KR101958277B1 - System and Method for Determining Characteristic of Battery Cell - Google Patents

Abstract

The present invention relates to a system and a method for differentiating a characteristic of a battery cell. According to the present invention, the system comprises: a plurality of detailed item capacity conditions classified in accordance with the steps of discharging, charging, and SOC of the battery cell, a plurality of detailed item capacity information corresponding to the plurality of detailed item open-voltage conditions, and a detailed item calculating part for obtaining each of a plurality of detailed item open-voltage information; and a final calculation part for calculating a final capacity characteristic information of the battery cell by assigning a predetermined weight to each of the obtained plurality of detailed cell capacity information, and calculating a final open-voltage characteristic information of the battery cell by assigning a predetermined weight to each of the obtained plurality of detailed item open-voltage information. According to the present invention, characteristics of a battery cell can be accurately determined by using a plurality of detailed capacity information and a plurality of open-voltage information in accordance with the steps of discharging, charging, and SOC of the battery cell.

Description

TECHNICAL FIELD [0001] The present invention relates to a system and method for determining characteristics of a battery cell,

The present invention relates to a system and method for determining characteristics of a battery cell, and more particularly, to a system and method for determining a characteristic of a battery cell, which determines the characteristics of the battery cell by taking into consideration both discharging and charging of the battery cell, .

In general, a large-capacity battery pack capable of generating a large amount of electric power can be used for driving an electric vehicle, an energy storage device, a satellite, a hybrid vehicle or an electric motorcycle, Battery cells may be connected in series and in parallel.

These battery packs have different charging times for different battery cells due to various use environments and internal resistance, and therefore, differences may occur in charge capacity during the same time. The battery pack may aging as the battery is repeatedly charged or discharged, and aging may proceed faster due to voltage imbalance or minute capacity imbalance.

In this way, in order to minimize the voltage unbalance and the minute capacity imbalance, conventionally, the characteristics of the battery cell are discriminated by using the discharging capacity and the internal resistance (open voltage), and the battery cells having similar characteristics are combined, So that the battery pack can be stably charged and discharged in series and in parallel. That is, battery cells having similar discharge capacities are classified into a first order and a battery cell grading method in which an internal resistance of a first classified battery cell is measured.

However, in the conventional method as described above, the characteristics of the battery cell can not be accurately discriminated because the battery cell is distinguished only by the information of the discharge capacity and the internal resistance without reflecting all the different electrical / chemical characteristics of the battery cell .

Therefore, a method for determining the characteristics of the battery cell with higher accuracy and reliability has become necessary.

Korean Patent Laid-Open Publication No. 2013-0123851 (Published Nov. 13, 2013)

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a battery cell capable of accurately determining characteristics of a battery cell using a plurality of capacity information and a plurality of open-circuit voltage information obtained in detail according to steps of discharging, And to provide a system and a method for distinguishing characteristics of the apparatus.

Further, the present invention includes other objects that can be achieved from the construction of the present invention described later, in addition to the objects explicitly mentioned.

According to an aspect of the present invention, there is provided a system for determining a characteristic of a battery cell, the system comprising: a plurality of detailed item capacity conditions classified according to a discharge, charge, and SOC of a battery cell; A detailed item calculating unit for obtaining a plurality of detailed item capacity information and a plurality of detailed item open-circuit voltage information corresponding to a voltage condition, and a weighting unit for giving a predetermined weight to each of the obtained plurality of detailed item capacity information, And a final calculation unit calculating capacity characteristic information and calculating a final open-circuit voltage characteristic information of the battery cell by giving a predetermined weight to each of the plurality of detailed open-circuit voltage information obtained.

Wherein the detailed item calculating unit obtains the detailed item capacity information using the voltage or current of the battery cell measured through the measuring unit under the detailed item capacity condition , The detail item open-circuit voltage information may be obtained by using the voltage or current of the battery cell measured through the measurement unit under the detailed-item open-circuit voltage condition.

Wherein the final calculation unit calculates the final capacity characteristic information of the battery cell by summing all of the plurality of capacity information calculated by giving a predetermined weight to each of the obtained plurality of detailed capacity information, It is possible to calculate the final open-circuit voltage characteristic information of the battery cell by summing all of the calculated plurality of open-circuit voltage information by assigning predetermined weights to each of the voltage information.

The total sum of the predetermined weights for each of the plurality of detailed item capacity information may have a value larger than a total sum of predetermined weights for each of the plurality of detailed item open-circuit voltage information.

The plurality of detailed item capacity conditions may include a discharge after the discharge (CC), a discharge after the charge (CC / CV), a discharge according to the SOC, or a combination of the discharge and the charge.

Wherein the plurality of sub-item open-circuit voltage conditions include a discharge (CC) and a post-rest state, a charge (CC / CV), and a post-rest state discharge, charge according to the SOC, or a combination of the discharge and the charge can do.

And a determination unit for determining characteristics of the battery cell using the calculated final capacity characteristic information of the battery cell and the calculated final open-circuit voltage characteristic information of the battery cell.

Meanwhile, a method of determining characteristics of a battery cell according to an embodiment of the present invention includes a plurality of detailed item capacity conditions classified in detail according to discharge, charging, and SOC of a battery cell, and a plurality Calculating a final capacity characteristic information of the battery cell by assigning a predetermined weight to each of the obtained plurality of detailed capacity information, And calculating a final open-circuit voltage characteristic information of the battery cell by giving a predetermined weight to each of the plurality of detailed-item open-circuit voltage information.

And measuring a voltage or a current of the battery cell, wherein the plurality of detailed item capacity conditions and the plurality of detailed item open-circuit voltage conditions corresponding to the details of the discharge, charge, and SOC stages of the battery cell The step of obtaining the plurality of detailed item capacity information and the plurality of detailed item open-circuit voltage information may include obtaining the plurality of detailed item capacity information using the voltage or the current of the battery cell measured in each of the plurality of detailed item capacity conditions, The plurality of detailed item open-circuit voltage information may be obtained by using the voltage or current of the battery cell measured in each of the plurality of detailed-item open-circuit voltage conditions.

Calculating a final capacity characteristic information of the battery cell by giving a predetermined weight to each of the obtained plurality of detailed cell capacities and assigning a predetermined weight to each of the plurality of detailed cell open- Calculating final capacity characteristic information of the battery cell by summing all of the plurality of capacity information calculated by applying predetermined weights to each of the obtained plurality of detailed capacity information, The final open-circuit voltage characteristic information of the battery cell can be calculated by summing all the plurality of calculated open-circuit voltage information by assigning predetermined weights to each of the plurality of detailed-item open-circuit voltage information obtained.

The total sum of the predetermined weights for each of the plurality of detailed item capacity information may have a value larger than a total sum of predetermined weights for each of the plurality of detailed item open-circuit voltage information.

The plurality of detailed item capacity conditions may include a discharge after the discharge (CC), a discharge after the charge (CC / CV), a discharge according to the SOC, or a combination of the discharge and the charge.

Wherein the plurality of sub-item open-circuit voltage conditions include a discharge (CC) and a post-rest state, a charge (CC / CV), and a post-rest state discharge, charge according to the SOC, or a combination of the discharge and the charge can do.

And determining the characteristics of the battery cell using the calculated final capacity characteristic information of the battery cell and the calculated final open-circuit voltage characteristic information of the battery cell.

As described above, according to the system and method for determining characteristics of a battery cell according to an embodiment of the present invention, when a plurality of detailed capacity information and a plurality of open-circuit voltage information are used according to the steps of discharging, charging, and SOC of a battery cell, The characteristics of the battery cell can be accurately discriminated because all of the different electrical / chemical characteristics of the battery cell are reflected.

Thus, there is an advantage that a battery pack of a serial and parallel combination capable of stably charging and discharging can be constructed.

On the other hand, the effects of the present invention are not limited to those described above, and other effects that can be derived from the constitution of the present invention described below are also included in the effects of the present invention.

1 is a block diagram of a system for determining the characteristics of a battery cell according to an embodiment of the present invention.
FIG. 2 is an exemplary diagram showing a plurality of detailed item capacity conditions, a plurality of detailed item open-circuit voltage conditions, and a weight given thereto according to an embodiment of the present invention.
3 is a flowchart illustrating a process of determining characteristics of a battery cell according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

1 is a block diagram of a system for determining the characteristics of a battery cell according to an embodiment of the present invention.

1, the battery cell characteristic determining system 1 includes a measuring unit 100, a detailed item calculating unit 200, a final calculating unit 300, and a determining unit 400.

A battery cell is a basic unit of a battery pack that can be used by charging or discharging electric energy, and can be formed using an anode, a cathode, a separator, an electrolyte, or the like. The battery cell may include a rechargeable secondary battery, such as a nickel-cadmium battery, a lead-acid battery, a nickel-metal hydride battery (NiMH), a lithium ion battery ) Or a lithium polymer battery (Lithium Polymer Battery).

The measurement unit 100 may measure the voltage or current of the battery cell. The measuring unit 100 may include a voltage measuring unit to measure a voltage of the battery cell or a Hall sensor or a shunt resistance to measure an amount of current output to the battery cell.

The detailed item calculation unit 200 calculates a detailed item capacity condition based on a plurality of detailed item capacity conditions and a plurality of detailed items corresponding to a plurality of detailed item open-circuit voltage conditions, which are classified in detail according to the steps of discharging, charging, and SOC (State Of Charge) Capacity information and a plurality of detailed item open-circuit voltage information, respectively. The capacity information of the battery cell is obtained not only in the case of discharging but also in a plurality of detailed item capacity conditions which are divided in detail according to the steps of charge and SOC in addition to discharge so that the characteristics of the battery cell can be accurately grasped . When the capacity information for discriminating the battery cell is secured, the open voltage information measured after the application of the rest period in the charging and discharging can be reflected in the determination of the battery cell.

Here, the plurality of detailed item capacity conditions may include a case of after discharging (CC), a case of after charging (CC / CV), a case of discharging according to the SOC, a case of charging or discharging and charging. The plurality of sub-item open-circuit voltage conditions may include discharging (CC) and after-dormancy, charging (CC / CV) and after-dormancy, discharging according to the step of SOC, charging, or combination of discharging and charging .

FIG. 2 illustrates an exemplary view showing a plurality of sub-item capacity conditions, a plurality of sub-item open-circuit voltage conditions, and a weight given thereto according to an embodiment of the present invention.

Referring to FIG. 2, for example, the discharge capacity CC may be detailed capacity information corresponding to a detailed item capacity condition indicating a state after discharge, and may be capacity information of the battery cell obtained after discharging the battery cell. The charging capacity CC is a detailed capacity condition indicating the case after the charging (CC), and may be the capacity information of the battery cell obtained after charging the battery cell by the constant current method. The charge capacity CV is a detail item capacity condition indicating the case after the charge (CV), and may be the capacity information of the battery cell obtained after the battery cell is charged by the constant voltage method. SOC (CC) _1 to SOC (CC) _4 The minute capacity is the capacity information measured after discharge, charge, or combination of discharge and charge according to SOC of 4 stages. SOC (CC) _ 1 discharge discharges to SOC 0 ~ 25% SOC (CC) _2 discharge is capacity information measured after SOC 25% ~ 50% discharge, SOC (CC) _ 3 discharge is capacity information after SOC 50% ~ 75% discharge, SOC CC) _4 discharge shows capacity information measured after discharging to SOC 75% ~ 100%.

The detailed item open-circuit voltage information corresponding to the discharge (CC) and the after-sleep state represents the open-circuit voltage information measured after discharging the battery cell and applying the predetermined idle period, and corresponds to the charge (CC / CV) The detailed item open-circuit voltage information represents the open-circuit voltage information measured after charging the battery cell and applying a predetermined rest period. SOC (CC) _1 to SOC (CC) _4 The microcavity is the open voltage information measured after discharging, charging, or combination of discharging and charging according to SOC of 4 stages. SOC (CC) _ 1 discharging is SOC 0 ~ 25% SOC (CC) _2 discharge is SOC (CC) _3 discharge, SOC (CC) _3 discharge is SOC (open circuit voltage) measured after discharging from 25% to 50% Information, and SOC (CC) _4 discharge indicate open voltage information measured after SOC 75% ~ 100% discharge.

On the other hand, the detailed item capacity condition and the detailed item open-circuit voltage condition are not limited to the above-described conditions, and any conditions that can reflect the different electric / chemical characteristics of the battery cell are possible.

As described above, the detailed item calculating unit 200 obtains a plurality of detailed item capacity information using the voltage or current of the battery cell measured through the measuring unit 100 under a plurality of detailed item capacity conditions, A plurality of detailed item open-circuit voltage information can be obtained using the voltage or current of the battery cell measured through the measuring unit 100 under the open-circuit voltage condition.

The final calculation unit 300 calculates a final capacity characteristic information of the battery cell by giving a predetermined weight to each of the obtained plurality of detailed capacity information, and assigns a predetermined weight to each of the obtained plurality of detailed item open-circuit voltage information So that the final open-circuit voltage characteristic information of the battery cell can be calculated.

More specifically, the final calculation unit 300 calculates the final capacity characteristic information of the battery cell by summing all the plurality of calculated capacity information by assigning predetermined weights to each of the obtained plurality of detailed item capacity information, The final open-circuit voltage characteristic information of the battery cell can be calculated by summing all the plurality of calculated open-circuit voltage information by assigning predetermined weights to the detailed-item open-circuit voltage information of the battery cell.

With reference to FIG. 2, for example, a weight that can be given to each of the plurality of detailed item capacity information is predetermined, and a weight that can be given to each of the plurality of detailed item open-circuit voltage information may be predetermined. Then, the final calculation unit 300 can calculate a plurality of pieces of capacity information by assigning weights to the plurality of pieces of detailed capacity information obtained through the detailed item calculation unit 200, The final capacity characteristic information of the cell can be calculated. The final calculation unit 300 can calculate a plurality of open-circuit voltage information by assigning weights to a plurality of detailed-item open-circuit voltage information obtained through the detailed-item calculation unit 200, and outputs the calculated plurality of open- So that the final open-circuit voltage characteristic information of the battery cell can be calculated.

In this case, the total sum of the predetermined weights for each of the plurality of detailed item capacity information may have a value larger than a total sum of predetermined weights for each of the plurality of detailed item open-circuit voltage information. In FIG. 2, the sum of predetermined weights for each of the plurality of detailed item capacity information is 0.8, and the sum of predetermined weights for each of the plurality of detailed item open-circuit voltage information may be 0.2, The reason why the sum of the weights determined in advance for each of the plurality of detailed item open-circuit voltage information is higher than the total sum of the predetermined weights for each of the plurality of detailed item open-circuit voltage information is that the characteristics of the battery cell are affected more by the capacity of the battery cell than the open- to be.

The characteristic determination system 1 of the battery cell may further include a storage unit (not shown) to store information on weights in advance and provide the information to the final calculator 300. [

The determining unit 400 may determine the characteristics of the battery cell using the calculated final capacity characteristic information of the battery cell and the calculated final open-circuit voltage characteristic information of the battery cell. The similarity between the final capacity characteristic information to which the weight is applied and the final open-circuit voltage characteristic information is determined to combine battery cells having similar characteristics, or to identify a defective unit battery cell and construct a battery pack of serial and parallel combination capable of stably charging and discharging .

Hereinafter, a method for determining characteristics of a battery cell according to an embodiment of the present invention will be described.

3 is a flowchart illustrating a process of determining characteristics of a battery cell according to an embodiment of the present invention.

Referring to FIG. 3, a plurality of detailed item capacity conditions, detailed item capacity information corresponding to a plurality of detailed item open-circuit voltage conditions, and a plurality of detailed items And the open-circuit voltage information, respectively (S300).

For this purpose, the voltage or current of the battery cell can be measured. The detail item calculating unit obtains a plurality of detailed item capacity information using the voltage or current of the battery cell measured in each of the plurality of detailed item capacity conditions, A plurality of detailed item open-circuit voltage information can be obtained by using the voltage or current of the battery cell measured under the open-circuit voltage condition.

Here, the plurality of detailed item capacity conditions may include a case of after discharging (CC), a case of after charging (CC / CV), a case of discharging according to the SOC, a case of charging or discharging and charging. The plurality of sub-item open-circuit voltage conditions may include discharging (CC) and after-dormancy, charging (CC / CV) and after-dormancy, discharging according to the step of SOC, charging, or combination of discharging and charging .

At this time, the capacity information of the battery cell is obtained not only in the case of discharging but also in a plurality of detailed item capacity conditions divided in detail according to the steps of charge and SOC in addition to discharge, so that the characteristics of the battery cell can be accurately grasped do. When the capacity information for discriminating the battery cell is secured, the open voltage information measured after the application of the rest period in the charging and discharging can be reflected in the determination of the battery cell.

Then, a predetermined weight is assigned to each of the plurality of detailed item capacity information thus obtained to calculate final capacity characteristic information of the battery cell, and a predetermined weight is given to each of the plurality of detailed item open- The voltage characteristic information can be calculated (S310).

More specifically, the final calculation unit calculates the final capacity characteristic information of the battery cell by summing all the plurality of calculated capacity information by assigning a predetermined weight to each of the obtained plurality of detailed item capacity information, The final open-circuit voltage characteristic information of the battery cell can be calculated by summing all of the calculated plurality of open-circuit voltage information by assigning a predetermined weight to each of the voltage information.

With reference to FIG. 2, for example, a weight that can be given to each of the plurality of detailed item capacity information is predetermined, and a weight that can be given to each of the plurality of detailed item open-circuit voltage information may be predetermined. Then, the final calculation unit may calculate a plurality of capacity information by weighting the plurality of detailed item capacity information obtained through the detailed item calculating unit, calculate the final capacity characteristic information of the battery cell by summing all the calculated plurality of capacity information . The final calculation unit may calculate a plurality of open-circuit voltage information by weighting the plurality of detailed-item open-circuit voltage information obtained through the detailed-item calculating unit, sum up all of the calculated plurality of open-circuit voltage information, Information can be calculated.

In this case, the total sum of the predetermined weights for each of the plurality of detailed item capacity information may have a value larger than a total sum of predetermined weights for each of the plurality of detailed item open-circuit voltage information. In FIG. 2, the sum of predetermined weights for each of the plurality of detailed item capacity information is 0.8, and the sum of predetermined weights for each of the plurality of detailed item open-circuit voltage information may be 0.2, The reason why the sum of the weights determined in advance for each of the plurality of detailed item open-circuit voltage information is higher than the total sum of the predetermined weights for each of the plurality of detailed item open-circuit voltage information is that the characteristics of the battery cell are affected more by the capacity of the battery cell than the open- to be.

The characteristics of the battery cell may be determined using the calculated final capacity characteristic information of the battery cell and the calculated final open-circuit voltage characteristic information of the battery cell (S320). The similarity between the final capacity characteristic information to which the weight is applied and the final open-circuit voltage characteristic information is determined to combine battery cells having similar characteristics, or to identify a defective unit battery cell and construct a battery pack of serial and parallel combination capable of stably charging and discharging .

Embodiments of the present invention include a computer-readable medium having program instructions for performing various computer-implemented operations. This medium records a program for executing the above-described characteristic determination method of the battery cell. The medium may include program instructions, data files, data structures, etc., alone or in combination. Examples of such media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD and DVD, programmed instructions such as floptical disk and magneto-optical media, ROM, RAM, And a hardware device configured to store and execute the program. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

1: Characteristic discrimination system of battery cell
100:
200: Details item calculating unit
300: final calculation unit
400:

Claims (14)

A plurality of detailed item capacity conditions and a plurality of detailed item capacity values corresponding to the plurality of detailed item open-circuit voltage conditions and a plurality of detailed item open-circuit voltage information corresponding to the discharge, charge, and SOC stages of the battery cell A detailed item calculation section, and
Calculating a final capacity characteristic information of the battery cell by giving a predetermined weight to each of the obtained plurality of detailed cell capacities and assigning a predetermined weight to each of the plurality of detailed cell open- The final open-circuit voltage characteristic information
Lt; / RTI >
Wherein the sum of predetermined weights for each of the plurality of detailed item capacity information has a value larger than a total sum of predetermined weights for each of the plurality of detailed item open circuit voltage information,
Wherein the plurality of detailed item capacity conditions include a case of after discharge (CC), a case of charge (CC / CV), a case of discharge, charge according to the SOC, or a combination of the discharge and the charge,
Wherein the plurality of sub-item open-circuit voltage conditions include a discharge (CC) and a post-rest, a charge (CC / CV) and a post-rest state, a discharge according to the SOC, a charge or a combination of the discharge and the charge ≪ / RTI &
Further comprising a determination unit for determining a characteristic of the battery cell using the calculated final capacity characteristic information of the battery cell and the calculated final open-circuit voltage characteristic information of the battery cell. The method of claim 1,
Further comprising a measurement unit for measuring a voltage or a current of the battery cell,
The detailed-
The detailed item capacity information is obtained using the voltage or current of the battery cell measured through the measurement unit under the detailed item capacity condition,
And obtains the detailed item open-circuit voltage information using the voltage or current of the battery cell measured through the measurement unit under the detail-item open-circuit voltage condition. 3. The method of claim 2,
Wherein the final calculation unit comprises:
Calculating a final capacity characteristic information of the battery cell by summing all the plurality of capacity information calculated by applying predetermined weights to each of the obtained plurality of detailed cell capacities,
And calculates the final open-circuit voltage characteristic information of the battery cell by summing all the plurality of calculated open-circuit voltage information by assigning predetermined weights to each of the plurality of detailed open-circuit voltage information obtained. delete delete delete delete A plurality of detailed item capacity conditions and a plurality of detailed item capacity values corresponding to the plurality of detailed item open-circuit voltage conditions and a plurality of detailed item open-circuit voltage information corresponding to the discharge, charge, and SOC stages of the battery cell Step, and
Calculating a final capacity characteristic information of the battery cell by giving a predetermined weight to each of the obtained plurality of detailed cell capacities and assigning a predetermined weight to each of the plurality of detailed cell open- And calculating the final open-circuit voltage characteristic information of the second transistor,
Wherein the sum of predetermined weights for each of the plurality of detailed item capacity information has a value larger than a total sum of predetermined weights for each of the plurality of detailed item open circuit voltage information,
Wherein the plurality of detailed item capacity conditions include a case of after discharge (CC), a case of charge (CC / CV), a case of discharge, charge according to the SOC, or a combination of the discharge and the charge,
Wherein the plurality of sub-item open-circuit voltage conditions include a discharge (CC) and a post-rest, a charge (CC / CV) and a post-rest state, a discharge according to the SOC, a charge or a combination of the discharge and the charge ≪ / RTI &
And determining the characteristics of the battery cell using the calculated final capacity characteristic information of the battery cell and the calculated final open-circuit voltage characteristic information of the battery cell. 9. The method of claim 8,
Further comprising measuring a voltage or current of the battery cell,
A plurality of detailed item capacity conditions and a plurality of detailed item capacity information corresponding to a plurality of detailed item open-circuit voltage conditions and a plurality of detailed item open-circuit voltage information corresponding to the discharge, charge, and SOC of the battery cell, In the obtaining step,
Wherein the plurality of detailed item capacity information is obtained by using the voltage or current of the battery cell measured in each of the plurality of detailed item capacity conditions and the voltage or current of the battery cell measured in each of the plurality of detailed item open- To obtain the plurality of detailed item open-circuit voltage information. The method of claim 9,
Calculating a final capacity characteristic information of the battery cell by giving a predetermined weight to each of the obtained plurality of detailed cell capacities and assigning a predetermined weight to each of the plurality of detailed cell open- Wherein the step of calculating the final open-circuit voltage characteristic information comprises:
Calculating a final capacity characteristic information of the battery cell by summing all the plurality of capacity information calculated by applying predetermined weights to each of the obtained plurality of detailed capacity information, And calculating the final open-circuit voltage characteristic information of the battery cell by summing all the plurality of calculated open-circuit voltage information. delete delete delete delete

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