# US 2019/0356140 A1 · Apparatus and method for battery module equalization

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- Number: US 2019/0356140 A1
- Document ID: US20190356140A1
- Status: Published application
- Kind: A1
- Application number: 16/462,403
- Filed: 2018-01-09
- Published: 2019-11-21
- Earliest claimed: 2017-05-24
- Assignees: LG Chem, Ltd.
- Applicants: LG Chem, Ltd.
- Inventors: Chang Hyun SUNG
- Web page: https://patentgrep.com/patent/US20190356140A1

## CPC

- H02J 7/52: for charge balancing, e.g. equalisation of charge between batteries
- H02J 7/54: Passive balancing, e.g. using resistors or parallel MOSFETs
- H01M 10/42: Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells (H01M10/60 takes precedence)
- H01M 10/482: {for several batteries or cells simultaneously or sequentially}
- H02J 7/56: Active balancing, e.g. using capacitor-based, inductor-based or DC-DC converters
- Y02E 60/10: Energy storage using batteries
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

An apparatus and a method of equalizing a battery module supplies an equalization current to a battery module which is diagnosed to have abnormality via an equalization current supply circuit when an abnormality is generated in a state of charge (SoC) of one or more battery modules, and equalize the SoC of the one or more battery modules.

## Claims

### Claim 1

An apparatus for equalizing a battery module, the apparatus comprising:
one or more cell module controllers (CMCs) which are connected with one or more battery modules, respectively, and measure voltages of both ends of a connected battery module among the one or more battery modules, respectively; and
a battery module controller (BMC) which calculates a state of charge (SoC) of each of the one or more battery modules based on the measured voltages of both ends of each battery module, and diagnoses an abnormality of each of the one or more battery modules based on the calculated SoC,
wherein the BMC controls one or more switches included in the one or more CMCs, respectively, based on a location of the battery module which is diagnosed to have the abnormality among the one or more battery modules, forms an equalization current supply circuit that is a closed circuit including the BMC and the battery module which is diagnosed to have the abnormality, and supplies an equalization current to the battery module which is diagnosed to have the abnormality via the equalization current supply circuit.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the BMC forms the equalization current supply circuit by controlling the switch included in the CMC connected with each battery module which is diagnosed to have the abnormality and a CMC connected to a front end of the CMC connected with the battery module which is diagnosed to have the abnormality.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein when the abnormality is not diagnosed in the one or more battery modules, the one or more CMCs maintain the one or more switches in an off state, and
when there is the battery module which is diagnosed to have the abnormality among the one or more battery modules, the BMC controls a state of the switch included in the CMC connected with each battery module which is diagnosed to have the abnormality and a CMC connected to a front end of the CMC connected with the battery module which is diagnosed to have the abnormality among the one or more switches in an on-state and forms the equalization current supply circuit including the battery module which is diagnosed to have the abnormality.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the BMC includes an auxiliary switch which controls an electrical conduction state with a CMC located at a first end among the one or more CMCs, and
when it is diagnosed that a battery module located at the first end has the abnormality, the BMC forms the equalization current supply circuit so as to include the battery module located at the first end by controlling electrical conduction states of the switch included in the CMC located at the first end and the auxiliary switch.

### Claim 5 (depends on 1)

The apparatus of claim 1, further comprising:
an equalization BUS and a communication BUS which connect the one or more CMCs and the BMC,
wherein the equalization BUS and the communication BUS connect the one or more CMCs and the BMC by a daisy chain connection with a first end and a last end.

### Claim 6 (depends on 5)

The apparatus of claim 5, wherein the equalization BUS includes:
a positive BUS which serially connects one or more CMCs located at odd-numbered places based on the CMC located at the last end among the one or more CMCs; and
a negative BUS which serially connects one or more CMCs located at even-numbered places based on the CMC located at the last end.

### Claim 7 (depends on 6)

The apparatus of claim 6 wherein each of the one or more CMCs further includes:
a connector which selectively connects the battery module connected to each of the CMCs, the switch included in each of the CMCs, and the equalization BUS;
a voltage sensor which measures voltages of both ends of the battery module connected to each of the CMCs;
a fuse which connects a negative electrode of the battery module connected to each of the CMCs and the one or more switches;
a balancer which discharges the battery module connected to each of the CMCs; and
a controller which controls an operation of the balancer based on the measured voltage.

### Claim 8 (depends on 5)

The apparatus of claim 5, wherein the BMC includes:
an equalization current supplier which supplies the equalization current to the battery module which is diagnosed to have the abnormality; and
a voltage sensor which measures a voltage of the equalization BUS,
wherein positive terminals of the equalization current supplier and the voltage sensor are connected with the positive BUS, and negative terminals of the equalization current supplier and the voltage sensor are connected with the negative BUS.

### Claim 9 (depends on 1)

The apparatus of claim 1, wherein the BMC forms a module location identifying circuit by controlling a switch included in a CMC of which a location is desired to be recognized among the one or more CMCs, and identifies the location of the CMC of which the location is desired to be recognized based on a voltage applied to the module location identifying circuit.

### Claim 10

A method of equalizing a battery module by a battery module equalizing apparatus, the method comprising:
measuring voltages of both ends of one or more battery modules connected to one or more cell module controllers (CMCs), respectively;
diagnosing an abnormality of each of the one or more battery modules based on a state of charge (SoC) of each of the one or more battery modules calculated based on the measured voltages of both ends of each of the one or more battery modules; and
controlling one or more switches included in the one or more CMCs, respectively, based on a location of the battery module which is diagnosed to have the abnormality among the one or more battery modules, and forming an equalization current supply circuit that is a closed circuit including an equalization current supplier that supplies an equalization current and the battery module which is diagnosed to have the abnormality.

### Claim 11 (depends on 10)

The method of claim 10, wherein the supplying of the equalization current includes forming the equalization current supply circuit by controlling the switch included in each of the CMCs connected with the battery module which is diagnosed to have the abnormality and a CMC connected to a front end of the CMC connected with the battery module which is diagnosed to have the abnormality.

### Claim 12 (depends on 10)

The method of claim 10, further comprising:
when the abnormality is not diagnosed in the one or more battery modules, maintaining the one or more switches in an off state,
wherein the supplying of the equalization current includes, when there is the battery module which is diagnosed to have the abnormality among the one or more battery modules, controlling a state of the switch included in each of the CMCs connected with the battery module which is diagnosed to have the abnormality and a CMC connected to a front end of the CMC connected with the battery module which is diagnosed to have the abnormality among the one or more switches in an on-state and forming the equalization current supply circuit including the battery module which is diagnosed to have the abnormality.

### Claim 13 (depends on 10)

The method of claim 10, wherein the supplying of the equalization current includes when it is diagnosed that a battery module located at a first end has abnormality, forming the equalization current supply circuit so as to include the battery module located at the first end by controlling electrical conduction states of the switch included in the CMC located at the first end and the auxiliary switch connected with the CMC located at the first end among the one or more CMCs.

### Claim 14 (depends on 10)

The method of claim 10, further comprising:
connecting, by an equalization BUS and a communication BUS, the one or more CMCs and the BMC,
wherein the equalization BUS and the communication BUS connect the one or more CMCs and the BMC by a daisy chain connection with a first end and a last end.

### Claim 15 (depends on 14)

The method of claim 14, wherein the equalization BUS includes:
a positive BUS which serially connects one or more CMCs located at odd-numbered places based on the CMC located at the last end among the one or more CMCs; and
a negative BUS which serially connects one or more CMCs located at even-numbered places based on the CMC located at the last end.

### Claim 16 (depends on 15)

The method of claim 15, wherein the measuring of each of the voltages includes:
selectively connecting the battery module connected to each of the CMCs, the switch included in each of the CMCs, and the equalization BUS;
measuring voltages of both ends of the battery module connected to each of the CMCs;
connecting a negative electrode of the battery module connected to each of the CMCs and the one or more switches; and
discharging the battery module connected to each of the CMCs.

### Claim 17 (depends on 14)

The method of claim 14, wherein the supplying of the equalization current includes:
supplying the equalization current to the battery module which is diagnosed to have the abnormality; and
measuring a voltage of the equalization BUS,
wherein positive terminals of the equalization current supplier and the voltage sensor are connected with the positive BUS, and negative terminals of the equalization current supplier and the voltage sensor are connected with the negative BUS.

### Claim 18 (depends on 10)

The method of claim 10, wherein the supplying of the equalization current includes:
forming a module location identifying circuit by controlling a switch included in a CMC of which a location is desired to be recognized among the one or more CMCs; and
identifying the location of the CMC of which the location is desired to be recognized based on a voltage applied to the module location identifying circuit.