US 9,318,779 B2Granted

Electric energy storage units connected in series and selectively charged/discharged via a balancing circuit or directly from a charger or to a load

AssigneesJapan Aerospace Exploration Agency, Japan Capacitor Industrial Co., Ltd.

InventorsMasatoshi Uno, Akio Kukita, Kazushige Ito, Tsutomu Sekido

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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.

Claims14

Dependent claims

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 configured to charge 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 configured to detect a voltage across the electrical energy storage module, across one or more of the electric energy storage banks, or across the charger;
a plurality of taps led out, respectively, from one of opposite terminals of the electric energy storage module, from the other terminal of the electric energy storage module and from one or more of a plurality of series-connection points between the electric energy storage units;
and
a switch control section configured to switch switches, wherein at least one of the switches is connected to one of the opposite terminals of the electric energy storage module, to the other terminal of the electric energy storage module, or to at least one of the plurality of series-connection points, the switch control section configured to allow one of the plurality of taps to be 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, the switch control section configured to control a first number of at least one of the plurality of electric energy storage units to bypass the charger and be charged via the balancing circuit when a second number of at least one of the plurality of electric energy storage units bypasses the balancing circuit and is charged directly from the charger.

4 more elements

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 configured to detect a voltage across the electrical energy storage module, across one or more of the electric energy storage banks, or across the load;
a plurality of taps led out, respectively, from one of opposite terminals of the electric energy storage module, from the other terminal of the electric energy storage module and from one or more of a plurality of series-connection points between the electric energy storage units;
and
a switch control section configured to switch switches, wherein at least one of the switches is connected to one of the opposite terminals of the electric energy storage module, to the other terminal of the electric energy storage module, or to at least one of the plurality of series-connection points, the switch control section configured to allow one of the plurality of taps to be 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, by sequentially turning on one switch at a time or by sequentially turning on a pair of switches at a time, based on a detection result from the voltage detection section, the switch control section configured to control a first number of at least one of the plurality of electric energy storage units to bypass the load and be discharged via the balancing circuit when a second number of at least one of the plurality of electric energy storage units bypasses the balancing circuit and is discharged directly to the load.

4 more elements

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 configured to charge 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 configured to detect a voltage across the electrical energy storage module, across one or more of the electric energy storage banks, or across the charger;
a plurality of taps led out, respectively, from one of opposite terminals of the electric energy storage module, from the other terminal of the electric energy storage module and from one or more of a plurality of series-connection points between the electric energy storage units;
and
a switch control section configured to switch switches, wherein at least one of the switches is connected to one of the opposite terminals of the electric energy storage module, to the other terminal of the electric energy storage module, or to at least one of the plurality of series-connection points, the switch control section configured to allow one of the plurality of taps to be connected to one of opposite terminals of the charger and another of the plurality of taps to be 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, by sequentially turning on a pair of switches at a time, the switch control section configured to repeatedly charge the same at least one electric energy storage unit directly from the charger when a remaining number of electric energy storage units is charged via the balancing circuit, in a time division manner.

4 more elements

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 configured to detect a voltage across the electrical energy storage module, across one or more of the electric energy storage banks, or across the load;
a plurality of taps led out, respectively, from one of opposite terminals of the electric energy storage module, from the other terminal of the electric energy storage module and from one or more of a plurality of series-connection points between the electric energy storage units;
and
a switch control section configured to switch switches, wherein at least one of the switches is connected to one of the opposite terminals of the electric energy storage module, to the other terminal of the electric energy storage module, or to at least one of the plurality of series-connection points, the switch control section configured to allow one of the plurality of taps to be connected to one of opposite terminals of the load and another of the plurality of taps to be 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, by sequentially turning on a pair of switches at a time, the switch control section configured to repeatedly discharge the same at least one electric energy storage unit directly to the load when a remaining number of electric energy storage units is discharged via the balancing circuit, in a time division manner.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/411,480Filed 2 Mar 2012 · continuation
Priority: JP 2009-2026842 Sep 2009
Published: US 2012/0194138 A12 Aug 2012
Granted: 19 Apr 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H01M 10/44
Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells: methods for charging or discharging
H02J 7/54
For charge balancing, e.g. equalisation of charge between batteries: passive balancing, e.g. using resistors or parallel MOSFETs
H02J 7/56
For charge balancing, e.g. equalisation of charge between batteries: active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters
H02J 7/345
Parallel operation in networks using both storage and other DC sources, e.g. providing buffering: using capacitors as storage or buffering devices