Method for managing battery, battery device, and battery system including same

Abstract

This method for managing a battery comprises the steps of: performing cell balancing of a plurality of battery cells; determining a maximum-voltage cell and a minimum-voltage cell among the plurality of battery cells; determining whether the minimum-voltage cell is the same cell as a minimum-voltage cell stored in a memory; if the minimum-voltage cell and the minimum-voltage cell stored in the memory are the same cell, determining whether a voltage value of the maximum-voltage cell and a voltage value of a maximum-voltage cell stored in the memory are the same; if the voltage value of the maximum-voltage cell and the voltage value of the maximum-voltage cell stored in the memory are the same, calculating a first voltage value difference between the maximum-voltage cell and the minimum-voltage cell; determining whether the first voltage value difference is greater than a second voltage value difference stored in the memory; and if the first voltage value difference is greater than the second voltage value difference stored in the memory, determining the minimum-voltage cell as a cell in which an abnormality has occurred.

Description

Battery management method, battery device, and battery system including the same

[0001] The present disclosure relates to a battery management method, a battery device, and a battery system including the same.

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motors in hybrid and electric vehicles, as well as for power storage.

[0003] It is necessary to control the charging / discharging of the battery or the connection to the battery before a situation arises where the battery may ignite due to an abnormal phenomenon. To this end, overvoltage diagnosis, which diagnoses whether the voltage of a single battery cell exceeds a specific value, and undervoltage diagnosis, which diagnoses whether the voltage of a single battery cell falls below a specific value, can be performed. However, there is a problem in that these diagnoses alone cannot prevent battery abnormalities in advance.

[0004] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art.

[0005] The present disclosure is intended to diagnose abnormal phenomena in secondary batteries.

[0006] The present disclosure is intended to identify a secondary battery in which an abnormality has occurred.

[0007] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below.

[0008] A battery management method according to embodiments for solving the above technical problem comprises the steps of: performing cell balancing of a plurality of battery cells; determining a maximum voltage cell and a minimum voltage cell among a plurality of battery cells; determining whether the minimum voltage cell and the minimum voltage cell stored in memory are the same cell; if the minimum voltage cell and the minimum voltage cell stored in memory are the same cell, determining whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same; if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same, calculating a first voltage value difference between the maximum voltage cell and the minimum voltage cell; determining whether the first voltage value difference is greater than the second voltage value difference stored in memory; and if the first voltage value difference is greater than the second voltage value difference stored in memory, determining the minimum voltage cell as a cell in which an abnormality has occurred.

[0009] It may further include a step of storing the first voltage value difference in memory.

[0010] If the minimum voltage cell and the minimum voltage cell stored in memory are not the same cell, the method may further include the steps of storing identification information and voltage value of the minimum voltage cell in memory; determining whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same; if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same, calculating the difference between the third voltage value of the maximum voltage cell and the minimum voltage cell; and storing the difference between the third voltage value in memory.

[0011] If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are not the same, the step of storing the voltage of the maximum voltage cell in memory may be further included.

[0012] A battery device according to embodiments comprises a battery module including a plurality of battery cells, a cell balancing circuit for performing cell balancing of the plurality of battery cells, and a memory for storing information on a minimum voltage cell and information on a maximum voltage cell among the plurality of battery cells; a battery management system (BMS) for controlling the cell balancing circuit to perform cell balancing of the plurality of battery cells, and when cell balancing is performed, determining the maximum voltage cell and the minimum voltage cell among the plurality of battery cells, determining whether the minimum voltage cell and the minimum voltage cell stored in memory are the same cell, and if the minimum voltage cell and the minimum voltage cell stored in memory are the same cell, determining whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same, and if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same, calculating a first voltage value difference between the maximum voltage cell and the minimum voltage cell, determining whether the first voltage value difference is greater than a second voltage value difference stored in memory, and if the first voltage value difference is greater than the second voltage value difference stored in memory, determining the minimum voltage cell as a cell in which an abnormality has occurred. Includes system)

[0013] The BMS can store the first voltage value difference in memory.

[0014] If the BMS determines whether the minimum voltage cell and the minimum voltage cell stored in memory are not the same cell, it stores the identification information and voltage value of the minimum voltage cell in memory, determines whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same, and if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same, it calculates the third voltage value difference between the maximum voltage cell and the minimum voltage cell and stores the third voltage value difference in memory.

[0015] If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are not the same, the BMS can store the voltage of the maximum voltage cell in memory.

[0016] If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are not the same, the BMS can store the voltage value of the maximum voltage cell in memory.

[0017] A battery system according to the embodiments includes a charging device, a plurality of battery cells charged by the charging device, and a memory that stores information of a minimum voltage cell and information of a maximum voltage cell among the plurality of battery cells, and performs cell balancing of the plurality of battery cells, determines a maximum voltage cell and a minimum voltage cell among the plurality of battery cells, determines whether the minimum voltage cell and the minimum voltage cell stored in the memory are the same cell, and if the minimum voltage cell and the minimum voltage cell stored in the memory are the same cell, determines whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, and if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, calculates a first voltage value difference between the maximum voltage cell and the minimum voltage cell, determines whether the first voltage value difference is greater than a second voltage value difference stored in the memory, and if the first voltage value difference is greater than a second voltage value difference stored in the memory, determines the minimum voltage cell as a cell in which an abnormality has occurred.

[0018] The battery device can store the first voltage value difference in memory.

[0019] If the battery device determines whether the minimum voltage cell and the minimum voltage cell stored in memory are not the same cell, it stores identification information and voltage value of the minimum voltage cell in memory, determines whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same, and if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are the same, it calculates the third voltage value difference between the maximum voltage cell and the minimum voltage cell and stores the third voltage value difference in memory.

[0020] If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are not the same, the battery device can store the voltage of the maximum voltage cell in memory.

[0021] If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in memory are not the same, the battery device can store the voltage value of the maximum voltage cell in memory.

[0022] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0023] FIG. 1 is a block diagram showing a battery system according to embodiments.

[0024] FIG. 2 is a block diagram showing a battery device according to embodiments.

[0025] FIG. 3 is a block diagram showing a battery management system (BMS) according to embodiments.

[0026] FIGS. 4 and FIGS. 5 are flowcharts illustrating a battery management method according to embodiments.

[0027] FIGS. 6 to 9 are tables showing the voltages of a plurality of battery cells, the minimum voltage cell, and the voltage difference between the maximum voltage cell and the minimum voltage cell according to the balancing process.

[0028] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor may appropriately define the concepts of terms to best describe his invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention; thus, various equivalents and modifications that can replace them may exist at the time of filing this application. Furthermore, as used in this specification, "comprise" or "include" and / or "comprising" or "including" specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups. Additionally, when describing embodiments of the present invention, "may" or "may" may include "one or more embodiments of the present invention."

[0029] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0030] The statement that two subjects of comparison are 'identical' means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0031] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0032] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0033] Furthermore, where it is stated that one component is "connected," "coupled," or "connected" to another component, it should be understood that while said components may be directly connected or connected to each other, another component may be "interposed" between each component, or that each component may be "connected," "coupled," or "connected" through another component. Additionally, when it is stated that a part is electrically coupled with another part, this includes not only cases where they are directly connected but also cases where they are connected with an intermediate element in between.

[0034] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise. That is, "and / or" includes any combination or any combination of the enumerated items. "C to D" means C or more and D or less, unless specifically stated otherwise.

[0035] FIG. 1 is a block diagram showing a battery system according to embodiments.

[0036] Referring to FIG. 1, a battery system (100) according to embodiments includes a battery device (110) and a charging device (120).

[0037] The battery device (110) may include at least one battery cell. The battery device (110) may include a battery pack in which at least one battery module is connected to each other in series or in parallel. The battery module may include at least one cell connected to each other in series or in parallel. The battery device (110) may be provided as a battery pack in which at least one battery cell is connected in multiple units (CTP: cell-to-pack method). The battery device (110) may be connected to a battery charging device (120). The battery device (110) may be charged by a charging current applied from the battery charging device (120). The battery device (110) may collect information on each battery cell and determine the charging method of the battery cell (e.g., CC (constant current) method, CV (constant voltage) method, etc.).

[0038] In some embodiments, the battery device (110) can estimate the state of charge (SOC) of the battery pack when the charging method of the battery pack is changed from the CC method to the CV method. The battery device (110) can measure the charge / discharge current, voltage, temperature, etc. of a plurality of battery cells and / or battery pack and estimate the SOC of the battery pack in various ways. When the SOC of the battery pack exceeds a threshold, the battery device (110) can determine the maximum voltage cell and the minimum voltage cell among the plurality of battery cells. The battery device (110) can store the voltage value of the maximum voltage cell and the identification information and voltage value of the minimum voltage cell. When the SOC of the battery pack exceeds a threshold, the battery device (110) can perform cell balancing. After cell balancing, the battery device (110) can determine the maximum voltage cell and the minimum voltage cell among the plurality of battery cells. The battery device (110) can determine whether the stored minimum voltage cell and the newly determined minimum voltage cell are the same cell based on the identification information of the stored minimum voltage cell and the identification information of the newly determined minimum voltage cell. If the stored minimum voltage cell and the newly determined minimum voltage cell are not the same cell, the battery device (110) can store the identification information and voltage value of the newly determined minimum voltage cell. If the stored minimum voltage cell and the newly determined minimum voltage cell are the same cell, the battery device (110) does not store the identification information and voltage value of the newly determined minimum voltage cell, and can determine whether the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are the same. If the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are not the same, the battery device (110) can store the voltage value of the newly determined maximum voltage cell. The battery device (110) can calculate and store the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell.If the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are the same, the battery device (110) may not store the voltage value of the newly determined maximum voltage cell, but instead calculate and store the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell.

[0039] The battery device (110) may perform additional cell balancing after charging or discharging is performed. When additional cell balancing is performed, the battery device (110) may determine the maximum voltage cell and the minimum voltage cell among a plurality of battery cells. Based on the identification information of the stored minimum voltage cell and the identification information of the newly determined minimum voltage cell, the battery device (110) may determine whether the stored minimum voltage cell and the newly determined minimum voltage cell are the same cell. If the stored minimum voltage cell and the newly determined minimum voltage cell are not the same cell, the battery device (110) may store the identification information and voltage value of the newly determined minimum voltage cell. If the stored minimum voltage cell and the newly determined minimum voltage cell are the same cell, the battery device (110) may not store the identification information and voltage value of the newly determined minimum voltage cell, and may determine whether the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are the same. If the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are not the same, the battery device (110) may store the voltage value of the newly determined maximum voltage cell. The battery device (110) may calculate the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell. If the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are the same, the battery device (110) may not store the voltage value of the newly determined maximum voltage cell and may calculate the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell. The battery device (110) may determine whether the calculated voltage difference is greater than the stored voltage difference. If the battery device (110) determines that the minimum voltage cell is an abnormal cell, the battery device (110) may determine that the calculated voltage difference is greater than the stored voltage difference. If the battery device (110) determines that the calculated voltage difference is not greater than the stored voltage difference, the battery device (110) may store the calculated voltage difference.If a fault occurs in a battery cell, the voltage imbalance between battery cells may worsen even if cell balancing is performed. According to the embodiments, the battery cell causing the voltage imbalance can be identified as the faulty cell.

[0040] The battery charging device (120) can charge the battery device (110). For example, the battery charging device (120) can charge the battery device (110) according to a charging method determined in the battery device (110). As another example, the battery charging device (120) can monitor the terminal voltage value of the battery device (110) in real time based on the charging profile of the battery device (110) and switch the charging method when a predetermined voltage threshold is reached.

[0041] FIG. 2 is a block diagram showing a battery device according to embodiments.

[0042] Referring to FIG. 2, the battery device (200) may include a battery module (210) between a positive pack terminal (202) and a negative pack terminal (204), a temperature sensor (220), a voltage sensor (230), a current sensor (240), and a battery management system (BMS) (250). The battery device (200) may also be referred to as a battery pack.

[0043] The battery module (210) may receive a charging current or provide a discharging current through the positive pack terminal (202) and the negative pack terminal (204). The battery module (210) may be electrically connected to an electric load and / or a charging device. The battery module (210) may be discharging to supply power to the electric load or charging by receiving power from the charging device. For example, the battery module (210) may be mounted on an electric vehicle, and the power stored in the battery module (210) may be supplied to the motor of the electric vehicle to drive the electric vehicle, and the power generated during regenerative braking of the electric vehicle may be supplied to the battery module (210). The battery module (210) may include a plurality of battery cells (211). The battery cell (210) may include a nickel-cadmium battery, a lead-acid battery, a nickel-metal hydride battery (NiMH), a lithium-ion battery, a lithium polymer battery, etc. A plurality of battery cells (211) may be connected in series and / or parallel.

[0044] The cell balancing circuit (220) performs cell balancing of a plurality of battery cells (211) under the control of the BMS (250). In some embodiments, the cell balancing circuit (220) may include a balancing resistor and a switch connecting the battery cell and the balancing resistor. The cell balancing circuit (220) may perform cell balancing using a passive cell balancing method that consumes power from a high-voltage battery cell (211) through the balancing resistor. The cell balancing circuit (220) may discharge the battery cell with a high voltage value among the plurality of battery cells (211). The cell balancing circuit (220) may perform cell balancing individually for each of the plurality of battery cells (211), or it may group the plurality of battery cells (211) together and perform cell balancing for each group.

[0045] A voltage sensor (230) may be connected between the terminals of an operating battery module (210) and / or between the terminals of a plurality of battery cells (211). The voltage sensor (230) may periodically measure the voltage values ​​of the battery module (210) and / or the plurality of battery cells (211). For example, the voltage sensor (230) may measure the voltage values ​​of both terminals of the battery module (210) at a sampling time period (Δt). Although FIG. 2 illustrates the voltage sensor (230) measuring the voltage between the terminals of the battery module (210) and / or the voltage values ​​between the terminals of the plurality of battery cells (211), the voltage sensor (230) may also be connected between the external terminals (202, 204) of the battery device (200) to periodically measure the terminal voltage values ​​of the battery module (210).

[0046] The current sensor (240) can periodically measure the current of the operating battery module (210). The voltage sensor (230) and the current sensor (240) are synchronized with each other so that they can measure the voltage value and the current of the battery module (210) at the same time, respectively. The current sensor (240) can measure the current of the battery module (210) at a sampling time period (Δt).

[0047] The BMS (250) can acquire information on sub-components (battery modules or battery cells) included in the battery module (210) and control the cell balancing operation of the battery module (210). The BMS (250) can perform balancing operations on the battery modules and / or cells constituting the battery module (210). The BMS (250) can receive state information (voltage, current, temperature, etc.) of the battery module from a detection device. Based on the state information received from the detection device, the BMS (250) can monitor and calculate the state of the battery module (210) (voltage, current, temperature, State of Charge (SOC), State of Health (SOH), etc.). Additionally, based on the state monitoring results, the BMS (250) may perform control functions (e.g., temperature control, balancing control, charge / discharge control, etc.) and protection functions (e.g., over-discharge, over-charge, over-current protection, short circuit, fire extinguishing function, etc.). Additionally, the BMS (250) may perform wired or wireless communication functions with external devices of the battery module (210) (e.g., upper controller, vehicle, ECU, PCS, etc.).

[0048] The BMS (250) may also control the charging and discharging operations and protection operations of the battery. To this end, the BMS (250) may include a charging and discharging control unit, a balancing control unit, and a protection unit.

[0049] The BMS (250) is a system that monitors the battery status and performs diagnostic, control, communication, and protection functions. It can calculate the charge / discharge status and change the charging method of the battery cell from CC to CV. The BMS (250) can calculate the battery life or state of health (SOH: State Of Health) and can cut off battery power (relay control) if necessary. The BMS (250) can control thermal management (cooling, heating, etc.), perform high-voltage interlock functions, and detect or calculate insulation and short-circuit conditions.

[0050] A relay can be a mechanical contactor that is turned on and off by the magnetic force of a coil, or a semiconductor switch such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

[0051] Relay control is a function that cuts off the power supply from the battery in the event of a problem with the vehicle and battery system, and can be configured with one or more relays and pre-charge relays at the positive and negative terminals, respectively.

[0052] Since there is a risk of inrush current occurring in the high-voltage capacitor on the inverter input side when the battery load is connected, pre-charge control may be equipped with a function to operate the pre-charge relay before connecting the main relay when the vehicle starts to prevent inrush current from entering, thereby connecting to a pre-charge resistor.

[0053] A high-voltage interlock circuit is a circuit that uses small signals to detect whether all high-voltage components in the entire automotive system are connected, and it can be equipped with the function of forcibly opening a relay if an open circuit occurs at any point on the entire loop.

[0054] The BMS (250) can determine which of the multiple battery cells (211) has an abnormality based on information from the battery module (210).

[0055] The BMS (250) can estimate the SOC of the battery module (210) when the charging method changes from the CC method to the CV method. The BMS (250) measures the charge / discharge current, voltage, temperature, etc. of the multiple battery cells (211) and / or the battery module (210) and can estimate the SOC of the battery module (210) in various ways. When the SOC of the battery module (210) exceeds a threshold, the BMS (250) can determine the maximum voltage cell and the minimum voltage cell among the multiple battery cells (211). The BMS (250) can store the voltage of the maximum voltage cell and the identification information and voltage values ​​of the minimum voltage cell. When the SOC of the battery module (210) exceeds a threshold, the BMS (250) can perform cell balancing. After cell balancing, the BMS (250) can determine the maximum voltage cell and the minimum voltage cell among the multiple battery cells (211). The BMS (250) can determine whether the stored minimum voltage cell and the newly determined minimum voltage cell are the same cell based on the identification information of the stored minimum voltage cell and the identification information of the newly determined minimum voltage cell. If the stored minimum voltage cell and the newly determined minimum voltage cell are not the same cell, the BMS (250) can store the identification information and voltage value of the newly determined minimum voltage cell. If the stored minimum voltage cell and the newly determined minimum voltage cell are the same cell, the BMS (250) does not store the identification information and voltage value of the newly determined minimum voltage cell, and can determine whether the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are the same. If the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are not the same, the BMS (250) can store the voltage value of the newly determined maximum voltage cell. The BMS (250) can calculate and store the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell.If the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are the same, the BMS (250) does not store the voltage value of the newly determined maximum voltage cell, and can calculate and store the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell.

[0056] The BMS (250) may perform additional cell balancing after charging or discharging is performed. When additional cell balancing is performed, the BMS (250) may determine the maximum voltage cell and the minimum voltage cell among the plurality of battery cells (211). Based on the identification information of the stored minimum voltage cell and the identification information of the newly determined minimum voltage cell, the BMS (250) may determine whether the stored minimum voltage cell and the newly determined minimum voltage cell are the same cell. If the stored minimum voltage cell and the newly determined minimum voltage cell are not the same cell, the BMS (250) may store the identification information and voltage value of the newly determined minimum voltage cell. If the stored minimum voltage cell and the newly determined minimum voltage cell are the same cell, the BMS (250) may not store the identification information and voltage value of the newly determined minimum voltage cell, and may determine whether the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are the same. If the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are not the same, the BMS (250) can store the voltage value of the newly determined maximum voltage cell. The BMS (250) can calculate the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell. If the voltage value of the stored maximum voltage cell and the voltage value of the newly determined maximum voltage cell are the same, the BMS (250) does not store the voltage value of the newly determined maximum voltage cell and can calculate the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell. The BMS (250) can determine whether the calculated voltage difference is greater than the stored voltage difference. If the calculated voltage difference is greater than the stored voltage difference, the BMS (250) can determine that the minimum voltage cell is an abnormal cell. If the calculated voltage difference is not greater than the stored voltage difference, the BMS (250) can store the calculated voltage difference.If a fault occurs in a battery cell, the voltage imbalance between battery cells may worsen even if cell balancing is performed. According to the embodiments, the battery cell causing the voltage imbalance can be identified as the faulty cell.

[0057] FIG. 3 is a block diagram showing a battery management system (BMS) according to embodiments.

[0058] As shown in FIG. 3, the BMS (300) may include an analog digital converter (ADC) (310), a memory (320), a processor (330), and a transmitter (340).

[0059] The ADC (310) can be connected to a voltage sensor (230 in FIG. 2) and a current sensor (240 in FIG. 2). The ADC (310) can convert the analog signal measured by the voltage sensor (230) and the current sensor (240) into a digital signal and output the digital signal.

[0060] The memory (320) can store the voltage value of the maximum voltage cell, identification information and voltage value of the minimum voltage cell.

[0061] The processor (330) can determine whether the battery cell (211 in FIG. 1) is abnormal based on the voltage value signal and current value signal transmitted from the ADC (310), and the voltage value of the maximum voltage cell and the identification information and voltage value of the minimum voltage cell stored in the memory (320). This will be explained with reference to FIG. 4 and FIG. 5 together.

[0062] FIGS. 4 and FIGS. 5 are flowcharts illustrating a battery management method according to embodiments.

[0063] Referring to FIG. 4, the battery charging device (120) charges the battery device (110) (S400).

[0064] When the charging method is changed from the CC method to the CV method, the processor (330) determines (S420) whether the current SOC exceeds the threshold SOC. The processor (330) can calculate the SOC based on the voltage value and / or current value measured by the voltage sensor (230) and / or current sensor (240).

[0065] When the SOC exceeds a threshold, the processor (330) determines the maximum voltage cell and the minimum voltage cell among the plurality of battery cells (211) (S404).

[0066] The processor (330) stores the voltage of the maximum voltage cell, identification information of the minimum voltage cell, and the voltage value (S406).

[0067] The processor (330) performs cell balancing (S408).

[0068] After cell balancing, the processor (330) determines the maximum voltage cell and the minimum voltage cell among the plurality of battery cells (211) (S410).

[0069] The processor (330) determines whether the minimum voltage cell stored in memory (320) and the newly determined minimum voltage cell are the same cell (S412) based on the identification information of the minimum voltage cell stored in memory (320) and the identification information of the newly determined minimum voltage cell.

[0070] If the minimum voltage cell stored in memory (320) and the newly determined minimum voltage cell are not the same cell, the processor (330) stores the identification information and voltage value of the newly determined minimum voltage cell (S414), and determines whether the voltage value of the maximum voltage cell stored in memory (320) and the voltage value of the newly determined maximum voltage cell are the same (S416).

[0071] If the minimum voltage cell stored in memory (320) and the newly determined minimum voltage cell are the same cell, the processor (330) does not store the identification information and voltage value of the newly determined minimum voltage cell, and determines whether the voltage value of the maximum voltage cell stored in memory (320) and the voltage value of the newly determined maximum voltage cell are the same (S416).

[0072] If the voltage value of the maximum voltage cell stored in memory (320) and the newly determined voltage value of the maximum voltage cell are not the same, the processor (330) stores the newly determined voltage value of the maximum voltage cell in memory (320) (S418).

[0073] The processor (330) calculates and stores the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell (S420).

[0074] If the voltage value of the maximum voltage cell stored in memory (320) is the same as the newly determined voltage value of the maximum voltage cell, the processor (330) does not store the newly determined voltage value of the maximum voltage cell in memory (320), and calculates and stores the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell (S420).

[0075] Referring to FIG. 5, the battery device (110) is charged or discharged (S500).

[0076] The processor (330) additionally performs cell balancing (S502).

[0077] When additional cell balancing is performed, the processor (330) determines the maximum voltage cell and the minimum voltage cell among the plurality of battery cells (211) (S504).

[0078] The processor (330) determines whether the minimum voltage cell stored in memory (320) and the newly determined minimum voltage cell are the same cell (S506) based on the identification information of the minimum voltage cell stored in memory (320) and the identification information of the newly determined minimum voltage cell.

[0079] If the minimum voltage cell stored in memory (320) and the newly determined minimum voltage cell are the same cell, the processor (330) does not store the identification information and voltage value of the newly determined minimum voltage cell in memory (320), and determines whether the voltage value of the maximum voltage cell stored in memory (320) and the voltage value of the newly determined maximum voltage cell are the same (S508).

[0080] If the voltage value of the maximum voltage cell stored in memory (320) and the newly determined voltage value of the maximum voltage cell are not the same, the processor (330) stores the newly determined voltage value of the maximum voltage cell in memory (320) (S510).

[0081] The processor (330) calculates the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell (S512).

[0082] If the voltage value of the maximum voltage cell stored in memory (320) is the same as the newly determined voltage value of the maximum voltage cell, the processor (330) does not store the newly determined voltage value of the maximum voltage cell in memory (320) and calculates the difference between the voltage values ​​of the maximum voltage cell and the minimum voltage cell (S512).

[0083] The processor (330) determines whether the calculated voltage value difference is greater than the voltage value difference stored in memory (320) (S514).

[0084] If the processor (330) determines that the minimum voltage cell is an abnormal cell (S516) if the calculated voltage value difference is greater than the voltage value difference stored in memory (320).

[0085] If the processor (330) does not have a greater difference in the calculated voltage value than the difference in the voltage value stored in the memory (320), it stores the difference in the calculated voltage value (S518).

[0086] If the minimum voltage cell stored in memory (320) and the newly determined minimum voltage cell are not the same cell, the processor (330) stores the identification information and voltage value of the newly determined minimum voltage cell in memory (320) (S520).

[0087] The processor (330) determines whether the voltage value of the maximum voltage cell stored in memory (320) is the same as the voltage value of the newly determined maximum voltage cell (S522).

[0088] If the voltage value of the maximum voltage cell stored in memory (320) and the newly determined voltage value of the maximum voltage cell are not the same, the processor (330) stores the newly determined voltage value of the maximum voltage cell in memory (320) (S524).

[0089] The processor (330) calculates and stores the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell (S526).

[0090] If the voltage value of the maximum voltage cell stored in memory (320) is the same as the newly determined voltage value of the maximum voltage cell, the processor (330) does not store the newly determined voltage value of the maximum voltage cell in memory (320), and calculates and stores the difference between the voltage value of the maximum voltage cell and the voltage value of the minimum voltage cell (S526).

[0091] If a fault occurs in a battery cell, the voltage imbalance between battery cells may worsen even if cell balancing is performed. According to the embodiments, the battery cell causing the voltage imbalance can be identified as the faulty cell.

[0092] FIGS. 6 to 9 are tables showing the voltages of a plurality of battery cells, the minimum voltage cell, and the difference in voltage values ​​between the maximum voltage cell and the minimum voltage cell according to the balancing process.

[0093] Referring to the table (600) in FIG. 6, among the battery cells measured after the first cell balancing (BALANCING 1), the voltage of the maximum voltage cell (CELL 1) is 10.2V, the voltage of the minimum voltage cell (CELL 2) is 9.7V, and the difference in voltage values ​​between the two cells is 0.5V. Among the battery cells measured after the Nth cell balancing (BALANCING N) (N is a positive number greater than or equal to 2), the voltage of the maximum voltage cell (CELL 3) is 10.4V, the voltage of the minimum voltage cell (CELL 2) is 9.8V, and the difference in voltage values ​​between the two cells is 0.6V.

[0094] Since the minimum voltage cell measured after the first cell balancing (BALANCING 1) and the minimum voltage cell measured after the Nth cell balancing (BALANCING N) are the same as CELL 2, and the voltage value difference increased from 0.5V after the first cell balancing (BALANCING 1) to 0.6V after the Nth cell balancing (BALANCING N), according to the embodiments, CELL 2 can be determined as a cell in which an abnormality has occurred.

[0095] Referring to the table (700) in FIG. 7, among the battery cells measured after the first cell balancing (BALANCING 1), the voltage of the maximum voltage cell (CELL 1) is 10.2V, the voltage of the minimum voltage cell (CELL 2) is 9.7V, and the difference in voltage values ​​between the two cells is 0.5V. Among the battery cells measured after the Nth cell balancing (BALANCING N) (N is a positive number greater than or equal to 2), the voltage of the maximum voltage cell (CELL 3) is 10.2V, the voltage of the minimum voltage cell (CELL 2) is 9.6V, and the difference in voltage values ​​between the two cells is 0.6V.

[0096] Since the minimum voltage cell measured after the first cell balancing (BALANCING 1) and the minimum voltage cell measured after the Nth cell balancing (BALANCING N) are the same as CELL 2, and the voltage value difference increased from 0.5V after the first cell balancing (BALANCING 1) to 0.6V after the Nth cell balancing (BALANCING N), according to the embodiments, CELL 2 can be determined as a cell in which an abnormality has occurred.

[0097] Referring to the table (800) in FIG. 8, among the battery cells measured after the first cell balancing (BALANCING 1), the voltage of the maximum voltage cell (CELL 1) is 10.2V, the voltage of the minimum voltage cell (CELL 2) is 9.7V, and the difference in voltage values ​​between the two cells is 0.5V. Among the battery cells measured after the Nth cell balancing (BALANCING N) (N is a positive number greater than or equal to 2), the voltage of the maximum voltage cell (CELL 3) is 10.1V, the voltage of the minimum voltage cell (CELL 2) is 9.7V, and the difference in voltage values ​​between the two cells is 0.4V.

[0098] Since the minimum voltage cell measured after the first cell balancing (BALANCING 1) and the minimum voltage cell measured after the Nth cell balancing (BALANCING N) are the same as CELL 2, and the voltage value difference decreased from 0.5V after the first cell balancing (BALANCING 1) to 0.4V after the Nth cell balancing (BALANCING N), according to the embodiments, identification information of the minimum voltage cell (CELL 2) and the voltage and voltage value of the maximum voltage cell (CELL 3) can be stored.

[0099] Referring to the table (900) in FIG. 9, among the battery cells measured after the first cell balancing (BALANCING 1), the voltage of the maximum voltage cell (CELL 1) is 10.0V, the voltage of the minimum voltage cell (CELL 2) is 9.7V, and the difference in voltage values ​​between the two cells is 0.3V. Among the battery cells measured after the Nth cell balancing (BALANCING N) (N is a positive number greater than or equal to 2), the voltage of the maximum voltage cell (CELL 1) is 10.0V, the voltage of the minimum voltage cell (CELL 4) is 9.6V, and the difference in voltage values ​​between the two cells is 0.4V.

[0100] Since the minimum voltage cell measured after the first cell balancing (BALANCING 1) and the minimum voltage cell measured after the Nth cell balancing (BALANCING N) are different, respectively, CELL 2 and CELL 4, according to the embodiments, identification information of the minimum voltage cell (CELL 4) and the voltage and voltage value of the maximum voltage cell (CELL 1) can be stored.

[0101] The embodiments described above may be implemented as hardware components, software components, and / or combinations of hardware and software components. For example, the devices, methods, and components described in the embodiments may be implemented using one or more general-purpose or special-purpose computers, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing unit may execute an operating system (OS) and one or more software applications executed on said operating system. Additionally, the processing unit may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing unit may be described as being used as a single unit, but those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or one processor and one controller. Additionally, other processing configurations, such as parallel processors, are also possible.

[0102] Software may include computer programs, code, instructions, or a combination of one or more of these, and may configure a processing unit to operate as desired or command the processing unit independently or collectively. Software and / or data may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave so as to be interpreted by the processing unit or to provide instructions or data to the processing unit. Software may be distributed over networked computer systems and may be stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

[0103] The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., either alone or in combination. The program instructions recorded on the medium may be those specifically designed and configured for the embodiment, or they may be those known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.

[0104] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

Claims

1. A step of performing cell balancing of multiple battery cells, A step of determining the maximum voltage cell and the minimum voltage cell among the plurality of battery cells above, A step of determining whether the above minimum voltage cell and the minimum voltage cell stored in memory are the same cell, If the minimum voltage cell and the minimum voltage cell stored in the memory are the same cell, a step of determining whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same. If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, the step of calculating the difference between the first voltage value of the maximum voltage cell and the minimum voltage cell, A step of determining whether the first voltage value difference is greater than the second voltage value difference stored in the memory, and If the difference in the first voltage value is greater than the difference in the second voltage value stored in the memory, the step of determining the minimum voltage cell as the cell where an abnormality has occurred A battery management method including 2. In Paragraph 1, Step of storing the above first voltage value difference in the memory A battery management method that further includes 3. In Paragraph 1, If the minimum voltage cell and the minimum voltage cell stored in the memory are not the same cell, the step of storing identification information and voltage value of the minimum voltage cell in the memory, A step of determining whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same. If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, a step of calculating the difference between the third voltage value of the maximum voltage cell and the minimum voltage cell, Step of storing the above third voltage value difference in the memory A battery management method that further includes 4. In Paragraph 3, If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are not the same, the step of storing the voltage of the maximum voltage cell in the memory. A battery management method that further includes 5. In Paragraph 1, If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are not the same, the step of storing the voltage value of the maximum voltage cell in the memory. A battery management method that further includes 6. A battery module comprising multiple battery cells, A cell balancing circuit that performs cell balancing of the plurality of battery cells, and A battery management system (BMS) comprising a memory storing information on a minimum voltage cell and information on a maximum voltage cell among a plurality of battery cells, controlling a cell balancing circuit to perform cell balancing of the plurality of battery cells, and when cell balancing is performed, determining a maximum voltage cell and a minimum voltage cell among the plurality of battery cells, determining whether the minimum voltage cell and the minimum voltage cell stored in the memory are the same cell, if the minimum voltage cell and the minimum voltage cell stored in the memory are the same cell, determining whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, calculating a first voltage value difference between the maximum voltage cell and the minimum voltage cell, determining whether the first voltage value difference is greater than the second voltage value difference stored in the memory, and if the first voltage value difference is greater than the second voltage value difference stored in the memory, determining the minimum voltage cell as a cell in which an abnormality has occurred. A battery device including 7. In Paragraph 6, The above BMS is a battery device that stores the first voltage value difference in the memory.

8. In Paragraph 6, If the minimum voltage cell and the minimum voltage cell stored in the memory are not the same cell, the above BMS stores identification information and voltage value of the minimum voltage cell in the memory, determines whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, and if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, calculates a third voltage value difference between the maximum voltage cell and the minimum voltage cell, and stores the third voltage value difference in the memory. Battery device.

9. In Paragraph 8, If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are not the same, the above BMS stores the voltage of the maximum voltage cell in the memory. Battery device.

10. In Paragraph 6, If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are not the same, the above BMS stores the voltage value of the maximum voltage cell in the memory. Battery device.

11. Charging device, and A battery device comprising a plurality of battery cells charged by the charging device and a memory storing information of a minimum voltage cell and a maximum voltage cell among the plurality of battery cells, performing cell balancing of the plurality of battery cells, determining a maximum voltage cell and a minimum voltage cell among the plurality of battery cells, determining whether the minimum voltage cell and the minimum voltage cell stored in the memory are the same cell, if the minimum voltage cell and the minimum voltage cell stored in the memory are the same cell, determining whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, calculating a first voltage value difference between the maximum voltage cell and the minimum voltage cell, determining whether the first voltage value difference is greater than the second voltage value difference stored in the memory, and if the first voltage value difference is greater than the second voltage value difference stored in the memory, determining the minimum voltage cell as a cell in which an abnormality has occurred. A battery system including 12. In Paragraph 11, The battery device stores the first voltage value difference in the memory. Battery system.

13. In Paragraph 11, The battery device stores identification information and voltage value of the minimum voltage cell in the memory if the minimum voltage cell and the minimum voltage cell stored in the memory are not the same cell, determines whether the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, and if the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are the same, calculates a third voltage value difference between the maximum voltage cell and the minimum voltage cell, and stores the third voltage value difference in the memory. Battery system.

14. In Paragraph 13, If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are not the same, the battery device stores the voltage of the maximum voltage cell in the memory. Battery system.

15. In Paragraph 11, If the voltage value of the maximum voltage cell and the voltage value of the maximum voltage cell stored in the memory are not the same, the battery device stores the voltage value of the maximum voltage cell in the memory. Battery system.

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