KR20210073336A - Apparatus and method for managing battery - Google Patents

Abstract

A battery management apparatus according to one embodiment of the present invention includes: a measuring unit that measures voltages and temperatures of a plurality of battery cells, and outputs a plurality of measured voltage values and a plurality of temperature values; and a control unit that receives the voltage values and the temperature values from the measuring unit, determines a first cell having the highest voltage and a second cell having the lowest voltage among the battery cells, calculates a voltage difference between the first cell and the second cell, calculates an inrush current between the first cell and the second cell based on the calculated voltage difference and the temperature values, and compares the calculated voltage difference with a voltage threshold to balance the battery cells based on the result of comparing the calculated inrush current with the current threshold when the calculated voltage difference is less than the voltage threshold. Thus, a number of cell relays are prevented from being damaged in the process of balancing the battery cells.

Description

BATTERY MANAGEMENT APPARATUS AND METHOD FOR MANAGING BATTERY

The present invention relates to a battery management apparatus and method, and more particularly, to a battery management apparatus and method capable of effectively performing balancing of battery cells.

Recently, as the demand for portable electronic products such as laptops, video cameras, and portable telephones is rapidly increasing and the development of electric vehicles, energy storage batteries, robots, satellites, etc. is in full swing, high-performance batteries that can be repeatedly charged and discharged have been developed. Research is being actively conducted.

Currently commercialized batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Among them, lithium batteries have almost no memory effect compared to nickel-based batteries, so they are free to charge and discharge and have a very high self-discharge rate. It is attracting attention due to its low energy density and high energy density.

On the other hand, when these batteries are connected in parallel, if the capacity between the batteries differs by more than a certain level, various problems such as battery ignition, rapid aging, and relay fusion due to inrush current may occur. Accordingly, in order to solve the capacity difference of batteries connected in parallel, a battery balancing technique has been disclosed in the prior art.

Patent Document 1 is a battery cell monitoring and balancing circuit that monitors voltage levels of a plurality of battery cells and performs balancing. Referring to Patent Document 1, in order to solve the problem caused by the capacity difference between battery cells described above, a configuration for balancing battery cells when the voltage difference between a plurality of battery cells is higher than a battery cell balance threshold is disclosed.

However, Patent Document 1 has a problem in that it does not recognize that components (eg, cell relay, main relay, etc.) of the battery pack may be damaged by the inrush current generated during the balancing process of the battery cells. That is, when Patent Document 1 focuses only on performing balancing based on a voltage difference between battery cells, the fact that internal components of the battery pack may be damaged during balancing of the battery cells is overlooked.

KR 10-0616163 B1

The present invention has been devised to solve the above problems, and an object of the present invention is to provide a battery management apparatus and method capable of preventing a plurality of cell relays from being damaged in a process of balancing a plurality of battery cells.

Other objects and advantages of the present invention may be understood by the following description, and will become more clearly understood by the examples of the present invention. In addition, it will be readily apparent that the objects and advantages of the present invention can be realized by means and combinations thereof indicated in the claims.

A battery management apparatus according to an aspect of the present invention includes: a measuring unit configured to measure voltages and temperatures of a plurality of battery cells, and output a plurality of measured voltage values and a plurality of temperature values; and receiving the plurality of voltage values and the plurality of temperature values from the measuring unit, and determining a first cell having the highest voltage and a second cell having the lowest voltage among the plurality of battery cells, the first cell and Calculate the voltage difference between the second cells, calculate the inrush current between the first cell and the second cell based on the calculated voltage difference and the plurality of temperature values, and calculate the calculated voltage difference with a voltage threshold and a controller configured to balance the plurality of battery cells based on a result of comparing and comparing the calculated voltage difference with the current threshold value when the calculated voltage difference is less than the voltage threshold value.

The plurality of battery cells may be configured such that a cell relay is connected to one end of each, and connected in parallel with each other according to an operation state of the connected plurality of cell relays.

The control unit calculates the resistance value of the first cell based on the temperature value of the first cell among the plurality of temperature values, and calculates the inrush current based on the calculated resistance value and the calculated voltage difference can be configured.

The controller may be configured to set the voltage threshold based on the calculated inrush current and the reference resistance value.

The controller may be configured to calculate a combined resistance value of the plurality of battery cells in consideration of the plurality of temperature values, and preset the calculated combined resistance value as the reference resistance value.

The control unit may be configured to preset the current threshold based on a preset number of expected driving for each of the plurality of cell relays.

The controller may be configured to connect the plurality of battery cells to perform the balancing when the calculated inrush current is less than the current threshold value.

The control unit may be configured to convert an operation state of the plurality of cell relays to a turn-on state to perform charging and discharging between the plurality of battery cells.

The battery management apparatus according to another aspect of the present invention may further include a charging unit connected to the plurality of battery cells and configured to charge each of the plurality of battery cells under the control of the controller.

The control unit may be configured to charge the second cell through the charging unit when the calculated inrush current is equal to or greater than the current threshold value.

The control unit selects a voltage value closest to the voltage of the second cell from among the plurality of voltage values, and charges the second cell through the charging unit only until the voltage of the second cell reaches the selected voltage value. can be configured to do so.

The control unit, when the voltage of the second cell reaches the selected voltage value, recalculates the inrush current, resets the voltage threshold based on the recalculated inrush current, the reset voltage threshold and the and balancing the plurality of battery cells based on a result of comparing a voltage difference between the first cell and the second cell and a result of comparing the recalculated inrush current with the current threshold.

A battery pack according to another aspect of the present invention may include the battery management device according to the present invention.

A battery management method according to another aspect of the present invention includes a voltage and temperature measuring step of measuring voltage and temperature of a plurality of battery cells; a cell determining step of determining a first cell having the highest voltage and a second cell having the lowest voltage among the plurality of battery cells; a voltage difference calculating step of calculating a voltage difference between the first cell and the second cell determined in the cell determining step; an inrush current calculation step of calculating a rush current between the first cell and the second cell based on the calculated voltage difference and the plurality of measured temperature values; a voltage comparison step of comparing the calculated voltage difference with a voltage threshold value; and a cell balancing step of balancing the plurality of battery cells based on a result of comparing the calculated inrush current and the current threshold value when the calculated voltage difference is less than the voltage threshold as a result of the comparison in the voltage comparison step. may include

According to one aspect of the present invention, there is an advantage that a plurality of cell relays can be prevented from being damaged in a balancing process of a plurality of battery cells.

In addition, according to an aspect of the present invention, since the need for balancing is determined by reflecting the current state of the plurality of battery cells, there is an advantage that unnecessary balancing can be prevented from being performed.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Since the following drawings attached to the present specification serve to further understand the technical idea of the present invention together with the detailed description of the present invention to be described later, the present invention should not be construed as being limited only to the matters described in such drawings.
1 is a diagram schematically illustrating a battery management apparatus according to an embodiment of the present invention.
2 is a diagram schematically illustrating a battery pack including a battery management apparatus according to an embodiment of the present invention.
3 is a diagram illustrating an exemplary configuration of a battery pack including a battery management apparatus according to an embodiment of the present invention.
4 is a graph showing an example of the expected number of driving of the cell relay according to the current threshold value.
5 is a diagram schematically illustrating a battery management method according to another embodiment of the present invention.
6 is a diagram illustrating in more detail a voltage comparison step and a cell balancing step in a battery management method according to another embodiment of the present invention.

The terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor may properly define the concept of the term in order to best describe his invention. Based on the principle that there is, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Therefore, the configuration shown in the embodiments and drawings described in the present specification is only the most preferred embodiment of the present invention and does not represent all of the technical spirit of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations.

In addition, in the description of the present invention, if it is determined that a detailed description of a related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms including an ordinal number such as 1st, 2nd, etc. are used for the purpose of distinguishing any one of various components from the others, and are not used to limit the components by such terms.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

In addition, a term such as a control unit described in the specification means a unit for processing at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

In addition, throughout the specification, when a part is "connected" with another part, it is not only "directly connected" but also "indirectly connected" with another element interposed therebetween. include

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram schematically illustrating a battery management apparatus 100 according to an embodiment of the present invention. 2 is a diagram schematically illustrating a battery pack 1 including the battery management apparatus 100 according to an embodiment of the present invention. 3 is a diagram illustrating an exemplary configuration of a battery pack 1 including the battery management apparatus 100 according to an embodiment of the present invention.

Referring to FIG. 2 , the battery pack 1 may include a battery cell 10 , a cell relay 20 , a main relay 30 , and the battery management apparatus 100 . More specifically, referring to FIG. 3 , the battery pack 1 may include a plurality of battery cells 10a, 10b, 10c, and 10d and a plurality of cell relays 20a, 20b, 20c, and 20d.

The plurality of battery cells 10a, 10b, 10c, and 10d may be configured such that a cell relay is connected to one end of each.

Here, the battery cell 10 includes a negative terminal and a positive terminal, and means one physically separable independent cell. For example, one pouch-type lithium polymer cell may be regarded as a battery cell.

In addition, as another embodiment of the battery pack 1 shown in FIGS. 2 and 3 , the battery cells 10 included in the battery pack 1 include a plurality of batteries in which one or more battery cells are connected in series and/or in parallel. It can be a module. That is, it should be noted that the embodiment in which the battery module may be provided in the battery pack is not limited or excluded by the term battery cell and the embodiment shown in the drawings.

However, hereinafter, for convenience of explanation, it will be described that the battery cell 10, which is a unit cell, is included in the battery pack 1 . In addition, the number of the plurality of battery cells 10a, 10b, 10c, and 10d is not limited, but hereinafter, for convenience of description, four battery cells are provided.

The cell relay may be distinguished from the main relay 30 disposed on the main charge/discharge path of the battery pack 1 . For example, in the embodiment of FIG. 3 , a cell relay may be connected to a positive terminal of each of the plurality of battery cells 10a, 10b, 10c, and 10d. The position where the cell relay 20 is disposed is not limited by the embodiment of FIG. 3 , and the cell relay 20 may be connected to any one terminal side of the positive terminal or the negative terminal of the corresponding battery cell 10 . . However, unlike the embodiment of FIG. 3 , when the cell relay 20 is connected to the negative terminal side of the battery cell 10 , a plurality of for measuring voltages of the plurality of battery cells 10a , 10b , 10c and 10d Note that the connection points of the sensing lines SL1, SL2, SL3, SL4, and SL5 may be changed.

In addition, the plurality of battery cells 10a, 10b, 10c, and 10d may be configured to be connected in parallel with each other according to the operation state of the connected plurality of cell relays 20a, 20b, 20c, and 20d.

For example, in the embodiment of FIG. 3 , the plurality of battery cells 10a , 10b , 10c , and 10d may be disposed in parallel with each other. Accordingly, when all of the operating states of the plurality of cell relays 20a, 20b, 20c, and 20d are turned on, the plurality of battery cells 10a, 10b, 10c, and 10d may all be connected in parallel.

Referring to FIG. 1 , the battery management apparatus 100 according to an embodiment of the present invention may include a measurement unit 110 , a control unit 120 , and a storage unit 140 .

The measuring unit 110 may be configured to measure voltages and temperatures of the plurality of battery cells 10a, 10b, 10c, and 10d.

The measuring unit 110 may include a voltage measuring unit 110 configured to measure the voltage of the battery cell and a temperature measuring unit 120 configured to measure the temperature of the battery cell.

The voltage measuring unit 110 may measure the voltage of each of the plurality of battery cells 10a, 10b, 10c, and 10d through the plurality of sensing lines SL1, SL2, SL3, SL4, and SL5.

For example, in the embodiment of FIG. 3 , the voltage measuring unit 110 may measure the voltage of the first battery cell 10a through the first sensing line SL1 and the fifth sensing line SL5 . Also, the voltage measuring unit 110 may measure the voltage of the second battery cell 10b through the second sensing line SL2 and the fifth sensing line SL5 . Also, the voltage measuring unit 110 may measure the voltage of the third battery cell 10c through the third sensing line SL3 and the fifth sensing line SL5 . Also, the voltage measuring unit 110 may measure the voltage of the fourth battery cell 10d through the fourth sensing line SL4 and the fifth sensing line SL5 .

For example, in the embodiment of FIG. 3 , since the plurality of cell relays 20a, 20b, 20c, and 20d are connected only to the positive terminals of the plurality of battery cells 10a, 10b, 10c, and 10d, the fifth sensing line SL5 ) may be commonly connected to the negative terminals of the plurality of battery cells 10a, 10b, 10c, and 10d. However, the configuration of the sensing line connected to the voltage measuring unit 110 is not limited by the embodiment of FIG. 3 . That is, unlike the embodiment of FIG. 3 , when the location where the cell relay is disposed is changed, it should be noted that the number of sensing lines and the connection location may be changed correspondingly.

The temperature measuring unit 120 may measure the temperature of each of the plurality of battery cells 10a, 10b, 10c, and 10d through the plurality of sensing lines SL6, SL7, SL8, and SL9. For example, a temperature sensor generally used may be applied to the temperature measurement unit 120 . That is, the temperature measurement unit 120 measures the heat conducted through the plurality of sensing lines SL6, SL7, SL8, and SL9 to measure the temperature of each of the plurality of battery cells 10a, 10b, 10c, and 10d. can

For example, in the embodiment of FIG. 3 , the temperature measuring unit 120 may measure the temperature of the first battery cell 10a through the sixth sensing line SL6 . Also, the temperature measuring unit 120 may measure the temperature of the second battery cell 10b through the seventh sensing line SL7 . Also, the temperature measurement unit 120 may measure the temperature of the third battery cell 10c through the eighth sensing line SL8. Also, the temperature measuring unit 120 may measure the temperature of the fourth battery cell 10d through the ninth sensing line SL9.

The measurement unit 110 may be configured to output a plurality of measured voltage values and a plurality of temperature values.

Specifically, the measurement unit 110 may be configured to be connected to the control unit 120 by wire and/or wirelessly to transmit/receive signals to and from each other.

For example, in the embodiment of FIG. 3 , the measurement unit 110 may be electrically connected to the control unit 120 through a wired line. In addition, the measuring unit 110 includes a voltage value of each of the plurality of battery cells 10a, 10b, 10c, and 10d measured by the voltage measuring unit 110 and a plurality of battery cells 10a measured by the temperature measuring unit 120 . , 10b, 10c, 10d) may be output to the controller 120 through the wired line.

The control unit 120 may be configured to receive the plurality of voltage values and the plurality of temperature values from the measurement unit 110 .

Also, the controller 120 may be configured to determine a first cell having the highest voltage and a second cell having the lowest voltage among the plurality of battery cells 10a, 10b, 10c, and 10d.

Preferably, the control unit 120 may sort the plurality of voltage values received from the measurement unit 110 according to the voltage magnitude. In addition, the controller 120 may determine a battery cell having the largest voltage level as the first cell and determine the battery cell having the smallest voltage level as the second cell.

For example, the voltage of the first battery cell 10a is 4.3 [V], the voltage of the second battery cell 10b is 4.25 [V], the voltage of the third battery cell 10c is 4.2 [V], It is assumed that the voltage of the fourth battery cell 10d is 4.15 [V]. The controller 120 may determine the first battery cell 10a as the first cell and the fourth battery cell 10d as the second cell according to the voltage level.

The controller 120 may be configured to calculate a voltage difference between the first cell and the second cell.

For example, it is assumed that the first battery cell 10a is determined as the first cell and the fourth battery cell 10d is determined as the second cell as in the previous embodiment. The controller 120 may calculate the voltage difference between the first cell and the second cell as 0.15 [V] (4.3 [V] - 4.15 [V]).

The controller 120 may be configured to calculate an inrush current between the first cell and the second cell based on the calculated voltage difference and the plurality of temperature values.

Here, the inrush current between the first cell and the second cell means a current that can flow from the first cell to the second cell when the first cell and the second cell are connected in parallel. That is, the inrush current refers to an amount of current that can flow from the first cell to the second cell due to a potential difference between the first cell and the second cell.

The controller 120 may calculate a resistance value of the first cell in order to calculate the inrush current. That is, the controller 120 may be configured to calculate the resistance value of the first cell based on the temperature value of the first cell among the plurality of temperature values.

Specifically, the controller 120 may calculate the resistance values of the first cell and the second cell with reference to the temperature-resistance profile stored in the storage unit 140 . That is, the controller 120 may calculate the resistance value of the first cell by substituting the temperature value of the first cell into the temperature-resistance profile.

In addition, the controller 120 may be configured to calculate the inrush current based on the calculated resistance value and the calculated voltage difference.

Specifically, the controller 120 may calculate the inrush current between the first cell and the second cell based on the calculated resistance value of the first cell and the voltage difference between the first cell and the second cell. Here, the controller 120 may calculate the inrush current using Ohm's law.

The controller 120 may be configured to compare the calculated voltage difference with a voltage threshold.

Here, the voltage threshold may be a value set by the controller 120 . That is, the controller 120 may set the voltage threshold based on the calculated inrush current and the reference resistance value. In this case, the controller 120 may set the voltage threshold value from the calculated inrush current and the reference resistance value using Ohm's law.

Preferably, the reference resistance value is a combined resistance value of the plurality of battery cells 10a, 10b, 10c, and 10d, and may be a value set by the controller 120 . Details of the control unit 120 setting the reference resistance value will be described later.

When the calculated voltage difference is less than the voltage threshold, the controller 120 balances the plurality of battery cells 10a, 10b, 10c, and 10d based on a result of comparing the calculated inrush current with the current threshold. It can be configured to

First, when the voltage difference between the first cell and the second cell is less than the voltage threshold, the controller 120 may compare the calculated inrush current with the current threshold. Here, the current threshold value is a value preset by the controller 120 based on the expected number of driving of the plurality of cell relays 20a, 20b, 20c, and 20d. Specific details of setting the current threshold will be described later.

That is, the controller 120 controls the plurality of battery cells 10a, 10b, 10c, and 10d based on the voltage difference between the battery cell with the highest voltage (the first cell) and the battery cell with the lowest voltage (the second cell). It can be determined first whether balancing is necessary.

Further, when the calculated inrush current is less than the current threshold, the controller 120 may be configured to connect the plurality of battery cells 10a, 10b, 10c, and 10d to perform the balancing.

That is, when balancing of the plurality of battery cells 10a, 10b, 10c, and 10d is performed, the controller 120 controls the battery cell with the lowest voltage from the battery cell with the highest voltage (the first cell) (the second cell). It may be determined whether there is a possibility that the plurality of cell relays 20a, 20b, 20c, and 20d may be damaged by the inrush current according to the potential difference between them. Accordingly, when the calculated inrush current is less than the current threshold, the controller 120 may connect the plurality of battery cells 10a, 10b, 10c, and 10d to perform balancing.

For example, in the embodiment of FIG. 3 , the controller 120 is connected to the first cell relay 20a through the first control line CL1 and the second cell relay 20b through the second control line CL2 . can be connected with In addition, the controller 120 may be connected to the third cell relay 20c through the third control line CL3 and may be connected to the fourth cell relay 20d through the fourth control line CL4 .

And, when the calculated inrush current is less than the current threshold value, the controller 120 sends the first control line CL1 , the second control line CL2 , the third control line CL3 and the fourth control line CL4 to the By outputting the turn-on control signal, the operating states of the first cell relay 20a, the second cell relay 20b, the third cell relay 20c, and the fourth cell relay 20d are switched to the turn-on state. can do it

In this case, the first battery cell 10a , the second battery cell 10b , the third battery cell 10c , and the fourth battery cell 10d may be electrically connected in parallel to each other to perform balancing. That is, the control unit 120 converts the operation state of the plurality of cell relays 20a, 20b, 20c, and 20d to a turn-on state, so that between the plurality of battery cells 10a, 10b, 10c, and 10d It may be configured to perform charging and discharging.

Before balancing the plurality of battery cells 10a, 10b, 10c, and 10d, the battery management apparatus 100 according to an embodiment of the present invention primarily determines whether balancing is required based on a voltage difference between the battery cells. and secondarily, by determining whether damage may be applied to the cell relay in the balancing process, it is possible to prevent the cell relay from being damaged in the balancing process.

Also, since the battery management apparatus 100 connects a plurality of battery cells 10a, 10b, 10c, and 10d connected in parallel to each other to perform balancing, balancing between battery cells may be performed quickly.

On the other hand, the control unit 120 provided in the battery management apparatus 100 according to an embodiment of the present invention is a processor, ASIC (application-specific integrated circuit) known in the art to execute various control logic performed in the present invention. , other chipsets, logic circuits, registers, communication modems, data processing devices, and the like. Also, when the control logic is implemented in software, the controller 120 may be implemented as a set of program modules. In this case, the program module may be stored in the memory and executed by the controller 120 . The memory may be inside or outside the control unit 120 , and may be connected to the control unit 120 by various well-known means.

Also, the battery management apparatus 100 according to an embodiment of the present invention may further include a storage unit 140 . For example, the storage unit 140 may store programs and data necessary for the control unit 120 to balance the battery cells. That is, the storage unit 140 may store data necessary for each component of the battery management apparatus 100 to perform an operation and function, a program or data generated while an operation and a function are performed. The storage unit 140 is not particularly limited in its type as long as it is a known information storage means capable of writing, erasing, updating, and reading data. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, registers, and the like. Also, the storage unit 140 may store program codes in which processes executable by the control unit 120 are defined.

Hereinafter, the content in which the control unit 120 sets the reference resistance value will be described in detail.

The controller 120 may be configured to calculate the combined resistance values of the plurality of battery cells 10a, 10b, 10c, and 10d in consideration of the plurality of temperature values.

Preferably, the controller 120 may calculate a resistance value of each of the plurality of battery cells 10a, 10b, 10c, and 10d based on the temperature-resistance profile stored in the storage unit 140 . Specifically, the control unit 120 substitutes the voltage values of the plurality of battery cells 10a, 10b, 10c, and 10d received from the measurement unit 110 into the temperature-resistance profile, and the plurality of battery cells 10a, 10b, 10c, 10d) each resistance value can be calculated.

In addition, the controller 120 may calculate the combined resistance value in consideration of the connection relationship between the plurality of calculated resistance values and the plurality of battery cells 10a, 10b, 10c, and 10d.

For example, in the embodiment of FIG. 3 , the plurality of battery cells 10a , 10b , 10c , and 10d are all connected in parallel. Accordingly, the controller 120 may calculate the combined resistance value according to a formula for calculating the combined resistance of battery cells connected in parallel. Specifically, the controller 120 may calculate the combined resistance value by inversely calculating the sum of admittances of the resistors of the plurality of battery cells 10a, 10b, 10c, and 10d.

The controller 120 may be configured to preset the calculated combined resistance value as the reference resistance value.

Thereafter, the controller 120 may set the voltage threshold by multiplying the set reference resistance value and the calculated inrush current. Also, the controller 120 may determine whether balancing of the plurality of battery cells 10a, 10b, 10c, and 10d is required by comparing the voltage difference between the first cell and the second cell with the voltage threshold.

The battery management apparatus 100 according to an embodiment of the present invention may not set the voltage threshold to a fixed value, but may set the voltage threshold by reflecting the current state of the plurality of battery cells 10a, 10b, 10c, and 10d. Accordingly, the battery management apparatus 100 may determine whether balancing is required by reflecting current states of the plurality of battery cells 10a, 10b, 10c, and 10d.

For example, if it is determined whether balancing is required using a fixed voltage threshold, even if balancing is not required according to the current state of the plurality of battery cells 10a, 10b, 10c, 10d, between the first cell and the second cell Balancing may be performed unnecessarily because the voltage difference is greater than or equal to a fixed voltage threshold. In addition, although balancing is required according to the current state of the plurality of battery cells 10a, 10b, 10c, and 10d, balancing is unnecessary because the voltage difference between the first cell and the second cell is less than a fixed voltage threshold. can be performed.

Therefore, since the battery management apparatus 100 determines the voltage threshold as a criterion for determining whether balancing is required by reflecting the current state of the plurality of battery cells 10a, 10b, 10c, and 10d, the plurality of battery cells ( Balancing may be adaptively performed in each state of 10a, 10b, 10c, and 10d).

More preferably, the controller 120 may set the combined resistance of the battery pack 1 including the plurality of battery cells 10a, 10b, 10c, and 10d as the reference resistance value.

For example, in the embodiment of FIG. 3 , the battery pack 1 includes a plurality of battery cells 10a, 10b, 10c, and 10d, as well as a plurality of cell relays 20a, 20b, 20c, 20d, and a main relay 30. may be included.

The controller 120 may calculate a combined resistance according to each configuration included in the battery pack 1 , and set the calculated combined resistance as the reference resistance value. Here, the resistance value for each component included in the battery pack 1 may be previously stored in the storage unit 140 .

That is, in the battery management apparatus 100 according to an embodiment of the present invention, in the balancing process of the plurality of battery cells 10a, 10b, 10c, and 10d, each configuration included in the battery pack 1 as well as the cell relay is applied. It has the advantage of being able to prevent damage in advance.

Hereinafter, the current threshold value will be described in detail.

The current threshold value may be a value preset by the controller 120 based on the expected number of driving of the plurality of cell relays 20a, 20b, 20c, and 20d. That is, the control unit 120 may be configured to preset the current threshold based on a preset number of expected driving for each of the plurality of cell relays 20a, 20b, 20c, and 20d.

The expected number of driving times and current threshold values of the plurality of cell relays 20a, 20b, 20c, and 20d will be described in detail with reference to FIG. 4 .

4 is a graph showing an example of the expected number of driving of the cell relay according to the current threshold value.

Referring to FIG. 4 , when the current applied to the cell relay is less than 300 [mA], the expected number of driving of the cell relay may exceed 100,000 times. And, when the current applied to the cell relay is 300 [mA], the expected number of driving of the cell relay may be 100,000 times. In addition, when the current applied to the cell relay is 400 [mA], the expected number of driving of the cell relay may be about 3,000 times.

For example, in the embodiment of FIG. 3 , it is assumed that the expected number of driving of the plurality of cell relays 20a , 20b , 20c and 20d is set to 100,000 circuits. The controller 120 may set the current threshold value to 300 [mA] with reference to the graph of FIG. 4 .

Thereafter, the controller 120 may determine whether to perform balancing by comparing the set current threshold value with the calculated magnitude of the inrush current.

That is, the battery management apparatus 100 according to an embodiment of the present invention does not perform balancing based only on the voltage or capacity difference between the plurality of battery cells 10a , 10b , 10c , and 10d, but does not perform balancing, and a rush generated during the balancing process. In consideration of damage to the cell relay due to current, it may be determined whether balancing is performed. Therefore, according to the battery management apparatus 100, the plurality of cell relays 20a, 20b, 20c, and 20d are prevented from being damaged in the process of balancing the plurality of battery cells 10a, 10b, 10c, and 10d. , the expected number of driving of the plurality of cell relays 20a, 20b, 20c, and 20d may be guaranteed.

The battery management apparatus 100 according to another embodiment of the present invention is connected to the plurality of battery cells 10a, 10b, 10c, and 10d, and according to the control of the controller 120, the plurality of battery cells 10a, It may further include a charging unit 130 configured to charge each of 10b, 10c, and 10d).

For example, in the embodiment of FIG. 3 , the charging unit 130 may be connected to the plurality of battery cells 10a , 10b , 10c and 10d in parallel. That is, the charging unit 130 may be connected in parallel to the main charging/discharging path of the battery pack 1 .

As another example, unlike the embodiment of FIG. 3 , the charging unit 130 may be connected to the positive terminal P+ and the negative terminal of the battery pack 1 . That is, the charging unit 130 may be a charging unit connected to the electrode terminal of the battery pack 1 to charge the battery cells.

The control unit 120 may be configured to charge the second cell through the charging unit 130 when the calculated inrush current is equal to or greater than the current threshold value.

As described above, when the calculated inrush current is less than the current threshold value, the controller 120 controls the operation state of the plurality of cell relays 20a, 20b, 20c, and 20d to the turn-on state, so that the plurality of battery cells (10a, 10b, 10c, 10d) were allowed to be balanced.

On the other hand, if the calculated inrush current is equal to or greater than the current threshold, damage may be applied to the plurality of cell relays 20a, 20b, 20c, and 20d in the balancing process of the plurality of battery cells 10a, 10b, 10c, and 10d. Therefore, the controller 120 does not control the operation state of the plurality of cell relays 20a, 20b, 20c, and 20d to the turn-off state.

In this case, the controller 120 may switch the operating states of the cell relay connected to the second cell and the main relay 30 to the turn-on state.

For example, in the embodiment of FIG. 3 , it is assumed that the second cell is the fourth battery cell 10d. The controller 120 may output a turn-on control signal through the fourth control line CL4 to convert the operation state of the fourth cell relay 20d connected to the fourth battery cell 10d to the turn-on state. have. In addition, the controller 120 may output a turn-on control signal through the fifth control line CL5 to convert the operation state of the main relay 30 to the turn-on state.

That is, the controller 120 may control the operating states of the cell relay and the main relay 30 connected to the second cell to be turned-on, so that the second cell and the charging unit 130 are connected. In this case, the second cell may be charged by the charging unit 130 .

Preferably, the controller 120 may be configured to select a voltage value closest to the voltage of the second cell from among the plurality of voltage values.

For example, as in the previous embodiment, the voltage of the first battery cell 10a is 4.3 [V], the voltage of the second battery cell 10b is 4.25 [V], and the voltage of the third battery cell 10c is It is assumed that the voltage is 4.2 [V] and the voltage of the fourth battery cell 10d is 4.15 [V]. Here, the second cell is the fourth battery cell 10d. The controller 120 may select the voltage (4.2 [V]) of the third battery cell 10c as a voltage value closest to the voltage (4.15 [V]) of the second cell.

In addition, the control unit 120 may be configured to charge the second cell through the charging unit 130 only until the voltage of the second cell reaches a selected voltage value.

Thereafter, when the voltage of the second cell reaches the selected voltage value, the controller 120 may be configured to recalculate the inrush current.

For example, with reference to the previous embodiment, it is assumed that the voltage of the second cell is charged from 4.15 [V] to 4.2 [V]. The control unit 120 calculates a voltage difference (1 [V]) between the voltage of the first cell (4.3 [V]) and the voltage of the charged second cell (4.2 [V]), and the calculated voltage difference (1 [V]) V]) and the inrush current may be recalculated based on the resistance value of the first cell.

In addition, the controller 120 may be configured to reset the voltage threshold based on the recalculated inrush current.

Specifically, the controller 120 may reset the voltage threshold by multiplying the recalculated inrush current by the set reference resistance value.

Thereafter, the controller 120 is configured to compare the reset voltage threshold with the voltage difference between the first cell and the second cell, and based on a result of comparing the recalculated inrush current with the current threshold, the plurality of may be configured to balance the battery cells 10a, 10b, 10c, and 10d of

For example, if the voltage difference between the first cell and the charged second cell is equal to or greater than the reset voltage threshold value, the controller 120 may compare the recalculated inrush current with the current threshold value. And, when the recalculated inrush current is less than the current threshold value, the controller 120 controls the operation state of the plurality of cell relays 20a, 20b, 20c, and 20d to a turn-on state, whereby a plurality of battery cells (10a, 10b, 10c, 10d) can be balanced.

That is, in the battery management apparatus 100 according to an embodiment of the present invention, if the inrush current is equal to or greater than the current threshold value, the plurality of cell relays 20a, 20b, 20c, and 20d may be damaged during the balancing process, so that the charging unit The second cell may be charged through 130 . In this case, since the second cell is charged, the recalculated inrush current may be smaller than the initially calculated inrush current. Accordingly, the battery management apparatus 100 performs balancing of the plurality of battery cells 10a, 10b, 10c, and 10d when the inrush current based on the potential difference between the first cell and the second cell is less than the current threshold value, thereby balancing Accordingly, it is possible to prevent damage to the plurality of cell relays 20a, 20b, 20c, and 20d.

The battery management apparatus 100 according to the present invention may be applied to a Battery Management System (BMS). That is, the BMS according to the present invention may include the above-described battery management apparatus 100 . In this configuration, at least some of each component of the battery management apparatus 100 may be implemented by supplementing or adding functions of the configuration included in the conventional BMS. For example, the measurement unit 110 , the control unit 120 , the charging unit 130 , and the storage unit 140 of the battery management apparatus 100 may be implemented as components of the BMS.

Also, the battery management apparatus 100 according to the present invention may be provided in the battery pack 1 . For example, as shown in FIGS. 2 and 3 , the battery pack 1 includes a plurality of battery cells 10a, 10b, 10c, and 10d, a plurality of cell relays 20a, 20b, 20c, 20d, and a main relay. 30 and the battery management device 100 may be included. In addition, the battery pack 1 may further include electronic components (relays, fuses, etc.) and a case.

5 is a diagram schematically illustrating a battery management method according to another embodiment of the present invention.

The battery management method may be performed by the battery management apparatus 100 according to an embodiment of the present invention.

5 , the battery management method according to another embodiment of the present invention includes a voltage and temperature measurement step (S100), a cell determination step (S200), a voltage difference calculation step (S300), an inrush current calculation step (S400), It may include a voltage comparison step (S500) and a cell balancing step (S600).

The temperature measuring step is a step of measuring the voltage and temperature of the plurality of battery cells 10a, 10b, 10c, and 10d, and may be performed by the measuring unit 110 .

For example, in the exemplary embodiment of FIG. 3 , the measurement unit 110 may include a plurality of battery cells 10a, 10b, and 10c through a plurality of sensing lines SL1, SL2, SL3, SL4, SL5, SL6, SL7, SL8, and SL9. , 10d) voltage and temperature can be measured.

In addition, the measurement unit 110 may transmit a plurality of measured voltage values and a plurality of temperature values to the control unit 120 .

The cell determining step ( S200 ) is a step of determining a first cell having the highest voltage and a second cell having the lowest voltage among the plurality of battery cells 10a , 10b , 10c and 10d , and is performed by the controller 120 . can be

The controller 120 may align the plurality of voltage values received from the measurement unit 110 , determine a battery cell having the largest voltage value as the first cell, and determine the battery cell having the smallest voltage value as the second cell.

For example, as in the previous embodiment, in the embodiment of FIG. 3 , the voltage of the first battery cell 10a is 4.3 [V], the voltage of the second battery cell 10b is 4.25 [V], and the third battery It is assumed that the voltage of the cell 10c is 4.2 [V] and the voltage of the fourth battery cell 10d is 4.15 [V].

The controller 120 may determine the first battery cell 10a as the first cell and determine the fourth battery cell 10d as the second cell.

The voltage difference calculating step S300 is a step of calculating the voltage difference between the first cell and the second cell determined in the cell determining step S200 , and may be performed by the controller 120 .

For example, in the previous embodiment, the control unit 120 calculates the difference between the voltage (4.3 [V]) of the first cell and the voltage (4.15 [V]) of the second cell, the voltage difference (0.15 [V]) can be calculated.

The inrush current calculation step ( S400 ) is a step of calculating the inrush current between the first cell and the second cell based on the calculated voltage difference and the plurality of measured temperature values, and may be performed by the controller 120 . .

Specifically, the control unit 120 may calculate the temperature value of the first cell among the plurality of temperature values received from the measurement unit 110 . In this case, the controller 120 may calculate the resistance value of the first cell by substituting the temperature value of the first cell into the temperature-resistance profile stored in the storage unit 140 .

Then, the controller 120 may calculate the inrush current by multiplying the calculated voltage difference between the first cell and the second cell by the calculated resistance value of the first cell.

The voltage comparison step S500 is a step of comparing the calculated voltage difference with a voltage threshold, and may be performed by the controller 120 .

Here, the voltage threshold may be set as a product of the inrush current calculated by the controller 120 and the reference resistance value set by the controller 120 .

In the cell balancing step (S600), if the calculated voltage difference is less than the voltage threshold as a result of the comparison in the voltage comparison step (S500), based on the result of comparing the calculated inrush current and the current threshold value, the plurality of The step of balancing the battery cells 10a, 10b, 10c, and 10d may be performed by the controller 120 .

The voltage comparison step S500 and the cell balancing step S600 will be described in detail with reference to FIG. 6 .

6 is a diagram illustrating in more detail a voltage comparison step (S500) and a cell balancing step (S600) in a battery management method according to another embodiment of the present invention.

Referring to FIG. 6 , the cell balancing step S600 may include a current comparing step S610 , a plurality of battery cell balancing steps S620 , and a second cell charging step S630 .

If the voltage difference calculated in the voltage comparison step S500 is less than the voltage threshold, balancing may not be performed. That is, in this case, the voltage difference between the plurality of battery cells 10a, 10b, 10c, and 10d may not be large enough to require balancing.

If the voltage difference calculated in the voltage comparison step S500 is equal to or greater than the voltage threshold, the current comparison step S610 may be performed.

The current comparison step S610 is a step of comparing the calculated inrush current with a current threshold value, and may be performed by the controller 120 .

Here, the current threshold value may be a current value preset according to the expected number of driving of the plurality of cell relays 20a, 20b, 20c, and 20d.

If the inrush current calculated in the current comparison step S610 is less than the current threshold value, a plurality of battery cell balancing steps S620 may be performed.

Balancing the plurality of battery cells ( S620 ) is a step in which balancing is performed by connecting the plurality of battery cells 10a , 10b , 10c , and 10d in parallel, and may be performed by the controller 120 .

For example, in the embodiment of FIG. 3 , the controller 120 turns the operating states of the first cell relay 20a, the second cell relay 20b, the third cell relay 20c, and the fourth cell relay 20d By controlling the -on state, the first battery cell 10a, the second battery cell 10b, the third battery cell 10c, and the fourth battery cell 10d may be connected in parallel.

In this case, the plurality of battery cells 10a, 10b, 10c, and 10d are caused by a potential difference between the first battery cell 10a, the second battery cell 10b, the third battery cell 10c, and the fourth battery cell 10d. ) performs charging and discharging and can be balanced.

When the inrush current calculated in the current comparison step S610 is equal to or greater than the current threshold value, the second cell charging step S630 may be performed.

The second cell charging step ( S630 ) is a step of charging the second cell and may be performed by the charging unit 130 .

Specifically, if the calculated inrush current is equal to or greater than the current threshold value, the controller 120 indicates that damage will be applied to the plurality of cell relays 20a, 20b, 20c, and 20d when the plurality of battery cell balancing steps S620 are performed. can judge Accordingly, the controller 120 may operate the charging unit 130 to charge the second cell in order to minimize the inrush current.

In this case, the controller 120 may control the operating states of the cell relay and the main relay 30 corresponding to the second cell to be turned-on so that the second cell is charged through the charging unit 130 . Through the relay control of the controller 120 , the charging unit 130 may charge the second cell.

Thereafter, when the voltage of the second cell is charged and reaches the voltage of the closest battery cell, the voltage difference calculating step S300 may be performed again.

For example, as in the previous embodiment, in the embodiment of FIG. 3 , the voltage of the first battery cell 10a is 4.3 [V], the voltage of the second battery cell 10b is 4.25 [V], and the third battery It is assumed that the voltage of the cell 10c is 4.2 [V], the voltage of the fourth battery cell 10d is 4.15 [V], and it is determined that the second cell is the fourth battery cell 10d. The charging unit 130 may charge the voltage of the second cell up to the voltage of the third battery cell 10c (4.2 [V]).

Then, as the voltage difference calculating step S300 is re-performed, the voltage difference between the first cell and the charged second cell may be recalculated. In addition, the inrush current may be recalculated by the recalculated voltage difference, and the voltage threshold may be reset.

As such, the battery management method according to another embodiment of the present invention prevents the plurality of cell relays 20a, 20b, 20c, and 20d from being damaged in the balancing process of the plurality of battery cells 10a, 10b, 10c, and 10d. There are advantages that can be

The embodiment of the present invention described above is not implemented only through the apparatus and method, and may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium in which the program is recorded. The implementation can be easily implemented by those skilled in the art to which the present invention pertains from the description of the above-described embodiments.

In the above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto and will be described below with the technical idea of the present invention by those of ordinary skill in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims.

In addition, since the present invention described above can be various substitutions, modifications and changes within the scope that does not depart from the technical spirit of the present invention for those of ordinary skill in the art to which the present invention pertains, the above-described embodiments and attachments It is not limited by the illustrated drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications may be made.

1: battery pack
10: battery cell
20: cell relay
30: main relay
100: battery management device
110: measurement unit
120: control unit
130: charging unit
140: storage

Claims (13)

a measuring unit configured to measure voltages and temperatures of a plurality of battery cells and output a plurality of measured voltage values and a plurality of temperature values; and
receiving the plurality of voltage values and the plurality of temperature values from the measuring unit, determining a first cell having the highest voltage and a second cell having the lowest voltage among the plurality of battery cells, and determining the first cell and the Calculate the voltage difference between the second cells, calculate the inrush current between the first cell and the second cell based on the calculated voltage difference and the plurality of temperature values, and compare the calculated voltage difference with a voltage threshold and a controller configured to balance the plurality of battery cells based on a result of comparing the calculated inrush current and the current threshold when the calculated voltage difference is less than the voltage threshold. Device.
According to claim 1,
The plurality of battery cells,
A battery management device, characterized in that a cell relay is connected to one end of each, and configured to be connected in parallel with each other according to an operation state of a plurality of connected cell relays.
According to claim 1,
The control unit is
and calculating the resistance value of the first cell based on the temperature value of the first cell among the plurality of temperature values, and calculating the inrush current based on the calculated resistance value and the calculated voltage difference. a battery management device.
According to claim 1,
The control unit is
and set the voltage threshold based on the calculated inrush current and the reference resistance value.
5. The method of claim 4,
The control unit is
and calculating the combined resistance values of the plurality of battery cells in consideration of the plurality of temperature values, and presetting the calculated combined resistance values as the reference resistance values.
3. The method of claim 2,
The control unit is
The battery management device, characterized in that configured to preset the current threshold based on a preset number of expected driving for each of the plurality of cell relays.
3. The method of claim 2,
The control unit is
When the calculated inrush current is less than the current threshold value, the battery management apparatus characterized in that the balancing is performed by connecting the plurality of battery cells.
8. The method of claim 7,
The control unit is
The battery management apparatus according to claim 1, wherein the operation state of the plurality of cell relays is switched to a turn-on state to perform charging and discharging between the plurality of battery cells.
According to claim 1,
Further comprising a charging unit connected to the plurality of battery cells and configured to charge each of the plurality of battery cells under the control of the control unit,
The control unit is
When the calculated inrush current is equal to or greater than the current threshold value, the battery management device is configured to charge the second cell through the charging unit.
10. The method of claim 9,
The control unit is
Selecting a voltage value closest to the voltage of the second cell from among the plurality of voltage values, and charging the second cell through the charging unit only until the voltage of the second cell reaches the selected voltage value Characterized by a battery management device.
11. The method of claim 10,
The control unit is
When the voltage of the second cell reaches the selected voltage value, the inrush current is recalculated, the voltage threshold is reset based on the recalculated inrush current, and the reset voltage threshold value is combined with the first cell and balancing the plurality of battery cells based on a result of comparing the voltage difference between the second cells and a result of comparing the recalculated inrush current with the current threshold.
12. A battery pack comprising the battery management device according to any one of claims 1 to 11.
a voltage and temperature measuring step of measuring voltages and temperatures of a plurality of battery cells;
a cell determining step of determining a first cell having the highest voltage and a second cell having the lowest voltage among the plurality of battery cells;
a voltage difference calculating step of calculating a voltage difference between the first cell and the second cell determined in the cell determining step;
an inrush current calculation step of calculating a rush current between the first cell and the second cell based on the calculated voltage difference and the plurality of measured temperature values;
a voltage comparison step of comparing the calculated voltage difference with a voltage threshold value; and
As a result of the comparison in the voltage comparison step, if the calculated voltage difference is less than the voltage threshold, a cell balancing step of balancing the plurality of battery cells based on a result of comparing the calculated inrush current with the current threshold includes a cell balancing step Battery management method, characterized in that configured to.

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