A battery fault management system

Abstract

The present invention discloses a battery fault management system. The present invention configures an electronic switch for each battery cell. Among them, the electronic switch of any battery cell is used to control the connection or disconnection of the any battery cell to or from the battery cell series circuit of the battery pack, and when disconnected, it can ensure the passage of the battery cell series circuit. In this way, based on the electronic switch, the troubleshooting of a single battery cell can be realized. That is, the present invention first collects the pressure data of the battery pack and the voltage, current and temperature data of each battery cell. Then, based on the foregoing data, it is determined whether each battery cell has a fault, and when a fault is determined, the electronic switch of the faulty battery cell is controlled to disconnect the connection between the battery cell and the battery cell series circuit. Based on this, the faulty battery cell can be disconnected from the circuit, so as to ensure the normal power supply of the normal battery cells to the device. Therefore, the present invention can enable the battery pack to continuously and uninterruptedly work normally. Therefore, while improving the working stability and sustainability, the maintenance cost is also reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery management, and in particular relates to a battery fault management system. Background Art

[0002] As an important form of new energy vehicles, the battery pack of electric vehicles has a significant impact on the safety and reliability of the vehicle. Therefore, with the rapid development of electric vehicles, higher requirements are placed on the fault detection and safety control of battery packs. At present, when the performance of individual cells in the battery pack is significantly degraded or a fault occurs, the existing battery management system will stop the discharge of the entire battery pack and shut down the battery pack to prevent the fault from further deteriorating, thereby avoiding safety accidents. At the same time, when a battery pack fails, it is usually impossible to replace the cells individually, and the maintenance method is usually to replace the entire battery pack. In this way, the battery pack will not be able to continue to work due to problems with individual cells. Based on this, how to provide a battery fault management system that can automatically eliminate faulty cells and ensure that the entire battery pack can continue to work has become an urgent problem to be solved. Summary of the Invention

[0003] The purpose of the present invention is to provide a battery fault management system to solve the problem in the prior art that when a single battery cell fails, the entire battery pack needs to be shut down, resulting in the battery pack being unable to continue working.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, a battery fault management system is provided, comprising:

[0006] A cell switch module, wherein the cell switch module includes a plurality of electronic switches, wherein the number of electronic switches is the same as the number of cells in the battery pack, each cell corresponds to an electronic switch, and each electronic switch is used to connect the corresponding cell to the cell series circuit of the battery pack, or disconnect the corresponding cell from the cell series circuit, and maintain the passage of the cell series circuit after disconnecting from the cell series circuit;

[0007] A battery monitoring module, wherein the battery monitoring module is used to collect voltage data, current data, temperature data of each battery cell and pressure data of the battery pack, and transmit the pressure data of the battery pack and the voltage data, current data and temperature data of each battery cell to the main control module;

[0008] The main control module is electrically connected to the battery monitoring module and each electronic switch respectively, and is used to judge whether there is a fault in each battery cell according to the pressure data, voltage data, current data and temperature data of each battery cell, and when it is judged that there is a fault in any battery cell, control the electronic switch corresponding to the any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit.

[0009] Based on the above disclosed content, the battery fault management system provided by the present invention configures an electronic switch for each battery cell in the battery pack. Among them, the electronic switch of any battery cell is used to control the access or disconnection of the any battery cell from the battery cell series circuit of the battery pack, and when disconnected, it can still ensure the path of the entire battery cell series circuit; thus, based on the foregoing electronic switch, the troubleshooting of a single battery cell can be realized, that is: the present invention collects the pressure data of the battery pack, as well as the voltage, current and temperature data of each battery cell through the battery monitoring module; then, through the foregoing data, it is judged whether there is a fault in each battery cell, and when a fault is judged, the electronic switch of the faulty battery cell is controlled to disconnect the connection between the battery cell and the battery cell series circuit; based on this, the faulty battery cell can be disconnected from the circuit, so as to ensure the normal power supply of the remaining normal battery cells to the device; thus, the present invention realizes the fault detection of a single battery cell and the disconnection process of the faulty battery cell, and can make the battery pack work continuously and normally; therefore, while improving the working stability and sustainability, it also reduces the maintenance cost, and is very suitable for large-scale application and promotion.

[0010] In a possible design, the main control module is used to judge whether there is a chemical fault in each battery cell according to the pressure data, voltage data and current data of each battery cell, and when it is judged that there is a chemical fault in any battery cell, control the electronic switch corresponding to the any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit; and

[0011] is used to judge whether there is a physical fault in each battery cell according to the pressure data, voltage data and temperature data of each battery cell, and when it is judged that there is a physical fault in any battery cell, control the electronic switch corresponding to the any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit.

[0012] In a possible design, the chemical fault includes: electrolyte decomposition fault, wherein the battery pack includes several battery blocks, each battery block includes multiple battery cells, and the pressure data includes the pressure data of each battery block;

[0013] The main control module is used to obtain the voltage data of each battery cell in the any battery block when it is judged that the pressure data of any battery block exceeds the first pressure threshold;

[0014] The main control module is used to determine the voltage change value of each battery cell in any battery block according to the voltage data of each battery cell in any battery block;

[0015] The main control module is used to determine whether there is a cell in any of the battery blocks whose voltage change value exceeds a change threshold;

[0016] If so, the main control module determines that the battery cell whose voltage change value exceeds the change threshold has an electrolyte decomposition fault.

[0017] In one possible design, the chemical fault further includes: a battery active material loss fault and a battery SEI film growth fault, wherein the voltage data of any battery cell includes sampled voltages at multiple sampling moments, and the current data of any battery cell includes sampled currents at multiple sampling moments;

[0018] The main control module is used to calculate the power of each battery cell at each sampling moment based on the sampled voltage and sampled current of each battery cell at multiple sampling moments;

[0019] The main control module is used to determine whether each battery cell has a battery active material loss fault based on the power of each battery cell at each sampling moment, and when it is determined that any battery cell has a battery active material loss fault, control the electronic switch corresponding to the any battery cell to disconnect the any battery cell from the battery cell series circuit;

[0020] The main control module is further used to judge whether each battery cell has a battery SEI film growth fault at any sampling moment based on the sampling voltage of each battery cell at any sampling moment, and when it is judged that any battery cell has a battery SEI film growth fault, control the electronic switch corresponding to any battery cell to disconnect the connection between any battery cell and the battery cell series circuit, wherein if the sampling voltage of any battery cell at any sampling moment is higher than the voltage threshold, it is determined that any battery cell has the battery SEI film growth fault.

[0021] In one possible design, the physical fault includes: a short circuit fault and a connection fault;

[0022] Wherein, for any battery cell in the battery pack, the main control module is used to obtain temperature change data of any battery cell based on the temperature data of the any battery cell;

[0023] The main control module is configured to determine that a short circuit fault exists in any of the battery cells when it is determined that the voltage data of any of the battery cells is 0 and the temperature change data exceeds a first temperature change threshold; or

[0024] Based on the voltage data of any of the battery cells, the voltage increase value of any of the battery cells is obtained, and when it is determined that the voltage increase value of any of the battery cells exceeds the increase threshold and the temperature change data exceeds the second temperature change threshold, it is determined that there is a connection fault in any of the battery cells.

[0025] In one possible design, the physical fault further includes: a mechanical damage fault, wherein the battery pack includes a plurality of battery blocks, each battery block includes a plurality of battery cells, and the pressure data includes pressure data of each battery block;

[0026] For any battery block among the plurality of battery blocks, the main control module is configured to determine whether the pressure data of the any battery block exceeds a second pressure threshold;

[0027] If so, the main control module determines whether the voltage data of each battery cell in any battery block are the same;

[0028] If so, the main control module determines that any of the battery blocks has a mechanical damage fault, and when it is determined that any of the battery blocks has a mechanical damage fault, it controls the electronic switches corresponding to each battery cell in any of the battery blocks to disconnect each battery cell from the battery cell series circuit, and simultaneously disconnect the battery pack from the external device.

[0029] In one possible design, the main control module is used to calculate the power of each battery cell based on the voltage data and current data of each battery cell;

[0030] The main control module is also used to manage the charging and discharging of the battery pack according to the power and voltage data of each battery cell.

[0031] In one possible design, when the battery pack is in a charging state, the power of each battery cell is the charging power;

[0032] a main control module, configured to determine whether a target cell exists in the battery pack based on the voltage data of each cell, wherein the target cell is a cell in the battery pack whose voltage data is greater than or equal to the maximum voltage;

[0033] If so, the main control module is used to control the electronic switch corresponding to the target battery cell to disconnect the target battery cell from the series circuit to stop charging the target battery cell;

[0034] A main control module is used to obtain the charging voltage of the charging pile corresponding to the battery pack, and reduce the charging voltage of the charging pile to obtain an updated charging voltage, wherein the updated charging voltage is equal to the charging voltage minus the voltage data of the target battery cell;

[0035] The main control module is used to obtain the total charging power of the battery pack at the current moment according to the charging power of each battery cell;

[0036] The main control module is used to judge whether the updated charging voltage is less than or equal to the minimum charging voltage, and to judge whether the total charging power reaches a preset power;

[0037] If so, the main control module disconnects the connection between the battery pack and the charging pile to stop charging the battery pack.

[0038] In a possible design, if the main control module determines that there is no target battery cell in the battery pack, it directly judges whether the charging voltage of the charging pile is less than or equal to the minimum charging voltage, and judges whether the total charging power reaches a preset power;

[0039] If so, the main control module disconnects the connection between the battery pack and the charging pile to stop charging the battery pack.

[0040] In a possible design, the main control module is used to determine the faulty battery cell according to the pressure data, the voltage data, the current data and the temperature data of each battery cell, and generate an alarm prompt to send to the operation and maintenance terminal, so that the operation and maintenance personnel corresponding to the operation and maintenance terminal can feedback the number of series-connected battery cells in the path to the main control module based on the alarm prompt. After receiving the number of series-connected battery cells in the path, the main control module controls the operation of the battery pack based on the number of series-connected battery cells in the path.

[0041] In a possible design, it further includes: a serial bus, wherein the main control module communicates with external devices and a battery monitoring module through the serial bus.

[0042] Beneficial effects:

[0043] (1) The present invention realizes the fault detection of a single battery cell and the disconnection treatment of the faulty battery cell, and can enable the battery pack to work continuously and normally; therefore, while improving the working stability and sustainability, it also reduces the maintenance cost, and is very suitable for large-scale application and promotion.

[0044] (2) The present invention can detect various physical and chemical faults existing in each battery cell through the voltage, current and temperature data of each battery cell, and in combination with the pressure data of the battery pack. Therefore, compared with the traditional technology, it can automatically eliminate all physical and chemical faults existing in the battery cell, thereby preventing the battery pack from catching fire and exploding due to faults, and thus avoiding personal and property hazards and losses.

[0045] (3) The present invention manages the charging and discharging of the battery pack based on the power and voltage data of each battery cell. Specifically, during charging, management is carried out on a cell-by-cell basis. That is, when the voltage of any one cell is greater than the maximum voltage, the electronic switch of that cell is controlled to disconnect the connection between that cell and the cell series circuit, thereby preventing overcharging. At the same time, the charging voltage of the charging pile is reduced. When it is determined that the reduced charging voltage is less than or equal to the minimum charging voltage and the current charging power of the battery pack reaches the preset power, the connection between the battery pack and the charging pile is disconnected (if the foregoing conditions are not met, continuous monitoring is carried out, and after a cell reaches the maximum voltage, the charging voltage is continuously reduced until the foregoing conditions are met). Of course, the same applies to discharge management. Based on this, the charging method provided by the present invention completely avoids overcharging of the battery cells, stops the heating and thermal runaway of the battery cells, while the discharging process completely avoids over-discharging of the battery cells, preventing excessive loss of the battery cell life. Thus, the battery pack can be fully charged or discharged to the maximum extent, thereby greatly improving the charging and discharging efficiency of the battery pack.

[0046] (4) The present invention also has the function of manually repairing battery faults. That is, after the main control module detects a faulty cell, it generates a corresponding alarm prompt to the operation and maintenance terminal. In this way, based on this alarm prompt, the operation and maintenance personnel can know the number of the faulty cell. Based on this, the battery pack can be disassembled and opened, and the faulty cell is manually cut and welded to disconnect it from the circuit, and the open circuit is conducted. At the same time, the number of series-connected cells of the path in the main control module is manually changed and rewritten. At this time, the main control module can adjust and manage the number of series-connected battery cells based on the number of series-connected cells of the path, thereby restoring the normal operation of the battery pack. Description of the Drawings

[0047] Figure 1 It is a system architecture diagram of the battery fault management system provided by an embodiment of the present invention;

[0048] Figure 2 It is a connection structure diagram of a battery cell and an electronic switch provided by an embodiment of the present invention;

[0049] Figure 3 It is a schematic diagram of the charging process provided by an embodiment of the present invention;

[0050] Figure 4 It is a schematic diagram of the discharging process provided by an embodiment of the present invention. Detailed Embodiments

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the present invention in combination with the accompanying drawings and the description of the embodiments or the prior art. Obviously, the following description of the structures of the accompanying drawings is only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. It should be noted here that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation to the present invention.

[0052] It should be understood that although terms such as first and second may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, the first unit may be referred to as the second unit, and similarly, the second unit may be referred to as the first unit, without departing from the scope of the exemplary embodiments of the present invention.

[0053] It should be understood that for the term "and / or" that may appear herein, it is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, B exists alone, and A and B exist simultaneously; for the term " / and" that may appear herein, it is a description of another association object relationship, indicating that two relationships may exist. For example, A / and B may represent: A exists alone, and A and B exist alone; in addition, for the character " / " that may appear herein, generally, it means that the front and rear associated objects are in an "or" relationship.

[0054] Embodiment:

[0055] See Figure 1 As shown, the battery fault management system provided in this embodiment may, but is not limited to, include a cell switch module, a main control module, and a battery monitoring module; wherein, the cell switch module is used to control each cell to access or disconnect from the cell series circuit of the battery pack. In this way, when a cell fails, based on this cell switch module, the faulty cell can be disconnected from the cell series circuit, so as to ensure the normal power supply of the remaining normal cells to the load; the battery monitoring module is used to monitor the working parameters of each cell and transmit them to the main control module, and the main control module can, based on the data transmitted by the aforementioned battery monitoring module, perform cell fault diagnosis and control the operation of the cell switch module to disconnect the faulty cell from the cell series circuit.

[0056] Optionally, for example, the cell switch module may include, but is not limited to, a number of electronic switches. The number of electronic switches is the same as the number of cells in the battery pack. Each cell corresponds to an electronic switch, and any one of the electronic switches is used to connect the corresponding cell to the cell series circuit of the battery pack, or to disconnect the corresponding cell from the cell series circuit, and after disconnecting from the cell series circuit, maintain the path of the cell series circuit. In this way, by configuring an electronic switch for each cell, the connection or disconnection between each cell and the cell series circuit can be achieved based on this electronic switch, thus providing a hardware basis for subsequent troubleshooting.

[0057] In specific applications, the following discloses one of the connection circuits between the cell and the electronic switch.

[0058] See Figure 2 As shown, for example, any one of the electronic switches is provided with a first terminal 1, a second terminal 2, a third terminal 3, and a control terminal 4. Among them, for any one of the cells in the battery pack, the positive electrode of the any one of the cells is electrically connected to the first terminal 1 of the corresponding electronic switch, the third terminal 3 of the electronic switch corresponding to the any one of the cells is electrically connected to the negative electrode of the any one of the cells, the second terminal 2 of the electronic switch corresponding to the any one of the cells is electrically connected to the negative electrode of the previous cell, and the negative electrode of the any one of the cells is also electrically connected to the second terminal 2 of the electronic switch corresponding to the next cell. In addition, the control terminal 4 of the electronic switch corresponding to any one of the cells is electrically connected to the main control module. In this way, by continuously connecting the next cell in series with the above connection structure, the circuit structure of the entire battery pack can be formed. After each cell is connected in series in this circuit structure, a cell series circuit is formed.

[0059] Taking Figure 2 the second cell as an example, when the second terminal 2 and the third terminal 3 of the electronic switch are cut off, and the second terminal 2 and the first terminal 1 are conducted, the positive electrode of the second cell is conducted with the negative electrode of the first cell, and the cell is connected to the cell series circuit. On the contrary, when the first terminal 1 and the second terminal 2 are cut off, and the second terminal 2 and the third terminal 3 are conducted, the positive electrode of the second cell is disconnected. Therefore, the cell is disconnected from the cell series circuit. At the same time, since the second terminal 2 and the third terminal 3 are conducted, the negative electrode of the first cell can be directly connected to the second terminal 2 of the electronic switch corresponding to the third cell. Therefore, if the first terminal 1 and the second terminal 2 of the electronic switch of the third cell are conducted, the first cell and the third cell are connected in series. Therefore, the entire cell series circuit will not be disconnected. Thus, it can be ensured that after the faulty cell is disconnected from the circuit, the entire cell series circuit is still a path, so that the remaining normal cells can continue to supply power to the outside.

[0060] Optionally, for example, the electronic switch may include, but is not limited to, a relay. Of course, other switching devices may also be used, as long as the foregoing functions can be achieved, and it is not limited to the foregoing example here.

[0061] Through the above design, based on the circuit structure, combined with the aforementioned battery monitoring module and the main control module, the disconnection of the faulty battery cell can be achieved. Specifically, the specific working processes of the battery monitoring module and the main control module are as follows:

[0062] The battery monitoring module is used to collect the voltage data, current data, temperature data of each battery cell and the pressure data of the battery pack, and transmit the pressure data of the battery pack and the voltage data, current data and temperature data of each battery cell to the main control module. The main control module is electrically connected to the battery monitoring module and each electronic switch respectively. It is used to judge whether there is a fault in each battery cell according to the pressure data, voltage data, current data and temperature data of each battery cell, and when it is judged that any battery cell has a fault, control the electronic switch corresponding to the any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit. In this way, combined with the battery monitoring module and the electronic switch module, the faulty battery cell in the battery pack can be disconnected from the battery cell series circuit of the whole battery pack, so as to ensure the continuous power supply of the normal battery cells in the whole battery pack to the load.

[0063] Through the above description, the battery fault management system provided in this embodiment realizes the fault detection of a single battery cell and the disconnection process of the faulty battery cell. In this way, the battery pack can work continuously and normally, so that while improving the working stability and sustainability, the maintenance cost can be reduced. Therefore, it is very suitable for large-scale application and promotion.

[0064] In a possible design, the specific process of the main control module for battery cell fault detection is disclosed below.

[0065] Optionally, in this embodiment, the chemical fault detection and physical fault detection of each battery cell can be realized according to the pressure data of the battery pack and the temperature, voltage and current data of each battery cell. Specifically, the main control module is used to judge whether there is a chemical fault in each battery cell according to the pressure data and the voltage data and current data of each battery cell, and when it is judged that any battery cell has a chemical fault, control the electronic switch corresponding to the any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit; and is used to judge whether there is a physical fault in each battery cell according to the pressure data, voltage data and temperature data of each battery cell, and when it is judged that any battery cell has a physical fault, control the electronic switch corresponding to the any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit.

[0066] In this embodiment, examples of chemical failures may include, but are not limited to: electrolyte decomposition failure (i.e., the electrolyte may decompose under high temperature or overcharge conditions to produce gas, thereby causing the battery cell to expand or even rupture), battery active material loss failure (in actual application, long-term charge and discharge cycles will cause the active material to fall off from the electrode, reducing the number of available lithium ions, thereby reducing the battery cell capacity) and battery SEI film growth failure (the solid electrolyte interface film (SEI) will increase the internal resistance of the battery cell as the use time increases, thereby affecting the battery cell performance); at the same time, examples of physical failures may include, but are not limited to: short circuit failure (due to manufacturing defects or physical damage, a short circuit may occur inside the battery cell, resulting in local overheating or even thermal runaway), connection failure (the connection between battery cell components may loosen or break due to vibration or corrosion, thereby affecting the battery cell as a whole) and mechanical damage failure (external impact or extrusion may cause damage to the internal structure of the battery cell, thereby affecting the battery cell performance).

[0067] Based on this, this embodiment can realize the detection of the aforementioned various types of physical and chemical faults; wherein, the specific detection method of each fault is disclosed below, which can be but is not limited to the following.

[0068] In specific applications, a battery pack usually contains several battery blocks, and each battery block contains multiple battery cells. Therefore, pressure detection is usually performed on a battery block basis. Based on this, the pressure data of the aforementioned battery pack includes the pressure data of multiple battery blocks. Therefore, the expansion of the battery cells in each battery block can be detected (i.e., expansion caused by decomposition of the electrolyte) based on the pressure data of each battery block. Optionally, the detection process can be but is not limited to as shown below.

[0069] The main control module is used to obtain the voltage data of each battery cell in any battery block when it is determined that the pressure data of any battery block exceeds the first pressure threshold; then, based on the voltage data of each battery cell in any battery block, determine the voltage change value of each battery cell in any battery block (the voltage data can be the sampled voltages at multiple consecutive sampling moments, so the voltage change value is obtained based on the difference between the sampled voltages at the current sampling moment and the previous sampling moment); then, it can be determined whether there are batteries in any battery block whose voltage change value exceeds the change threshold; wherein, if there are batteries whose voltage change value exceeds the change threshold, it can be determined that the batteries whose voltage change value exceeds the change threshold have an electrolyte decomposition fault; at this time, the main control module can issue an instruction to actuate the electronic switch corresponding to the batteries with the electrolyte decomposition fault, thereby cutting off the connection between the batteries with the electrolyte decomposition fault and the battery series circuit, and thereby disconnecting the batteries with the fault from the battery series circuit.

[0070] Similarly, as described above, the voltage data of each battery cell includes the sampling circuits at multiple sampling times. Therefore, the current data is the same, that is, it includes the sampled currents at multiple sampling times. Based on this, the active material loss fault detection and SEI film growth fault detection of each battery cell can be performed according to the aforementioned multiple sampled voltages and sampled currents.

[0071] In specific implementation, in this embodiment, the active material loss fault detection is performed by calculating the power of each battery cell (i.e., the capacity reduction caused by the loss of active material). The detection process is as follows: The main control module is used to calculate the power of each battery cell at each sampling time according to the sampled voltages and sampled currents of each battery cell at multiple sampling times. Then, according to the power of each battery cell at each sampling time, it is determined whether each battery cell has a battery active material loss fault. When it is determined that any battery cell has a battery active material loss fault, the electronic switch corresponding to the any battery cell is controlled to disconnect the connection between the any battery cell and the battery cell series circuit.

[0072] In this embodiment, the calculation method of the power of any battery cell at each sampling time is: use the sampling time × sampled voltage × sampled current (of course, if each sampling window is a period of time during sampling, then the sampling time is replaced by the corresponding sampling duration). In this way, based on the aforementioned method, the power of each battery cell at each sampling time can be calculated. Then, sum the power of each battery cell at each sampling time to obtain the power of the any battery cell. Next, for any battery cell, perform an integral operation on the power of the any battery cell to obtain an integral value (this value is used for the standard stored or released power). Finally, if the integral value is less than the set value, it is determined that the capacity of the any battery cell is too low and there is an active material loss fault. At this time, the main control module can also control the electronic switch corresponding to the any battery cell to act, so as to disconnect the connection between the any battery cell and the battery cell series circuit.

[0073] Furthermore, for the detection of the SET film growth fault, the main control module determines whether each battery cell has a battery SEI film growth fault at any sampling time according to the sampled voltage of each battery cell at any sampling time. When it is determined that any battery cell has a battery SEI film growth fault, the electronic switch corresponding to the any battery cell is controlled to disconnect the connection between the any battery cell and the battery cell series circuit. In this embodiment, if the sampled voltage of the any battery cell at the any sampling time is higher than the voltage threshold, it is determined that the any battery cell has the battery SEI film growth fault. Of course, the aforementioned first pressure threshold, change threshold, and voltage threshold can be specifically set according to actual use and are not specifically limited here.

[0074] In this way, based on the above explanation, chemical fault detection of each battery cell can be achieved; similarly, physical fault detection is achieved based on the pressure data of each battery block, as well as the temperature data and voltage data of each battery cell; specifically, the physical fault detection process can be, but is not limited to, as shown below.

[0075] First, for short-circuit fault detection, this embodiment still takes any battery cell in the battery pack as an example for explanation; wherein, the main control module is used to obtain the temperature change data of any battery cell based on the temperature data of any battery cell; then, the main control module can determine that any battery cell has a short-circuit fault when it is determined that the voltage data of any battery cell is 0 and the temperature change data exceeds the first temperature change threshold; in this embodiment, the process of obtaining the temperature change data is the same as the process of obtaining the voltage change value, and will not be repeated here; at the same time, when the battery cell is short-circuited, the voltage across the battery cell will become 0, and at the same time, the temperature will rise instantly. Therefore, based on the aforementioned voltage data and temperature change data, it can be determined whether any battery cell has a short-circuit fault.

[0076] Similarly, when performing connection fault detection, the main control module derives the voltage increase value of any battery cell based on the voltage data of any battery cell, and determines that any battery cell has a connection fault when it determines that the voltage increase value of any battery cell exceeds the increase threshold and the temperature change data exceeds the second temperature change threshold; in this embodiment, when the connection between the battery cell components is loosened or disconnected due to vibration or corrosion, the connection is equivalent to a short circuit. At this time, the voltage will increase and the temperature will also increase; based on this, according to the voltage increase value and temperature change data of any battery cell, it can be determined whether any battery cell has a connection fault.

[0077] Of course, the aforementioned first temperature change threshold, second temperature change threshold and increase threshold are also pre-set and can be specifically set according to actual use, and are not specifically limited here.

[0078] Furthermore, for the detection of mechanical damage faults, this embodiment is also implemented based on the pressure data of each battery block and the voltage data of each battery cell in each battery block; wherein, for any battery block among several battery blocks, the main control module is used to determine whether the pressure data of the any battery block exceeds the second pressure threshold; if so, the main control module determines whether the voltage data of the individual battery cells in the any battery block are the same; if they are the same, the main control module determines that a mechanical damage fault has occurred in the any battery block, and when it is determined that a mechanical damage fault has occurred in the any battery block, controls the electronic switches corresponding to the individual battery cells in the any battery block to disconnect the individual battery cells from the battery cell series circuit, and simultaneously disconnects the battery pack from the external device.

[0079] In specific applications, when the battery pack is subjected to external impact or extrusion, the pressure of each battery block inside it will inevitably change. At this time, if abnormal pressure is detected, it is necessary to determine whether the fault is caused by mechanical damage or expansion fault caused by electrolyte decomposition through the voltages of the individual battery cells inside the battery block. Among them, when the voltages of the individual battery cells in the battery pack are the same or within the same voltage range (for example, the voltage difference between the individual battery cells is within the preset difference range), at this time, it indicates that the battery pack has been squeezed or impacted, resulting in mechanical damage. Based on this, to ensure safety, it is necessary to disconnect the connection between each battery cell and the battery cell series circuit, and at the same time, disconnect the connection between the battery pack and the external device. Of course, the connection between all the battery cells in the battery pack and the battery cell series circuit can be disconnected.

[0080] From the above description, the battery fault management system provided in this embodiment can complete all physical and chemical fault detections of the battery cells through the pressure data of each battery block in the battery pack, as well as the voltage, current, and temperature data of each battery cell, and automatically eliminate the corresponding faults after detection. Based on this, the safety of battery use can be ensured.

[0081] In a possible design, this embodiment can also perform charge and discharge management of the battery pack based on the voltage and current data of the above-mentioned individual battery cells, that is: the main control module is used to calculate the power of each battery cell according to the voltage data and current data of each battery cell; then, according to the power and voltage data of each battery cell, perform charge management and discharge management on the battery pack.

[0082] See Figure 3 As shown below, the following provides the charge management process of the battery pack:

[0083] In specific applications, the main control module is used to determine whether there is a target battery cell in the battery pack based on the voltage data of each battery cell, where the target battery cell is the battery cell in the battery pack whose voltage data is greater than or equal to the maximum voltage; in this embodiment, when the voltage data of any battery cell reaches the maximum voltage at a certain moment, it indicates that the any battery cell is fully charged. At this time, it is necessary to disconnect the connection between the any battery cell and the battery cell series circuit, that is: the main control module controls the electronic switch corresponding to the target battery cell to disconnect the connection between the target battery cell and the series circuit to stop charging the target battery cell.

[0084] Next, the main control module is used to obtain the charging voltage of the battery pack corresponding to the charging pile and reduce the charging voltage of the charging pile to obtain the updated charging voltage, where the updated charging voltage is equal to the charging voltage minus the voltage data of the target cell; in this embodiment, it is equivalent to subtracting the voltage of the fully charged cell from the charging voltage of the charging pile every time a cell is fully charged, thereby reducing the charging voltage; at this time, it is necessary to combine the battery pack's power and the charging voltage of the charging pile at this time (i.e., the aforementioned updated charging voltage) to determine whether to stop charging the entire battery pack, that is:

[0085] The main control module is used to obtain the total charging power of the battery pack at the current moment according to the charging power of each cell; in this embodiment, the charging power of each cell has been described above, and by summing the charging power of each cell, the total charging power of the battery pack at the current moment is obtained; at this time, it is necessary to determine whether the updated charging voltage is less than or equal to the minimum charging voltage, and determine whether the total charging power reaches the preset power; among them, if the foregoing conditions are met, the connection between the battery pack and the charging pile is disconnected to stop charging the battery pack; otherwise, it is necessary to continue to monitor whether the voltage data of each cell reaches the maximum voltage one by one, and continuously monitor until the foregoing total charging power reaches the preset power and the charging voltage is less than or equal to the minimum charging voltage.

[0086] At the same time, in this embodiment, if the main control module determines that there is no target cell in the battery pack, it directly determines whether the charging voltage of the charging pile is less than or equal to the minimum charging voltage, and determines whether the total charging power reaches the preset power; then, when the foregoing conditions are met, the connection between the battery pack and the charging pile can be disconnected to stop charging the battery pack.

[0087] Based on this, the charging process can be summarized as follows:

[0088] When it is detected that a certain cell is charged to the highest voltage (i.e., the collected voltage data is greater than or equal to the maximum voltage), the main control module drives the electronic switch connected to the cell through the CAN bus to disconnect the cell from the circuit. At the same time, the main control module controls the charging pile to reduce the charging voltage through the CAN bus (i.e., reduce the voltage data of the cell), and continue to cycle and monitor until the charging voltage reaches the minimum voltage of the charging pile and the total electrical energy of the battery pack reaches the preset power, the main control module controls the total charging relay to stop charging through the CAN bus; in this way, this charging process completely avoids the problem of overcharging of the cell, prevents the cell from heating up and thermal runaway, thereby greatly improving the charging safety.

[0089] Similarly, the discharging process is the same as the charging process in principle, that is, during the discharging process, the power of each cell is the discharging power, and the process is as follows:

[0090] See Figure 4 As shown, the main control module is used to determine whether there is a specified battery cell in the battery pack based on the voltage data of each battery cell. Here, the specified battery cell is the battery cell in the battery pack whose voltage data is less than or equal to the lowest voltage. In this embodiment, when the voltage data of any battery cell reaches the lowest voltage at a certain moment, it means that the power of the any battery cell has been exhausted. At this time, it is necessary to disconnect the connection between the any battery cell and the battery cell series circuit, that is: if so, the main control module is used to control the electronic switch corresponding to the specified battery cell to disconnect the specified battery cell from the series circuit to stop discharging the specified battery cell.

[0091] Next, the main control module is used to obtain the lowest load voltage corresponding to the battery pack (for example, on an electric vehicle, it is the lowest voltage set by the motor controller), and reduce the total voltage of the entire battery pack to obtain the updated total voltage, where the updated total voltage is equal to the total voltage of the entire battery pack minus the voltage data of the specified battery cell. In this embodiment, it is equivalent to subtracting the voltage of the discharged battery cell from the total voltage of the battery pack every time a battery cell is determined to be discharged, thereby reducing the overall voltage. At this time, it is necessary to combine the discharged power of the battery pack and the aforementioned updated total voltage to determine whether to stop discharging the entire battery pack. The process is as follows:

[0092] The main control module is used to obtain the total discharged power of the battery pack at the current moment according to the discharged power of each battery cell. In this embodiment, by summing the discharged power of each battery cell, the total discharged power of the battery pack at the current moment can be obtained. At this time, it can be determined whether the updated total voltage is less than or equal to the lowest load voltage (that is, Figure 4 the total lowest voltage in), and determine whether the total discharged power reaches the preset discharged power. Among them, if the foregoing conditions are met, the connection between the battery pack and the load is disconnected to stop discharging the battery pack; otherwise, it is necessary to continue to monitor whether the voltage data of each battery cell is less than or equal to the lowest voltage one by one, and continuously monitor until the foregoing total discharged power reaches the preset discharged power and the total voltage of the battery pack is less than or equal to the lowest load voltage. Of course, when there is no specified battery cell in the battery pack, it is directly determined whether the total voltage of the battery pack is less than or equal to the lowest load voltage, and whether the total discharged power reaches the preset discharged power, so as to perform the discharge management of the battery pack according to the judgment result.

[0093] Based on this, the discharge process of the entire battery pack is as follows:

[0094] When a certain battery cell is collected to the lowest voltage, the main control module drives the electronic switch connected to the battery cell through the CAN bus to disconnect the battery cell from the circuit and continue cyclic monitoring. Until the discharge voltage reaches the lowest load voltage set by the motor controller and the total discharge capacity of the entire battery pack reaches the preset discharge capacity, the main control module controls the total discharge relay to stop discharging through the CAN bus. In this way, this discharge process completely avoids the problem of over-discharge of the battery cells and prevents excessive loss of the battery cell life. Therefore, the service life of the battery can be greatly improved.

[0095] In a specific embodiment, for example, the aforementioned battery monitoring module may include, but is not limited to, a pressure sensor, a temperature sensor, a voltage sensor, a current sensor, etc. In this way, the voltage, current, and temperature data of each battery cell and the pressure data of each battery block can be collected. Of course, the options of each sensor can be specifically set according to actual use and are not specifically limited here.

[0096] In addition, for example, the entire system may also include, but is not limited to, a serial bus. Among them, the main control module communicates with external devices (such as the aforementioned charging pile, total discharge relay, etc.) and the battery monitoring module through the serial bus. Optionally, for example, the communication bus may include, but is not limited to, a CAN bus, an RS serial line (RS232, RS485 serial line, etc.) or a daisy chain communication network composed of the aforementioned communication serial buses. Of course, the specific communication method can also be specifically set according to actual use and is not limited to the aforementioned examples here.

[0097] In a possible design, a second aspect of this embodiment provides another battery management method, which is different from the first aspect of the embodiment in that the battery cell switch module is not provided, that is, no electronic switch is provided in the circuit of the battery pack. Instead, when a faulty battery cell is detected, an alarm prompt is output by the system, so that the maintenance personnel physically cut off the faulty battery cell.

[0098] Specifically, its working process is as follows:

[0099] The main control module is further configured to determine a faulty battery cell based on the pressure data, the voltage data, the current data, and the temperature data of each battery cell, and generate an alarm prompt to send to the operation and maintenance terminal, so that the operation and maintenance personnel corresponding to the operation and maintenance terminal can feedback the number of connected battery cell strings to the main control module based on the alarm prompt. So that after the main control module receives the number of connected battery cell strings, it controls the operation of the battery pack based on the number of connected battery cell strings.

[0100] In this embodiment, when the main control module detects a faulty battery cell, it will read the number of the faulty battery cell. Then, an alarm prompt is generated based on the number of the faulty battery cell and sent to the operation and maintenance terminal. In this way, the operation and maintenance personnel can know the number of the faulty battery cell based on this alarm prompt. Based on this, the battery pack can be disassembled and opened, and the faulty battery cell can be detached from the circuit by manual cutting and welding, and the open circuit can be made conductive. At the same time, the number of series-connected battery cells in the path of the main control module is manually changed and rewritten and input into the main control module. At this time, the main control module can adjust and manage the number of series-connected battery cells based on the number of series-connected battery cells in the path, so as to restore the normal operation of the battery pack. Of course, the specific control algorithm can be pre-stored in the system. As long as the number of series-connected battery cells in the path is manually re-input, it can be matched with the algorithm to control the battery pack. And in practical applications, the manual management method provided in the second aspect of this embodiment or the automatic management method provided in the first aspect of the embodiment can be selected.

[0101] Therefore, through the above detailed description of the battery fault management system, the present invention has the following advantages:

[0102] (1) The present invention realizes the fault detection of a single battery cell and the detachment treatment of the faulty battery cell, and can make the battery pack work continuously and normally. Therefore, while improving the working stability and sustainability, the maintenance cost is also reduced, which is very suitable for large-scale application and promotion.

[0103] (2) Compared with the traditional technology, it can automatically eliminate all physical and chemical faults existing in the battery cells, thus preventing the battery pack from catching fire and exploding due to faults, and avoiding personal and property hazards and losses.

[0104] (3) The charging method provided by the invention completely avoids overcharging of the battery cells, stops the heating and thermal runaway of the battery cells, and the discharging process completely avoids over-discharging of the battery cells, stopping excessive loss of the battery cell life. Thus, the battery pack can be fully charged or discharged to the maximum extent, thereby greatly improving the charge and discharge efficiency of the battery pack.

[0105] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A battery fault management system, characterized in that, Comprising: A cell switch module, the cell switch module includes a plurality of electronic switches. Among them, the number of electronic switches is the same as the number of cells in the battery pack. Each cell corresponds to an electronic switch, and any one of the electronic switches is used to connect the corresponding cell to the cell series circuit of the battery pack, or disconnect the corresponding cell from the cell series circuit, and after disconnecting from the cell series circuit, maintain the path of the cell series circuit; A battery monitoring module, wherein the battery monitoring module is used to collect voltage data, current data, temperature data of each cell, and pressure data of the battery pack, and transmit the pressure data of the battery pack and voltage data, current data and temperature data of each cell to the main control module; A main control module, electrically connected to the battery monitoring module and each electronic switch respectively, and is used to judge whether there is a fault in each cell according to the pressure data, voltage data, current data and temperature data of each cell, and when it is judged that any one of the cells has a fault, control the electronic switch corresponding to the any one of the cells to disconnect the connection between the any one of the cells and the cell series circuit; The main control module is used to judge whether there is a chemical fault in each cell according to the pressure data, voltage data and current data of each cell, and when it is judged that any one of the cells has a chemical fault, control the electronic switch corresponding to the any one of the cells to disconnect the connection between the any one of the cells and the cell series circuit; and It is used to judge whether there is a physical fault in each cell according to the pressure data, voltage data and temperature data of each cell, and when it is judged that any one of the cells has a physical fault, control the electronic switch corresponding to the any one of the cells to disconnect the connection between the any one of the cells and the cell series circuit; The physical faults include: short - circuit fault and connection fault; Among them, for any one of the cells in the battery pack, the main control module is used to obtain the temperature change data of the any one of the cells based on the temperature data of the any one of the cells; The main control module is used to determine that the any one of the cells has a short - circuit fault when it is judged that the voltage data of the any one of the cells is 0 and the temperature change data exceeds the first temperature change threshold; or Based on the voltage data of the any one of the cells, obtain the voltage increase value of the any one of the cells, and when it is judged that the voltage increase value of the any one of the cells exceeds the increase threshold and the temperature change data exceeds the second temperature change threshold, determine that the any one of the cells has a connection fault; The chemical faults include: electrolyte decomposition fault. Among them, the battery pack includes a plurality of battery blocks, each battery block includes a plurality of cells, and the pressure data includes the pressure data of each battery block; The main control module is used to obtain the voltage data of each cell in the any one of the battery blocks when it is judged that the pressure data of any one of the battery blocks exceeds the first pressure threshold; The main control module is used to determine the voltage change value of each cell in the any one of the battery blocks according to the voltage data of each cell in the any one of the battery blocks; The main control module is used to judge whether there is a cell in the any one of the battery blocks whose voltage change value exceeds the change threshold; If so, the main control module determines that the battery cell with the voltage change value exceeding the change threshold has an electrolyte decomposition fault.

2. The battery fault management system according to claim 1, wherein The chemical faults also include: battery active material loss fault and battery SEI film growth fault. Among them, the voltage data of any battery cell includes the sampled voltages at multiple sampling moments, and the current data of the any battery cell includes the sampled currents at multiple sampling moments. The main control module is configured to calculate the power of each battery cell at each sampling moment according to the sampled voltages and sampled currents of each battery cell at multiple sampling moments. The main control module is configured to determine whether there is a battery active material loss fault in each battery cell according to the power of each battery cell at each sampling moment, and when it is determined that any battery cell has a battery active material loss fault, control the electronic switch corresponding to the any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit. The main control module is further configured to determine whether there is a battery SEI film growth fault in each battery cell at the any sampling moment according to the sampled voltage of each battery cell at the any sampling moment, and when it is determined that any battery cell has a battery SEI film growth fault, control the electronic switch corresponding to the any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit. Among them, if the sampled voltage of the any battery cell at the any sampling moment is higher than the voltage threshold, it is determined that the any battery cell has the battery SEI film growth fault.

3. The battery fault management system according to claim 1, wherein The physical faults also include: mechanical damage fault. Among them, the battery pack includes several battery blocks, each battery block includes multiple battery cells, and the pressure data includes the pressure data of each battery block. For any one of the several battery blocks, the main control module is configured to determine whether the pressure data of the any battery block exceeds the second pressure threshold. If so, the main control module determines whether the voltage data of each battery cell in the any battery block is the same. If so, the main control module determines that the any battery block has a mechanical damage fault, and when it is determined that the any battery block has a mechanical damage fault, controls the electronic switches corresponding to each battery cell in the any battery block to disconnect the connection between each battery cell and the battery cell series circuit, and at the same time disconnects the connection between the battery pack and the external device.

4. A battery fault management system according to claim 1, wherein The main control module is configured to calculate the power of each battery cell according to the voltage data and current data of each battery cell. The main control module is further configured to perform charge management and discharge management on the battery pack according to the power and voltage data of each battery cell.

5. A battery fault management system according to claim 4, wherein When the battery pack is in the charging state, the power of each battery cell is the charging power. The main control module is configured to determine whether there is a target battery cell in the battery pack based on the voltage data of each battery cell, where the target battery cell is the battery cell in the battery pack with the voltage data greater than or equal to the maximum voltage. If so, the main control module is configured to control the electronic switch corresponding to the target battery cell to disconnect the connection between the target battery cell and the series circuit to stop charging the target battery cell. The main control module is used to obtain the charging voltage of the battery pack corresponding to the charging pile, and reduce the charging voltage of the charging pile to obtain the updated charging voltage, where the updated charging voltage is equal to the charging voltage minus the voltage data of the target cell; The main control module is used to obtain the total charging power of the battery pack at the current moment according to the charging power of each cell; The main control module is used to determine whether the updated charging voltage is less than or equal to the minimum charging voltage, and determine whether the total charging power reaches the preset power; If so, the main control module disconnects the connection between the battery pack and the charging pile to stop charging the battery pack.

6. The battery fault management system according to claim 5, characterized in that, If the main control module determines that there is no target cell in the battery pack, it directly determines whether the charging voltage of the charging pile is less than or equal to the minimum charging voltage, and determines whether the total charging power reaches the preset power; If so, the main control module disconnects the connection between the battery pack and the charging pile to stop charging the battery pack.

7. A battery fault management system according to claim 1, wherein, The main control module is further used to determine the faulty cells according to the pressure data, the voltage data, current data and temperature data of each cell, and generate an alarm prompt to be sent to the operation and maintenance terminal, so that the operation and maintenance personnel corresponding to the operation and maintenance terminal can feedback the number of series-connected cells in the conducting path to the main control module based on the alarm prompt. After receiving the number of series-connected cells in the conducting path, the main control module controls the operation of the battery pack based on the number of series-connected cells in the conducting path.

Images