Power storage device, power storage control device, and power storage control method

Patent metadata

Field	Value
Publication number	US-2016233556-A1
Application number	US-201415022511-A
Country	US
Kind code	A1
Filing date	Aug 12, 2014
Priority date	Sep 26, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

The present disclosure provides a power storage device, a power storage control device, and a power storage control method for suppressing a burden imposed on a cell when voltages of cells are equalized.
A power storage device includes: a plurality of cells which are connected in series; a series resonance circuit configured to include a reactor and a capacitor; and a power storage control device configured to control a connection state of the cells and the series resonance circuit. The power storage control device causes energy to be transferred between equal numbers of cells via the series resonance circuit.

First claim

1 . A power storage device comprising:
a plurality of cells which are connected in series; a series resonance circuit configured to include a reactor and a capacitor; and a power storage control device configured to control a connection state of the cells and the series resonance circuit, wherein the power storage control device causes energy to be transferred between equal numbers of cells via the series resonance circuit.

2 . The power storage device according to claim 1 , wherein, after the power storage control device connects first cells including at least one cell to the series resonance circuit, the power storage control device connects second cells which include cells equal in number to the first cells and have a lower total voltage than the first cells to the series resonance circuit.

3 . The power storage device according to claim 2 , wherein the power storage control device selects a plurality of consecutive cells as the first cells, and selects consecutive cells equal in number to the first cells as the second cells.

4 . The power storage device according to claim 2 , wherein, when the first cells are connected to the series resonance circuit and then the direction of a current flowing in the series resonance circuit changes, the power storage control device disconnects the first cells from the series resonance circuit.

5 . The power storage device according to claim 4 , wherein, when the second cells are connected to the series resonance circuit and then the direction of a current flowing in the series resonance circuit changes, the power storage control device disconnects the second cells from the series resonance circuit.

6 . The power storage device according to claim 5 , wherein the power storage control device maintains a state in which all the cells are disconnected from the series resonance circuit during a set period after the first and/or second cells are disconnected from the series resonance circuit, and determines whether or not transfer of energy is to be finished based on a voltage of the cells during the set period.

7 . The power storage device according to claim 1 ,
wherein the series resonance circuit includes a resistance, and wherein the power storage control device detects the direction of a current flowing in the series resonance circuit based on a potential difference of both ends of the resistance.

8 . The power storage device according to claim 1 , wherein the power storage control device switches connection of the series resonance circuit and the cells using a resonance frequency of the series resonance circuit.

9 . The power storage device according to claim 1 , wherein a resonance frequency of the series resonance circuit is a frequency when an imaginary component in a Cole-Cole plot of internal impedances of the cells measured using an AC impedance method becomes 0.

10 . The power storage device according to claim 2 , wherein the power storage control device causes a cell having a maximum voltage to be included in the first cells.

11 . The power storage device according to claim 10 , wherein the power storage control device causes a cell having a minimum voltage to be included in the second cells.

12 . The power storage device according to claim 2 , further comprising:
a switch configured to connect or disconnect the cells and the series resonance circuit, wherein the power storage control device controls a connection state of the cells and the series resonance circuit by controlling an operation of the switch.

13 . The power storage device according to claim 2 , wherein the cells have a discharge characteristic that a change of a voltage is 0.25 V or lower in a series of sections spanning 50% or more of a section of a charge ratio of 0% to 100%.

14 . A power storage control device configured to control a connection state of a plurality of cells which are connected in series and a series resonance circuit which includes a reactor and a capacitor, and to cause energy to be transferred between equal numbers of cells via the series resonance circuit.

15 . A power storage control method of a control device which controls a connection state of a plurality of cells which are connected in series and a series resonance circuit which includes a reactor and a capacitor to cause energy to be transferred between equal numbers of cells via the series resonance circuit.

Assignees

• Sony Corp

Inventors

• Nakamura Kazuo
• Ozawa Atsushi

Classifications

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02J7/56

  Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters · CPC title

• H01M16/00 Primary

  Structural combinations of different types of electrochemical generators · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title