KR102609874B1 - Method of diagnosing failure of battery pack system using resistance factor - Google Patents

Abstract

A method for diagnosing failure of a battery pack system using a resistance factor is disclosed. The method of diagnosing a failure of the battery pack system includes the battery pack system voltage (V1), the output voltage of the battery pack system (V2), the total voltage of each of the plurality of battery cells (V3), and the voltage of each of the plurality of battery cells. Measuring the difference between the maximum and minimum values (V4) and the final injection current (I) of the battery pack system, respectively; and (b) the battery pack system voltage (V1), the output voltage (V2), the total voltage of each of the plurality of battery cells (V3), and the difference between the maximum and minimum voltages between the battery cells (V4). and diagnosing a failure of the battery pack system using the resistance value calculated from the final injection current (I). The failure diagnosis method of the battery pack system can quickly and accurately diagnose the cause of resistance in the battery pack system without a separate device.

Description

Failure diagnosis method of battery pack system using resistance factor {METHOD OF DIAGNOSING FAILURE OF BATTERY PACK SYSTEM USING RESISTANCE FACTOR}

The present invention relates to a method for diagnosing a fault in a battery pack system using a resistance factor.

As the distribution of electric vehicles (EV) and energy storage systems (ESS) spreads due to global low-carbon, eco-friendly policies, the operation of high energy density medium to large battery systems (modules, packs) is required. In the case of medium-to-large batteries used in electric vehicles and ESS, many parts such as bus bars, wire harnesses, and relays are used to connect single cells in series or parallel. If a failure (poor contact, corrosion, etc.) occurs in the corresponding component, resistance increases in the battery module or battery pack system, which becomes an important factor in determining battery performance.

However, it is difficult to easily determine which component in the battery module or battery pack system is causing the failure, and in order to do so, there is the inconvenience of having to use a device that can check whether the component is failing.

Therefore, research is required on a method to quickly and accurately diagnose the cause of resistance in a battery pack system without a separate device.

KR 10-2022-0061862 A

The purpose of the present invention is to solve the above problems and to provide a method for quickly and accurately diagnosing the cause of resistance in a battery pack system without a separate device.

According to one aspect of the present invention, (a) battery pack system voltage (V1), output voltage of the battery pack system (V2), total voltage of each of a plurality of battery cells (V3), and each of the plurality of battery cells Measuring the difference between the maximum and minimum voltages (V4) and the final injection current (I) of the battery pack system, respectively; and (b) the battery pack system voltage (V1), the output voltage (V2), the total voltage of each of the plurality of battery cells (V3), and the difference between the maximum and minimum voltages between the battery cells (V4). And diagnosing a failure of the battery pack system using the resistance value calculated from the final injection current (I), wherein the battery pack system 10 includes a battery module 100 and a battery management system. , BMS) 200, a relay (switch) 300, a first bus bar 400, and a first wire harness 500, and the battery module 100 includes a plurality of battery cells 110, a first bus bar 400, and a first wire harness 500. A method for diagnosing a fault in a battery pack system including two bus bars 120 and a second wire harness 130 is provided.

In addition, the first bus bar 400 connects the battery module 100, the battery management system (BMS) 200, and the relay (switch) 300 to each other, and the second bus bar 120 may connect the plurality of battery cells 110 to each other.

In addition, the first wire harness 500 is a wire for measuring the battery pack system voltage (V1), the output voltage (V2) of the battery pack system, or the battery management system (BMS) voltage, and the second The wire harness 130 may be a wire for measuring the battery module voltage or the battery cell voltage, respectively.

Additionally, a method of diagnosing a fault in the battery pack system may be to determine a fault location in the battery pack system.

Additionally, the plurality of battery cells may be connected to each other in series or parallel.

In addition, step (b) is (b-1) a resistance value (R1) calculated using Equation 1 below from the battery pack system voltage (V1), the output voltage (V2), and the final injection current (I). It may include diagnosing a malfunction of the battery pack system using the method.

[Equation 1]

R1 = ｜(V1-V2) / I｜

In equation 1 above,

V1 is the battery pack system voltage,

V2 is the output voltage of the battery pack system,

I is the final injection current value of the battery pack system.

In addition, when R1 in step (b-1) exceeds a predetermined value, 1 selected from the group consisting of the output unit of the battery pack system, the relay 300, the first bus bar 400, and the first wire harness 500 It may be a diagnosis that something is broken.

In addition, step (b) (b-2) is calculated using Equation 2 below from the battery pack system voltage (V1), the total voltage of each of the plurality of battery cells (V3), and the final injection current (I). It may include diagnosing a failure of the battery pack system using the resistance value (R2).

[Equation 2]

R2 = ｜(V1-V3) / I｜

In equation 2 above,

V1 is the battery pack system voltage,

V3 is the total voltage of each of the plurality of battery cells,

I is the final injection current value of the battery pack system.

Additionally, if R2 in step (b-2) exceeds a predetermined value, it may be diagnosed that one or more types selected from the group consisting of the second bus bar 120 and the second wire harness 130 are broken.

In addition, step (b) is (b-3) a resistance value calculated using Equation 3 below from the difference value (V4) between the maximum and minimum voltages of each of the plurality of battery cells and the final injection current (I) ( It may include diagnosing a failure of the battery pack system using R3).

[Equation 3]

R3 = ｜(V4) / I ｜

In Equations 1 to 3 above,

V4 is the difference between the maximum and minimum voltages of each of the plurality of battery cells,

I is the final injection current value of the battery pack system.

Additionally, if R3 in step (b-3) exceeds a predetermined value, it may be diagnosed that the battery cell 110 is broken.

In addition, step (a) includes (a-1) measuring the final injection current (I) of the battery pack system and the output voltage (V2) of the battery pack system; (a-2) checking the battery pack system voltage (V1) and the voltage of each of the plurality of battery cells; and (a-3) calculating the total sum of voltages (V3) and the difference (V4) between the maximum and minimum values of each voltage from the voltages of each of the plurality of battery cells.

In addition, the battery pack system voltage V1 is a voltage measured by the battery management system (BMS) electrically connected to the first wire harness, and the voltage of each of the plurality of battery cells is electrically connected to the second wire harness. It may be a voltage measured in the connected battery management system (BMS).

Additionally, the battery pack system may be used in any one selected from the group consisting of electric vehicles and energy storage devices.

According to another aspect of the present invention, (1) battery pack system voltage (V1), output voltage of the battery pack system (V2), total voltage of each of a plurality of battery cells (V3), and the plurality of battery cells Measuring the difference between the maximum and minimum values of each voltage (V4) and the final injection current (I) of the battery pack system; and (2) the battery pack system voltage (V1), the output voltage (V2), the total voltage of each of the plurality of battery cells (V3), and the difference between the maximum and minimum voltages between the battery cells (V4) And diagnosing a failure of the battery pack system using the resistance value calculated from the final injection current (I), wherein the battery pack system 10 includes a plurality of battery modules 100A and 100B and a battery management system. (battery management system, BMS) 200, a relay (switch) 300, a first bus bar 400, and a first wire harness 500, and the plurality of battery modules 100A and 100B each Failure diagnosis of a battery pack system comprising a plurality of battery cells 110, a second bus bar 120, a second wire harness 130, and a battery cell monitoring unit (CMU) 140. A method is provided.

In addition, the first bus bar 400 connects the battery module 100, the battery management system (BMS) 200, and the relay (switch) 300 to each other, and the second bus bar 120 may connect the plurality of battery cells 110 and the battery cell monitoring unit (CMU) 140 to each other.

In addition, the first wire harness 500 is a wire for measuring the battery pack system voltage (V1), the output voltage (V2) of the battery pack system, or the battery management system (BMS) voltage, and The two-wire harness 130 may be a wire for measuring the battery module voltage, the battery cell voltage, or the battery cell monitoring unit voltage (CMU).

Additionally, the plurality of battery modules may be connected to each other in series or parallel.

The fault diagnosis method of the battery pack system of the present invention measures the output voltage (V2) of the battery pack system, and determines the voltage value (battery pack system voltage, a plurality of voltage values) provided by the battery management system (BMS) included in the battery pack system. By calculating the resistance from the voltage of each battery cell and diagnosing the cause and presence of a failure, the cause of resistance in the battery pack system can be quickly and accurately diagnosed without a separate device.

Since these drawings are for reference in explaining exemplary embodiments of the present invention, the technical idea of the present invention should not be interpreted as limited to the attached drawings.
Figure 1 shows a schematic diagram of a battery pack system including one battery module and used when diagnosing a failure of the battery pack system according to an embodiment of the present invention.
Figure 2 shows a schematic diagram of a battery pack system including two battery modules and used when diagnosing a failure of the battery pack system according to an embodiment of the present invention.
Figure 3 is a schematic diagram showing a process for diagnosing a failure of a battery pack system according to an embodiment of the present invention.
Figure 4 is an algorithm showing a process for diagnosing a failure of a battery pack system according to an embodiment of the present invention.
Figure 5 shows a current application profile applied in an embodiment of the present invention.
Figure 6 shows a circuit diagram of the battery pack system in a normal state.
Figure 7 shows a circuit diagram of a battery pack system in which one or more types selected from the group consisting of the output unit, relay (switch), first bus bar, and first wire harness of the battery pack system are broken.
Figure 8 shows a circuit diagram of a battery pack system in which one or more types selected from the group consisting of a second bus bar and a second wire harness are broken.
Figure 9 shows a circuit diagram of a battery pack system in which a battery cell has failed.

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

However, the following description is not intended to limit the present invention to specific embodiments, and in describing the present invention, if it is determined that a detailed description of related known technology may obscure the gist of the present invention, the detailed description will be omitted. .

The terminology used herein is only used to describe specific embodiments and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, or a combination thereof described in the specification, but are not intended to indicate the presence of one or more other features or It should be understood that this does not exclude in advance the possibility of the presence or addition of numbers, steps, operations, components, or combinations thereof.

Additionally, terms including ordinal numbers, such as first, second, etc., which will be used below, may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention.

Additionally, when a component is referred to as being "formed" or "laminated" on another component, it may be formed or laminated directly on the entire surface or one side of the surface of the other component, but may also mean that the component is "formed" or "laminated" on another component. It should be understood that other components may exist.

Hereinafter, a method for diagnosing a fault in a battery pack system using a resistance factor will be described in detail. However, this is presented as an example, and the present invention is not limited thereby, and the present invention is only defined by the scope of the claims to be described later.

FIG. 1 is a schematic diagram of a battery pack system including one battery module and used when diagnosing a failure of a battery pack system according to an embodiment of the present invention, and FIG. 3 is a diagram of a battery according to an embodiment of the present invention. It is a schematic diagram showing a process for diagnosing a failure of a pack system, and Figure 4 is an algorithm showing a process for diagnosing a failure of a battery pack system according to an embodiment of the present invention. Here, each of the steps below can be performed by a computer or directly by an operator, and the operator can measure, calculate, determine, and diagnose failures using a computer or directly.

Referring to FIGS. 1, 3, and 4, the present invention provides (a) a battery pack system voltage (V1), an output voltage of the battery pack system (V2), a total sum of voltages of each of a plurality of battery cells (V3), and the plurality of battery cells. Measuring the difference between the maximum and minimum voltages of each battery cell (V4) and the final injection current (I) of the battery pack system; and (b) the battery pack system voltage (V1), the output voltage (V2), the total voltage of each of the plurality of battery cells (V3), and the difference between the maximum and minimum voltages between the battery cells (V4). And diagnosing a failure of the battery pack system using the resistance value calculated from the final injection current (I), wherein the battery pack system 10 includes a battery module 100 and a battery management system. , BMS) 200, a relay (switch) 300, a first bus bar 400, and a first wire harness 500, and the battery module 100 includes a plurality of battery cells 110, a first bus bar 400, and a first wire harness 500. 2. A method for diagnosing a fault in a battery pack system including a bus bar 120 and a second wire harness 130 is provided.

In addition, the first bus bar 400 connects the battery module 100, the battery management system (BMS) 200, and the relay (switch) 300 to each other, and the second bus bar 120 may connect the plurality of battery cells 110 to each other.

In addition, the first wire harness 500 is a wire for measuring the battery pack system voltage (V1), the output voltage (V2) of the battery pack system, or the battery management system (BMS) voltage, and the second The wire harness 130 may be a wire for measuring the battery module voltage or the battery cell voltage, respectively.

In detail, the first wire harness 500 and the battery management system 200 are electrically connected so that the battery pack system voltage V2 can be measured by the battery management system 200.

Additionally, since the second wire harness 130 and the battery management system 200 are electrically connected, the voltage of each of the plurality of battery cells 110 can be measured by the battery management system 200.

Additionally, a method of diagnosing a fault in the battery pack system may be to determine a fault location in the battery pack system.

Additionally, the plurality of battery cells may be connected to each other in series or parallel.

In addition, step (b) is (b-1) a resistance value (R1) calculated using Equation 1 below from the battery pack system voltage (V1), the output voltage (V2), and the final injection current (I). It may include diagnosing a malfunction of the battery pack system using the method.

[Equation 1]

R1 = ｜(V1-V2) / I｜

In equation 1 above,

V1 is the battery pack system voltage,

V2 is the output voltage of the battery pack system,

I is the final injection current value of the battery pack system.

In addition, when R1 in step (b-1) exceeds a predetermined value, 1 selected from the group consisting of the output unit of the battery pack system, the relay 300, the first bus bar 400, and the first wire harness 500 It may be a diagnosis that something is broken.

Here, the predetermined value is a threshold at which a failure occurs, and the threshold may vary depending on the battery pack system used. For example, in an embodiment of the present invention, the predetermined value is 0.1 Ω, and if R1 exceeds 0.1 Ω (0.1 Ω < R1), the output unit, relay 300, and first bus bar 400 of the battery pack system and the first wire harness 500 may be diagnosed as having failed.

In addition, step (b) (b-2) is calculated using Equation 2 below from the battery pack system voltage (V1), the total voltage of each of the plurality of battery cells (V3), and the final injection current (I). It may include diagnosing a failure of the battery pack system using the resistance value (R2).

[Equation 2]

R2 = ｜(V1-V3) / I｜

In equation 2 above,

V1 is the battery pack system voltage,

V3 is the total voltage of each of the plurality of battery cells,

I is the final injection current value of the battery pack system.

Additionally, if R2 in step (b-2) exceeds a predetermined value, it may be diagnosed that one or more types selected from the group consisting of the second bus bar 120 and the second wire harness 130 are broken.

Here, the predetermined value is a threshold at which a failure occurs, and the threshold may vary depending on the battery pack system used. For example, in an embodiment of the present invention, the predetermined value is 0.1 Ω, and if R2 exceeds 0.1 Ω (0.1 Ω < R2), the voltage from the group consisting of the second bus bar 120 and the second wire harness 130 It can be diagnosed that one or more selected types are broken.

In addition, step (b) is (b-3) a resistance value calculated using Equation 3 below from the difference value (V4) between the maximum and minimum voltages of each of the plurality of battery cells and the final injection current (I) ( It may include diagnosing a failure of the battery pack system using R3).

[Equation 3]

R3 = ｜(V4) / I ｜

In Equations 1 to 3 above,

V4 is the difference between the maximum and minimum voltages of each of the plurality of battery cells,

I is the final injection current value of the battery pack system.

Additionally, if R3 in step (b-3) exceeds a predetermined value, it may be diagnosed that the battery cell 110 is broken.

Here, the predetermined value is a threshold at which a failure occurs, and the threshold may vary depending on the battery pack system used. For example, in an embodiment of the present invention, the predetermined value is 0.1 Ω, and if R3 exceeds 0.1 Ω (0.1 Ω < R3), the battery cell 110 can be diagnosed as broken.

In addition, step (a) includes (a-1) measuring the final injection current (I) of the battery pack system and the output voltage (V2) of the battery pack system; (a-2) checking the battery pack system voltage (V1) and the voltage of each of the plurality of battery cells; and (a-3) calculating the total sum of voltages (V3) and the difference (V4) between the maximum and minimum values of each voltage from the voltages of each of the plurality of battery cells.

The battery pack system voltage (V1) is a voltage measured by the battery management system (BMS) electrically connected to the first wire harness, and the voltage of each of the plurality of battery cells is electrically connected to the second wire harness. It may be a voltage measured by a battery management system (BMS).

Additionally, the battery pack system may be used in any one selected from the group consisting of electric vehicles and energy storage devices.

FIG. 2 is a schematic diagram of a battery pack system including two battery modules and used when diagnosing a failure of a battery pack system according to an embodiment of the present invention, and FIG. 3 is a diagram of a battery according to an embodiment of the present invention. It is a schematic diagram showing a process for diagnosing a failure of a pack system, and Figure 4 is an algorithm showing a process for diagnosing a failure of a battery pack system according to an embodiment of the present invention. Here, each of the steps below can be performed by a computer or directly by an operator, and the operator can measure, calculate, determine, and diagnose failures using a computer or directly.

Referring to FIGS. 2 to 4, the present invention provides (1) a battery pack system voltage (V1), an output voltage of the battery pack system (V2), a total sum of voltages of each of a plurality of battery cells (V3), and the plurality of batteries. Measuring the difference between the maximum and minimum voltages of each cell (V4) and the final injection current (I) of the battery pack system; and (2) the battery pack system voltage (V1), the output voltage (V2), the total voltage of each of the plurality of battery cells (V3), and the difference between the maximum and minimum voltages between the battery cells (V4) And diagnosing a failure of the battery pack system using the resistance value calculated from the final injection current (I), wherein the battery pack system 10 includes a plurality of battery modules 100A and 100B and a battery management system. (battery management system, BMS) 200, a relay (switch) 300, a first bus bar 400, and a first wire harness 500, and the plurality of battery modules 100A and 100B each Failure diagnosis of a battery pack system comprising a plurality of battery cells 110, a second bus bar 120, a second wire harness 130, and a battery cell monitoring unit (CMU) 140. Provides a method.

In addition, the first bus bar 400 connects the battery module 100, the battery management system (BMS) 200, and the relay (switch) 300 to each other, and the second bus bar 120 may connect the plurality of battery cells 110 and the battery cell monitoring unit (CMU) 140 to each other.

In addition, the first wire harness is a wire for measuring the battery pack system voltage (V1), the output voltage (V2) of the battery pack system, or the battery management system (BMS) voltage, and the second wire harness may be a wire for measuring the battery module voltage, the battery cell voltage, or the battery cell monitoring unit voltage (CMU), respectively.

Additionally, the plurality of battery modules may be connected to each other in series or parallel.

[Example]

Hereinafter, the present invention will be described with reference to preferred embodiments. However, this is for illustrative purposes only and does not limit the scope of the present invention.

<Battery pack system failure diagnosis>

A battery pack system was arbitrarily configured to check whether a fault was diagnosed using the fault diagnosis method of the battery pack system according to the present invention. Figure 1 shows a schematic diagram of a battery pack system used in one embodiment of the present invention. In detail, the 4s 1p module shown in Figure 1 was constructed and tested using an 18650 cylindrical battery, and current was applied at a rated voltage of 12.0 ~ 16.8 V, a rated capacity of 3.5 Ah, and SOC50 (14.6 V).

Figure 5 shows a current application profile applied in an embodiment of the present invention. Referring to FIG. 5, current was applied, and each current was applied for 10 seconds and rested for 20 seconds. Specifically, 0.3 C discharge (-1.05 A) -> 0.3 C charge (1.05 A) -> 0.5 C discharge (-1.75 A) -> 0.5 C charge (1.75 A) -> 1 C discharge (-3.5 A) - Current was applied in the following order: > 1 C charge (3.5 A) -> 1.5 C discharge (-5.25 A) -> 1.5 C charge (5.25 A).

The predetermined value for diagnosing a malfunction in the battery pack system used in an embodiment of the present invention is 0.1 Ω, and when the resistance values R1, R2, and R3 each exceed 0.1 Ω, the battery pack system is diagnosed as malfunctioning.

Example 1: Steady State

Figure 6 shows a circuit diagram of the battery pack system in a normal state. A circuit was prepared according to Figure 6. In FIG. 6, V1 represents the battery pack system voltage, V2 represents the output voltage of the battery pack system, and V _A , V _B , V _C , and V _D represent the voltages of the battery cells, respectively.

In Figure 6, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V _D ) according to the applied current (A) were measured. From the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX - V _MIN ) are calculated as follows. It is summarized in Table 1.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 14.262 14.263 14.284 0.004 1.05 14.919 14.973 14.897 0.006 -1.75 14.044 13.949 14.080 0.003 1.75 15.135 15.225 15.097 0.007 -3.5 13.478 13.295 13.551 0.010 3.5 15.682 15.894 15.607 0.012 -5.25 12.871 12.621 12.988 0.017 5.25 16.265 16.63 16.148 0.020

The resistance values calculated using Table 1 above are summarized in Table 2 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 0.0010 0.0028 0.004 1.05 0.0514 0.0015 0.006 -1.75 0.0543 0.0025 0.002 1.75 0.0514 0.0015 0.004 -3.5 0.0523 0.0024 0.003 3.5 0.0606 0.0017 0.003 -5.25 0.0476 0.0026 0.003 5.25 0.0695 0.0021 0.004

According to Table 2, since R1 is 0.1 Ω or less, it can be confirmed that at least one selected from the group consisting of the output unit, relay, first bus bar, and first wire harness of the battery pack system is not broken.

Additionally, since R2 is 0.1 Ω or less, it can be confirmed that at least one selected from the group consisting of the second bus bar and the second wire harness is not broken. Meanwhile, the R2 value appears to be 0.002 Ω on average, so it can be confirmed that the resistance of the second bus bar or the second wire harness is 0.002 Ω.

Additionally, since R3 is less than 0.1 Ω, it can be confirmed that the battery cell is not broken.

Example 2: At least one type from the group consisting of the output unit, relay, first bus bar, and first wire harness of the battery pack system is broken

Figure 7 shows a circuit diagram of a battery pack system in which one or more types selected from the group consisting of the output unit, relay (switch), first bus bar, and first wire harness of the battery pack system are broken. In detail, in the normal circuit diagram of FIG. 6, failures such as poor contact and corrosion are prevented by adding a resistor (red dotted line) to the portion where the output unit, relay (switch), first bus bar, or first wire harness of the battery pack system is located. The circuit diagram shows when this occurs. A circuit was prepared according to Figure 7. In FIG. 7, V1 represents the battery pack system voltage, V2 represents the output voltage of the battery pack system, and V _A , V _B , V _C , and V _D represent the voltages of the battery cells, respectively.

Example 2-1: When the added resistor is 0.27 Ω

In FIG. 7, when the added resistor is 0.27 Ω, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V) according to the applied current (A), respectively. _D ) was measured, and from the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX) - V _MIN ) was calculated and summarized in Table 3 below.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 14.255 13.969 14.255 0.001 1.05 14.859 15.147 14.856 0.005 -1.75 14.051 13.581 14.054 0.003 1.75 15.058 15.535 15.053 0.010 -3.5 13.532 12.624 13.530 0.009 3.5 15.558 16.5 15.554 0.014 -5.25 12.975 11.604 12.964 0.016 5.25 16.109 17.553 16.095 0.020

The resistance values calculated using Table 3 above are summarized in Table 4 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 0.2724 0 0.0010 1.05 0.2743 0.0029 0.0048 -1.75 0.2686 0.0017 0.0017 1.75 0.2726 0.0029 0.0057 -3.5 0.2594 0.0006 0.0026 3.5 0.2691 0.0011 0.004 -5.25 0.2611 0.0021 0.0030 5.25 0.2750 0.0027 0.0038

According to Table 4, since R1 exceeds 0.1 Ω, it can be confirmed that one or more types selected from the group consisting of the output unit, relay (switch), first bus bar, and first wire harness of the battery pack system are broken.

In addition, it can be seen that the resistance value (R1) is calculated as the resistance value (0.27 Ω) of the resistor added to represent the failure.

Meanwhile, since R2 and R3 are each less than 0.1 Ω, it can be confirmed that the second bus bar, second wire harness, and battery cell are not broken.

Example 2-2: When the added resistor is 0.55 Ω

In FIG. 7, when the added resistor is 0.55 Ω, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V) according to the applied current (A), respectively. _D ) was measured, and from the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX) - V _MIN ) was calculated and summarized in Table 5 below.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 14.256 13.675 14.257 0.003 1.05 14.868 15.444 14.867 0.004 -1.75 14.052 13.092 14.054 0.003 1.75 15.071 16.028 15.065 0.008 -3.5 13.519 11.604 13.526 0.009 3.5 15.579 17.497 15.573 0.011 -5.25 12.944 10.071 12.954 0.017 5.25 16.123 18.973 16.115 0.021

The resistance values calculated using Table 5 above are summarized in Table 6 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 0.5533 0.0010 0.0029 1.05 0.5486 0.0010 0.0038 -1.75 0.5486 0.0011 0.0017 1.75 0.5469 0.0034 0.0046 -3.5 0.5471 0.002 0.0026 3.5 0.548 0.0017 0.0031 -5.25 0.5472 0.0019 0.0032 5.25 0.5429 0.0015 0.004

According to Table 6, since R1 exceeds 0.1 Ω, it can be confirmed that one or more types selected from the group consisting of the output unit, relay (switch), first bus bar, and first wire harness of the battery pack system are broken.

In addition, it can be seen that the resistance value (R1) is calculated as the resistance value (0.55 Ω) of the resistor added to represent the failure.

Meanwhile, since R2 and R3 are each less than 0.1 Ω, it can be confirmed that the second bus bar, second wire harness, and battery cell are not broken.

Example 2-3: When the added resistor is 1 Ω

In FIG. 7, when the added resistor is 1 Ω, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V) according to the applied current (A), respectively. _D ) was measured, and from the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX) - V _MIN ) was calculated and summarized in Table 7 below.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 14.287 13.196 14.257 0.003 1.05 14.869 15.923 14.868 0.005 -1.75 14.055 12.293 14.053 0.004 1.75 15.066 16.817 15.067 0.007 -3.5 13.517 9.999 13.521 0.010 3.5 15.583 19.191 15.574 0.015 -5.25 12.938 7.635 12.947 0.018 5.25 16.132 21.495 16.121 0.021

The resistance values calculated using Table 7 above are summarized in Table 8 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 1.0390 0.0286 0.0029 1.05 1.0038 0.0010 0.0048 -1.75 1.0069 0.0011 0.0023 1.75 1.0006 0.0005 0.0040 -3.5 1.0051 0.0011 0.0029 3.5 1.0309 0.0026 0.0043 -5.25 1.0101 0.0017 0.0034 5.25 1.0215 0.0021 0.0040

According to Table 8, since R1 exceeds 0.1 Ω, it can be confirmed that one or more types selected from the group consisting of the output unit, relay (switch), first bus bar, and first wire harness of the battery pack system are broken.

In addition, it can be seen that the resistance value (R1) is calculated as the resistance value (1 Ω) of the resistor added to represent the fault.

Meanwhile, since R2 and R3 are each less than 0.1 Ω, it can be confirmed that the second bus bar, second wire harness, and battery cell are not broken.

Example 3: At least one selected from the group consisting of the second bus bar and the second wire harness is broken

Figure 8 shows a circuit diagram of a battery pack system in which one or more types selected from the group consisting of a second bus bar and a second wire harness are broken. In detail, in the normal circuit diagram of FIG. 6, the circuit diagram is shown when a failure such as poor contact or corrosion occurs by adding a resistor (red dotted line) to the portion where the second bus bar or second wire harness is located. A circuit was prepared according to Figure 8. In FIG. 8, the battery pack system voltage, V2, represents the output voltage of the battery pack system, and V _A , V _B , V _C , and V _D represent the voltages of the battery cells, respectively.

Example 3-1: When the added resistor is 0.29 Ω

In FIG. 8, when the added resistor is 0.29 Ω, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V) according to the applied current (A), respectively. _D ) was measured, and from the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX) - V _MIN ) was calculated and summarized in Table 9 below.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 13.985 13.981 14.288 0.003 1.05 15.2 15.205 14.895 0.002 -1.75 13.58 13.571 14.085 0.005 1.75 15.602 15.611 15.095 0.003

The resistance values calculated using Table 9 above are summarized in Table 10 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 0.0038 0.2886 0.0029 1.05 0.0048 0.2905 0.0019 -1.75 0.0051 0.2886 0.0029 1.75 0.0051 0.2897 0.0017

According to Table 10, since R2 exceeds 0.1 Ω, it can be confirmed that at least one selected from the group consisting of the second bus bar and the second wire harness has failed.

In addition, it can be seen that the resistance value (R2) is calculated as the resistance value (0.29 Ω) of the resistor added to represent the failure.

Meanwhile, since R1 and R3 are each less than 0.1 Ω, it can be confirmed that the output unit, relay (switch), first bus bar, first wire harness, and battery cell of the battery pack system are not broken.

Example 3-2: When the added resistor is 0.52 Ω

In FIG. 8, when the added resistor is 0.52 Ω, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V) according to the applied current (A), respectively. _D ) was measured, and from the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX) - V _MIN ) was obtained and summarized in Table 11 below.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 13.745 13.71 14.293 0.002 1.05 15.451 15.481 14.901 0.002 -1.75 13.176 13.12 14.089 0.003 1.75 16.021 16.064 15.098 0.002

The resistance values calculated using Table 11 above are summarized in Table 12 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 0.0333 0.5219 0.0019 1.05 0.0286 0.5238 0.0019 -1.75 0.0320 0.5217 0.0017 1.75 0.0246 0.5274 0.0011

According to Table 12, since R2 exceeds 0.1 Ω, it can be confirmed that at least one selected from the group consisting of the second bus bar and the second wire harness has failed.

In addition, it can be seen that the resistance value (R2) is calculated as the resistance value (0.52 Ω) of the resistor added to represent the failure.

Meanwhile, since R1 and R3 are each less than 0.1 Ω, it can be confirmed that the output unit, relay (switch), first bus bar, first wire harness, and battery cell of the battery pack system are not broken.

Example 3-3: When the added resistor is 1 Ω

In FIG. 8, when the added resistor is 1 Ω, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V) according to the applied current (A), respectively. _D ) was measured, and from the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX) - V _MIN ) was obtained and summarized in Table 13 below.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 13.233 13.192 14.301 0.002 1.05 15.952 16.016 14.878 0.002 -1.75 12.301 12.234 14.094 0.003 1.75 16.888 16.949 15.109 0.002

The resistance values calculated using Table 13 above are summarized in Table 14 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 0.0390 1.0171 0.0019 1.05 0.0610 1.0229 0.0019 -1.75 0.0383 1.0246 0.0017 1.75 0.0349 1.0166 0.0011

According to Table 14, since R2 exceeds 0.1 Ω, it can be confirmed that at least one selected from the group consisting of the second bus bar and the second wire harness has failed.

In addition, it can be seen that the resistance value (R2) is calculated as the resistance value (1 Ω) of the resistor added to represent the failure.

Meanwhile, since R1 and R3 are each less than 0.1 Ω, it can be confirmed that the output unit, relay (switch), first bus bar, first wire harness, and battery cell of the battery pack system are not broken.

Example 4: Battery cell failure

Figure 9 shows a circuit diagram of a battery pack system in a state in which a battery cell has failed. In detail, in the normal circuit diagram of FIG. 6, the circuit diagram is shown when a failure such as poor contact or corrosion occurs by adding a resistor (red dotted line) to the corresponding part inside the battery cell. A circuit was prepared according to Figure 9. In FIG. 9, V1 represents the measured battery pack system voltage, V2 represents the output voltage of the battery pack system, and V _A , V _B , V _C , and V _D represent the voltages of the battery cells, respectively.

Example 4-1: When the added resistor is 0.22 Ω

In Figure 9, when the added resistor is 0.22 Ω, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V) according to the applied current (A), respectively. _D ) was measured, and from the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX) - V _MIN ) was calculated and summarized in Table 15 below.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 14.047 13.986 14.057 0.239 1.05 15.159 15.22 15.148 0.238 -1.75 13.679 13.562 13.696 0.397 1.75 15.521 15.625 15.506 0.395

The resistance values calculated using Table 15 above are summarized in Table 16 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 0.0581 0.0095 0.2276 1.05 0.0581 0.0105 0.2276 -1.75 0.0669 0.0097 0.2269 1.75 0.0594 0.0086 0.2257

According to Table 16, since R3 exceeds 0.1 Ω, it can be confirmed that the battery cell has failed in the battery pack system.

In addition, it can be seen that the resistance value (R3) is calculated as the resistance value (0.22 Ω) of the resistor added to represent the fault.

Meanwhile, since R1 and R2 are each less than 0.1 Ω, it can be confirmed that the output unit, relay (switch), first bus bar, first wire harness, second bus bar, and second wire harness of the battery pack system are not broken. .

Example 4-2: When the added resistor is 0.53 Ω

In Figure 9, when the added resistor is 0.53 Ω, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V) according to the applied current (A), respectively. _D ) was measured, and from the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX) - V _MIN ) was calculated and summarized in Table 17 below.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 13.729 13.64 13.740 0.566 1.05 15.497 15.575 15.484 0.567 -1.75 13.144 13.009 13.157 0.943 1.75 16.082 16.225 16.063 0.942

The resistance values calculated using Table 17 above are summarized in Table 18 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 0.0848 0.0105 0.5390 1.05 0.0743 0.0124 0.54 -1.75 0.0771 0.0074 0.5389 1.75 0.0817 0.0109 0.5383

According to Table 18, since R3 exceeds 0.1 Ω, it can be confirmed that the battery cell has failed in the battery pack system.

In addition, it can be seen that the resistance value (R3) is calculated as the resistance value (0.53 Ω) of the resistor added to represent the failure.

Meanwhile, since R1 and R2 are each less than 0.1 Ω, it can be confirmed that the output unit, relay (switch), first bus bar, first wire harness, second bus bar, and second wire harness of the battery pack system are not broken. .

Example 4-3: When the added resistor is 1 Ω

In Figure 9, when the added resistor is 1 Ω, the battery pack system voltage (V1), output voltage (V2), and battery cell voltage (V _A , V _B , V _C , and V) according to the applied current (A), respectively. _D ) was measured, and from the voltage of the battery cells, the total voltage of each cell (V3 = V _A + V _B + V _C + V _D ) and the difference between the maximum and minimum voltages of each battery cell (V4 = V _MAX) - V _MIN ) was obtained and summarized in Table 19 below.

Current (A) V1 (V) V2 (V) V3 (V) V4 (V) -1.05 13.253 13.231 13.271 1.045 1.05 15.99 16.021 15.979 1.045 -1.75 12.301 12.267 12.319 1.776 1.75 16.892 16.942 16.876 1.738

The resistance values calculated using Table 19 above are summarized and shown in Table 20 below.

Current (A) Resistance value (R1) (Ω)
(|(V1-V2)/I|) Resistance value (R2) (Ω)
(|(V1-V3)/I|) Resistance value (R3) (Ω)
(|(V4)/I|) -1.05 0.0210 0.0171 0.9952 1.05 0.0295 0.0105 0.9952 -1.75 0.0194 0.0103 1.0149 1.75 0.0285 0.0091 0.9931

According to Table 20, since R3 exceeds 0.1 Ω, it can be confirmed that the battery cell has failed in the battery pack system.

In addition, it can be seen that the resistance value (R3) is calculated as the resistance value (1 Ω) of the resistor added to represent the fault.

Meanwhile, since R1 and R2 are each less than 0.1 Ω, it can be confirmed that the output unit, relay (switch), first bus bar, first wire harness, second bus bar, and second wire harness of the battery pack system are not broken. .

The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

10: Battery pack system
100, 100A, 100B: Battery module
110: battery cell
120: second bus bar
130: second wire harness
140: Battery cell monitoring unit (CMU)
200: Battery Management System (BMS)
300: relay (switch)
400: first bus bar
500: first wire harness

Claims (18)

(a) Battery pack system voltage (V1), output voltage of the battery pack system (V2), total sum of voltage of each of the plurality of battery cells (V3), difference between the maximum and minimum values of the voltage of each of the plurality of battery cells measuring the value (V4) and the final injection current (I) of the battery pack system, respectively;
(b-1) Failure of the battery pack system is detected using the resistance value (R1) calculated from the battery pack system voltage (V1), the output voltage (V2), and the final injection current (I) using Equation 1 below. Diagnosing steps;
(b-2) Using the resistance value (R2) calculated using Equation 2 below from the battery pack system voltage (V1), the total voltage of each of the plurality of battery cells (V3), and the final injection current (I) diagnosing a malfunction of the battery pack system; and
(b-3) A battery pack system using the difference value (V4) between the maximum and minimum voltages of each of the plurality of battery cells and the resistance value (R3) calculated using Equation 3 below from the final injection current (I) Diagnosing a malfunction; including,
The battery pack system includes a battery module, a battery management system (BMS), a relay (switch), a first busbar, and a first wire harness,
The battery module includes a plurality of battery cells, a second bus bar, and a second wire harness,
If R1 in step (b-1) exceeds a predetermined value, it is diagnosed that one or more types selected from the group consisting of the output unit of the battery pack system, the relay (switch), the first bus bar, and the first wire harness are broken. do,
If R2 in step (b-2) exceeds a predetermined value, it is diagnosed that one or more types selected from the group consisting of the second bus bar and the second wire harness are broken,
A fault diagnosis method of a battery pack system, wherein the battery cell is diagnosed as faulty when R3 in step (b-3) exceeds a predetermined value:
[Equation 1]
R1 = ｜(V1-V2) / I｜
[Equation 2]
R2 = ｜(V1-V3) / I｜
[Equation 3]
R3 = ｜(V4) / I ｜
In Equations 1 to 3 above,
V1 is the battery pack system voltage,
V2 is the output voltage of the battery pack system,
V3 is the total voltage of each of the plurality of battery cells,
V4 is the difference between the maximum and minimum voltages of each of the plurality of battery cells,
I is the final injection current value of the battery pack system. According to paragraph 1,
The first bus bar connects the battery module, the battery management system, and the relay (switch) to each other,
A fault diagnosis method of a battery pack system, wherein the second bus bar connects the plurality of battery cells to each other. According to paragraph 1,
The first wire harness is a wire for measuring the battery pack system voltage (V1), the output voltage (V2) of the battery pack system, or the battery management system (BMS) voltage,
A fault diagnosis method of a battery pack system, wherein the second wire harness is a wire for measuring the battery module voltage or the battery cell voltage, respectively. According to paragraph 1,
The fault diagnosis method of the battery pack system is characterized in that the fault diagnosis method of the battery pack system determines a fault location of the battery pack system. According to paragraph 1,
A fault diagnosis method for a battery pack system, characterized in that the plurality of battery cells are connected to each other in series or parallel. delete delete delete delete delete delete According to paragraph 1,
Step (a) is
(a-1) measuring the final injection current (I) of the battery pack system and the output voltage (V2) of the battery pack system;
(a-2) checking the battery pack system voltage (V1) and the voltage of each of the plurality of battery cells; and
(a-3) calculating the total sum of voltages (V3) and the difference (V4) between the maximum and minimum values of each voltage from the voltages of each of the plurality of battery cells; a battery comprising a. How to diagnose failure of pack system. According to clause 12,
The battery pack system voltage (V1) is a voltage measured at the battery management system (BMS) electrically connected to the first wire harness,
A fault diagnosis method for a battery pack system, wherein the voltage of each of the plurality of battery cells is a voltage measured by the battery management system (BMS) electrically connected to the second wire harness. According to paragraph 1,
A failure diagnosis method of a battery pack system, wherein the battery pack system is used in any one selected from the group consisting of electric vehicles and energy storage devices. (1) Battery pack system voltage (V1), output voltage of the battery pack system (V2), total sum of voltage of each of the plurality of battery cells (V3), difference between the maximum and minimum voltages of each of the plurality of battery cells measuring the value (V4) and the final injection current (I) of the battery pack system, respectively;
(2-1) Failure of the battery pack system is detected using the resistance value (R1) calculated from the battery pack system voltage (V1), the output voltage (V2), and the final injection current (I) using Equation 1 below. Diagnosing steps;
(2-2) Using the resistance value (R2) calculated using Equation 2 below from the battery pack system voltage (V1), the total voltage of each of the plurality of battery cells (V3), and the final injection current (I) diagnosing a malfunction of the battery pack system; and
(2-3) A battery pack system using the difference value (V4) between the maximum and minimum voltages of each of the plurality of battery cells and the resistance value (R3) calculated using Equation 3 below from the final injection current (I) Diagnosing a malfunction; including,
The battery pack system includes a plurality of battery modules, a battery management system (BMS), a relay (switch), a first bus bar, and a first wire harness,
The plurality of battery modules each include a plurality of battery cells, a second bus bar, a second wire harness, and a battery cell monitoring unit (CMU),
If R1 in step (2-1) exceeds a predetermined value, it is diagnosed that one or more types selected from the group consisting of the output unit of the battery pack system, the relay (switch), the first bus bar, and the first wire harness are broken. do,
If R2 in step (2-2) exceeds a predetermined value, it is diagnosed that one or more types selected from the group consisting of the second bus bar and the second wire harness are broken,
A method for diagnosing a battery pack system failure, wherein the battery cell is diagnosed as having failed when R3 in step (2-3) exceeds a predetermined value:
[Equation 1]
R1 = ｜(V1-V2) / I｜
[Equation 2]
R2 = ｜(V1-V3) / I｜
[Equation 3]
R3 = ｜(V4) / I ｜
In Equations 1 to 3 above,
V1 is the battery pack system voltage,
V2 is the output voltage of the battery pack system,
V3 is the total voltage of each of the plurality of battery cells,
V4 is the difference between the maximum and minimum voltages of each of the plurality of battery cells,
I is the final injection current value of the battery pack system. According to clause 15,
The first bus bar connects the battery module, the battery management system, and the relay (switch) to each other,
A fault diagnosis method of a battery pack system, wherein the second bus bar connects the plurality of battery cells and the battery cell monitoring unit (CMU) to each other. According to clause 15,
The first wire harness is a wire for measuring the battery pack system voltage (V1), the output voltage (V2) of the battery pack system, or the battery management system (BMS) voltage, respectively,
A fault diagnosis method of a battery pack system, wherein the second wire harness is a wire for measuring the battery module voltage, the battery cell voltage, or the battery cell monitoring unit voltage (CMU). According to clause 15,
A fault diagnosis method for a battery pack system, characterized in that the plurality of battery modules are connected to each other in series or parallel.