CN118265919A - Battery diagnostic device and method for detecting leakage current - Google Patents

Abstract

An apparatus for diagnosing a battery located in a battery system including one or more batteries may include: at least one processor; and a memory configured to store at least one instruction for execution by the at least one processor. The at least one instruction may include: instructions for collecting state of charge information of a battery in a standby mode state of the battery system; instructions for calculating an amount of power change of the battery during a hold period of the standby mode based on the collected state-of-charge information and the pre-stored initial state-of-charge information; and instructions for comparing the calculated amount of power change with an expected amount of discharged power of the battery and determining whether leakage current occurs in the battery system based on a result of the comparison.

Description

Battery diagnostic device and method for detecting leakage current

Technical Field

This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0130145 filed in the Korean Intellectual Property Office on October 12, 2022, and Korean Patent Application No. 10-2023-0068061 filed in the Korean Intellectual Property Office on May 26, 2023, the entire contents of which are incorporated herein by reference.

The present invention relates to a battery diagnosis apparatus and method, and more particularly, to a battery diagnosis apparatus and method for detecting leakage current in a battery system based on an amount of power variation in a standby mode state of the battery system.

Background technique

A secondary battery is a battery that can be recharged and reused even after being discharged. Secondary batteries can be used as energy sources for small devices such as mobile phones, tablets, vacuum cleaners, and can also be used as energy sources for medium and large devices such as ESS (Energy Storage System) of automobiles and smart grids.

Secondary batteries are applied to systems in the form of components such as battery modules in which a plurality of battery cells are connected in series and in parallel or battery packs in which battery modules are connected in series and in parallel according to system requirements. In the case of medium or large-sized equipment such as electric vehicles, a high-capacity battery system in which a plurality of battery packs are connected in parallel can be applied in order to meet the required capacity of the equipment.

In order to stably operate the battery system, the insulation state of each electrical component provided in the battery system must be well maintained. If the insulation state is not maintained, leakage current may occur and a malfunction or fire may occur in the battery system and the device.

As a leakage current detection technique, a method of determining whether a leakage current is generated in a battery system using a leakage current detection sensor provided at a specific position is mainly adopted.

However, when a minute current leaks from the battery system to the power converter (PCS) or a leakage current is generated due to a ground fault in the battery assembly, the leakage current cannot be detected using conventional techniques.

Therefore, as a technology capable of solving the problems of the related art, there is a need for an appropriate technology capable of accurately detecting whether a leakage current occurs in a battery system without using a leakage current detection sensor.

Summary of the invention

[technical problem]

To solve one or more problems in the related art, embodiments of the present disclosure provide a battery diagnosis apparatus capable of detecting whether a leakage current is generated in a battery system without using a leakage current detection sensor.

In order to solve one or more problems in the related art, an embodiment of the present disclosure also provides a battery diagnosis method using the battery diagnosis device.

[Technical solutions]

To achieve the purpose of the present disclosure, a device for diagnosing a battery in a battery system including one or more batteries may include: at least one processor; and a memory configured to store at least one instruction executed by the at least one processor.

At least one instruction may include: an instruction for collecting charging status information of a battery in a standby mode state of the battery system; an instruction for calculating an amount of power change of the battery during a holding period of the standby mode based on the collected charging status information and pre-stored initial charging status information; and an instruction for comparing the calculated amount of power change with an expected discharge power amount of the battery and determining whether leakage current occurs in the battery system based on the comparison result.

Instructions for collecting charging status information of a battery may include: instructions for collecting an open circuit voltage value (Vocv) measured after a predetermined time has elapsed once the battery system switches to a standby mode; instructions for determining a charging status value (SOC) based on the open circuit voltage value (Vocv); and instructions for storing the calculated charging status value (SOC) as an initial charging status value (SOC_init).

The instructions for collecting state of charge information of the battery may include instructions for determining a state of charge value (SOC) of the battery at each predefined time in a standby mode state of the battery system.

The instruction for calculating the power variation amount of the battery may include an instruction for calculating the power variation amount based on a difference (ΔSOC) between a pre-stored initial state of charge value (SOC_init) and the determined state of charge value (SOC).

The expected discharge power amount may be defined based on at least one of: the self-discharge power amount of the battery; and the internal supply power amount provided by the battery to a power requesting device located inside the battery system.

The expected discharge power amount may be defined as a value obtained by multiplying a predefined weighting coefficient by the sum of the self-discharge power amount and the power amount supplied by the battery to a battery management system (BMS).

The instructions for determining whether leakage current has occurred in the battery system may include instructions for determining that leakage current has occurred in the battery if the calculated amount of power variation exceeds an expected amount of discharge power.

The at least one instruction may further include: an instruction for collecting a temperature value of the battery in a standby mode state of the battery system; and an instruction for calculating a temperature variation amount based on the collected temperature value.

Instructions for determining whether leakage current has occurred in the battery system may include instructions for determining that leakage current has occurred in the battery when a first condition in which a calculated power change exceeds an expected discharge power amount and a second condition in which a calculated temperature change exceeds a predefined reference temperature change are satisfied.

The at least one instruction also includes an instruction for determining whether the battery is performing a balancing control operation. Here, the instruction for determining whether a leakage current has occurred in the battery system may include an instruction for determining that a leakage current has occurred in the battery when a first condition in which the calculated power change amount exceeds the expected discharge power amount and a third condition in which the battery does not perform a balancing control operation are satisfied.

The instructions for determining whether a leakage current occurs in the battery system may include instructions for detecting one or more batteries in which the leakage current is generated among a plurality of batteries included in the battery system.

According to another embodiment of the present disclosure, a method for diagnosing a battery by a battery diagnostic device located in a battery system including one or more batteries may include: collecting charging status information of the battery in a standby mode state of the battery system; calculating the power change of the battery during the holding period of the standby mode based on the collected charging status information and pre-stored initial charging status information; and comparing the calculated power change with the expected discharge power of the battery, and determining whether leakage current occurs in the battery system based on the comparison result.

Collecting the charging state information of the battery may include: collecting an open circuit voltage value (Vocv) measured after a predetermined time has elapsed once the battery system switches to a standby mode; determining a charging state value (SOC) based on the open circuit voltage value (Vocv); and storing the calculated charging state value (SOC) as an initial charging state value (SOC_init).

Collecting the state of charge information of the battery may include determining a state of charge value (SOC) of the battery at each predefined time in the standby mode state of the battery system.

Calculating the power variation amount of the battery may include calculating the power variation amount based on a difference (ΔSOC) between a pre-stored initial state of charge value (SOC_init) and the determined state of charge value (SOC).

The expected discharge power amount may be defined based on at least one of: a self-discharge power amount of the battery; and an internal supply power amount provided by the battery to a power requesting device located inside the battery system.

The expected discharge power amount may be defined as a value obtained by multiplying a predefined weighting coefficient by the sum of the self-discharge power amount and the power amount supplied by the battery to a battery management system (BMS).

Determining whether a leakage current has occurred in the battery system may include determining that a leakage current has occurred in the battery if the calculated power variation amount exceeds an expected discharge power amount.

The method may further include: collecting a temperature value of the battery in a standby mode state of the battery system; and calculating a temperature variation amount based on the collected temperature value.

Determining whether leakage current has occurred in the battery system may include determining that leakage current has occurred in the battery when a first condition in which a calculated power change exceeds an expected discharge power amount and a second condition in which a calculated temperature change exceeds a predefined reference temperature change are satisfied.

The method may further determine whether the battery is performing a balancing control operation. Here, determining whether a leakage current has occurred in the battery system may include: determining that a leakage current has occurred in the battery when a first condition in which the calculated power change amount exceeds the expected discharge power amount and a third condition in which the battery is not performing a balancing control operation are satisfied.

Determining whether a leakage current occurs in the battery system may include detecting one or more batteries in which the leakage current is generated among a plurality of batteries included in the battery system.

According to another embodiment of the present disclosure, a battery system may include: a plurality of batteries; and a battery management device for monitoring and controlling the plurality of batteries.

The battery management device can be configured to: collect charging status information of each battery in a standby mode state of the battery system; calculate the power change of each battery during the maintenance period of the standby mode based on the collected charging status information and pre-stored initial charging status information; and compare the calculated power change with the expected discharge power of each battery, and determine whether leakage current occurs in the battery system based on the comparison result.

[Beneficial Effects]

According to the embodiments of the present disclosure, it is possible to more accurately determine whether a leakage current occurs in a battery system, and detect a battery in which the leakage current occurs without using a leakage current detection sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a battery system according to an embodiment of the present invention.

FIG. 2 is an operational flow chart of a method for diagnosing a battery according to the present invention.

FIG. 3 is an operational flow chart of a method for diagnosing a battery according to an embodiment of the present invention.

FIG. 4 is an operational flow chart of a method for diagnosing a battery according to another embodiment of the present invention.

FIG. 5 is a block diagram showing an implementation example of a battery system according to an embodiment of the present invention.

6 and 7 are block diagrams for explaining the operation of the battery system shown in FIG. 5 .

FIG. 8 is a block diagram of an apparatus for diagnosing a battery according to an embodiment of the present invention.

10: Battery

100: Battery components

200, 700: Battery diagnostic device

Detailed ways

[Best Mode for Carrying Out the Present Disclosure]

The present invention can be modified in various forms and have various embodiments, and its specific embodiments are shown in the accompanying drawings by way of example and will be described in detail below. However, it should be understood that there is no intention to limit the present invention to specific embodiments, on the contrary, the present invention will cover all modifications, equivalents and alternatives that fall within the spirit and technical scope of the present invention. Throughout the description of the drawings, similar reference numerals represent similar elements.

It should be understood that although various elements may be described herein using terms such as first, second, A, B, etc., these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the present invention. As used herein, the term "and/or" includes a combination of multiple associated listings or any of multiple associated listings.

It should be understood that when an element is referred to as being "coupled" or "connected" to another element, it can be directly coupled or connected to the other element, or there can be intervening elements. Conversely, when an element is referred to as being "directly coupled" or "directly connected" to another element, there are no intervening elements.

The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "include", "comprise", "include", "contain" and/or "have" are used herein to specify the presence of the features, integers, steps, operations, constituent elements, parts and/or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, constituent elements, parts and/or combinations thereof.

Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Some terms used herein are defined below.

The state of charge value (SOC) refers to the current state of charge of the battery expressed in percentage points [%], and the state of health (SOH) may be the current condition of the battery compared to its ideal or original condition expressed in percentage points [%].

A battery cell is a minimum unit for storing electricity, and a battery module refers to an assembly in which a plurality of battery cells are electrically connected.

A battery pack or battery rack refers to a system of the smallest single structure assembled by electrically connecting module units, which are set by the battery manufacturer. A battery pack or battery rack may be monitored and controlled by a battery management device/system (BMS). A battery pack or battery rack may include several battery modules and a battery protection unit or any other protection device.

A battery library refers to a large battery rack system configured by connecting several racks in parallel. The library BMS of the battery library can monitor and control several rack BMSs, and each rack BMS manages the battery racks.

A battery assembly may include a plurality of electrically connected battery cells and refers to an assembly used as a power source by being applied to a specific system or device. Here, a battery assembly may mean a battery module, a battery pack, a battery rack, or a battery bank, but the scope of the present invention is not limited to these entities.

FIG. 1 is a block diagram showing a battery system according to an embodiment of the present invention.

1 , the battery system may include a battery assembly 100 including a plurality of batteries 10 (BAT# 1 to BAT#N) and a battery diagnostic apparatus 200 .

A plurality of batteries 10 may be electrically connected to form a battery assembly 100 .

The battery system according to the present invention can be implemented by being included in an ESS (energy storage system), but the scope of the present invention is not limited thereto. In other words, the battery system according to the present invention can be applied to various devices and operates to detect abnormal batteries by performing the method for detecting abnormal batteries as described below.

The battery 10 according to the present invention may refer to a battery cell, but the scope of the present invention is not limited thereto. In other words, the battery system according to the present invention may perform a method for detecting an abnormal battery described below for a battery cell, a battery module, a battery rack, or a battery pack to detect an object in which an abnormality has occurred.

The battery diagnostic device 200 may be implemented by being included in a battery management device/system (BMS) located inside the battery system.

The battery diagnostic device 200 can calculate the battery power variation based on the state information collected in the standby mode state of the battery system, determine whether leakage current is generated in the battery system based on this, and identify the battery in which the leakage current is generated. In an embodiment, the battery diagnostic device 200 can determine whether leakage current is generated in the battery system and identify the battery in which the leakage current is generated based on one or more of the battery power variation in the standby mode state of the battery system, the battery temperature variation, and whether a balancing control operation is performed.

In other words, unlike the related art using a leakage current detection sensor, the present invention can diagnose whether a leakage current has occurred by using a device for collecting status information that is necessarily provided in a battery system.

Hereinafter, various embodiments of the present invention will be described in detail with reference to FIGS. 2 to 8 .

FIG. 2 is an operational flow chart of a method for diagnosing a battery according to the present invention.

When the battery system switches to the standby mode (S210), the battery diagnosis device 200 may collect SOC information of the battery while maintaining the standby mode (S220). Here, the charge state information may include an identifier of the corresponding battery and a charge state value (SOC) of the corresponding battery.

The battery diagnostic apparatus 200 may collect the open circuit voltage value (Vocv) measured by the voltage measuring device, and determine the state of charge value (SOC) based on the collected open circuit voltage value (Vocv). Here, the battery diagnostic apparatus 200 may check the state of charge value (SOC) matching the collected open circuit voltage value (Vocv) in the graph of the V _OCV -SOC relationship of the corresponding battery, and may determine the matching state of charge value (SOC) as the state of charge value (SOC) of the corresponding battery.

The battery diagnosis device 200 may determine the state of charge (SOC) of the battery at every predefined time. For example, the battery diagnosis device 200 may determine the state of charge (SOC) of the battery every second.

The battery diagnosis device 200 may calculate the battery power variation amount during the period of maintaining the standby mode (S230). Here, the battery diagnosis device 200 may calculate the power variation amount based on the collected charging state information and the pre-stored initial charging state information.

More specifically, the battery diagnostic apparatus 200 may determine an initial state of charge value (SOC_init) based on an initially measured open circuit voltage value after the battery system is switched to the standby mode, and store the initial state of charge value (SOC_init) in a storage device (e.g., a nonvolatile memory). Thereafter, the battery diagnostic apparatus 200 may calculate the amount of power variation at a corresponding time point based on a difference between the initial state of charge value (SOC_init) stored in the storage device and a state of charge value (SOC_present) determined according to an open circuit voltage value measured at a later time point.

The battery diagnosis device 200 may compare the calculated power variation with a predefined threshold value (S240). Here, the threshold value may be defined as an expected discharge power amount of the corresponding battery.

The battery diagnosis device 200 may determine whether leakage current occurs in the battery system based on the result of comparing the power variation with the predefined threshold value (S250). Here, when the power variation exceeds the predefined threshold value, the battery diagnosis device 200 may determine that leakage current occurs in the corresponding battery.

In other words, the battery diagnosis apparatus 200 according to the embodiment of the present invention may determine that abnormal self-discharge, ie, leakage current, of the corresponding battery occurs when the amount of power variation during the standby mode maintenance period exceeds a set threshold (eg, expected discharge power amount).

FIG. 3 is an operational flow chart of a method for diagnosing a battery according to an embodiment of the present invention.

When the battery system switches to the standby mode (S310), the battery diagnostic device 200 may collect an initial open circuit voltage value (Vocv_init) of the battery (S320). Here, the initial open circuit voltage value (Vocv_init) may correspond to an open circuit voltage value measured at a time point when a predefined time (e.g., 30 minutes) has elapsed after switching to the standby mode.

The battery diagnostic apparatus 200 may determine an initial state of charge value (SOC_init) based on the initial open circuit voltage value (Vocv_init), and store the determined initial state of charge value (SOC_init) in a storage device (e.g., a nonvolatile memory) (S330). Here, the battery diagnostic apparatus 200 may check a state of charge value (SOC) that matches the initial open circuit voltage value (Vocv_init) in a graph of a Vocv-SOC relationship of the corresponding battery, and may determine the matched state of charge value (SOC) as the initial state of charge value (SOC_init) of the corresponding battery.

Thereafter, the battery diagnosis apparatus 200 may collect the open circuit voltage value (Vocv) measured by the voltage measurement device, and determine the state of charge (SOC_present) at the present time (the time point of collecting the open circuit voltage value) based on the collected open circuit voltage value (Vocv) ( S340 ).

The battery diagnosis apparatus 200 may calculate a difference (ΔSOC) between an initial state of charge value (SOC_init) stored in the storage device and a state of charge value (SOC_present) at the current time (S350), and calculate a power variation (ΔP) at the time point based on the calculated difference (ΔSOC) (S360).

Thereafter, the battery diagnosis apparatus 200 may compare the calculated power variation (ΔP) with a predefined threshold value (S370). Here, the threshold value may be defined as an expected discharge power amount of the corresponding battery.

In an embodiment, the expected discharge power amount may be defined based on at least one of the self-discharge power amount (P_sd) of the battery and the internal supply power amount (P_in) provided by the battery to the power request device located inside the battery system. Here, the self-discharge power amount (P_sd) may mean the expected self-discharge power amount calculated based on the self-discharge rate of the battery stored in advance. In addition, the power request device may refer to a device that operates by receiving power from the battery in the standby mode state of the battery system.

In an embodiment, the expected discharge power amount may be defined as the sum of the self-discharge power amount of the battery and the internal supply power amount (P_sd+P_in). For example, the expected discharge power amount may be defined as the sum of the self-discharge power amount of the battery and the power amount supplied from the battery to the battery management system (BMS) in standby mode (P_sd+P_bms).

In another embodiment, the expected discharge power amount may be defined as a value obtained by multiplying a predefined weighting factor (w) by the sum of the self-discharge power amount of the battery and the internal supply power amount (w*(P_sd+P_in)). Here, the weighting factor w is a value defined to prevent misdiagnosis due to errors in the open circuit voltage value and the SOC value, and may be defined as a specific value greater than 1.0 and less than or equal to 1.3, for example.

When the power variation amount ΔP is less than or equal to the threshold value (eg, the expected discharge power amount) (No in S370 ), the battery diagnosis apparatus 200 may return to step S340 and perform subsequent processes again.

If the power variation amount (ΔP) exceeds the threshold value (expected discharge power amount) (Yes in S370 ), the battery diagnosis device 200 may determine that a leakage current has occurred in the corresponding battery ( S380 ).

In an embodiment, when the battery system includes a plurality of batteries, the battery diagnosis apparatus 200 may detect a battery having a leakage current among the plurality of batteries.

Specifically, battery diagnosis device 200 may calculate power variation ΔP of each of batteries BAT#1 to BAT#N, detect a battery whose power variation ΔP exceeds a threshold value (eg, expected discharge power amount), and determine that leakage current is generated in the corresponding battery.

Here, when it is determined that leakage current is generated in all batteries included in the battery system, the battery diagnostic device 200 may determine that leakage current is generated in the entire battery system. For example, when it is determined that leakage current is generated in all battery packs included in the battery rack, the battery diagnostic device 200 may determine that leakage current is generated in the entire battery rack.

FIG4 is an operation flow chart of a method for diagnosing a battery according to another embodiment of the present invention. Specifically, FIG4 shows a battery diagnosis method, in which the battery diagnosis device determines whether leakage current is generated by further considering at least one of a temperature change amount and whether a balancing control operation is performed in addition to the power change amount.

In this embodiment, the battery diagnostic device 200 can determine that a leakage current is generated in the corresponding battery when a first condition is satisfied in which the amount of power change in the standby mode exceeds the expected amount of discharge power and one or more of a second condition and a third condition are further satisfied, wherein the second condition is a condition that the amount of temperature change in the standby mode exceeds a predefined reference temperature change, and the third condition is a condition that the battery is in a state where a balancing control operation is not performed.

4, when the battery system switches to the standby mode (S410), the battery diagnostic device 200 can collect the state information of the battery while maintaining the standby mode (S420). Here, the state information may include one or more of the identifier, the state of charge value (SOC) and the temperature value (T) of the corresponding battery.

The battery diagnosis device 200 may collect the battery status information at every predefined time. For example, the battery diagnosis device 200 may collect the battery state of charge value (SOC) and temperature value (T) every second.

The battery diagnosis device 200 may calculate a power variation (ΔP) and a temperature variation (ΔT) of the battery during a period in which the standby mode is maintained, and determine whether a battery balancing control operation is being performed ( S430 ).

More specifically, the battery diagnostic device 200 may determine an initial state of charge value (SOC_init) based on an initially measured open circuit voltage value after the battery system is switched to the standby mode, and calculate a power change amount (ΔP) at a corresponding time point based on a difference between the initial state of charge value (SOC_init) and a state of charge value (SOC_present) at a later time point. In addition, the battery diagnostic device 200 may store an initially measured temperature value (T_init) after the battery system is switched to the standby mode in the storage device, and calculate a temperature change amount (ΔT) at a corresponding measurement time point based on a difference between the stored initial temperature value (T_init) and a temperature value measured at a later time point (T_present). Furthermore, the battery diagnostic device 200 may determine whether to perform a battery balancing control operation in conjunction with a balancing circuit that performs a balancing control operation to resolve an unbalanced state of a battery or a battery management device that controls the balancing circuit.

The battery diagnosis device 200 may determine whether one or more of the first condition, the second condition, and the third condition are satisfied, wherein the first condition is a condition that the calculated power variation (ΔP) exceeds the expected discharge power, the second condition is a condition that the calculated temperature variation (ΔT) exceeds a predefined reference temperature variation, and the third condition is a state in which the battery does not perform a balancing control operation (S440). Here, the reference temperature variation of the second condition may be defined as an average value of temperature variations of batteries other than the battery to be diagnosed, or may be defined as a value obtained by multiplying the average value by a predefined weighting coefficient.

The battery diagnosis apparatus 200 may determine whether leakage current occurs in the battery system based on whether one or more of the first condition, the second condition, and the third condition are satisfied ( S450 ).

In one embodiment, the battery diagnosis device 200 can determine that leakage current is generated in the battery when the battery to be diagnosed meets the first condition and the second condition. In other words, when the power change amount in the standby mode exceeds the expected discharge power amount and the temperature change amount exceeds the reference value, it can be determined that leakage current is generated in the corresponding battery.

In another embodiment, the battery diagnostic device 200 may determine that leakage current is generated in the battery when the battery to be diagnosed satisfies the first condition and the third condition. In other words, when the power change amount in the standby mode exceeds the expected discharge power amount and the battery is in a state where the balancing control operation is not performed, it may be determined that leakage current is generated in the corresponding battery. If the battery is performing a balancing control operation, the charge/discharge amount used for balancing is reflected when calculating the power change amount, and therefore, accurate diagnosis is performed only by whether the first condition is satisfied. In order to prevent erroneous diagnosis due to the balancing operation, in addition to the first condition, the battery diagnostic device 200 may also consider the third condition to determine whether leakage current occurs.

In another embodiment, the battery diagnosis apparatus 200 may determine that a leakage current is generated in the battery when the battery to be diagnosed satisfies all of the first condition, the second condition, and the third condition.

FIG. 5 is a block diagram showing an implementation example of a battery system according to an embodiment of the present invention, and FIGS. 6 and 7 are block diagrams for explaining operations of the battery system shown in FIG. 5 .

5 , the battery system according to the embodiment of the present invention may be implemented by being included in a battery pack 100'.

The battery pack 100' may include a plurality of battery modules (Module #1 to Module #N), and each of the battery modules may include a plurality of battery cells 10' (CELL #1 to CELL #N).

The battery diagnosis device according to the present invention may correspond to a battery management system (PBMS) 200' of the battery pack 100' or be included in the battery management system (PBMS) 200'.

When the battery pack is switched to the standby mode, the battery management system (PBMS) may collect initial open circuit voltage values (Vocv_init) of the corresponding battery cells, determine initial state of charge values (SOC_init) of the corresponding battery cells, and store them in a storage device (e.g., a non-volatile memory). In addition, the battery management system (PBMS) may collect and store initial temperature values (T_init) of the corresponding battery cells in the storage device.

Thereafter, while maintaining the standby mode of the battery pack, the battery management system (PBMS) may calculate the power change amount (ΔP) of each of the battery cells per unit time based on the SOC value change amount (ΔSOC=SOC_init-SOC_present). In addition, the battery management system (PBMS) may calculate the temperature value change amount (ΔT=T_init-T_present) per unit time while maintaining the standby mode of the battery pack.

The battery management system (PBMS) may determine whether the leakage current is generated by determining whether one or more of the first to third conditions are satisfied for each of the battery cells.

For example, referring to FIG. 6 , the battery management system (PBMS) detects a battery cell in which the power variation ΔP exceeds the expected discharge power amount (satisfying the first condition) among a plurality of battery cells, and determines that a leakage current is generated in the corresponding battery (cell #2 of module #1). As another example, the battery management system (PBMS) detects a battery cell in which the power variation (ΔP) exceeds the expected discharge power amount (satisfying the first condition) and the temperature variation (ΔT) exceeds the reference temperature variation (satisfying the second condition) among a plurality of battery cells, and determines that a leakage current is generated in the corresponding battery (cell #2 of module #1). For another example, when the battery management system (PBMS) determines a cell in which the power variation (ΔP) exceeds the expected discharge power amount (satisfying the first condition), the temperature variation (ΔT) exceeds the reference temperature variation (satisfying the second condition), and the cell balancing operation is not performed (satisfying the third condition), it determines that a leakage current is generated in the corresponding battery (cell #2 of module #1).

7 , when it is determined that the leakage current is generated among all the battery cells included in the battery pack, the battery management system (PBMS) may determine that the leakage current is generated in the entire battery pack.

The battery management system (PBMS) may transmit leakage current diagnostic information to an upper battery management device. For example, the battery management system (PBMS) may transmit the leakage current diagnostic result to at least one of a rack battery management system (RBMS), a battery segment controller (BSC), an energy management system (EMS), and a power management system (PMS). Here, the leakage current diagnostic information may include one or more of whether leakage current occurs, the number of batteries generating leakage current, and an identifier of the battery generating leakage current.

Meanwhile, unlike FIGS. 5 to 7 , the battery system according to an embodiment of the present invention may be implemented by being included in a battery module, a battery rack or a battery library, and the method for diagnosing leakage current according to the present invention may be performed in the same manner even for these cases.

FIG. 8 is a block diagram of an apparatus for diagnosing a battery according to an embodiment of the present invention.

The battery diagnosis device 800 according to the embodiment of the present invention may include at least one processor 810 , a memory 820 configured to store at least one instruction executed by the processor, and a transceiver 830 connected to a network for communication.

At least one instruction may include: an instruction for collecting charging status information of a battery in a standby mode state of the battery system; an instruction for calculating an amount of power change of the battery during a holding period of the standby mode based on the collected charging status information and pre-stored initial charging status information; and an instruction for comparing the calculated amount of power change with an expected discharge power amount of the battery and determining whether leakage current occurs in the battery system based on the comparison result.

Instructions for collecting charging status information of a battery may include: instructions for collecting an open circuit voltage value (Vocv) measured after a predetermined time has elapsed once the battery system switches to a standby mode; instructions for determining a charging status value (SOC) based on the open circuit voltage value (Vocv); and instructions for storing the calculated charging status value (SOC) as an initial charging status value (SOC_init).

The instructions for collecting state of charge information of the battery may include instructions for determining a state of charge value (SOC) of the battery at each predefined time in a standby mode state of the battery system.

The instruction for calculating the power variation amount of the battery may include an instruction for calculating the power variation amount based on a difference (ΔSOC) between a pre-stored initial state of charge value (SOC_init) and the determined state of charge value (SOC).

The expected discharge power amount may be defined based on at least one of: a self-discharge power amount of the battery; and an internal supply power amount provided by the battery to a power requesting device located inside the battery system.

The expected discharge power amount may be defined as a value obtained by multiplying a predefined weighting coefficient by the sum of the self-discharge power amount and the power amount supplied by the battery to a battery management system (BMS).

The instructions for determining whether leakage current has occurred in the battery system may include instructions for determining that leakage current has occurred in the battery if the calculated amount of power variation exceeds an expected amount of discharge power.

The at least one instruction may further include: an instruction for collecting a temperature value of the battery in a standby mode state of the battery system; and an instruction for calculating a temperature variation amount based on the collected temperature value.

Instructions for determining whether leakage current has occurred in the battery system may include instructions for determining that leakage current has occurred in the battery when a first condition in which a calculated power change exceeds an expected discharge power amount and a second condition in which a calculated temperature change exceeds a predefined reference temperature change are satisfied.

The at least one instruction also includes an instruction for determining whether the battery is performing a balancing control operation. Here, the instruction for determining whether a leakage current has occurred in the battery system may include an instruction for determining that a leakage current has occurred in the battery when a first condition in which the calculated power change amount exceeds the expected discharge power amount and a third condition in which the battery is not performing a balancing control operation are satisfied.

The instructions for determining whether a leakage current occurs in the battery system may include instructions for detecting one or more batteries in which the leakage current is generated among a plurality of batteries included in the battery system.

The instructions for determining whether a leakage current occurs in the battery system may include instructions for determining that the leakage current is generated in the entire battery system when determining that the leakage current is generated in all battery cells included in the battery system.

The battery diagnosis apparatus 800 may further include an input interface 840 , an output interface 850 , a storage device 860 , etc. The various components included in the battery diagnosis apparatus 800 are connected through a bus 770 to communicate with each other.

Here, the processor 810 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor for executing the method according to an embodiment of the present invention. The memory (or storage device) may include at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory may include at least one of a read-only memory (ROM) and a random access memory (RAM).

The operation of the method according to an embodiment of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. The computer-readable recording medium includes all types of recording devices in which data readable by a computer system is stored. In addition, the computer-readable recording medium can be distributed in a networked computer system to store and execute a computer-readable program or code in a distributed manner.

Although some aspects of the present invention have been described in the context of an apparatus, it can also be represented by a description according to a corresponding method, wherein a block or apparatus corresponds to a method step or a feature of a method step. Similarly, the aspects described in the context of a method can also represent the features of a corresponding block or project or a corresponding apparatus. Some or all of the method steps can be performed by (or using) hardware devices (such as, for example, microprocessors, programmable computers, or electronic circuits). In some embodiments, one or more of the most important method steps can be performed by such an apparatus.

In the foregoing, the present invention has been described with reference to exemplary embodiments thereof, but those skilled in the art will appreciate that various corrections and changes may be made to the present invention within the scope without departing from the spirit and scope of the invention described in the appended claims.

Claims (23)

1. An apparatus for diagnosing a battery located in a battery system including one or more batteries, the apparatus comprising:

At least one processor; and

A memory for storing at least one instruction for execution by the at least one processor,

Wherein the at least one instruction comprises:

instructions for collecting state of charge information of the battery in a standby mode state of the battery system;

Instructions for calculating an amount of change in power of the battery during a hold period of the standby mode based on the collected state of charge information and pre-stored initial state of charge information;

instructions for comparing the calculated amount of power change with an expected amount of discharged power of the battery and determining whether leakage current occurs in the battery system based on a result of the comparison.

2. The apparatus of claim 1, wherein the instructions for collecting state of charge information of the battery comprise:

Instructions for collecting an open circuit voltage value (Vocv) measured after a predetermined time elapses once the battery system is switched to a standby mode;

instructions for determining a state of charge value (SOC) based on the open circuit voltage value (Vocv); and

Instructions for storing the calculated state of charge value (SOC) as an initial state of charge value (soc_init).

3. The apparatus of claim 1, wherein the instructions for collecting state of charge information of the battery comprise instructions for determining the state of charge value (SOC) of the battery at each predefined time in the standby mode state of the battery system.

4. The apparatus of claim 3, wherein the instructions for calculating the amount of power change of the battery include instructions for calculating the amount of power change based on a difference (Δsoc) between the pre-stored initial state of charge value (soc_init) and the determined state of charge value (SOC).

5. The apparatus of claim 1, wherein the expected amount of discharge power is defined based on at least one of: an amount of self-discharge power of the battery; and an internal supply power amount supplied by the battery to a power requesting device located inside the battery system.

6. The device of claim 5, wherein the expected amount of discharged power is defined as a value obtained by multiplying a predefined weighting coefficient by a sum of the amount of self-discharged power and an amount of power supplied from the battery to a battery management device (BMS).

7. The apparatus of claim 1, wherein the instructions for determining whether leakage current has occurred in the battery system comprise instructions for determining that leakage current has occurred in the battery if the calculated amount of power change exceeds the expected amount of discharged power.

8. The apparatus of claim 1, wherein the at least one instruction further comprises:

Instructions for collecting a temperature value of the battery in a standby mode state of the battery system;

Instructions for calculating a temperature variation based on the collected temperature values.

9. The apparatus of claim 8, wherein the instructions for determining whether leakage current has occurred in the battery system comprise instructions for determining that leakage current has occurred in the battery if a first condition is satisfied in which the calculated amount of power change exceeds the expected amount of discharged power and a second condition in which the calculated amount of temperature change exceeds a predefined reference amount of temperature change.

10. The apparatus of claim 1, wherein the at least one instruction further comprises instructions to determine whether the battery is performing a balancing control operation.

Wherein the instructions for determining whether leakage current has occurred in the battery system include instructions for determining that leakage current has occurred in the battery if a first condition in which the calculated amount of change in power exceeds the expected amount of discharged power and a third condition in which the battery does not perform a balance control operation are satisfied.

11. The apparatus of claim 1, wherein the instructions for determining whether leakage current occurs in the battery system comprise instructions for detecting one or more batteries in which leakage current is generated among a plurality of batteries included in the battery system.

12. A method for diagnosing a battery by a battery diagnostic device located in a battery system comprising one or more batteries, the method comprising:

collecting state of charge information of the battery in a standby mode state of the battery system;

calculating an amount of change in power of the battery during a hold period of the standby mode based on the collected state-of-charge information and the pre-stored initial state-of-charge information;

the calculated amount of change in power is compared with the expected amount of discharged power of the battery, and it is determined whether leakage current occurs in the battery system based on the comparison result.

13. The method of claim 12, wherein collecting the state of charge information of the battery comprises:

Collecting an open circuit voltage value (Vocv) measured after a predetermined time elapses once the battery system is switched to a standby mode;

determining a state of charge value (SOC) based on the open circuit voltage value (Vocv); and

The calculated state of charge value (SOC) is stored as an initial state of charge value (soc_init).

14. The method of claim 12, wherein collecting the state of charge information of the battery comprises determining a state of charge value (SOC) of the battery at each predefined time in the standby mode state of the battery system.

15. The method of claim 14, wherein calculating the power variation of the battery comprises calculating the power variation based on a difference (Δsoc) between the pre-stored initial state of charge value (soc_init) and the determined state of charge value (SOC).

16. The method of claim 12, wherein the expected amount of discharge power is defined based on at least one of: an amount of self-discharge power of the battery; and an internal supply power amount supplied by the battery to a power requesting device located inside the battery system.

17. The method of claim 16, wherein the expected amount of discharged power is defined as a value obtained by multiplying a predefined weighting coefficient by a sum of the amount of self-discharged power and an amount of power supplied from the battery to a battery management device (BMS).

18. The method of claim 12, wherein determining whether leakage current occurs in the battery system comprises: determining that a leakage current has occurred in the battery in the case where the calculated amount of power change exceeds the expected amount of discharged power.

19. The method of claim 12, further comprising:

Collecting a temperature value of the battery in a standby mode state of the battery system;

The temperature change amount is calculated based on the collected temperature values.

20. The method of claim 19, wherein determining whether leakage current has occurred in the battery system comprises determining that leakage current has occurred in the battery if a first condition is satisfied in which the calculated amount of power change exceeds the expected amount of discharged power and a second condition in which the calculated amount of temperature change exceeds a predefined reference amount of temperature change.

21. The method of claim 12, further comprising determining whether the battery is performing a balancing control operation,

Wherein determining whether leakage current occurs in the battery system comprises: in the case where the first condition in which the calculated amount of change in electric power exceeds the expected amount of discharged electric power and the third condition in which the battery does not perform the balance control operation are satisfied, it is determined that a leakage current has occurred in the battery.

22. The method of claim 12, wherein determining whether leakage current occurs in the battery system comprises detecting one or more batteries in which leakage current is generated among a plurality of batteries included in the battery system.

23. A battery system, comprising:

a plurality of batteries; and

Battery management means for monitoring and controlling the plurality of batteries,

Wherein the battery management device is configured to:

collecting state of charge information for each battery in a standby mode state of the battery system;

Calculating an amount of change in power of each battery during a hold period of the standby mode based on the collected state-of-charge information and the pre-stored initial state-of-charge information;

The calculated amount of power change is compared with the expected amount of discharged power of each battery, and it is determined whether leakage current occurs in the battery system based on the comparison result.