a voltage detection section for detecting a voltage across or across each of one or more of the electric energy storage banks, or a discharging voltage from the electric energy storage banks to the load;

a plurality of taps led out, respectively, from one of opposite terminals of the electric energy storage module and/or the other terminal of the electric energy storage module and/or one or more of a plurality of series-connection points between the electric energy storage units, through respective switches; and

a switch control section for switching the switches such that one of the plurality of taps is connected to one of opposite terminals of the load and another of the plurality of taps is connected to the other terminal of the load, the switch control section being operable, with respect to each of a plurality of groups set by grouping the plurality of electric energy storage units, to sequentially switch the switches so as to repeatedly discharge the same at least one electric energy storage unit not via the balancing circuit but directly to the load, in a time division manner.