System for diagnosing battery cell by using direct connection type battery management system

Abstract

The present invention relates to a system for diagnosing cells using a direct-connected battery management system in direct physical and electrical contact with respective electrodes of the cells and measuring respective voltages of the cells and currents of a plurality of cells. And calculating the impedance of each battery cell on the basis of the measured voltage and current, diagnosing the state of each battery cell through the impedance, and sending a diagnosis result to a main battery management system in a wireless manner.

Description

Technical Field

[0001] This invention relates to a system for diagnosing battery cells using a Direct Battery Management System (DBS). The DBS directly and physically contacts the electrodes of each battery cell and measures the voltage of each battery cell and the current of multiple battery cells. Based on the measured voltage and current, the impedance of each battery cell is calculated, and the state of each battery cell is diagnosed through the impedance. The diagnostic results are then wirelessly transmitted to the main DBS. Background Art

[0002] In recent years, with the rapid growth in demand for electric vehicles, battery packs for electric and hybrid vehicles have received increasing attention. These batteries need to operate safely for extended periods in harsh environments, requiring extremely high performance. Therefore, the hundreds or thousands of cells that make up the battery pack need to be precisely managed at all times. Battery packs installed in vehicles typically consist of multiple battery modules connected in series and / or parallel, as well as multiple slave battery management systems (BMS). Each battery module contains multiple cells.

[0003] Each slave battery management system monitors and controls the status of the battery modules it is assigned to manage. Recently, with the increasing demand for high-capacity, high-power battery packs, the number of battery modules contained within these packs is also increasing. To support this technological development and achieve efficient management of the battery modules within the pack, battery management system technologies are continuously being developed.

[0004] Existing technology measures the average voltage, average current, and average temperature of the entire battery module composed of multiple cells, and then diagnoses the condition of the individual cells based on these average voltage, average current, and average temperature. However, in this approach, it is difficult to take action on the specific cell causing the problem, thus reducing the reliability of the cell diagnostic results.

[0005] Furthermore, existing technologies connect and communicate between the battery cell, slave battery management system, and master battery management system via wired connections. However, wired connections require channel switching to perform data multiplexing during communication between the slave and master battery management systems. This process generates noise, reducing the reliability of data transmission between the slave and master battery management systems. Moreover, existing technologies require the application or installation of isolation elements at multiple locations to prevent electromagnetic interference caused by the connecting wires, which also poses a problem. To address this issue, technologies for wireless communication between the slave and master battery management systems have been developed in recent years, as illustrated in Korean Patent Registration No. 10-2203247. However, this technology only discloses wireless communication between the slave and master battery management systems; the battery cell and slave battery management system are still connected via wired connections. As a result, the problems inherent in wired connections between the battery cell and slave battery management system persist. The voltages of the cells within a single battery module vary, resulting in different levels of noise from each cell. This noise is not only voltage-dependent but also varies with cell performance, making it impossible to correct signals from multiple cells. Furthermore, the noise caused by muxing in the communication between the slave and master battery management systems also occurs during muxing between the cells and the slave system. Because the aforementioned isolators are limited by cost and installation space, they cannot completely eliminate electromagnetic interference, leading to indirect interference. These factors, along with other factors, cause noise superimposed on normal data, reducing the reliability of data transmission between the cells and the slave battery management system. In other words, even existing technologies for wireless communication battery management systems have failed to solve the various problems inherent in existing wired communication.

[0006] Therefore, there is a need to develop a technology that can diagnose the performance of individual cells and reduce noise generated during communication, thereby improving the reliability of the battery management system and enabling the safe operation of the cells. Summary of the Invention

[0007] The purpose of this invention is to provide a system for diagnosing battery cells using a direct-connect battery management system. The direct-connect battery management system has direct physical and electrical contact with the electrodes of each battery cell and measures the voltage of each battery cell and the current of multiple battery cells. Based on the measured voltage and current, the impedance of each battery cell is calculated, and the state of each battery cell is diagnosed through the impedance. The diagnostic results are then wirelessly sent to the main battery management system.

[0008] To address the aforementioned issues, one embodiment of the present invention discloses a cell diagnostic system. This cell diagnostic system includes: multiple directly connected battery management systems and multiple cells electrically connected to a battery module; and a main battery management system that wirelessly communicates with the directly connected battery management systems. The directly connected battery management systems include: a cell access unit with a port that directly and electrically contacts the exposed electrodes of the cell; a voltage measurement unit electrically connected to the cell access unit and measuring the cell voltage in a circuit configuration; a current measurement unit electrically connected to the cell access unit and measuring the cell current in a circuit configuration; a diagnostic unit that diagnoses whether the cell is abnormal based on the measured voltage, current, and temperature information; and a first wireless communication unit that sends the diagnostic results of the diagnostic unit to the main battery management system; the diagnostic results sent by the first wireless communication unit are received by a second wireless communication unit of the main battery management system.

[0009] In one embodiment of the present invention, the positive and negative terminals of the battery cell are all directly connected to the port of the battery cell access unit, the voltage and current of each battery cell are measured, the status of each battery cell is diagnosed, and the diagnosis results of each battery cell are sent to the main battery management system.

[0010] In one embodiment of the present invention, the direct-connected battery management system can analyze the voltage and current of each cell to measure the impedance of each cell, perform fire alarm diagnosis based on the impedance of each cell, and send the fire alarm diagnosis results to the main battery management system.

[0011] In one embodiment of the present invention, the direct-connected battery management system further includes: a cell balancing unit, which adjusts the voltage difference of each cell to keep the voltage of each cell consistent; and an impedance calculation unit, which calculates the impedance of the cell based on the voltage and current of each cell.

[0012] In one embodiment of the present invention, the direct-connect battery management system is composed of a substrate, and the cell access unit, the voltage measurement unit, the current measurement unit, the temperature measurement unit, the diagnostic unit, the first wireless communication unit, the cell equalization unit and the impedance calculation unit can be configured on the same substrate.

[0013] In one embodiment of the present invention, the direct-connected battery management system includes a plurality of cell balancing elements, each of which includes a cell switching element and a cell energy storage element. The plurality of cell balancing elements can perform cell balancing between adjacent cells.

[0014] In one embodiment of the present invention, the battery module includes a plurality of battery cells connected in series with each other, and one side of each battery cell may be configured with a positive terminal and a negative terminal.

[0015] According to one embodiment of the present invention, the direct-connect battery management system receives electrical signals through direct physical and electrical contact with multiple battery cells, thereby preventing noise caused by channel switching in wired communication and improving the reliability of data received from multiple battery cells.

[0016] According to one embodiment of the present invention, a direct-connect battery management system receives electrical signals through direct physical and electrical contact with multiple battery cells, thereby preventing uncorrectable noise due to the different voltages of the individual battery cells and improving the reliability of data received from multiple battery cells.

[0017] According to one embodiment of the present invention, the electrodes of each cell are connected to the port of the cell access unit of the direct-connected battery management system, thereby allowing the voltage of each cell to be measured. In this case, by eliminating the wires themselves that may generate electromagnetic interference, the accuracy of the data of each cell can be improved, and measures can be taken quickly for cells that are judged to have problems based on their respective diagnostic results.

[0018] According to one embodiment of the present invention, the impedance of each cell is measured by cell equalization, and the condition of the cell is diagnosed based on the measured impedance to prevent accidents such as battery explosion.

[0019] According to one embodiment of the present invention, the battery module is physically connected to a direct-connect battery management system, which improves the vibration durability of the cell diagnostic system compared to existing battery management systems, thereby extending battery life and improving the reliability of the transmitted and received data. Attached Figure Description

[0020] Figure 1 This outlines the communication method between the battery cell and the battery management system in existing approaches.

[0021] Figure 2 This outlines the problems that occur during the reuse process in existing methods.

[0022] Figure 3 This outlines the problems caused by multiple cells that each measure different voltages in existing methods.

[0023] Figure 4 This outlines the problems caused by cell assemblies that measure different voltages in existing methods.

[0024] Figure 5 The schematic diagram illustrates the structure of a system for diagnosing battery cells using a direct-connect battery management system, according to one embodiment of the present invention.

[0025] Figure 3 The structure of a battery module and its connection structure with a direct-connect battery management system are illustrated by way of example according to an embodiment of the present invention.

[0026] Figure 9 This diagram outlines a system for diagnosing battery cells using existing methods.

[0027] Figure 10 This schematically illustrates a system for diagnosing battery cells according to one embodiment of the present invention.

[0028] Figure 11 The diagram schematically illustrates the connection structure of a battery cell and a direct-connected battery management system according to an embodiment of the present invention.

[0029] Figure 12 The connection structure of the battery cell and the direct-connected battery management system according to another embodiment of the present invention is schematically shown.

[0030] Figure 13 Figure 14 The schematic diagram illustrates the structure of a direct-connected battery management system in one embodiment of the present invention, which performs the process of calculating the impedance of each cell through cell equalization.

[0031] Figure 15 This schematically illustrates the frequency of the input signal and the impedance information of the battery cell at different temperatures according to an embodiment of the present invention.

[0032] Figure 16 The execution process of the diagnostic unit and the first wireless communication unit according to an embodiment of the present invention is illustrated in a schematic diagram. Detailed Implementation

[0033] Various embodiments and / or configurations are disclosed below with reference to the accompanying drawings. In the following description, for illustrative purposes, several specific details are disclosed to facilitate a general understanding of more than one configuration. However, those skilled in the art will recognize that these configurations can be implemented even without these specific details. The following description and drawings will describe in detail several specific exemplary configurations of more than one configuration. However, these configurations are merely illustrative, and a portion of the various methods within the principles of the various configurations can be utilized. The description is intended to encompass these configurations and their equivalents.

[0034] Furthermore, various forms and features will be disclosed in the form of systems that may include a plurality of devices, a plurality of parts and / or a plurality of modules. However, it should also be understood that various systems may further include a plurality of devices, a plurality of parts and / or a plurality of modules, and / or may not include the plurality of devices, a plurality of parts, a plurality of modules mentioned in connection with the accompanying drawings.

[0035] The use of terms such as “example,” “model,” “illustration,” etc., in this specification does not imply that any model or design described is superior or more advantageous than other multiple models or designs. The terms “unit,” “part,” “module,” “system,” “interface,” etc., used below generally refer to computer-related entities, such as hardware, a combination of hardware and software, or software.

[0036] Furthermore, the terms “comprising” and / or “including” indicate the presence of the feature and / or component, but should be interpreted as not excluding the presence of more than one other feature, component and / or group thereof, or the addition of more than one other feature, component and / or group thereof.

[0037] Furthermore, terms containing ordinal numbers such as "first" and "second" may be used when describing various components, but the components should not be limited to those terms. The purpose of using these terms is solely to distinguish one component from others. For example, a first component may be named a second component without departing from the scope of the claims of this invention; similarly, a second component may be named a first component. The term "and / or" includes a combination of multiple related description items or a single item from multiple related description items.

[0038] Furthermore, in the various embodiments of the present invention, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms such as those defined in general dictionaries may be interpreted as having the same meaning as in the context of the relevant description, and should not be interpreted in an unusual or overly formalistic manner unless explicitly defined in the embodiments of the present invention.

[0039] Figures 1 to 4 This paper outlines the communication method between the cell and the battery management system in existing methods and the problems that occur in these existing methods.

[0040] In summary, Figure 1 This is the background technology of the present invention, which illustrates first-generation and second-generation communication methods between the battery cell, the slave-controlled battery management system, and the main battery management system 30. Figure 2 This illustrates the noise caused by channel switching required for multiplexing in wired communication. Figure 3 The diagram illustrates the noise caused by electrical floating during wired communication between multiple battery cells, each measuring different voltages, and the slave-controlled battery management system. Figure 4This diagram outlines the problems that occur in wired communication between multiple cell groups, each measuring different voltages, and the slave-controlled battery management system.

[0041] Specifically, if Figure 1 As shown, in the existing first-generation battery management system, the battery cell is connected and communicates with the slave battery management system via a wired connection, and the slave battery management system is also connected and communicates with the main battery management system 30 via a wired connection.

[0042] The communication method in the first-generation battery management system, such as Figure 2 As shown, multiple slave battery management systems are connected to a single master battery management system 30. The single master battery management system 30 receives signals from the slave battery management systems (20) in sequence and multiplexes them.

[0043] The inventors of this invention derived the following problem from the system described above.

[0044] During the mutation process, each slave battery management system sequentially switches its connection with the main battery management system 30 before communicating with it. For example, when the first slave battery management system is connected to the main battery management system 30, the channel (or switch) between the first slave battery management system and the main battery management system 30 is in the ON state, while the channels between the other slave battery management systems and the main battery management system 30 are in the Off state.

[0045] Then, when the channel of the second slave battery management system is in the On state, the channels of the other slave battery management systems besides the second slave battery management system are in the Off state. The same process is performed on the third slave battery management system, the fourth slave battery management system, and so on, until the last slave battery management system.

[0046] During the process of switching the connection switch between the master battery management system 30 and the slave battery management system (20) to ON / OFF as described above, noise will inevitably occur, which will cause the data transmitted and received between the slave battery management system and the master battery management system 30 to be incorrect, thereby reducing the reliability of the data.

[0047] To solve this problem, as... Figure 1 The second-generation communication method shown is a technology being developed for wireless communication between the slave battery management system and the main battery management system 30.

[0048] However, even in this case, multiple cells will be grouped, and multiple signal output lines in the grouped cells will be connected to a single slave-controlled battery management system.

[0049] That is, even in this case, a single slave-controlled battery management system essentially connects multiple signal lines from multiple cell packs; similarly, Figure 2 The noise problem caused by the rapid switching of ON / OFF occurs when the slave-controlled battery management system receives signals from the grouped cells via multiple signal lines.

[0050] For example, assuming there are a total of 25 battery cells, existing second-generation technology measures the overall voltage and current of 5 individual cells and transmits these measured signals to the slave-controlled battery management system via additional wired communication. Therefore, the slave-controlled battery management system receives information from all 25 cells via a total of 5 signal lines. In this process, due to… Figure 2 The switching action shown generates noise.

[0051] Moreover, such as Figure 3 As shown, for example, when a cell is subjected to a voltage of 3V, if multiple cells are connected in series, the cells at the end of the series will be subjected to a higher voltage than the cells at the beginning of the series.

[0052] That is, each battery cell has a different voltage. Due to the different voltages, noise will occur during wired communication because each battery cell is subjected to a different voltage.

[0053] Moreover, this noise not only varies with voltage but also exhibits different characteristics depending on the cell's lifespan and the presence of vibration, thus placing it in a state that cannot be corrected by general rules and affecting existing data signals. For example, the noise cancellation methods for a cell subjected to 3V voltage are different from those for a cell subjected to 24V voltage, making it impossible to accurately receive signals from the cell.

[0054] Figure 4 This shows the latest version of the battery management system that utilizes a portion of the aforementioned second-generation wireless technology.

[0055] Figure 4 This includes multiple battery cells (in) Figure 4 The measurement module connects to the first electrode of the first cell (equivalent to the first cell in a multi-cell array) and the electrode of the last cell (equivalent to the last cell in a multi-cell array). Figure 4 The second electrode of the fourth cell (the fourth one in the series) is used to measure the voltage of the four cells connected in series.

[0056] The information measured by the measurement module is processed by the communication module, and the connection is established with the slave battery management system via wired communication through the communication port.

[0057] In the aforementioned environment, the battery management system is connected to multiple measurement boards, and data is received from each measurement board for each cell group (in...). Figure 4The measured value is for 4 battery cells.

[0058] In this situation, the slave battery management system needs to eliminate the noise generated during the channel switching process in the aforementioned multiplexing steps, as well as the noise caused by the voltage applied to each cell group, before it can receive the correct data, but in reality, it cannot solve this problem.

[0059] In particular, Figure 4 In this scenario, the fourth cell, which is the last cell in the first cell group, is subjected to a 12V voltage of 3V*4 (e.g., the voltage difference between the ground voltage of the measuring board and the voltage of the last cell). The eighth cell, which is the last cell in the second cell group, is subjected to a 24V voltage. If the number of cells reaches hundreds, the voltage difference applied to the cell groups will be very large, requiring different methods or degrees of noise compensation. However, this is practically impossible. Applying such dissimilar voltages will not only affect data communication but also voltage / current measurements.

[0060] In the aforementioned first and second generation battery management systems, the reliability of data is inevitably low.

[0061] This invention introduces a new architecture for a direct-connect battery management system, rather than an access structure between the second-generation battery cell and the slave-controlled battery management system. This prevents data errors caused by noise and other factors, and enables accurate measurement and transmission of information from more than one battery cell.

[0062] Figure 5 The structure of a system for diagnosing battery cells (11.1 to 11.8, hereinafter 11) using a direct-connect battery management system 20 according to an embodiment of the present invention is illustrated in the schematic diagram.

[0063] like Figure 5 As shown, the diagnostic system for cell 11 includes: multiple direct-connected battery management systems 20, electrically connected to multiple cells 11 contained in the battery module 10; and a main battery management system 30, which wirelessly communicates with the direct-connected battery management systems 20; the direct-connected battery management system 20 includes: a cell access unit 21, having a port that directly and electrically contacts the exposed electrodes of the cell 11; a voltage measurement unit 23, electrically connected to the cell access unit 21 and measuring the voltage of the cell 11 in a circuit configuration; a current measurement unit 24, electrically connected to the cell access unit 21 and measuring the current of the cell 11 in a circuit configuration; a diagnostic unit 26, which diagnoses whether the cell 11 is abnormal based on the measured voltage, current, and temperature information; and a first wireless communication unit 27, which sends the diagnostic results of the diagnostic unit 26 to the main battery management system 30; the diagnostic results sent by the first wireless communication unit 27 are received by the second wireless communication unit 31 of the main battery management system 30.

[0064] Moreover, the direct-connect battery management system 20 is actually composed of a substrate, and the cell access unit 21, the voltage measurement unit 23, the current measurement unit 24, the temperature measurement unit 25, the diagnostic unit 26 and the first wireless communication unit 27 are disposed on the same substrate.

[0065] The battery cell is equivalent to the battery cell used as a power source in electric or hybrid vehicles.

[0066] Specifically, the present invention includes: a battery cell 11; and a battery management system (hereinafter referred to as the battery management system) for managing a battery pack or battery module consisting of multiple battery cells 11.

[0067] Batteries typically consist of cells, modules, and packs. First, the cell is the basic unit of a lithium-ion battery that uses electrical energy for charging and discharging. It is made by assembling the positive electrode, negative electrode, separator, and electrolyte into a square or cylindrical aluminum casing.

[0068] The battery cell 11 needs to have high capacity per unit volume or unit weight in order to achieve the highest performance in a limited space. The battery cell for vehicles has a much longer lifespan than the battery for ordinary mobile devices. It can withstand the impact generated during driving and can still work normally at high temperatures above a certain benchmark or low temperatures below a certain benchmark. Therefore, it needs to have corresponding reliability and stability in its design.

[0069] To protect the multiple battery cells described above from external shocks such as heat and vibration, the multiple battery cells are bundled together in a certain number and placed in a frame to form a battery assembly, referred to as battery module 10. A battery module 10 may consist of approximately 6 to 10 battery cells, and recently modules with approximately 12 to 48 battery cells connected in series or parallel have also been used. A battery module 10 consisting of 12 battery cells 11 typically has a capacity of approximately 2 to 3 kWh.

[0070] A battery pack is formed by assembling multiple battery modules 10 as described above, along with the battery management system and cooling device. A battery pack may contain 8 to 40 battery modules 10, which can be connected in series, parallel, or in a hybrid configuration. Typically, one battery pack is installed in a vehicle. The modular battery pack described above facilitates battery maintenance and allows the use of more efficient batteries with reduced weight and size.

[0071] On the other hand, the present invention uses a direct-connection battery management system 20, which makes direct physical and electrical contact with each of the multiple battery cells 11 contained in a battery module 10, to diagnose and prevent accidents for each of the battery cells 11. This will be described below.

[0072] As an embodiment of the present invention Figure 5 The battery module 10 shown contains 8 cells 11, but the battery module 10 in another embodiment of the present invention is not limited to this and may contain fewer than 8 or more cells 11.

[0073] In another embodiment of the invention, a direct-connect battery management system can also be provided for each individual cell on a one-to-one basis.

[0074] In this invention, a main battery management system 30 and a plurality of direct-connect battery management systems 20 communicate wirelessly and each of the direct-connect battery management systems 20 sends and receives data.

[0075] Please refer to Figure 8 The cell access unit 21 includes multiple positive (+) terminal contacts (22.A, where A is an odd number, hereinafter referred to as 22.1) and multiple negative (-) terminal contacts (22.B, where B is an even number, hereinafter referred to as 22.2). One of its features is the elimination of electromagnetic interference isolation elements (EMI Isolators) found in existing battery management systems. The positive terminal contact 22.1 and the negative terminal contact 22.2 are ports that directly contact the exposed electrodes of the cell 11 in a physical and electrical manner, receiving and transmitting signals between the cell 11 and the direct-connected battery management system 20.

[0076] At this time, since the signal is not first aggregated to a port equipped with additional signal processing before being transmitted to a specific processing unit (e.g., MCU), the electrical signal received by the direct-connect battery management system 20 or its internal processing module is based on the current or voltage flowing in the cell 11 itself. This type of signal is a raw (RAW) signal unaffected by external factors. The positive contact 22.1 is in contact with the positive terminal of the cell 11, and the negative contact 22.2 is in contact with the negative terminal of the cell 11. Moreover, the direct-connect battery management system 20 is electrically connected to the multiple cells 11 contained in the battery module 10, and the positive contact 22.1 and the negative contact 22.2 are in contact with the respective electrodes of the cell 11, so that the cell access unit 21 can transmit and receive electrical signals with each cell 11.

[0077] As described above, the raw signal is directly transmitted to the direct-connect battery management system 20. Multiple measurement units within the direct-connect battery management system 20 perform accurate measurements based on the raw signal and then transmit the data wirelessly to the main battery management system 30, thus enabling more accurate diagnostics and data communication. In the aforementioned... Figure 1 In the first or second generation, data or signals are lost during the process of being sent to the slave battery management system, making it impossible to achieve the correct diagnosis and data communication as described above.

[0078] The voltage measurement unit 23 and the current measurement unit 24 measure the voltage of each cell 11 and the current of the battery module 10 based on the electrical signals received from each cell 11 of the cell access unit 21. By using the voltage information corresponding to each cell 11 and the current information of the battery module 10, the state of each cell 11 can be diagnosed, thereby improving the reliability of the diagnostic results.

[0079] More specifically, by measuring the voltage and current of the cell 11 over time, the waveforms of the output voltage and output current of the cell 11 over time can be measured.

[0080] In one embodiment of the present invention, the temperature measurement unit 25 is included in the direct-connect battery management system 20 and measures the temperature of the battery cell 11. The battery cell 11 may fail to charge at low temperatures, and it may also malfunction due to sudden temperature changes; therefore, it is necessary to measure the temperature of the battery cell 11 at all times. Furthermore, the temperature information, voltage information, and current information of the battery cell 11 are important factors to consider when diagnosing the condition of the battery cell 11.

[0081] The diagnostic unit 26 diagnoses the state of each cell 11 based on the voltage information received from the voltage measurement unit 23, the current information received from the current measurement unit 24, and the temperature information received from the temperature measurement unit 25. For example, abnormal states of the cell 11 include overvoltage (overcharge), undervoltage (over-discharge), overcurrent, ultra-high temperature, and ultra-low temperature.

[0082] More specifically, please refer to Figure 13 The direct-connected battery management system 20 may further include: a cell balancing unit 28 for performing cell balancing; and an impedance calculation unit 29 for calculating impedance through cell balancing; and diagnosing the state of each cell 11 through the calculated impedance.

[0083] Preferably, the cell balancing unit 28 further generates an input signal with a specific frequency through cell balancing, and the impedance calculation unit 29 calculates the impedance of each cell 11 based on the voltage information, the current information, the frequency information of the specific frequency and the temperature information through a trained inference model based on an artificial neural network.

[0084] A more detailed explanation of the impedance calculation process will be provided later. Figure 14 Further explanation follows. The diagnostic unit 26 diagnoses each of the battery cells 11 by their respective impedance, thereby improving the reliability of the diagnostic results and preventing battery accidents such as fires.

[0085] Please refer to the above again. Figure 5 The first wireless communication unit 27 of the direct-connect battery management system 20 is connected to the wireless antenna of the direct-connect battery management system 20, and the second wireless communication unit 31 of the main battery management system 30 is connected to the wireless antenna of the main battery management system 30.

[0086] The direct-connect battery management system 20 and the main battery management system 30 communicate wirelessly with each other via the wireless antennas of the direct-connect battery management system 20 and the main battery management system 30. Although Figure 5 Although not illustrated, preferably, the second wireless communication unit 31 of the main battery management system 30 and the first wireless communication units 27 of the plurality of direct-connected battery management systems 20 each transmit and receive signals.

[0087] Figures 6 to 8 The structure of a battery module 10 and its connection structure with a direct-connect battery management system 20 according to an embodiment of the present invention are illustrated by way of example.

[0088] like Figures 6 to 8 As shown, the battery module 10 includes a plurality of battery cells 11 connected in series with each other, and each battery cell 11 has a positive terminal and a negative terminal on one side.

[0089] Specifically, Figure 6This schematically illustrates a battery module 10 in one embodiment of the present invention, comprising a structure of six cells 11 arranged in a cross configuration. Assuming the cell at the top is the first cell 11.1, and assuming that cells 11.1 to 11.6 are sequentially arranged from the first cell 11.1 to the sixth cell 11.6 at the bottom, the first cell 11.1 to the sixth cell 11.6 are connected in series to form the battery module 10. The left terminal of the first cell 11.1 is called the negative terminal, and the right terminal is called the positive terminal. When current flows into the right positive terminal of the first cell 11.1, the left negative terminal of the first cell 11.1 is connected in series with the left positive terminal of the second cell, and the right negative terminal of the second cell is connected in series with the right positive terminal of the third cell. Preferably, the first cell 11.1 to the sixth cell 11.6 are connected in series.

[0090] Figure 7 An embodiment of the present invention is shown where the battery module 10 and the direct-connected battery management system 20 are in direct physical and electrical contact. Figure 7 In the middle, the direct-connect battery management system 20 (represented by an elliptical dashed line) is physically and electrically attached to one side of the battery module 10, as shown below. Figure 8 As shown, each of the battery cells 11 communicates with the direct-connected battery management system 20.

[0091] Figure 8 The connection structure of the battery cell 11 and the connection structure between the battery module 10 and the battery cell access unit 21 are shown. The battery cell 11 is as follows... Figure 6 The battery module 10 is formed by alternating positive and negative terminals connected in series. The positive contact 22.1 of the cell access unit 21 is connected to the positive terminal of the cell 11, and the negative contact 22.2 of the cell access unit 21 is connected to the negative terminal of the cell 11. At the positive and negative terminals, the electrical signal of the cell 11 is input to the corresponding positive and negative contact 22.1 and negative contact 22.2 of the cell 11. The cell access unit 21 sends the electrical signal to the voltage measurement unit 23 and the current measurement unit 24. The voltage measurement unit 23 measures the voltage of the cell 11 based on the electrical signal, and the current measurement unit 24 measures the current of the cell 11 based on the electrical signal.

[0092] On the other hand, in another embodiment of the present invention, the plurality of battery cells 11 may be randomly arranged without alternating with each other. However, the plurality of battery cells 11 are connected in series to form a battery module 10. Moreover, in yet another embodiment of the present invention, unlike... Figure 8 As shown, the number of battery cells 11 is not limited to 8 cells 11. The battery module may contain fewer than 8 cells 11 or more than 8 cells 11.

[0093] Figure 9 This diagram outlines a system for diagnosing cell 11 using existing methods. Figure 10 This schematically illustrates a system for diagnosing battery cells according to one embodiment of the present invention.

[0094] like Figure 9 As shown, in an existing system for diagnosing battery cells 11, a battery module 10 containing multiple battery cells 11 is connected to a measuring board via a wired connection. The measuring board measures the voltage, current, and temperature of the battery module 10, which are the average voltage, average current, and average temperature of the multiple battery cells 11 contained in the battery module 10. The slave battery management system sends the measured voltage, current, and temperature of the battery module 10 to the master battery management system 30. The master battery management system 30 diagnoses the battery module 10 as a whole based on the received voltage, current, and temperature information.

[0095] Figure 10 This illustration shows the structure of a battery module 10 according to an embodiment of the present invention, in which multiple battery cells 11 are each connected to a direct-connect battery management system 20. In this case, the direct-connect battery management system 20 includes... Figure 9 The structure of the measurement board and slave battery management system shown indicates that, in the absence of wired communication requiring additional switching, execution... Figure 9 Measuring plate and Figure 9 All functions performed by the slave-controlled battery management system.

[0096] Furthermore, a key technical feature of this invention is that each of the battery cells 11 makes direct physical and electrical contact with multiple ports (contacts) provided in the direct-connect battery management system 20. Since communication between the battery cells 11 and the direct-connect battery management system 20 is not achieved through a structure with predetermined signal processing, such as a communication line, the direct-connect battery management system 20 can receive the original (RAW) electrical signal of the current flowing in the battery cells 11 without being affected by external interference. Therefore, the direct-connect battery management system 20 can diagnose the battery cells 11 more accurately than existing battery cell diagnostic technologies, thereby improving the reliability of the diagnostic results for the battery cells 11.

[0097] Furthermore, the direct-connected battery management system 20 and the battery cell 11 each receive and generate signals, measure the voltage of each battery cell 11 and the current of multiple battery cells, and can accurately diagnose the state of each battery cell.

[0098] The diagnostic unit 26 of the direct-connect battery management system 20 does not diagnose the cells 11 by averaging values ​​across a wide range of battery modules 10 as in the prior art. Instead, it utilizes the electrical information of each cell 11 in raw (RAW) data format to diagnose each cell 11 individually.

[0099] Furthermore, the voltage flowing from the battery cell 11 is typically high-level, and data problems or malfunctions in the direct-connect battery management system 20 may occur when transmitting and receiving high-voltage electrical signals. Therefore, the direct-connect battery management system 20 also includes a high-voltage sensor. When the voltage of the electrical signals received from multiple battery cells 11 exceeds a preset reference, the high-voltage sensor converts the high voltage into a safe voltage and sends it to the voltage measurement unit 23, the current measurement unit 24, and the temperature measurement unit 25. The voltage measurement unit 23, the current measurement unit 24, and the temperature measurement unit 25 measure the voltage, current, and temperature of the battery cell 11 based on the received information. Specifically, the measured voltage is then used for calibration corresponding to the conversion operation performed by the high-voltage sensor.

[0100] Figure 11 and Figure 12 The connection structure of the battery cell 11 and the direct-connected battery management system 20 according to several embodiments of the present invention is shown in a schematic diagram.

[0101] In summary, Figure 11 An embodiment of the present invention is shown, in which multiple battery cells 11 are connected to a direct-connect battery management system 20. Figure 12 Another embodiment of the invention is shown, in which each cell 11 is connected to a direct-connect battery management system 20.

[0102] Specifically, if Figure 11 As shown, multiple battery cells 11 can be connected to a direct-connect battery management system 20. The electrodes of the multiple battery cells 11 are physically and electrically attached to and communicate with the cell access unit 21 of the direct-connect battery management system 20. The cell access unit 21 includes multiple positive contact portions 22.1 and multiple negative contact portions 22.2, and is attached to the positive and negative terminals of each of the multiple battery cells to receive and generate signals.

[0103] like Figure 12 As shown, each cell 11 can be connected to a direct-connect battery management system 20. The electrodes of a cell 11 are physically and electrically attached to and communicate with the cell access unit 21 of the direct-connect battery management system 20. The cell access unit 21 includes a single positive contact portion 22.1 and a single negative contact portion 22.2, which are attached to the positive and negative terminals of a single cell and receive and generate signals.

[0104] Regarding the description of the present invention, Figure 11 The connection structure shown is used as the basis for explanation.

[0105] Figures 13 to 14The structure of a direct-connect battery management system 20, which performs the process of calculating the impedance of each cell through cell equalization, is schematically shown in one embodiment of the present invention.

[0106] like Figure 13 As shown, the direct-connect battery management system 20 further includes: a cell balancing unit 28, which adjusts the voltage difference of each cell 11 to keep the voltage of each cell 11 consistent; and an impedance calculation unit 29, which calculates the impedance of each cell 11 based on its voltage and current. Moreover, the direct-connect battery management system is constructed from a single substrate, with the cell access unit 21, the voltage measurement unit 23, the current measurement unit 24, the temperature measurement unit 25, the diagnostic unit 26, the first wireless communication unit 27, the cell balancing unit 28, and the impedance calculation unit 29 disposed on the same substrate.

[0107] Moreover, such as Figure 14 As shown, the direct-connected battery management system 20 includes multiple cell balancing elements, each including a cell switching element and a cell energy storage element. The multiple cell balancing elements perform cell balancing between adjacent cells.

[0108] The cell balancing unit 28 includes an energy storage unit, a power distribution unit, and a switching control unit. The energy storage unit includes one or more cell switching elements and one or more cell energy storage elements. The cell switching element can be a single element such as a diode, transistor, or a logic circuit programmed IC chip or SoC, or it can be a module composed of multiple single elements. Moreover, the cell energy storage element includes one or more elements capable of storing electricity, such as capacitors, and preferably also includes passive elements such as inductors or resistors.

[0109] In one embodiment of the present invention, the energy storage unit is connected between the positive terminal of the first battery cell 11.1 and the positive terminal of the second battery cell (not shown). When the voltage measurement value of the first battery cell 11.1 is higher than that of the second battery cell, and it is necessary to transfer the power of the first battery cell to the second battery cell, the battery cell equalization unit 28 performs a first charging step by charging a portion of the power stored in the first battery cell 11.1 into the first energy storage element through the operation of the first battery cell switching element (first battery cell switching element a and first battery cell switching element b) controlled by the switching control unit. The switch connecting the positive terminal of the first battery cell 11.1 and the first energy storage element is closed, so that a portion of the power of the first battery cell 11.1 can move to the first battery cell energy storage element. At this time, the amount of charge entering the first battery cell energy storage element can be adjusted by controlling the first battery cell switching element.

[0110] When the first battery cell storage element is fully charged, the battery cell balancing unit 28, through the operation of the first battery cell switching element and the second battery cell switching element (second battery cell switching element a and second battery cell switching element b) controlled by the switching control unit, performs a second charging step to charge a portion of the power stored in the first battery cell 11.1 into the second battery cell storage element. Alternatively, according to an embodiment of the present invention, the second charging step can be performed before the first charging step by the operation of the switching control unit. In this case, the amount of charge into the second battery cell storage element can be adjusted by controlling the second battery cell switching element. Furthermore, the battery cell balancing unit 28, through the operation of the first battery cell switching element controlled by the switching control unit, performs a first discharging step to discharge the power stored in the first battery cell storage element and transfer it to the power distribution unit. The power distribution unit transfers the power received via the first battery cell switching element to the second battery cell through the positive terminal of the second battery cell, resulting in an increase in the voltage of the second battery cell. At this time, the discharge amount of the first storage element can be adjusted by controlling the first battery cell switching element; preferably, the first battery cell switching element is turned on and off at a specific period to transfer power to the power distribution unit.

[0111] When the second energy storage element is fully charged, the cell balancing unit 28, through the operation of the second cell switching element controlled by the switching control unit, performs a second discharge step to discharge the power stored in the second cell energy storage element and transfer it to the power distribution unit. The power received via the second cell switching element is transferred to the second cell through the positive terminal, resulting in a voltage increase in the second cell. At this time, the discharge amount of the second cell energy storage element can be adjusted by controlling the second cell switching element; preferably, the second cell switching element is turned on and off at specific intervals to transfer power to the power distribution unit. Through this series of processes, cell balancing between the first cell 11.1 and the second cell is performed. Not only is cell balancing performed between the first cell 11.1 and the second cell, but the cell balancing process between the remaining cells is also performed in the same way.

[0112] As previously described, the cell balancing unit 28 repeatedly performs charging and discharging steps on the cell energy storage element using a cell switching element. The amount of discharge during the repeatedly performed discharging step can be variably controlled through the action of the cell switching element, thereby generating an input signal with a specific frequency. For example, if the action of repeatedly closing cell switching element a for 5 seconds and opening cell switching element b for 5 seconds is performed, the impedance calculation unit 29 can generate an input signal of 100mHz (=0.1Hz).

[0113] Furthermore, according to one embodiment of the present invention, the power distribution unit can synthesize the frequencies of the input signals generated in the first discharge step and the input signals generated in the second discharge step to generate input signals with completely different frequencies. Please refer to... Figure 15 The frequency of the input signal is one of the important parameters when measuring the impedance information of the battery cell 11. The process of measuring the impedance of the battery cell based on the frequency of the input signal will be described below.

[0114] The impedance calculation unit 29 measures impedance based on voltage, current, and a specific frequency. Specifically, the impedance calculation unit 29 calculates impedance using an input signal of a specific frequency generated during the cell balancing process performed by the cell balancing unit 28. The impedance calculation unit 29 uses a trained inference model to calculate impedance. This inference model is equivalent to a model pre-trained with multiple training data derived from a battery model that calculates the impedance of cell 11 based on the vehicle's power mode and environmental conditions. The impedance information of cell 11 at the specific frequency is calculated based on these multiple training data, the waveform of the output voltage, and the waveform of the output current. The waveforms of the output voltage and output current are included in the voltage and current information received by the direct-connected battery management system 20 from cell 11. In an embodiment of the present invention, preferably, the impedance of the cell is calculated only using the waveforms of the output voltage and the output current. However, according to another embodiment of the present invention, the temperature information obtained by the temperature measurement unit 25 can be used to calculate the impedance of the cell. A battery cell is a device that generates electricity through a chemical reaction. This process involves the input or output of heat, therefore battery performance is closely related to temperature. In fact, please refer to... Figure 15 It can be confirmed that the impedance information changes with temperature.

[0115] The following reference Figure 15 By analyzing the waveform of the impedance information, the current state and malfunction of the cell 11 can be determined. Since the impedance information is a value that changes with frequency, an additional measuring device is usually required when measuring impedance. However, this invention can measure the impedance of each cell 11 using the input signal generated during the cell equalization process without an additional measuring device. Based on this, diagnostic results for the cell 11 can be calculated and provided to the user.

[0116] Figure 16 The execution process of the diagnostic unit 26 and the first wireless communication unit 27 according to an embodiment of the present invention is illustrated in a schematic diagram.

[0117] like Figure 16As shown, the positive and negative terminals of the battery cell 11 are all directly in contact with the port of the battery cell access unit 21. The battery cell 11 is diagnosed by measuring voltage, current and temperature, and the diagnostic results of each battery cell 11 are sent to the main battery management system 30.

[0118] Furthermore, the direct-connected battery management system 20 analyzes the voltage and current of each of the battery cells 11 to measure the impedance of each of the battery cells 11, performs fire alarm diagnosis based on the impedance of each of the battery cells 11, and sends the fire alarm diagnosis results to the main battery management system 30.

[0119] Specifically, the diagnostic unit 26 diagnoses each cell 11 based on voltage and current information corresponding to that cell 11, including the following: if the voltage of a cell 11 exceeds a preset maximum voltage reference, it is determined to be overvoltage (overcharge); if the voltage of a cell 11 is lower than a preset minimum voltage reference, it is determined to be undervoltage (over-discharge); if the current of a cell 11 exceeds a preset maximum current reference, it is determined to be overcurrent; and based on the temperature measurement, it diagnoses battery overheating, etc., for each cell 11. Furthermore, it receives impedance information of the cell 11 calculated based on the voltage and current information. Impedance is a major factor in battery fires; a cell 11 with high impedance may overheat and catch fire or explode during discharge. Therefore, the diagnostic unit 26 frequently measures the impedance and diagnoses whether the cell 11 is abnormal.

[0120] The direct-connect battery management system is attached to the positive and negative terminals of each cell and measures the voltage and current of the cell 11. This improves the reliability of cell 11 diagnostic results compared to existing technologies that measure the average voltage and average current of multiple cells 11 in the battery module 10. Furthermore, in one embodiment of the invention, when one or more cells 11 in the battery module 10 exhibit performance abnormalities, the malfunctioning cell can be quickly removed, thereby preventing situations where excessively high charging voltages of the remaining cells 11 in the battery module 10 adversely affect the overall performance and lifespan of the cell 11.

[0121] As described above, although limited embodiments and accompanying drawings have been provided, those skilled in the art can make various modifications and variations from the description. For example, the described techniques can be performed in a different order than the described methods, and / or elements such as systems, structures, devices, and circuits can be combined or integrated in other forms than the described methods, or substituted or replaced by other elements or equivalents, all while achieving satisfactory results. Therefore, all other implementations, other embodiments, and equivalents thereof fall within the scope of the claims.

Claims

1. A diagnostic system for battery cells, located inside a vehicle, characterized in that, include: Multiple direct-connect battery management systems are located inside the vehicle and electrically connected to the multiple cells contained in the battery module; and, The main battery management system is located inside the vehicle and communicates wirelessly with the direct-connect battery management system. The direct-connect battery management system includes: The battery cell access unit is provided with a port that makes direct physical and electrical contact with the exposed electrodes of the battery cell; A voltage measurement unit is electrically connected to the cell access unit and measures the cell voltage in a circuit configuration; The current measuring unit is electrically connected to the cell access unit and measures the current of the cell in a circuit configuration; The diagnostic unit uses measured voltage, current, and temperature information to diagnose whether the battery cell is malfunctioning; and, The first wireless communication unit sends the diagnostic results of the diagnostic unit to the main battery management system; The diagnostic results sent by the first wireless communication unit are received by the second wireless communication unit of the main battery management system.

2. The cell diagnostic system according to claim 1, characterized in that, The positive and negative terminals of the battery cell are all in direct contact at the port of the battery cell access unit. Measure the voltage of each battery cell and the current of each battery cell. For the aforementioned battery cell, diagnose the condition of the battery cell. The diagnostic results of each battery cell are sent to the main battery management system.

3. The cell diagnostic system according to claim 2, characterized in that, The direct-connect battery management system. By analyzing the voltage and current of each battery cell, the impedance of each battery cell can be measured. Fire alarm diagnosis is performed based on information including the impedance of each of the battery cells. The fire alarm diagnosis results are sent to the main battery management system.

4. The cell diagnostic system according to claim 1, characterized in that, The direct-connect battery management system also includes: A cell balancing unit adjusts the voltage difference between the individual cells to maintain a consistent voltage across them; and... The impedance calculation unit calculates the impedance of each battery cell based on its respective voltage and current.

5. The cell diagnostic system according to claim 4, characterized in that, The direct-connect battery management system consists of a single base plate. The cell access unit, the voltage measurement unit, the current measurement unit, the temperature measurement unit, the diagnostic unit, the first wireless communication unit, the cell balancing unit, and the impedance calculation unit are configured on the same substrate.

6. The cell diagnostic system according to claim 1, characterized in that, The direct-connect battery management system includes multiple cell balancing elements. The cell balancing element includes a cell switching element and a cell energy storage element. The multiple cell balancing elements perform cell balancing between adjacent cells.

7. The cell diagnostic system according to claim 1, characterized in that, The battery module includes multiple battery cells connected in series. Each of the battery cells has a positive terminal and a negative terminal on one side.

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