Battery control circuit, battery control device, and battery pack

Patent metadata

Field	Value
Publication number	US-11159028-B2
Application number	US-201816138226-A
Country	US
Kind code	B2
Filing date	Sep 21, 2018
Priority date	Dec 8, 2017
Publication date	Oct 26, 2021
Grant date	Oct 26, 2021

Abstract

A battery control circuit controls a balance of cell voltage values of cells coupled in series, and includes connection terminals respectively coupling to a positive electrode of a corresponding cell, a ground terminal coupled to an internal ground of the battery control circuit and coupling to a negative electrode of a cell located at a lowest stage of the cells, a control circuit to select, from the connection terminals, at least one connection terminal coupled to the internal ground via an internal current path of the battery control circuit, and a current generation circuit to supply a terminal current whose current value varies according to the cell voltage value of the cell whose positive electrode is coupled to the at least one of the connection terminals selected by the control circuit, from the at least one of the connection terminals to the internal ground via the internal current path.

First claim

What is claimed is:

1. A battery control circuit for controlling a balance of cell voltage values of a plurality of cells that are coupled in series in a plurality of stages, comprising:
an internal ground;
an internal current path;
a plurality of connection terminals, electrically connected to the internal ground via the internal current path, and configured to couple to positive electrodes of the plurality of cells, respectively;
a ground terminal, electrically connected to the internal ground, and configured to couple to a negative electrode of a cell located at a lowest stage of the plurality of cells;
a control circuit configured to select one of the plurality of cells to be discharged by selecting one of the plurality of connection terminals; and
a current generation circuit configured to generate a plurality of terminal currents having current values which vary according to voltages between respective adjacent terminal pairs among the plurality of connection terminals and the ground terminal,
wherein the current generation circuit shifts the voltages between the respective adjacent terminal pairs with reference to a potential of the internal ground, thereby generating the plurality of terminal currents based on the shifted voltages,
wherein the selected one of the plurality of connection terminals, selected by the control circuit, is one of terminals forming one of the adjacent terminal pairs and having a potential higher than the other of the terminals forming the one of the adjacent terminal pairs, and
wherein the control circuit selects one terminal current, from among the plurality of currents generated by the current generation circuit, to be supplied from the selected one of the plurality of connection terminals to the internal ground via the internal current path.

2. The battery control circuit as claimed in claim 1 , wherein the current generation circuit supplies a terminal current to one of the plurality of connection terminals coupled to a positive electrode of a cell whose monitored cell voltage value exceeds a first threshold value.

3. The battery control circuit as claimed in claim 2 , wherein the current generation circuit supplies no terminal current to all of the plurality of connection terminals in a case in which the cell voltage value of all of the plurality of cells exceeds the first threshold value.

4. The battery control circuit as claimed in claim 2 , wherein the current generation circuit supplies no terminal current to one of the plurality of connection terminals coupled to a positive electrode of a cell whose monitored cell voltage value is lower than a second threshold value that is smaller than the first threshold value.

5. The battery control circuit as claimed in claim 1 , wherein the current generation circuit supplies no terminal current to one of the plurality of connection terminals coupled to a positive electrode of a cell whose cell voltage value is monitored, nor to one of the plurality of connection terminals coupled to a negative electrode of a cell whose cell voltage value is monitored, during a time in which the cell voltage values are monitored.

6. The battery control circuit as claimed in claim 1 , wherein the control circuit includes
a cell selector configured to select one of the plurality of cells whose cell voltage value is to be monitored,
a cell voltage detector configured to acquire a monitored result of the cell voltage value of the one of the plurality of cells selected by the cell selector, and
a selector configured to select at least one of the plurality of connection terminals to which the terminal current is to be supplied, using the monitored result acquired by the cell voltage detector and the one of the plurality of cells selected by the cell selector.

7. A battery control device comprising:
a cell balance circuit configured to balance cell voltage values of a plurality of cells coupled in series in a plurality of stages; and
a battery control circuit configured to control the cell balance circuit,
wherein the battery control circuit includes
an internal ground;
an internal current path;
a plurality of connection terminals electrically connected to the internal ground via the internal current path, and configured to couple to positive electrodes of the plurality of cells, respectively,
a ground terminal, electrically connected to the internal ground of the battery control circuit, and configured to couple to a negative electrode of a cell located at a lowest stage of the plurality of cells,
a control circuit configured to select one of the plurality of cells to be discharged by selecting one of the plurality of connection terminals, and
a current generation circuit configured to generate a plurality of terminal currents having current values which vary according to voltages between respective adjacent terminal pairs among the plurality of connection terminals and the ground terminal,

wherein the current generation circuit shifts the voltages between the respective adjacent terminal pairs with reference to a potential of the internal ground, thereby generating the plurality of terminal currents based on the shifted voltages,
wherein the selected one of the plurality of connection terminals, selected by the control circuit, is one of terminals forming one of the adjacent terminal pairs and having a potential higher than the other of the terminals forming the one of the adjacent terminal pairs, and
wherein the control circuit selects one terminal current, from among the plurality of currents generated by the current generation circuit, to be supplied from the selected one of the plurality of connection terminals to the internal ground via the internal current path.

8. The battery control device as claimed in claim 7 , wherein the current generation circuit of the battery control circuit supplies a terminal current to one of the plurality of connection terminals coupled to a positive electrode of a cell whose monitored cell voltage value exceeds a first threshold value.

9. The battery control device as claimed in claim 8 , wherein the current generation circuit of the battery control circuit supplies no terminal current to all of the plurality of connection terminals in a case in which the cell voltage value of all of the plurality of cells exceeds the first threshold value.

10. The battery control device as claimed in claim 8 , wherein the current generation circuit of the battery control circuit supplies no terminal current to one of the plurality of connection terminals coupled to a positive electrode of a cell whose monitored cell voltage value is lower than a second threshold value that is smaller than the first threshold value.

11. A battery pack comprising:
a plurality of cells coupled in series in a plurality of stages;
a cell balance circuit configured to balance cell voltage values of the plurality of cells; and
a battery control circuit configured to control the cell balance circuit,
wherein the battery control circuit includes
an internal ground;
an internal current path;
a plurality of connection terminals electrically connected to the internal ground via the internal current path, and configured to couple to positive electrodes of the plurality of cells, respectively,
a ground terminal, electrically connected to the internal ground, and configured to couple to a negative electrode of a cell located at a lowest stage of the plurality of cells,
a control circuit configured to select one of the plurality of cells to be discharged by selecting one of the plurality of connection terminals, and
a current generation circuit configured to generate a plurality of terminal currents having current

Assignees

• Shibata Kohei
• Mitsumi Electric Co Ltd

Inventors

• Shibata Kohei

Classifications

• H02J7/585

  Sequential battery discharge in systems with a plurality of batteries · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/54 Primary

  Passive balancing, e.g. using resistors or parallel MOSFETs · CPC title

• H01M10/425

  Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00) · CPC title

• H01M2010/4271

  Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing · CPC title