KR102695870B1 - Apparatus and method for diagnosing battery fault, and battery pack including the apparatus - Google Patents

Abstract

A device and method for diagnosing a fault in a battery, and a battery pack including the device, are provided. The device according to one embodiment of the present invention includes a detection unit electrically connected to the battery and generating detection data indicating a state of the battery; and a control unit operably coupled to the detection unit and configured to collect the detection data from the detection unit. The control unit is configured to determine a diagnostic target value indicating a state of the battery based on the detection data. The control unit is configured to set a diagnostic flag associated with the diagnostic target value to a first value indicating that the battery is abnormal or a second value indicating that the battery is normal, based on the diagnostic target value. The control unit is configured to set an increase factor to a third value when a fault detection count associated with the diagnostic target value is less than a reference value. When the fault detection count is less than the reference value and the diagnostic flag is set to the first value, the fault detection count is increased using the increase factor.

Description

Apparatus and method for diagnosing battery fault, and battery pack including the apparatus

The present invention relates to a device and method for diagnosing a failure of a battery using a failure detection count, and to a battery pack including the device.

Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly and the development of electric vehicles, energy storage batteries, robots, and satellites has become full-fledged, research on high-performance batteries capable of repeated charging and discharging is actively being conducted.

Currently commercialized batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium batteries. Among these, lithium batteries are receiving attention due to their advantages such as the fact that they have almost no memory effect compared to nickel-based batteries, are free to charge and discharge, have a very low self-discharge rate, and have high energy density.

Battery failure can occur due to various reasons. For example, if the battery is over-voltage, under-voltage, over-charged, over-discharged, or overheated, not only will the battery's lifespan be drastically reduced, but there is also a risk of explosion.

Therefore, it is necessary to diagnose battery failure while continuously monitoring the state of the battery. Patent Document 1 discloses a technology of increasing an error count whenever an error is found during the performance of an operation for battery control (e.g., monitoring the output voltage of the battery), and executing a protection operation (e.g., resetting the microcontroller) when the error count exceeds a threshold.

However, the increase in the error count of Patent Document 1 is unrelated to the frequency of error occurrence or the number of times the error occurs continuously. That is, the error count increases steadily every time an error occurs. Therefore, there is a disadvantage in that the minimum period from the time the error first occurs to the time the error count reaches the threshold is fixed.

(Patent Document 1) Republic of Korea Patent Publication No. 10-1570475 (Registration Date: November 13, 2015)

The present invention has been made to solve the above problems, and the purpose of the present invention is to provide a device and method for diagnosing a battery failure more quickly by controlling the increase or decrease per unit time of a failure detection count according to a change over time in a diagnostic target value indicating the state of the battery, and a battery pack including the device.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly known by the embodiments of the present invention. In addition, it will be easily understood that the objects and advantages of the present invention can be realized by the means and combinations thereof indicated in the claims.

Various embodiments of the present invention to achieve the above purpose are as follows.

According to one embodiment of the present invention, a device for diagnosing a fault in a battery includes a detection unit electrically connected to the battery and generating detection data indicating a state of the battery; and a control unit operably coupled to the detection unit and configured to collect the detection data from the detection unit. The control unit is configured to determine a diagnostic target value indicating a state of the battery based on the detection data. The control unit is configured to set a diagnostic flag associated with the diagnostic target value to a first value indicating that the battery is abnormal or a second value indicating that the battery is normal, based on the diagnostic target value. The control unit is configured to set an increase factor to a third value when a fault detection count associated with the diagnostic target value is less than a reference value. When the fault detection count is less than the reference value and the diagnostic flag is set to the first value, the fault detection count is increased using the increase factor.

The control unit may set the increase factor to a fourth value when the fault detection count is greater than or equal to the reference value. The control unit may be configured to increase the fault detection count using the increase factor when the fault detection count is greater than or equal to the reference value and the diagnostic flag is set to the first value. The fourth value may be greater than the third value.

The control unit may set the reduction factor to a fifth value when the fault detection count is less than the reference value. The control unit may be configured to decrease the fault detection count using the reduction factor when the fault detection count is less than the reference value and the diagnostic flag is set to the second value.

The control unit may set the reduction factor to a sixth value when the fault detection count is greater than or equal to the reference value. The control unit may be configured to reduce the fault detection count using the reduction factor when the fault detection count is greater than or equal to the reference value and the diagnostic flag is set to the second value. The sixth value may be smaller than the fifth value.

The control unit may be configured to reset the fault detection count when the fault detection count is less than the reference value and the diagnostic flag is set to the second value.

The above diagnostic target value may be any one of the voltage, current, temperature, SOC, SOH or internal resistance of the battery. The control unit may set the first value to the diagnostic target value when the diagnostic target value is out of a predetermined normal range. The control unit may be configured to set the second value to the diagnostic target value when the diagnostic target value is within the normal range.

The above control unit may be configured to output a diagnostic message when the increased fault detection count is greater than an upper limit value greater than the reference value.

A battery pack according to another embodiment of the present invention includes the device.

A method for diagnosing a fault in a battery according to another embodiment of the present invention comprises: a step in which a control unit collects detection data indicating a state of the battery from a detection unit electrically connected to the battery; a step in which the control unit determines a diagnostic target value based on the detection data; a step in which the control unit sets a diagnostic flag associated with the diagnostic target value based on the diagnostic target value to a first value indicating that the battery is abnormal or a second value indicating that the battery is normal; a step in which the control unit sets an increase factor to a third value when a fault detection count associated with the diagnostic target value is less than a reference value; and a step in which the control unit increases the fault detection count using the increase factor when the fault detection count is less than the reference value and the diagnostic flag is set to the first value.

The method may further include a step of the control unit setting the increase factor to a fourth value when the fault detection count is greater than or equal to the reference value; and a step of the control unit increasing the fault detection count using the increase factor when the fault detection count is greater than or equal to the reference value and the diagnostic flag is set to the first value. The fourth value may be greater than the third value.

The method may further include a step of the control unit setting a reduction factor to a fifth value when the fault detection count is less than the reference value; and a step of the control unit decreasing the fault detection count using the reduction factor when the fault detection count is less than the reference value and the diagnostic flag is set to the second value.

The method may further include a step of the control unit setting the reduction factor to a sixth value when the fault detection count is greater than or equal to the reference value; and a step of the control unit decreasing the fault detection count using the reduction factor when the fault detection count is greater than or equal to the reference value and the diagnostic flag is set to the second value. The sixth value may be smaller than the fifth value.

According to at least one of the embodiments of the present invention, a battery failure can be diagnosed more quickly by adjusting the increase or decrease per unit time of a failure detection count according to a change in a diagnostic target value indicating a state of the battery over time.

The 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.

The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical idea of the present invention; therefore, the present invention should not be interpreted as being limited to matters described in such drawings.
FIG. 1 is a drawing exemplarily showing the configuration of a battery pack including a device for diagnosing a failure of a battery according to one embodiment of the present invention.
FIGS. 2 and 3 are exemplary graphs that are referenced to explain the relationship between the first diagnostic target value and the first diagnostic flag determined from detection data indicating the state of the battery in the device of FIG. 1.
FIG. 4 is an exemplary graph referenced for explaining a first operation in which the device of FIG. 1 adjusts a first fault detection count based on the first diagnostic flag of FIG. 3.
FIG. 5 is an exemplary graph referenced to explain a second operation in which the device of FIG. 1 adjusts the first fault detection count based on the first diagnostic flag of FIG. 3.
FIG. 6 is an exemplary graph showing a first fault detection count adjusted according to the first diagnostic flag of FIG. 3.
FIG. 7 is an exemplary graph showing a second fault detection count associated with the first fault detection count of FIG. 6.
FIG. 8 is a flowchart showing a method for diagnosing a battery failure according to another embodiment of the present invention.
FIG. 9 is a flowchart showing a method for diagnosing a battery failure according to another embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms or words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, and should be interpreted as meanings and concepts that conform to the technical idea of the present invention based on the principle that the inventor can appropriately define the concept of the term in order to explain his or her own invention in the best way.

Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

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

Terms that include ordinal numbers, such as first, second, etc., are used to distinguish one of the various components from the rest, and are not used to limit the components by such terms.

Throughout the specification, when a part is said to "include" a component, this does not mean that it excludes other components, unless otherwise specifically stated, but rather that it may include other components. In addition, terms such as <control unit> described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

Additionally, throughout the specification, when a part is said to be "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other elements in between.

FIG. 1 is a drawing exemplarily showing the configuration of a battery pack (10) including a device (100) for diagnosing a failure of a battery (20) according to one embodiment of the present invention.

Referring to FIG. 1, the battery pack (10) includes a plus terminal (P+), a minus terminal (P-), a battery (20), a switch (30), and a device (100).

The battery (20) includes at least one unit cell (21). The type of the unit cell (21) is not particularly limited as long as it is rechargeable, such as a lithium ion cell. When the battery (20) includes a plurality of unit cells (21), each unit cell (21) can be electrically connected in series or in parallel to another unit cell (21).

A switch (30) is installed on at least one of a first power line (11) connecting a positive terminal and a positive terminal (P+) of a battery (20) and a second power line (12) connecting a negative terminal and a negative terminal (P-) of a battery (20). The switch (30) may be a mechanical switch such as a magnetic relay or a semiconductor switch such as a MOSFET. The switch (30) is turned on and off in response to a switching signal (S) from a control unit (120). When the switch (30) is controlled to be on, charging and discharging of the battery pack (10) becomes possible. On the other hand, when the switch (30) is controlled to be off, charging and discharging of the battery pack (10) is stopped.

The device (100) is provided to diagnose a failure of a battery (20) and output a diagnostic message indicating the result of the diagnosis. The device (100) includes a detection unit (110) and a control unit (120).

The detection unit (110) is electrically connected to the battery (20) and configured to generate detection data indicating the state of the battery (20). The state of the battery (20) depends on at least one of the voltage, current, and temperature of the battery (20).

The detection unit (110) may include at least one of a voltage sensor (111), a current sensor (112), and a temperature sensor (113). The voltage sensor (111) is configured to measure a voltage between a positive terminal and a negative terminal of the battery (20). The current sensor (112) is configured to measure a current flowing through the battery (20) when the battery pack (10) is charged or discharged. The temperature sensor (113) is configured to measure a temperature of the battery (20). The detection data represents at least one of a voltage measured by the voltage sensor (111), a current measured by the current sensor (112), and a temperature measured by the temperature sensor (113).

The control unit (120) is operably coupled to the detection unit (110) and the switch (30), and is configured to periodically collect detection data generated by the detection unit (110) from the detection unit (110).

The control unit (120) may be implemented to include at least one of hardware-wise ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), microprocessors, and other electrical units for performing functions. In addition, the control unit (120) may have a built-in memory device (121) (241), and the memory device (121) may be, for example, a RAM, a ROM, a register, a hard disk, an optical recording medium, or a magnetic recording medium. The memory device (121) may store, update, and/or erase a program including various control logics executed by the control unit (120), and/or data generated when the control logic is executed.

The control unit (120) communicates with the external device (1) through a communication channel (13). The communication channel (13) supports wired or wireless communication. The wired communication may be, for example, CAN (control area network) communication, and the wireless communication may be, for example, Zigbee or Bluetooth communication. If it supports wired or wireless communication between the control unit (120) and the external device (1), the type of communication protocol is not particularly limited. The external device (1) may include a device that visually and/or audibly outputs arbitrary information, such as a display or a speaker. When the external device (1) receives a diagnostic message from the control unit (120), the external device (1) may visually and/or audibly output information indicating that the battery (20) is faulty.

The control unit (120) determines at least one diagnostic target value from the detection data from the detection unit (110), and then determines whether the diagnostic target value is within a predetermined normal range. The diagnostic target value indicates the state of the battery (20), and may be, for example, the voltage, current, or temperature of the battery. If the diagnostic target value is out of the normal range, the control unit (120) sets the diagnostic flag associated with the diagnostic target value to a first value, and otherwise sets the diagnostic flag to a second value. The first value (e.g., 1) indicates that the state of the battery (20) is abnormal. The second value (e.g., 0) indicates that the state of the battery (20) is normal.

For example, let's say that a predetermined normal range related to the voltage of the battery (20) is 3.2 to 3.7 V. Then, if the voltage indicated by the detection data is less than 3.2 V or greater than 3.7 V, a first value is set in the diagnostic flag. On the other hand, if the voltage indicated by the detection data is 3.5 V, a second value is set in the diagnostic flag.

As another example, let's say that the predetermined normal range associated with the current of the battery (20) is -100 to 100 A. Then, if the current indicated by the detection data is less than -100 A or greater than 100 A, a first value is set in the diagnostic flag. On the other hand, if the current indicated by the detection data is 50 A, a second value is set in the diagnostic flag.

As another example, let's say that the predetermined normal range associated with the temperature of the battery (20) is -10 to 40°C. Then, if the temperature indicated by the detection data is lower than -10°C or higher than 40°C, a first value is set in the diagnostic flag. On the other hand, if the temperature indicated by the detection data is 25°C, a second value is set in the diagnostic flag.

The control unit (120) may determine at least one diagnostic target value other than the voltage, current, and temperature of the battery (20) based on the detection data from the detection unit (110), and then set the diagnostic flag to a first value or a second value based on the determined diagnostic target value. Examples of the diagnostic target values other than the voltage, current, and temperature of the battery (20) include SOC (State Of Charge), SOH (State Of Health), internal resistance, etc.

For example, let's say that the predetermined normal range associated with the SOC of the battery (20) is 15 to 85%. Then, if the SOC calculated by the control unit (120) based on the detection data is less than 15% or greater than 85%, the first value is set in the diagnostic flag. On the other hand, if the SOC calculated by the control unit (120) is 70%, the second value is set in the diagnostic flag.

As another example, let's say that the predetermined normal range associated with the SOH of the battery (20) is 90 to 100%. Then, if the SOH calculated by the control unit (120) based on the detection data is less than 90%, the first value is set in the diagnostic flag. On the other hand, if the SOH calculated by the control unit (120) is 98%, the second value is set in the diagnostic flag.

As another example, let's say that a predetermined normal range associated with the internal resistance of the battery (20) is 50 to 100 mΩ. Then, if the internal resistance calculated by the control unit (120) based on the detection data is less than 50 mΩ or greater than 100 mΩ, a first value is set in the diagnostic flag. On the other hand, if the internal resistance calculated by the control unit (120) is 80 mΩ, a second value is set in the diagnostic flag.

Data indicating a predetermined normal range associated with each diagnostic target value indicating the status of the battery (20) may be stored in advance in the memory device (121) of the control unit (120).

In the memory device (121) of the control unit (120), a fault detection count associated with at least one diagnostic target value is recorded. The fault detection count reflects a change in the diagnostic target value indicating the state of the battery (20) over time, and is used by the control unit (120) to accurately determine whether the state of the battery (20) is normal or abnormal.

The control unit (120) is configured to increase, decrease, or initialize the fault detection count according to the value set in the diagnostic flag. The control unit (120) can record the fault detection count as the latest value in the memory device (121) each time the fault detection count is increased, decreased, or initialized.

The control unit (120) can linearly or non-linearly increase the fault detection count whenever it is confirmed that the diagnostic flag is set to the first value. Accordingly, when the diagnostic flag is continuously set to the first value, the fault detection count also increases continuously. To this end, the control unit (120) determines an increase factor for increasing the fault detection count based on the result of comparing the fault detection count with the reference value.

If the fault detection count is less than the reference value (e.g., 7), the control unit (120) sets the increase factor to a third value (e.g., 2). If the fault detection count is greater than or equal to the reference value, the control unit (120) can set the increase factor to a fourth value. The fourth value is equal to or greater than the third value. If the fourth value is greater than the third value, the increase amount of the fault detection count due to the first value being set in the diagnostic flag varies based on the reference value.

Separately from the increase factor, the control unit (120) can determine a decrease factor based on the result of comparing the fault detection count with a reference value. The decrease factor is for decreasing the fault detection count.

If the fault detection count is less than the reference value, the control unit (120) can set the reduction factor to a fifth value (e.g., 2).

If the fault detection count is greater than or equal to the reference value, the control unit (120) can set the reduction factor to a sixth value. The sixth value is equal to or smaller than the fifth value. If the sixth value is greater than the fifth value, the reduction amount of the fault detection count due to the second value being set in the diagnostic flag varies based on the reference value.

Alternatively, the control unit (120) may reset the fault detection count if it is confirmed that the second value is set to the diagnostic flag two or more consecutive predetermined times (e.g., 3) even if the fault detection count is equal to or greater than the reference value, and otherwise decrease the fault detection count using a decrease factor set to the fifth or sixth value.

Alternatively, if the fault detection count is less than the reference value, the setting of the reduction factor by the control unit (120) may be omitted. Specifically, if the fault detection count is less than the reference value and the second value is set in the diagnostic flag, the control unit (120) may reset the fault detection count instead of decreasing the fault detection count using the reduction factor.

Alternatively, the control unit (120) may reset the fault detection count in response to the diagnostic flag being set to the second value, regardless of whether the fault detection count is below the threshold value.

The reset fault detection count becomes a predetermined initial value (e.g., 0).

If the fault detection count increases beyond a reference value to a predetermined upper limit (e.g., 12), the control unit (120) outputs a diagnostic message. The diagnostic message can be transmitted to an external device (1) coupled to the control unit (120) via a communication channel (13). The diagnostic message is intended to notify the external device (1) that the battery (20) is faulty.

Independently of the output of the diagnostic message, if the fault detection count exceeds the upper limit, the control unit (120) can control the switch (30) to the off state. Accordingly, since the charging and discharging of the battery (20) is stopped, the battery (20) can be protected from overvoltage, undervoltage, overcharge, overdischarge, or overheating.

FIG. 2 and FIG. 3 are exemplary graphs for explaining the relationship between the first diagnostic target value and the first diagnostic flag determined from the detection data indicating the state of the battery (20) by the device (100) of FIG. 1, and FIG. 4 is an exemplary graph for explaining the first operation of the device (100) of FIG. 1 adjusting the first fault detection count based on the first diagnostic flag of FIG. 3. The first diagnostic target value is not particularly limited as long as it is related to the state of the battery (20), such as voltage, current, temperature, SOC, SOH, and internal resistance of the battery (20). Hereinafter, the explanation will continue on the assumption that the first diagnostic target value is the voltage of the battery (20).

Fig. 2 is a graph showing changes in the voltage of the battery (20), which is the first diagnostic target value, during the period from time point t ₀ to time point t _10. Fig. 3 is a graph showing changes in the value set to the first diagnostic flag corresponding to the first diagnostic target value of Fig. 2.

The time interval (e.g., unit time 0.001 second) between two adjacent time points (e.g., t ₄ and t ₅ ) illustrated in FIGS. 2 to 4 may be constant. Let us assume that the fault detection count recorded in the memory device (121) of the control unit (120) at time point t ₀ is 0 (i.e., initialization value), the first value is 1, the second value is 0, the third value is 2, the fourth value is 3, the fifth value is 2, the sixth value is 1, the first reference value is 7, and the first upper limit value is 12.

Referring to FIG. 2, 11 voltage samples collected by the control unit (120) from the detection unit (110) during the period from time point t ₀ to time point t ₁₀ can be confirmed. The voltages at time points t ₁ , t ₂ , t ₄ , t ₅ , t ₆ , t ₇ , t ₉ , and t ₁₀ are out of the normal range, and the voltages at time points t ₀ , t ₃ , and t ₈ are within the normal range. Accordingly, as illustrated in FIG. 3 , during the period from time points t ₀ to t ₁ , the period from time points t ₃ to t ₄ , and the period from time points t ₈ to t ₉ , the first diagnostic flag is set to the second value 0, whereas during other periods, the first diagnostic flag is set to the first value 1.

Referring to FIGS. 2 to 4, at time t ₀ , since the first diagnostic flag is set to the second value, the control unit (120) maintains the first failure detection count at 0. Since the first failure detection count at time t ₀ is less than the first reference value of 7, the control unit (120) sets the first increase factor to the third value.

At time t ₁ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₁ , the first fault detection count is increased from 0 to 2. Since the first fault detection count at time t ₁ is less than the first reference value of 7, the control unit (120) maintains the first increase factor at the third value and the first decrease factor at the fifth value, respectively.

At time t ₂ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₂ , the first fault detection count is increased from 2 to 4. Since the first fault detection count at time t ₂ is less than the first reference value of 7, the control unit (120) maintains the first increase factor at the third value and the first decrease factor at the fifth value, respectively.

At time t ₃ , since the first diagnostic flag is set to the second value, the control unit (120) decreases the first fault detection count using the first decrease factor. Accordingly, at time t ₃ , the fault detection count is decreased from 4 to 2. Since the fault detection count at time t ₃ is less than the first reference value of 7, the control unit (120) maintains the first increase factor at the third value and the first decrease factor at the fifth value, respectively.

At time t ₄ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₄ , the first fault detection count is increased from 2 to 4. Since the first fault detection count at time t ₄ is less than the first reference value of 7, the control unit (120) maintains the first increase factor at the third value and the first decrease factor at the fifth value, respectively.

At time t ₅ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first failure detection count using the first increase factor. Accordingly, at time t ₅ , the first failure detection count is increased from 4 to 6. Since the first failure detection count at time t ₅ is less than the first reference value of 7, the control unit (120) maintains the first increase factor at the third value and the first decrease factor at the fifth value, respectively.

At time t ₆ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₆ , the first fault detection count is increased from 6 to 8. Since the first fault detection count at time t ₆ is greater than the first reference value of 7, the control unit (120) sets the first increase factor to the fourth value and the first decrease factor to the sixth value, respectively.

At time t ₇ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first failure detection count using the first increase factor. Accordingly, at time t ₇ , the first failure detection count is increased from 8 to 11. Since the first failure detection count at time t ₇ is greater than or equal to the first reference value of 7, the control unit (120) can maintain the first increase factor at the fourth value and the first decrease factor at the sixth value, respectively.

At time t ₈ , since the first diagnostic flag is set to the second value, the control unit (120) decreases the first fault detection count using the first decrease factor. Accordingly, at time t ₈ , the first fault detection count is decreased from 11 to 10. Since the first fault detection count at time t ₈ is greater than or equal to the first reference value of 7, the control unit (120) can maintain the first increase factor at the fourth value and the first decrease factor at the sixth value, respectively.

At time t ₉ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count by using the first increase factor. Accordingly, at time t ₉ , the first fault detection count is increased from 10 to 13, which is greater than the first upper limit value of 12. In response to the first fault detection count increasing to or exceeding the first upper limit value, the control unit (120) can transmit a diagnostic message indicating that the battery (20) is faulty (e.g., undervoltage) to the external device (1) through the communication channel (13).

FIG. 5 is an exemplary graph referenced to explain a second operation in which the device (100) of FIG. 1 adjusts the first failure detection count based on the first diagnostic flag of FIG. 3.

Referring to FIGS. 2, 3, and 5, at time t ₀ , since the first diagnostic flag is set to the second value, the control unit (120) maintains the first failure detection count at 0. Since the first failure detection count at time t ₀ is less than the reference value of 7, the control unit (120) sets the first increase factor to the third value and the first decrease factor to the fifth value, respectively.

At time t ₁ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₁ , the first fault detection count is increased from 0 to 2. Since the first fault detection count at time t ₁ is less than the reference value of 7, the control unit (120) maintains the first increase factor at the third value.

At time t ₂ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₂ , the first fault detection count is increased from 2 to 4. Since the first fault detection count at time t ₂ is less than the reference value of 7, the control unit (120) maintains the first increase factor at the third value.

At time t ₃ , since the first diagnostic flag is set to the second value, the control unit (120) can reset the first failure detection count. Accordingly, at time t ₃ , the first failure detection count is decreased from 4 to 0. Since the first failure detection count at time t ₃ is less than the reference value of 7, the control unit (120) maintains the first increase factor at the third value.

At time t ₄ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₄ , the first fault detection count is increased from 0 to 2. Since the first fault detection count at time t ₄ is less than the reference value of 7, the control unit (120) maintains the first increase factor at the third value.

At time t ₅ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₅ , the first fault detection count is increased from 2 to 4. Since the first fault detection count at time t ₅ is less than the reference value of 7, the control unit (120) maintains the first increase factor at the third value.

At time t ₆ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₆ , the first fault detection count is increased from 4 to 6. Since the first fault detection count at time t ₆ is less than the reference value of 7, the control unit (120) maintains the first increase factor at the third value.

At time t ₇ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first failure detection count using the first increase factor. Accordingly, at time t ₇ , the first failure detection count is increased from 6 to 8. Since the first failure detection count at time t ₇ is greater than or equal to the reference value of 7, the control unit (120) can set the first increase factor to the fourth value and the first decrease factor to the sixth value, respectively.

At time t ₈ , since the first diagnostic flag is set to the second value, the control unit (120) decreases the first fault detection count using the first decrease factor. Accordingly, at time t ₈ , the first fault detection count is decreased from 8 to 7. Since the first fault detection count at time t ₈ is greater than or equal to the reference value of 7, the control unit (120) can maintain the first increase factor at the fourth value and the first decrease factor at the sixth value, respectively.

At time t ₉ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first failure detection count using the first increase factor. Accordingly, at time t ₉ , the first failure detection count is increased from 7 to 10. Since the first failure detection count at time t ₉ is greater than or equal to the reference value of 7, the control unit (120) can maintain the first increase factor at the fourth value and the first decrease factor at the sixth value, respectively.

At time t ₁₀ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count by using the first increase factor. Accordingly, at time t ₁₀ , the first fault detection count is increased from 10 to 13, which is greater than the first upper limit value of 12. In response to the first fault detection count increasing to or exceeding the first upper limit value, the control unit (120) can transmit a diagnostic message indicating that the battery (20) is faulty (e.g., undervoltage) to the external device (1) through the communication channel (13).

Meanwhile, the control unit (120) can simultaneously monitor two or more diagnostic target values indicating the state of the battery (20). The two or more diagnostic target values are each associated with different diagnostic flags and fault detection counts. For example, the control unit (120) can adjust the first fault detection count based on the voltage of the battery (20) as the first diagnostic target value, while adjusting the second fault detection count based on the SOC of the battery (20) as the second diagnostic target value. The first fault detection count can be adjusted by the control unit (120) according to the first diagnostic flag associated with the voltage of the battery (20), as described above. The second fault detection count is used to diagnose whether the battery (20) is in an over-charge or over-discharge state. The control unit (120) can set a second diagnostic flag (not shown) to a first value or a second value based on the second diagnostic dash value, and can adjust (i.e., increase, decrease, or reset) a second fault detection count according to the second diagnostic flag. The second diagnostic flag can be set to the first value if the second diagnostic target value (e.g., SOC) is out of a predetermined normal range, and can be set to the second value otherwise.

Two or more fault detection counts may be related to each other, and a reference value associated with another fault detection count may be changed based on one of the fault detection counts. For example, as the SOC of the battery (20) decreases, the voltage of the battery (20) tends to decrease. Therefore, the control unit (120) may change at least one of the first reference value and the first upper limit value associated with the first fault detection count based on the second fault detection count. Of course, the control unit (120) may also change at least one of the second reference value and the second upper limit value associated with the second fault detection count based on the first fault detection count. Hereinafter, an operation of adjusting two fault detection counts that are related to each other will be described with reference to FIGS. 6 and 7.

FIG. 6 is an exemplary graph showing a first fault detection count adjusted according to the first diagnostic flag of FIG. 3, and FIG. 7 is an exemplary graph showing a second fault detection count related to the first fault detection count of FIG. 6.

The first fault detection count during the period from time t ₀ to t ₃ shown in Fig. 6 changes in the same way as the first fault detection count of Fig. 3.

Meanwhile, referring to FIG. 7, at time t ₄ , the second fault detection count reaches a second reference value of 8 associated with the second fault detection count. In response to the second fault detection count increasing to or exceeding the second reference value, the control unit (120) decreases the first reference value of 7 associated with the first fault detection count by a first adjustment value (e.g., 1). Accordingly, at time t ₄ , the first reference value is decreased from 7 to 6. Alternatively, and unlike as illustrated, when the second fault detection count increases to or exceeding the second reference value, the first upper limit may be decreased by the first adjustment value instead of or together with the first reference value.

At time t ₅ , since the diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₅ , the first fault detection count is increased from 4 to 6. Since the first fault detection count at time t ₅ is equal to the first reference value, 6, the control unit (120) sets the first increase factor to the fourth value and the second decrease factor to the sixth value, respectively. In addition, the control unit (120) may decrease the second reference value associated with the second fault detection count by a second adjustment value (e.g., 1) in response to the first fault detection count increasing to or exceeding the first reference value. The second adjustment value may be a predetermined value equal to, smaller than, or larger than the first adjustment value. Accordingly, at time t ₅ , the second reference value is decreased from 8 to 7. Alternatively, and not as shown, if the first fault detection count increases above the first threshold, the second upper limit may be decreased by the second adjustment value instead of or together with the second threshold.

At time t ₆ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count using the first increase factor. Accordingly, at time t ₆ , the first fault detection count is increased from 6 to 9. The control unit (120) maintains the first increase factor at the fourth value and the second decrease factor at the sixth value, respectively.

At time t ₇ , since the first diagnostic flag is set to the first value, the control unit (120) increases the first fault detection count by using the first increase factor. Accordingly, at time t ₇ , the first fault detection count is increased from 9 to the first upper limit value, 12. In response to the first fault detection count increasing to more than the first upper limit value, the control unit (120) can transmit a diagnostic message indicating that the voltage of the battery (20) is in an abnormal state (e.g., undervoltage) to the external device (1) through the communication channel (13).

The second fault detection count increases or decreases depending on the second diagnostic flag (not shown). Referring to FIG. 7, at time t ₇ , the second fault detection count reaches the second upper limit value, 13. In response to the second fault detection count increasing to or exceeding the second upper limit value, the control unit (120) may transmit a diagnostic message indicating that the SOC of the battery (20) is in an abnormal state (e.g., over-discharge) to the external device (1) through the communication channel (13).

In FIGS. 6 and 7, the second diagnostic target value associated with the first diagnostic target value is exemplified as the SOC of the battery (20), but is not limited thereto. For example, the second diagnostic target value may be the temperature, internal resistance, or other parameters of the battery (20) in addition to the SOC.

FIG. 8 is a flowchart showing a method for diagnosing a failure of a battery (20) according to another embodiment of the present invention.

Referring to FIGS. 1 to 4 and FIG. 8, in step S800, the control unit (120) collects detection data indicating the state of the battery (20) from the detection unit (110).

In step S810, the control unit (120) determines a first diagnostic target value based on the detection data.

In step S820, the control unit (120) determines whether the first diagnostic target value is within a predetermined normal range. If the value of step S820 is “NO”, step S832 is performed. If the value of step S820 is “YES”, step S834 is performed.

In step S832, the control unit (120) sets a first value to the first diagnostic flag.

In step S834, the control unit (120) sets a second value to the first diagnostic flag.

In step S840, the control unit (120) determines whether the first failure detection count recorded in the memory device (121) is less than the first reference value. If the value of step S840 is “YES”, step S852 is performed. If the value of step S840 is “NO”, step S854 is performed.

The control unit (120) may decrease the first reference value or the first upper limit value by the first adjustment value if the second fault detection count associated with the first fault detection count is already equal to or greater than the second reference value before step S840. If the second fault detection count associated with the first fault detection count is less than the second reference value, the control unit (120) may set a predetermined seventh value as the first reference value and a predetermined eighth value as the first upper limit value, respectively. Similarly, if the first fault detection count is less than the first reference value, the control unit (120) may set a predetermined ninth value (e.g., 8) as the second reference value and a predetermined tenth value (e.g., 13) as the second upper limit value, respectively.

In step S852, the control unit (120) sets the first increase factor to the third value and sets the first decrease factor to the fifth value.

In step S854, the control unit (120) sets the first increase factor to a fourth value and sets the first decrease factor to a sixth value. The fourth value is equal to or greater than the third value. The sixth value is equal to or less than the fifth value.

In step S860, the control unit (120) determines whether the first diagnostic flag is set to the first value. If the value of step S860 is “YES”, step S872 is performed. If the value of step S860 is “NO”, step S874 is performed.

In step S872, the control unit (120) increases the first failure detection count using the first increase factor.

In step S874, the control unit (120) decreases the first failure detection count using the first reduction factor.

In step S880, the control unit (120) determines whether the first fault detection count is equal to or greater than the first upper limit value. If the value of step S880 is “YES”, step S890 is performed.

In step S890, the control unit (120) outputs a diagnostic message indicating that the battery (20) is faulty.

FIG. 9 is a flowchart showing a method for diagnosing a failure of a battery (20) according to another embodiment of the present invention.

Referring to FIGS. 1 to 3, 5 and 9, in step S900, the control unit (120) collects detection data indicating the status of the battery (20) from the detection unit (110).

In step S910, the control unit (120) determines a first diagnostic target value based on the detection data.

In step S920, the control unit (120) determines whether the detection data is within a predetermined normal range. If the value of step S920 is “NO”, step S932 is performed. If the value of step S920 is “YES”, step S934 is performed.

In step S932, the control unit (120) sets a first value to the first diagnostic flag.

In step S934, the control unit (120) sets a second value to the first diagnostic flag.

In step S940, the control unit (120) determines whether the first failure detection count recorded in the memory device (121) is less than the first reference value. If the value of step S940 is “YES”, step S952 is performed. If the value of step S940 is “NO”, step S954 is performed.

The control unit (120) may decrease the first reference value or the first upper limit value by the first adjustment value if the second failure detection count associated with the first failure detection count is already equal to or greater than the second reference value before step S940. If the second failure detection count associated with the first failure detection count is less than the second reference value, the control unit (120) may set a predetermined seventh value as the first reference value and a predetermined eighth value as the first upper limit value, respectively. Similarly, if the first failure detection count is less than the first reference value, the control unit (120) may set a predetermined ninth value (e.g., 8) as the second reference value and a predetermined tenth value (e.g., 13) as the second upper limit value, respectively.

In step S952, the control unit (120) sets the first increase factor to a third value.

In step S954, the control unit (120) sets the first increase factor to a fourth value and sets the first decrease factor to a sixth value. The fourth value is equal to or greater than the third value.

In step S960, the control unit (120) determines whether the first diagnostic flag is set to the first value. If the value of step S960 is “YES”, step S972 is performed. If the value of step S960 is “NO”, step S974 is performed.

In step S972, the control unit (120) increases the first failure detection count using the first increase factor.

In step S974, the control unit (120) determines whether the first reduction factor is set to the sixth value. If the value of step S974 is “NO”, step S976 is performed. If the value of step S974 is “YES”, step S978 is performed.

In step S976, the control unit (120) resets the first failure detection count.

In step S978, the control unit (120) decreases the first failure detection count using the first reduction factor.

In step S980, the control unit (120) determines whether the first fault detection count is equal to or greater than the first upper limit value. If the value of step S980 is “YES”, step S990 is performed.

In step S990, the control unit (120) outputs a diagnostic message indicating that the battery (20) is faulty.

The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded, and such implementation can be easily implemented by an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

According to the above-described embodiments, by adjusting the increase or decrease per unit time of the fault detection count associated with each diagnostic target value according to the change over time of each diagnostic target value indicating the state of the battery (20), the fault of the battery (20) can be diagnosed more quickly.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by those skilled in the art within the scope of the technical idea of the present invention and the equivalent scope of the patent claims to be described below.

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

1: External device
10: Battery pack
20: Battery
30: Switch
100: Device
110: Detection Unit
120: Control Unit
121: Memory Device

Claims (13)

In a device for diagnosing battery failure,
A detection unit electrically connected to the battery and generating detection data indicating the status of the battery; and
A control unit configured to determine a diagnostic target value indicating the state of the battery based on the detection data collected from the detection unit,
The above control unit,
Based on the above diagnostic target value, the diagnostic flag associated with the above diagnostic target value is set to a first value indicating that the battery is abnormal or a second value indicating that the battery is normal,
If the fault detection count associated with the above diagnostic target value is less than the reference value and the above diagnostic flag is set to the first value, the fault detection count is increased using the third value as an increase factor,
A device configured to increase the fault detection count by using a fourth value greater than the third value as the increase factor when the fault detection count is greater than or equal to the reference value and the diagnostic flag is set to the first value.
delete In the first paragraph,
The above control unit,
If the above fault detection count is less than the above reference value, the reduction factor is set to the fifth value,
A device configured to decrease the fault detection count using the reduction factor when the fault detection count is less than the reference value and the diagnostic flag is set to the second value.
In the third paragraph,
The above control unit,
If the above fault detection count is greater than or equal to the reference value, the reduction factor is set to the sixth value,
When the fault detection count is greater than or equal to the reference value and the diagnostic flag is set to the second value, the fault detection count is configured to be reduced using the reduction factor.
The device wherein the sixth value is smaller than the fifth value.
In a device for diagnosing battery failure,
A detection unit electrically connected to the battery and generating detection data indicating the status of the battery; and
A control unit configured to determine a diagnostic target value indicating the state of the battery based on the detection data collected from the detection unit,
The above control unit,
Based on the above diagnostic target value, the diagnostic flag associated with the above diagnostic target value is set to a first value indicating that the battery is abnormal or a second value indicating that the battery is normal,
When the above diagnostic flag is set to the first value, the fault detection count associated with the diagnostic target value is increased,
A device configured to reset the fault detection count when the fault detection count is less than a reference value and the diagnostic flag is set to the second value.
In the first paragraph,
The above diagnostic target value is one of the voltage, current, temperature, SOC, SOH or internal resistance of the battery,
The above control unit,
If the above diagnostic target value is out of the specified normal range, the first value is set to the above diagnostic target value,
A device configured to set the second value to the diagnostic target value when the diagnostic target value is within the normal range.
In the first paragraph,
The above control unit,
A device configured to output a diagnostic message when the increased fault detection count is greater than an upper limit value greater than the reference value.
A battery pack comprising the device according to any one of claims 1 and 3 to 7.
In a method for diagnosing a battery failure,
A step in which the control unit collects detection data indicating the status of the battery from a detection unit electrically connected to the battery;
A step in which the control unit determines a diagnostic target value based on the detection data;
A step in which the control unit sets a diagnostic flag associated with the diagnostic target value based on the diagnostic target value to a first value indicating that the battery is abnormal or a second value indicating that the battery is normal;
The step of the control unit increasing the fault detection count by using the third value as an increase factor when the fault detection count associated with the diagnostic target value is less than the reference value and the diagnostic flag is set to the first value; and
A method comprising: a step of increasing the fault detection count by using a fourth value greater than the third value as the increase factor when the control unit determines that the fault detection count is greater than or equal to the reference value and the diagnostic flag is set to the first value.
delete In Article 9,
The step of the control unit setting the reduction factor to a fifth value when the fault detection count is less than the reference value; and
A method further comprising the step of decreasing the fault detection count using the reduction factor when the control unit determines that the fault detection count is less than the reference value and the diagnostic flag is set to the second value.
In Article 11,
The step of the control unit setting the reduction factor to a sixth value when the fault detection count is greater than or equal to the reference value; and
The control unit further includes a step of decreasing the fault detection count using the reduction factor when the fault detection count is greater than or equal to the reference value and the diagnostic flag is set to the second value.
A method wherein the sixth value is smaller than the fifth value. In a method for diagnosing a battery failure,
A step in which the control unit collects detection data indicating the status of the battery from a detection unit electrically connected to the battery;
A step in which the control unit determines a diagnostic target value based on the detection data;
A step in which the control unit sets a diagnostic flag associated with the diagnostic target value based on the diagnostic target value to a first value indicating that the battery is abnormal or a second value indicating that the battery is normal;
The step of the control unit increasing the fault detection count associated with the diagnostic target value when the diagnostic flag is set to the first value; and
A method, wherein the control unit comprises a step of resetting the fault detection count when the fault detection count is less than a reference value and the diagnostic flag is set to the second value.

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