CN211018294U

CN211018294U - Charge control device, battery management system, and battery pack

Info

Publication number: CN211018294U
Application number: CN201890000653.1U
Authority: CN
Inventors: 金源坤; 李基瑛
Original assignee: LG Chem Ltd
Current assignee: Lg Energy Solution
Priority date: 2017-11-07
Filing date: 2018-08-13
Publication date: 2020-07-14
Anticipated expiration: 2028-08-13
Also published as: KR102259965B1; KR20190051483A; WO2019093625A1

Abstract

The charge control device according to the present disclosure includes a high voltage charging line, a low voltage charge switch unit configured to selectively connect at least one of a plurality of battery modules to the low voltage charging line, and a control unit electrically connected to the high voltage charge switch unit and the low voltage charge switch unit. The control unit is configured to calculate the state of charge of the plurality of battery modules. When at least one of the plurality of battery modules reaches a full charge state, the control unit is further configured to turn off the high-voltage charge switching unit, and determine the at least one battery module as a supplementary charge target based on the calculated charge state. The control unit is further configured to selectively turn on the low-voltage charging switching unit to perform the supplementary charging of the at least one battery module determined as the supplementary charging target.

Description

Charge control device, battery management system, and battery pack

Technical Field

The present disclosure relates to a charge control device, a battery management system, and a battery pack, and more particularly, to a charge control device for charging a battery including a plurality of battery modules to a full charge state, and a battery management system and a battery pack including the same.

The present application claims priority from korean patent application No.10-2017-0147196, filed in korea at 11/7/2017, the disclosure of which is incorporated herein by reference.

Background

Recently, the demand for portable electronic products such as notebook computers, camcorders, and mobile phones has been sharply increased, and as secondary batteries for energy storage, robots, and satellites have been widely developed, many studies on high-performance secondary batteries capable of being repeatedly recharged are being conducted.

Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, lithium secondary batteries, and the like, among which the lithium secondary batteries have little or no memory effect, and thus the lithium secondary batteries are receiving much attention than nickel-based secondary batteries due to advantages of free charge and discharge, very low self-discharge rate, and high energy density of the lithium secondary batteries.

Batteries are used in various fields, and in many cases, a large capacity is required in recent years in fields where batteries such as electric vehicles or smart grid systems are used very much. In order to increase the capacity of the battery pack, a method for increasing the capacity of the secondary battery or the battery cell itself may be used, but in this case, there are disadvantages in that the effect of increasing the capacity is not so high, there is a physical limitation on the size expansion of the secondary battery, and it is not easy to manage. Therefore, in general, a battery pack including a plurality of battery modules connected in series and parallel is widely used.

The electrical and chemical characteristics of the battery modules constituting the battery pack may not be the same. In addition, as the number of charge/discharge cycles of the battery pack increases, the degree of deterioration of each battery module varies, and the difference in performance between the battery modules may increase. Thus, during charging of the battery pack to a fully charged state, the state of charge of each battery module may increase at a different rate.

During charging of the battery pack to a fully charged state, the degraded battery module may increase the state of charge at a higher rate than the non-degraded battery module. This is because the full charge capacity of the deteriorated battery module is lower than that of the non-deteriorated battery module. Therefore, during the charging of the battery pack, the charging states of each battery module may be different from each other.

Conventionally, in order to reduce the difference in the state of charge between the battery modules, a step-down balance of forcibly discharging the battery modules having a higher state of charge is mainly used. However, the problem with the buck balance is the energy consumption during the balance. In addition, when the step-down balancing is performed, the charge states of all the battery modules are reduced, and the charge time taken to fully charge the battery pack is also increased.

Disclosure of Invention

Technical problem

The present disclosure is designed to solve the above-mentioned problems, and therefore the present disclosure aims to provide a charge control device capable of achieving effective balance between modules during charging of a high-voltage battery to a fully charged state, and a battery management system and a battery pack including the charge control device according to the present disclosure.

These and other objects and advantages of the present disclosure will be understood by the following description, and will be apparent from the embodiments of the present disclosure. Further, it will be readily understood that the objects and advantages of the present disclosure can be realized by the means set forth in the appended claims and combinations thereof.

Technical solution

In order to achieve the above object, a charge control device according to an embodiment of the present disclosure is a device for controlling charging of a battery including a plurality of battery modules connected in series, and includes a high-voltage charging line configured to apply high-voltage charging power to both ends of the plurality of battery modules, the high-voltage charging line having a high-voltage charging switching unit; a low voltage charging line configured to apply low voltage charging power to both ends of at least one of the plurality of battery modules; a low voltage charging switching unit configured to selectively connect at least one of the plurality of battery modules to a low voltage charging line; and a control unit electrically connected to the high-voltage charge switching unit and the low-voltage charge switching unit. The control unit is configured to calculate the state of charge of the plurality of battery modules. When at least one of the plurality of battery modules reaches a full charge state, the control unit is further configured to turn off the high-voltage charge switching unit and determine the at least one battery module as a supplementary charge target based on the calculated charge state. The control unit is further configured to: the low-voltage charging switching unit is selectively turned on to perform a supplementary charging of at least one battery module determined as a supplementary charging target.

In addition, the charging control apparatus according to the present disclosure may further include a connector unit configured to be connectable to an external charging device. The connector unit is connected to one end of each of the high voltage charging line and the low voltage charging line.

In addition, the connector unit may include an input terminal configured to be connected to an external charging device, a first output terminal connected to a high voltage charging line, and a second output terminal connected to a low voltage charging line.

In addition, a positive electrode input terminal provided in the input terminals may be connected to each of the positive electrode output terminals of the first and second output terminals, and a negative electrode input terminal provided in the input terminals may be connected to each of the negative electrode output terminals of the first and second output terminals.

In addition, the low voltage charging switching unit may include a plurality of low voltage charging circuits connected in parallel, one end connected to the low voltage charging circuit and the other end connected to both ends of the battery module, and each of the low voltage charging circuits may include at least one unit switch to selectively open (open) and close (close) a current path.

In addition, the control unit may be further configured to: when the charge states of all of the plurality of battery modules reach the full charge state, all of the cell switches provided in the plurality of low voltage charging circuits are turned off.

In addition, the charge control device according to the present disclosure may further include a voltage measurement unit configured to measure voltages of the plurality of battery modules, a current measurement unit configured to measure magnitudes of charge currents of the plurality of battery modules, and a temperature measurement unit configured to measure temperatures of the plurality of battery modules.

In addition, the control unit may be further configured to: the state of charge of each battery module is calculated and monitored using the measured voltage values, the measured current values, and the measured temperature values of the plurality of battery modules received from the voltage measuring unit, the current measuring unit, and the temperature measuring unit.

In addition, the control unit may be further configured to determine at least one battery module having the lowest state of charge among the plurality of battery modules as the supplementary charging target.

In addition, when a battery module having the same state of charge as the battery module being complementarily charged is detected during the complementary charging, the control unit may be further configured to determine the battery modules having the same state of charge together as the complementary charging target.

In addition, in order to achieve the above object, a battery management system according to the present disclosure includes a charge control device according to the present disclosure.

In addition, in order to achieve the above object, a battery pack according to the present disclosure includes a charge control device according to the present disclosure.

Advantageous effects

According to the present disclosure, when a battery module that needs to be charged is selected for charge equalization between battery modules, a battery module having a low state of charge may be selectively charged.

Therefore, with this aspect of the present disclosure, it is possible to avoid energy waste in the module balancing process and achieve rapid charge equalization between battery modules.

Specifically, according to an aspect of the present disclosure, when connected to an external charging device, high-voltage charging power and low-voltage charging power are supplied from one external charging device, so that a charge equalization circuit is simple.

The present disclosure may have various other effects, and these and other effects will be understood from the following description, and will be apparent from the embodiments of the present disclosure.

Drawings

The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the detailed description of the disclosure described below, serve to provide a further understanding of the technical aspects of the disclosure, and therefore the disclosure should not be construed as being limited to the accompanying drawings.

Fig. 1 is a schematic view showing a connection configuration of a charge control device according to an embodiment of the present disclosure.

Fig. 2 is a schematic view showing a detailed configuration of a connector unit according to an embodiment of the present disclosure.

Fig. 3 is a schematic view illustrating a connection configuration of a plurality of battery modules and a low voltage charging switching unit according to an embodiment of the present disclosure.

Fig. 4 is a schematic view illustrating a connection configuration of a plurality of battery modules and a discharge circuit according to an embodiment of the present disclosure.

Fig. 5 is a schematic flowchart illustrating a charge control method according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms or words used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation.

Therefore, the embodiments described herein and the illustrations shown in the drawings are only the most preferred embodiments of the present disclosure, but are not intended to fully describe the technical aspects of the present disclosure, and therefore it should be understood that various other equivalents and modifications can be made thereto at the time of filing this application.

The charge control device according to the present disclosure is a device for controlling charging of a battery. Here, the battery may include at least one secondary battery. The charge control device according to the present disclosure may control charging of a plurality of battery modules included in a battery pack. In particular, the charge control device according to the present disclosure may be applied to a battery including a plurality of battery modules connected in series.

Referring to fig. 1, the charge control device according to the embodiment of the present disclosure may include a high voltage charging line L1, a low voltage charging line L2, a low voltage charge switching unit 200, and a control unit 300.

The high voltage charging line L1 may apply the high voltage charging power to both ends of the high voltage battery B including the plurality of battery modules 10, that is, the high voltage charging line L1 may be connected to both ends of the plurality of battery modules 10 connected in series to transmit the high voltage charging power to the plurality of battery modules 10.

In addition, the high voltage charging line L1 may include a high voltage charging switching unit 100 in the embodiment of fig. 1, the high voltage charging switching unit 100 is provided on the high voltage charging line L1 having one end connected to the positive electrode terminals of the plurality of battery modules 10 to cut off the high voltage charging power transmitted to the plurality of battery modules 10.

The low voltage charging line L2 may apply the low voltage charging power to both ends of at least one of the plurality of battery modules 10 to this end, the low voltage charging switching unit 200 may be configured to selectively connect at least one of the plurality of battery modules 10 to the low voltage charging line L2.

For example, as shown in the configuration of fig. 1, the low voltage charging switch unit 200 may be disposed between the low voltage charging line L2 and the plurality of battery modules 10, here, the low voltage charging switch unit 200 may be connected to each of both ends of each battery module 10, in addition, the low voltage charging switch unit 200 may be configured to respectively connect the positive electrode line and the negative electrode line of the low voltage charging line L2 to the positive electrode terminal and the negative electrode terminal of each battery module 10.

The control unit 300 may be electrically connected to the high-voltage charging switching unit 100 and the low-voltage charging switching unit 200. Preferably, the control unit 300 may be configured to output a signal controlling the turning on or off of the high voltage charging switching unit 100. In addition, the control unit 300 may be configured to output a signal controlling the turn-on or turn-off of the low voltage charging switching unit 200.

The control unit 300 may be configured to calculate states of charge (SOCs) of the plurality of battery modules 10. For example, the control unit 300 may calculate the SOCs of the plurality of battery modules 10 based on measured voltage values, measured current values, and/or measured temperature values of the plurality of battery modules 10.

When at least one of the plurality of battery modules 10 reaches a full charge state, the control unit 300 may be configured to turn off the high voltage charge switching unit 100. For example, the control unit 300 may calculate the SOCs of the plurality of battery modules 10, and determine the battery module 10 that reaches the full charge state based on the calculated SOCs. In addition, when the battery module 10 reaching the full charge state is determined, the control unit 300 may turn off the high-voltage charge switching unit 100 to cut off the high-voltage charge power, in order to prevent overcharge of the battery module 10.

The control unit 300 may be configured to determine at least one battery module 10 as a supplementary charging target based on the SOCs of the plurality of battery modules 10. Specifically, the control unit 300 may calculate the SOCs of the plurality of battery modules 10, and determine the battery module 10 at the lowest SOC as the supplementary charging target based on the calculated SOCs.

For example, when four battery modules 10 are connected in series, if it is assumed that the SOC of each of the four battery modules 10 is 100%, 90%, 80%, and 100%, the battery module 10 having the 80% SOC may be determined as the supplementary charging target.

The control unit 300 may perform the supplementary charging of the at least one battery module 10 determined as the supplementary charging target, in this case, the control unit 300 may selectively turn on the low voltage charging switching unit 200 to connect the low voltage charging line L2 to both ends of the at least one battery module 10 determined as the supplementary charging target.

Preferably, the charge control device according to the present disclosure may further include a connector unit 400 as shown in the embodiment of fig. 1.

The connector unit 400 may be configured to be connectable to the external charging device 50. That is, the connector unit 400 may be attached to and detached from the external charging apparatus 50. For example, when the high-voltage battery B is a battery mounted in an electric vehicle, the connector unit 400 may be a charging connector provided in the electric vehicle. In addition, the external charging device 50 may be a charger for an electric vehicle.

In addition, the connector unit 400 may be connected to one end of each of the high voltage charging line L1 and the low voltage charging line L2, for example, as shown in the configuration of fig. 1, the connector unit 400 may be connected to each of the positive electrode line and the negative electrode line of the high voltage charging line L1 and the low voltage charging line L2, by which configuration the connector unit 400 may transmit the high voltage charging power transmitted from the external charging device 50 to the high voltage charging line L1, and in addition, the connector unit 400 may transmit the low voltage charging power transmitted from the external charging device 50 to the low voltage charging line L2.

More preferably, as shown in the embodiment of fig. 1, the connector unit 400 may include an input terminal 410, a first output terminal 430, and a second output terminal 450.

The input terminal 410 is configured to be connected to the external charging device 50 to receive an input of the high-voltage charging power output from the external charging device 50.

The first output terminal 430 may output high-voltage charging power capable of charging all of the plurality of battery modules 10 during the charging of the high-voltage battery B here, the first output terminal 430 may be connected to the positive electrode line and the negative electrode line of the high-voltage charging line L1.

The second output terminal 450 may output low-voltage charging power capable of individually charging the battery module 10 having a low SOC during charging of the high-voltage battery B to a fully charged state, here, the second output terminal 450 may be connected to the positive electrode line and the negative electrode line of the low-voltage charging line L2.

In an embodiment of the present disclosure, the low voltage charging line L2 may further include a transformer 500 to reduce the charging power to a level capable of complementary charging at least one battery module 10. here, the power conversion ratio of the transformer 500 may be determined based on the number of battery modules to complementary charge through the low voltage charging line L2. for example, the number of battery modules 10 capable of being complementary charged may be selected in the range of 1 to N-1.

In addition, preferably, as shown in the embodiment of fig. 1, the charge control device according to the present disclosure may include a voltage measuring unit 610, a current measuring unit 630, and a temperature measuring unit 650.

The voltage measuring unit 610 may be electrically coupled with the control unit 300 to transmit and receive an electrical signal. In addition, the voltage measuring unit 610 may measure the voltage across each battery module 10 at time intervals under the control of the control unit 300 and output a signal indicating the magnitude of the measured voltage to the control unit 300. In this case, the control unit 300 may determine the voltage of each battery module 10 according to the signal output from the voltage measuring unit 610. For example, the voltage measuring unit 610 may be implemented using a voltage measuring circuit commonly used in the art. The circuit configuration of the voltage measuring unit 610 for measuring the voltage of each battery module 10 will be apparent to those skilled in the art, and a detailed description thereof will be omitted herein.

The current measuring unit 630 may be electrically coupled with the control unit 300 to transmit and receive an electrical signal. In addition, the current measuring unit 630 may repeatedly measure the magnitude of the charging current or the discharging current of each battery module 10 at time intervals under the control of the control unit 300 and output a signal indicating the measured magnitude of the current to the control unit 300. In this case, the control unit 300 may determine the magnitude of the current according to the signal output from the current measuring unit 630. For example, the current measuring unit 630 may be implemented using a hall sensor or a sensing resistor, which are commonly used in the art. The hall sensor or sense resistor may be mounted on a line through which current flows. The circuit configuration of the current measuring unit 630 for measuring the magnitude of the charging current or the discharging current of each battery module 10 will be apparent to those skilled in the art, and a detailed description thereof will be omitted herein.

The temperature measuring unit 650 is electrically coupled with the control unit 300 to transmit and receive an electrical signal. In addition, the temperature measuring unit 650 may repeatedly measure the temperature of each battery module 10 at time intervals and output a signal indicating the magnitude of the measured temperature to the control unit 300. In this case, the control unit 300 may determine the temperature of each battery module 10 according to the signal output from the temperature measuring unit 650. For example, the temperature measuring unit 650 may be implemented using a thermocouple commonly used in the art. The circuit configuration of the temperature measuring unit 650 for measuring the temperature of each battery module 10 will be apparent to those skilled in the art, and a detailed description thereof will be omitted herein.

The control unit 300 may calculate and monitor the SOC of each battery module 10 using the measured voltage values, the measured current values, and the measured temperature values of the plurality of battery modules 10 received from the voltage measuring unit 610, the current measuring unit 630, and the temperature measuring unit 650. That is, the control unit 300 may calculate and monitor the SOC of each battery module 10 during the charge or discharge of the plurality of battery modules 10.

In one aspect of the present disclosure, the control unit 300 may be configured to estimate the SOC of each battery module 10 by integrating the charging current and the discharging current of each battery module 10. Here, the initial SOC at the start of charging or discharging of each battery module 10 may be determined using an Open Circuit Voltage (OCV) of each battery module 10 measured before the start of charging or discharging. To this end, the control unit 300 includes an OCV-SOC lookup table defining the SOC for each OCV, and may map the SOC corresponding to the COV of each battery module 10 according to the lookup table.

Here, for SOC estimation using the Extended Kalman filter, reference may be made to Gregory L. the paper "Extended Kalman filtering for battery management systems of L iPB-based HEVbattery packs part 1,2and 3 (Extended Kalman filtering of battery management system of HEV battery pack based on L iPB, Parts 1,2and 3)" (Journal of Power Source 134, 2004, p.252-261).

In addition to the current integration method or the extended kalman filter described above, the SOC of each battery module 10 may be determined by any other known method for estimating the SOC by selectively using the voltage, current, and temperature of each battery module 10.

The control unit 300 may be configured to determine the full charge capacity of each battery module 10. The full charge capacity is used to calculate the SOC. The full charge capacity may be calculated by the control unit 300 while the battery module 10 is charged from the fully discharged state to the fully charged state. The full charge capacity may be determined by any other method known in the art to which this disclosure pertains.

Preferably, when the battery module 10 having the same SOC as the battery module 10 being complementarily charged is detected during the complementary charging, the control unit 300 may determine the battery modules 10 having the same SOC together as the complementary charging target.

For example, assuming that all the battery modules 10 are charged through the high voltage charging line L1, four battery modules 10 connected in series, a first battery module, a second battery module, a third battery module, and a fourth battery module, respectively, reach 100%, 80%, 90%, and 100% SOC in this case, the control unit 300 may first perform the supplementary charging of the second battery module such that the SOC reaches 90%, in this case, the control unit 300 may determine an existing third battery module having 90% SOC together as the supplementary charging target in addition to the second battery module that is subjected to the supplementary charging, and simultaneously perform the supplementary charging of the second battery module and the third battery module.

More preferably, the control unit 300 may be configured to turn off all of the plurality of low-voltage charge switching units 200 when the SOC of all of the plurality of battery modules 10 reaches the full charge state.

Meanwhile, in order to perform the above-described operations, the control unit 300 may be implemented such that it selectively includes a processor, an Application Specific Integrated Circuit (ASIC), a chipset, a logic circuit, a register, a communication modem, and/or a data processing device known in the art.

Referring to fig. 2, a connector unit 400 according to an embodiment of the present disclosure may include a first output terminal 430, a second output terminal 450, and an input terminal 410.

In the embodiment of fig. 2, the first output terminal 430 may output high-voltage charging power, which is transmitted from an external charging device to the connector unit 400, to the high-voltage charging line L1 through the positive and negative electrode output terminals.

In the embodiment of fig. 2, the second output terminal 450 may output the low-voltage charging power transmitted from the external charging device to the connector unit 400 to the low-voltage charging line L2 through the positive electrode output terminal and the negative electrode output terminal.

The input terminal 410 may include a positive electrode input terminal and a negative electrode input terminal. In the embodiment of fig. 2, the input terminal 410 may receive input of high-voltage charging power and low-voltage charging power from an external charging device through the positive electrode input terminal and the negative electrode input terminal.

Here, the positive electrode input terminal 410 may be connected to each of a positive electrode output terminal of the first output terminal 430 and a positive electrode output terminal of the second output terminal 450. In addition, the negative electrode input terminal 410 may be connected to each of a negative electrode output terminal of the first output terminal 430 and a negative electrode output terminal of the second output terminal 450.

With this configuration of the present disclosure, high-voltage charging power and low-voltage charging power are supplied from one external charging apparatus through one connector, and thus there is an advantage that a charge equalization circuit can be simplified.

Referring to fig. 3, the low voltage charging switching unit 200 according to the embodiment of the present disclosure may be connected to the low voltage charging line L2 at one side and to the plurality of

battery modules

11, 12, 13, 14 at the other side between the low voltage charging line L2 and the plurality of

battery modules

11, 12, 13, 14 as shown in fig. 3.

In addition, the low voltage charging switching unit 200 may include a plurality of low voltage charging circuits C here, the low voltage charging circuits C may be individually connected to the plurality of

battery modules

11, 12, 13, 14 to selectively connect the low voltage charging line L2 to at least one battery module 10 selected from the plurality of

battery modules

11, 12, 13, 14, in this case, the low voltage charging circuit C may have one end connected to the low voltage charging line L2 and the other end connected to both ends of the battery module 10.

For example, as shown in the configuration of fig. 3, the low voltage charging switching unit 200 may include a first charging circuit C1, a second charging circuit C2, a third charging circuit C3, and a fourth charging circuit C4. here, the first charging circuit C1 may connect both ends of the low voltage charging circuit L2 with both ends of the first battery module 11. likewise, the second charging circuit C2 may connect both ends of the low voltage charging circuit L2 with both ends of the second battery module 12. in addition, the third charging circuit C3 and the fourth charging circuit C4 may connect both ends of the low voltage charging circuit L2 with both ends of the third battery module 13 and the fourth battery module 14. although not shown in fig. 3, the fifth to nth charging circuits may have similar configurations when N battery modules 10 are connected in series.

For example, as shown in the configuration of fig. 3, the first charging circuit C1, the second charging circuit C2, the third charging circuit C3, and the fourth charging circuit C4 may be connected in parallel to both ends of the low voltage charging circuit L2, although not shown in fig. 3, the fifth to nth charging circuits may have a similar configuration when N battery modules 10 are connected in series.

Further, preferably, the low voltage charging circuit C may have at least one cell switch to selectively open/close the current path. In particular, the low voltage charging circuit C may have a plurality of cell switches, each of which is connected to both ends of the battery module 10. For example, as shown in the configuration of fig. 3, the first charging circuit C1 may include a first switch C1_1 and a second switch C1_2 connected to the positive electrode terminal and the negative electrode terminal of the first battery module 11, respectively. Also, the second charging circuit C2 may include first and second switches C2_1 and C2_2 connected to the positive and negative electrode terminals of the second battery module 12, respectively. In addition, likewise, the third and fourth charging circuits C3 and C4 may include first and second switches C3_1 and C4_1 and C3_ 2and C4_ 2. Although not shown in fig. 3, the fifth to nth charging circuits may also have a similar configuration when N battery modules 10 are connected in series.

In addition, preferably, the control unit 300 may be configured to output signals capable of individually controlling the turn-on or turn-off of the first switches C1_1, C2_1, C3_1, C4_1 and the second switches C1_2, C2_2, C3_2, C4_2 provided in the plurality of low voltage charging circuits C, whereby the control unit may be configured to select at least one of the plurality of battery modules 10 and individually connect the selected battery module 10 to the low voltage charging circuit L2 through the low voltage charging circuit C.

Further, preferably, the control unit 300 may turn off all the cell switches provided in the plurality of low-voltage charging circuits C when the SOCs of all the plurality of battery modules 10 reach the full charge state. For example, in the embodiment shown in fig. 3, when all of the first, second, third, and

fourth battery modules

11, 12, 13, and fourth battery modules reach a fully charged state, the control unit 300 may turn off all of the first switches C1_1, C2_1, C3_1, C4_1, and second switches C1_2, C2_2, C3_2, C4_ 2.

With this configuration of the present disclosure, there is an advantage in that the battery module 10 having a low SOC can be selectively charged. Therefore, according to this aspect of the present disclosure, there is an advantage in that the SOC of all the battery modules can be uniformly maintained and rapid charge equalization between the battery modules is achieved.

Fig. 4 is a schematic diagram illustrating a connection configuration of a plurality of battery modules and a discharge circuit according to an embodiment of the present disclosure.

Referring to fig. 4, the charge control device according to the embodiment of the present disclosure may include a plurality of discharge circuits D, each of which is connected to a plurality of

battery modules

11, 12, 13, 14. In the charge control apparatus according to the embodiment of the present invention, a plurality of discharge circuits D may be provided together with a plurality of low-voltage charge circuits C shown in fig. 3.

Preferably, the first discharge circuit D1 may be connected to both ends of the first battery module 11 and include a first discharge switch S1 and a first discharge resistor R1. Also, the second discharge circuit D2 may be connected to both ends of the second battery module 12, and include a second discharge switch S2 and a second discharge resistor R2. In addition, also, the third and fourth discharge circuits D3 and D4 may be connected to both ends of the third and fourth battery modules 13 and D4, respectively, and include third and fourth discharge switches S3 and S4 and third and fourth discharge resistors R3 and R4, respectively. Although not shown in fig. 4, the fifth to nth discharge circuits may also have a similar configuration when N battery modules 10 are connected in series.

Preferably, the control unit may output a signal capable of individually controlling the turn-on or turn-off of the discharge switches S provided in the plurality of discharge circuits D. Thereby, the control unit may select at least one of the plurality of battery modules 10 and individually discharge the selected battery module 10.

The charge control device according to the embodiment of the present disclosure can simultaneously perform forced discharge and complementary charge. That is, the charge control device may simultaneously perform the forced discharge of at least one of the plurality of battery modules 10 and the supplementary charge of at least one of the plurality of battery modules 10 using the low-voltage charge circuit C and the discharge circuit D shown in the embodiments of fig. 3 and 4.

Preferably, the charge control device according to the present disclosure can operate in both a fast charge mode and a normal charge mode.

Here, the rapid charging mode is a mode in which the plurality of battery modules 10 are rapidly charged to a fully charged state using forced discharge, high-voltage charge, and supplementary charge. However, the fast charge mode may ensure fast charging, but may have energy loss due to forced discharge.

For example, when four battery modules 10 are connected in series, if it is assumed that the SOC of each of the four battery modules 10 is 100%, 80%, 85%, and 80%, the control unit may forcibly discharge the battery module 10 having the SOC of 100% to reduce the SOC from 100% to 85%, and charge all the battery modules 10 at the SOC of 85%, 80%, 85%, and 80% by high-voltage charging. Subsequently, when at least one battery module 10 reaches a fully charged state, the high voltage charging may be stopped. That is, the SOC of the four battery modules 10 at this time may be 100%, 95%, 100%, and 95%. In addition, the control unit may perform supplementary charging of two battery modules 10 having an SOC of 95% to fully charge all the battery modules 10.

In addition, the normal charging mode is a mode in which the battery module 10 is charged to a fully charged state using the boost charging without energy loss.

For example, when four battery modules 10 are connected in series, if it is assumed that the SOC of each of the four battery modules 10 is 100%, 80%, 85%, and 80%, the control unit may perform the supplementary charging of two battery modules 10 having an 80% SOC to increase the SOC from 80% to 85%. Subsequently, the existing battery modules 10 having the 85% SOC may be determined together as the boost charging target, and the three battery modules 10 having the 85% SOC may be boost charged to fully charge all the battery modules 10.

The charge control device according to the present disclosure may be applied to a Battery Management System (BMS). That is, the BMS according to the present disclosure may include the charge control device according to the present disclosure as described above. In this configuration, at least some components of the charge control device according to the present disclosure may be implemented by supplementing or adding functions of components included in the conventional BMS. For example, the control unit, the voltage measuring unit, the current measuring unit, and the temperature measuring unit of the charge control device according to the present disclosure may be implemented as components of the BMS.

In addition, the charge control device according to the present disclosure may be provided in a battery pack. That is, the battery pack according to the present disclosure may include the charge control device according to the present disclosure as described above. Here, the battery pack may include at least one secondary battery, a charge control device, an electric appliance (BMS, relay, fuse, etc.), and a case.

Fig. 5 is a schematic flowchart illustrating a charge control method according to an embodiment of the present disclosure. In fig. 5, the object of performing each step may be each component of the charge control device according to the present disclosure as described above.

As shown in fig. 5, at the start of charging in S110, the control unit turns on the high voltage charging switching unit mounted on the high voltage charging line (S110). Then, a charging current flows through the plurality of battery modules, i.e., the first to nth battery modules, and the charging of the plurality of battery modules is started.

The start of charging may be caused in accordance with a charging start request signal transmitted from the external charging apparatus. To receive the charging start request signal, the connector unit may include a communication interface, and the control unit may be electrically coupled to transmit and receive an electrical signal through the communication interface.

In S120, the control unit calculates and monitors the SOCs of the plurality of battery modules during the charging of the high-voltage battery. Here, the SOC may be calculated using a current integration method or an extended kalman filter.

In S130, the control unit determines whether at least one of the plurality of battery modules reaches a full charge state during charging of the plurality of battery modules.

When the determination result in S130 is yes, the control unit turns off the high-voltage charging switching unit to temporarily stop the charging in S140. In contrast, when the determination result in S130 is no, the control unit performs S120 to continuously charge the high voltage battery.

When the charging is temporarily stopped in S140, the control unit compares the SOCs of the plurality of battery modules and determines the battery module having the lowest SOC as the supplementary charging target in S150. In the embodiment shown in fig. 3, the third battery module 13 may be determined as the supplementary charging target when it is assumed that the SOC of the first battery module 11, the second battery module 12, the third battery module 13, and the fourth battery module 14 is 100%, 90%, 80%, and 100%, respectively.

Subsequently, in S160, the control unit turns on the cell switch of the low-voltage charging switch unit connected to the battery module determined as the supplementary charging target to connect the corresponding battery module to the low-voltage charging line and to supplement-charge the corresponding battery module.

Subsequently, in S170, the control unit calculates and monitors the SOCs of the plurality of battery modules during the charging of the battery module determined as the supplementary charging target. Here, the SOC may be calculated using a current integration method or an extended kalman filter.

Subsequently, in S180, the control unit determines whether there is a battery module having the same SOC as the battery module determined as the supplementary charging target.

When the determination in S180 is yes, the control unit moves the process to S150. In contrast, when the determination in S180 is no, the control unit moves the process to S190 to continuously perform the supplementary charging of the supplementary charging target battery module.

When the determination in S180 is yes, the control unit determines, in S150, the battery module having the same SOC as the battery module determined as the complementary charging target together as the complementary charging target. In the embodiment shown in fig. 3, the control unit may determine the second battery module 12 having the same SOC as the third battery module 13 together as the complementary charging target and simultaneously perform the complementary charging of the second battery module 12 and the third battery module 13, on the assumption that the SOCs of the first battery module 11, the second battery module 12, the third battery module 13, and the fourth battery module 14 are 100%, 90%, and 100%, respectively, and the third battery module 13 is a battery module that is determined as the complementary charging target and is complementarily charged.

Meanwhile, when the determination in S180 is no, the control unit determines whether all the battery modules reach the full charge state in S190.

When the determination result in S190 is yes, the control unit determines that the high-voltage battery reaches its fully charged state and terminates the charging process. In contrast, when the determination result in S190 is negative, the control unit moves the process to S170 to continuously perform the supplementary charging of the supplementary charging target battery module. Therefore, when one of the battery modules reaches its full charge state, the supplementary charging is sequentially performed from the battery module having the lowest SOC. Eventually, the SOC of all the battery modules reaches 100%.

In addition, since the supplementary charging is performed while the module balancing is performed, the module balancing is performed with the SOC of all the battery modules increased on average. Therefore, it is possible to reduce energy consumed by forced discharge during the balancing of the modules and to reduce the time taken to fully charge the battery module.

As a specific example, when it is assumed that the SOC of the battery modules is 100%, 90%, 80%, and 85% at a specific time point when four battery modules are charged, the conventional balancing method forcibly discharges all the modules having the SOC of 100%, 90%, and 85% to adjust the SOC of all the battery modules to 80%. Thus, the process involves energy consumption corresponding to a 35% total change in SOC. The energy consumed at this time is converted into heat at the discharge circuit. In addition, as the SOC of the battery module decreases to 80%, the difference from the full charge capacity increases on average, and the time taken to fully charge the battery module also increases.

In contrast, according to an embodiment of the present disclosure, a battery module having an 80% SOC is complementarily charged. In addition, when the SOC of the recharging battery module is increased from 80% to 85%, the existing battery module having the 85% SOC is also determined as the recharging target, and two battery modules having the 85% SOC are recharged. In addition, when the SOC of the two battery modules that are subjected to the complementary charging increases from 85% to 90%, the existing battery module having the 90% SOC is also determined as the complementary charging target, and the three battery modules having the 90% SOC are subjected to the complementary charging. In addition, the SOC of the three battery modules that are additionally charged increases from 90% to 100%, all the battery modules reach the full charge state and the charging ends.

Although the present disclosure has been described above with respect to a limited number of embodiments and drawings, the present disclosure is not limited thereto, and it will be apparent to those skilled in the art that various modifications and changes may be made thereto within the technical scope of the present disclosure and the equivalent scope of the appended claims.

Meanwhile, the term "unit" such as "control unit", "switch unit", and "measurement unit" is used herein, but it is obvious to those skilled in the art that this indicates a logical component unit and does not necessarily indicate a component that may or should be physically separated from other components.

Claims

1. A charge control device for controlling charging of a battery including a plurality of battery modules connected in series, the charge control device comprising:

a high voltage charging line configured to apply high voltage charging power to both ends of the plurality of battery modules, the high voltage charging line having a high voltage charging switching unit;

a low voltage charging line configured to apply low voltage charging power to both ends of at least one of the plurality of battery modules;

a low voltage charging switching unit configured to selectively connect at least one of the plurality of battery modules to the low voltage charging line; and

a control unit electrically connected to the high voltage charging switching unit and the low voltage charging switching unit,

wherein the control unit is configured to calculate the state of charge of the plurality of battery modules,

the control unit is further configured to: turning off the high-voltage charge switching unit when at least one of the plurality of battery modules reaches a full charge state, and determining at least one battery module as a supplementary charge target based on the calculated charge state, an

The control unit is further configured to: selectively turning on the low-voltage charge switching unit to supplement-charge the at least one battery module determined as a supplement-charging target.

2. The charge control device according to claim 1, further comprising:

a connector unit configured to be connectable to an external charging device, the connector unit being connected to one end of each of the high voltage charging line and the low voltage charging line.

3. The charge control device of claim 2, wherein the connector unit comprises an input terminal configured to be connected to the external charging device, a first output terminal connected to the high voltage charging line, and a second output terminal connected to the low voltage charging line.

4. The charge control device according to claim 3, wherein a positive-electrode input terminal provided in the input terminals is connected to each of the first output terminal and the second output terminal, and

a negative electrode input terminal provided in the input terminal is connected to each of the negative electrode output terminals of the first output terminal and the second output terminal.

5. The charge control device according to claim 1, wherein the low-voltage charge switching unit includes a plurality of low-voltage charge circuits connected in parallel, one end of which is connected to the low-voltage charge line, and the other end of which is connected to both ends of the battery module, and

each of the low voltage charging circuits includes at least one cell switch to selectively open and close a current path.

6. The charge control device of claim 5, wherein the control unit is further configured to: turning off all of the cell switches provided in the plurality of low voltage charging circuits when the state of charge of all of the plurality of battery modules reaches a full state of charge.

7. The charge control device according to claim 1, further comprising:

a voltage measurement unit configured to measure voltages of the plurality of battery modules;

a current measuring unit configured to measure a magnitude of a charging current of the plurality of battery modules; and

a temperature measurement unit configured to measure temperatures of the plurality of battery modules.

8. The charge control device of claim 7, wherein the control unit is further configured to: calculating and monitoring a state of charge of each battery module using the measured voltage values, the measured current values, and the measured temperature values of the plurality of battery modules received from the voltage measuring unit, the current measuring unit, and the temperature measuring unit.

9. The charge control device according to claim 1, wherein the control unit is further configured to determine at least one battery module having a lowest state of charge among the plurality of battery modules as a supplementary charge target.

10. The charge control device according to claim 9, wherein when a battery module having the same state of charge as a battery module being complementarily charged is detected during complementary charging, the control unit is further configured to determine the battery modules having the same state of charge together as the complementary charge target.

11. A battery management system, comprising:

the charge control device according to any one of claims 1 to 10.

12. A battery pack, comprising:

the charge control device according to any one of claims 1 to 10.