CN118265919A

CN118265919A - Battery diagnostic device and method for detecting leakage current

Info

Publication number: CN118265919A
Application number: CN202380014395.8A
Authority: CN
Inventors: 李忠勇
Original assignee: Lg Energy Solution
Current assignee: Lg Energy Solution
Priority date: 2022-10-12
Filing date: 2023-06-19
Publication date: 2024-06-28

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

The present application claims priority and benefit from korean patent application No. 10-2022-013045 filed on 10 month 12 of 2022 and korean patent application No.10-2023-0068061 filed on 5 month 26 of 2023, which are incorporated herein by reference in their entireties.

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

Background

The secondary battery is a battery that can be recharged and reused even after discharging. The secondary battery may be used as an energy source for small-sized devices such as cellular phones, tablet computers, dust collectors, and also as an energy source for medium-and large-sized devices such as ESS (energy storage system) of automobiles and smart grids.

Secondary batteries are applied to a system in the form of an assembly such as a battery module in which a plurality of battery cells are connected in series and parallel or a battery pack in which battery modules are connected in series and parallel according to the system requirements. In the case of a medium-or large-sized device such as an electric vehicle, a high-capacity battery system in which a plurality of battery packs are connected in parallel may be applied in order to satisfy the required capacity of the device.

In order to stably operate the battery system, it is necessary to well maintain the insulating state of each electrical component provided in the battery system. If the insulating 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 or not 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 the conventional technique.

Therefore, as a technology capable of solving the problems of the related art, an appropriate technology capable of accurately detecting whether or not a leakage current occurs in a battery system without using a leakage current detection sensor is required.

Disclosure of Invention

[ Technical problem ]

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

To solve one or more problems in the related art, embodiments of the present disclosure also provide a battery diagnosis method using such a battery diagnosis apparatus.

Technical scheme

To achieve the objects of the present disclosure, 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 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; 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.

The instructions for collecting state of charge information of the battery may include: instructions for collecting an open circuit voltage value (Vocv) measured after a predetermined time elapses once the battery system is switched to the 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).

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 instructions for calculating the power variation amount of the battery may include instructions for calculating the power variation amount based on a difference value (Δsoc) between a pre-stored initial state of charge value (soc_init) and a determined state of charge value (SOC).

The expected amount of discharge power may be defined based on at least one of: the amount of self-discharge power 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 amount of discharged power may be defined as a value obtained by multiplying a predefined weighting coefficient by the sum of the amount of self-discharged power and the amount of power supplied by the battery to a battery management device (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 in the event that the calculated amount of power change exceeds the expected amount of discharged power.

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

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 in the case where a first condition 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 are satisfied.

The at least one instruction further includes instructions for determining whether the battery is performing a balancing control operation. Here, the instruction for determining whether or not the leakage current has occurred in the battery system may include an instruction for determining that the leakage current has occurred in the battery in the case where a first condition in which the calculated amount of change in electric power exceeds the expected amount of discharged electric power and a third condition in which the battery does not perform the balance control operation are satisfied.

The instructions for determining whether leakage current occurs in the battery system may include instructions for detecting one or more batteries in which leakage current occurs 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 state of charge information of a 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; and 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.

Collecting state of charge information of the battery may include: collecting an open circuit voltage value (Vocv) measured after a predetermined time elapses once the battery system is switched to the standby mode; determining a state of charge value (SOC) based on the open circuit voltage value (Vocv); and storing the calculated state of charge value (SOC) as an initial state of charge value (soc_init).

Collecting state of charge information of the battery may include determining a state of charge value (SOC) of the battery at each predefined time in a 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 value (Δsoc) between a pre-stored initial state of charge value (soc_init) and a determined state of charge value (SOC).

Determining whether leakage current has occurred in the battery system may include determining that leakage current has occurred in the battery if the calculated amount of power change exceeds the expected amount of discharged power.

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

Determining whether leakage current occurs in the battery system may include: in the case where the first condition in which the calculated amount of change in electric power exceeds the expected amount of electric power to be discharged and the second condition in which the calculated amount of change in temperature exceeds the predefined reference amount of change in temperature are satisfied, it is determined that the leakage current has occurred in the battery.

The method may further determine whether the battery is performing a balancing control operation. Here, determining whether leakage current occurs in the battery system may include: 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 the leakage current has occurred in the battery.

Determining whether leakage current occurs in the battery system may include detecting one or more batteries in which 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 may be configured to: collecting charge state information of 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; and comparing the calculated amount of power variation with an expected amount of discharged power of each battery, and determining whether leakage current occurs in the battery system based on the comparison result.

[ Advantageous effects ]

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

Drawings

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

Fig. 2 is an operational flowchart of a method for diagnosing a battery according to the present invention.

Fig. 3 is an operational flowchart of a method for diagnosing a battery according to an embodiment of the present invention.

Fig. 4 is an operational flowchart 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.

Fig. 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 cell

100: Battery assembly

200. 700: Battery diagnosis device

Detailed Description

Best mode for practicing the disclosure

The invention is capable of modification in various forms and embodiments, and its specific embodiments are shown by way of example in the drawings and will be described in detail below. It should be understood, however, that there is no intention to limit the invention to the specific embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and technical scope of the invention. Like reference numerals refer to like elements throughout the description of the drawings.

It will be understood that although terms such as first, second, A, B, etc. may be used herein to describe various elements, 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 could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term "and/or" includes a combination of a plurality of associated listed items or any of a plurality of associated listed items.

It will 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 intervening elements may be present. In contrast, when an element is referred to as being "directly coupled" or "directly connected" to another element, there are no intervening elements present.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "contains," "containing," "including" and/or "having," when used herein, specify the presence of stated features, integers, steps, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their 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 as follows.

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 [% ].

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

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

The battery pack refers to a large-sized battery rack system configured by connecting a plurality of racks in parallel. The library BMS of the battery library may monitor and control a plurality of rack BMSs, each of which manages a battery rack.

A battery assembly may include a plurality of battery cells that are electrically connected, and refers to an assembly that serves as a power source by being applied to a particular system or device. Here, the 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.

Referring to fig. 1, a battery system may include a battery assembly 100 and a battery diagnosis apparatus 200, the battery assembly 100 including a plurality of batteries 10 (bat#1 to bat#n).

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

The battery system according to the present invention may 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 may be applied to various devices and operated to detect an abnormal battery by performing a method for detecting an abnormal battery as described below.

The battery 10 according to the present invention may mean 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 with respect to 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 diagnosis device 200 may be implemented by being included in a battery management device/system (BMS) located inside the battery system.

The battery diagnosis apparatus 200 may calculate the battery power variation amount 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 diagnosis apparatus 200 may determine whether a leakage current is generated in the battery system and identify a battery in which the leakage current is generated based on one or more of a battery power variation amount, a battery temperature variation amount, and whether a balance control operation is performed in a standby mode state of the battery system.

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

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

When the battery system is switched to the standby mode (S210), the battery diagnosis apparatus 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 diagnosis apparatus 200 may collect an open circuit voltage value (Vocv) measured by the voltage measurement device and determine a state of charge value (SOC) based on the collected open circuit voltage value (Vocv). Here, the battery diagnosis apparatus 200 may check a state of charge value (SOC) that matches the collected open circuit voltage value (Vocv) in a graph of V _OCV -SOC relationship of the corresponding battery, and may determine the matched state of charge value (SOC) as the state of charge value (SOC) of the corresponding battery.

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

The battery diagnosis apparatus 200 may calculate a battery power variation during a period in which the standby mode is maintained (S230). Here, the battery diagnosis apparatus 200 may calculate the amount of power change based on the collected state-of-charge information and the initial state-of-charge information stored in advance.

More specifically, the battery diagnosis apparatus 200 may determine an initial state of charge value (soc_init) based on the 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 diagnosis apparatus 200 may calculate the amount of change in electric power at the corresponding point in time based on the difference between the initial state of charge value (soc_init) stored in the storage device and the state of charge value (soc_present) determined from the open-circuit voltage value measured at the later point in time.

The battery diagnosis device 200 may compare the calculated power variation amount with a predefined threshold (S240). Here, the threshold value may be defined as an expected amount of discharged power 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 amount with a predefined threshold value (S250). Here, when the amount of power change exceeds a predefined threshold, the battery diagnosis device 200 may determine that a leakage current is generated in the corresponding battery.

In other words, the battery diagnosis device 200 according to the embodiment of the invention may determine that abnormal self-discharge, i.e., leakage current, of the corresponding battery is generated when the amount of power change during the standby mode holding period exceeds a set threshold (e.g., an expected amount of discharged power).

When the battery system is switched to the standby mode (S310), the battery diagnosis 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 point of time when a predefined time (e.g., 30 minutes) has elapsed after switching to the standby mode.

The battery diagnosis 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 diagnosis apparatus 200 may check a state of charge value (SOC) that matches an initial open circuit voltage value (vocv_init) in a graph of Vocv-SOC relation 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 point of time at which the open circuit voltage value is collected) based on the collected open circuit voltage value (Vocv) (S340).

The battery diagnosis apparatus 200 may calculate a difference value (Δsoc) between the initial state of charge value (soc_init) stored in the storage device and the state of charge value (soc_present) at the current time (S350), and calculate an amount of power change (Δp) at the point of time based on the calculated difference value (Δsoc) (S360).

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

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

In an embodiment, the expected amount of discharged power may be defined as the sum of the amount of self-discharged power of the battery and the amount of internally supplied power (p_sd+p_in). For example, the expected amount of discharged power may be defined as the sum (p_sd+p_bms) of the amount of self-discharged power of the battery and the amount of power supplied from the battery to a Battery Management System (BMS) in the standby mode.

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

When the amount of power change Δp is less than or equal to the threshold value (e.g., the amount of expected discharged power) (no in S370), the battery diagnosis device 200 may return to step S340 and execute the subsequent process again.

If the amount of power change (Δp) exceeds the threshold value (the amount of expected discharged power) (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 device 200 may detect a battery having a leakage current among the plurality of batteries.

Specifically, the battery diagnosis apparatus 200 may calculate the power variation Δp of each of the batteries bat#1 to bat#n, detect a battery in which the power variation Δp exceeds a threshold (e.g., an expected amount of discharged power), and determine that a leakage current is generated in the corresponding battery.

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

Fig. 4 is an operational flowchart of a method for diagnosing a battery according to another embodiment of the present invention. Specifically, fig. 4 shows a battery diagnosis method in which the battery diagnosis apparatus determines whether or not to generate a leakage current by further considering at least one of the amount of temperature change and whether or not to perform a balance control operation, in addition to the amount of power change.

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

Referring to fig. 4, when the battery system is switched to the standby mode (S410), the battery diagnosis apparatus 200 may collect state information of the battery while maintaining the standby mode (S420). Here, the state information may include one or more of an identifier, a state of charge value (SOC), and a temperature value (T) of the corresponding battery.

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

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

More specifically, the battery diagnosis apparatus 200 may determine an initial state of charge value (soc_init) based on the initially measured open circuit voltage value after the battery system is switched to the standby mode, and calculate the amount of power change (Δp) at the corresponding point in time based on a difference between the initial state of charge value (soc_init) and the state of charge value (soc_present) at a later point in time. In addition, the battery diagnosis apparatus 200 may store an initial 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). Further, the battery diagnosis device 200 may determine whether to perform the battery balance control operation in combination with a balance circuit that performs the balance control operation to solve an unbalanced state of the battery or a battery management device that controls the balance circuit.

The battery diagnosis device 200 may determine whether one or more of a first condition, a second condition, and a third condition are satisfied, wherein the first condition is a condition that the calculated amount of power change (Δp) exceeds the expected amount of discharged power, the second condition is a condition that the calculated amount of temperature change (Δt) exceeds a predefined reference temperature change, and the third condition is a state in which the battery does not perform the balance control operation (S440). Here, the reference temperature variation amount of the second condition may be defined as an average value of the temperature variation amounts of the 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 device 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 apparatus 200 may determine that a leakage current is generated in the battery when the battery to be diagnosed satisfies the first condition and the second condition. In other words, when the amount of power change in the standby mode exceeds the expected amount of discharge power and the amount of temperature change exceeds the reference value, it may be determined that a leakage current is generated in the corresponding battery.

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 the first condition and the third condition. In other words, when the amount of power variation in the standby mode exceeds the expected amount of discharged power and the battery is in a state in which the balance control operation is not performed, it may be determined that the leakage current is generated in the corresponding battery. If the battery is performing the balance control operation, the charge/discharge amount for balance is reflected in calculating the power variation amount, and therefore, the diagnosis is accurately made only by whether the first condition is satisfied. In order to prevent erroneous diagnosis due to the balancing operation, the battery diagnosis apparatus 200 may consider a third condition in addition to the first 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 fig. 6 and 7 are block diagrams for explaining the operation of the battery system shown in fig. 5.

Referring to fig. 5, a battery system according to an 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 (modules #1 to #n), and each of the battery modules may include a plurality of battery CELLs 10' (CELL #1 to CELL #n).

The battery diagnosis apparatus according to the present invention may correspond to the 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 respective battery cells, determine initial state of charge values (soc_init) of the respective battery cells, and store them in a storage device (e.g., a nonvolatile memory). In addition, a battery management system (PBMS) may collect and store initial temperature values (t_init) of the respective 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 variation (Δp) of each of the battery cells per unit time based on the SOC value variation (Δsoc=soc_init-soc_present). Further, the battery management system (PBMS) may calculate a temperature value variation amount per unit time (Δt=t_init-t_present) while maintaining the standby mode of the battery pack.

A battery management system (PBMS) may determine whether to generate a leakage current 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 whose power variation Δp exceeds the expected amount of discharge power (satisfies the first condition) among the plurality of battery cells, and determines that a leakage current is generated in the corresponding battery (cell #2 of the module # 1). As another example, the battery management system (PBMS) detects a battery cell in which the amount of power change (Δp) exceeds the amount of expected discharge power (satisfies the first condition) and the amount of temperature change (Δt) exceeds the reference amount of temperature change (satisfies the second condition) among the plurality of battery cells and determines that a leakage current is generated in the corresponding battery (cell #2 of the module # 1). For another example, the battery management system (PBMS) determines that a leakage current is generated in the corresponding battery (the cell #2 of the module # 1) when a cell in which the amount of power change (Δp) exceeds the amount of expected discharged power (the first condition is satisfied), the amount of temperature change (Δt) exceeds the reference amount of temperature change (the second condition is satisfied), and in which the cell balancing operation is not performed (the third condition is satisfied) is determined among the plurality of battery cells.

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

The battery management system (PBMS) may transmit leakage current diagnostic information to the upper battery management device. For example, the battery management system (PBMS) may transmit the leakage current diagnosis 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 fig. 5 to 7, the battery system according to the embodiment of the present invention may be implemented by being included in a battery module, a battery rack, or a battery bank, and the method for diagnosing leakage current according to the present invention may be performed in the same manner even for these cases.

The battery diagnosis apparatus 800 according to an 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 to communicate.

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

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

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

Here, the processor 810 may mean a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), or a dedicated processor for performing a 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 Read Only Memory (ROM) and Random Access Memory (RAM).

Operations of the method according to the embodiment of the present invention may be embodied 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. Furthermore, the computer readable recording medium can be distributed among networked computer systems to store and execute computer readable programs or codes in a distributed manner.

Although some aspects of the present invention have been described in the context of apparatus, it may also represent descriptions of corresponding methods in which a block or apparatus corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of methods may also represent features of corresponding blocks or items or corresponding devices. Some or all of the method steps may 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 may be performed by such an apparatus.

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

Claims

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.