Battery fault management system

Abstract

The invention discloses a battery fault management system, which is characterized in that each battery cell is provided with an electronic switch, the electronic switch of any battery cell is used for controlling the any battery cell to be connected to or separated from a battery cell series circuit of a battery pack, and when the electronic switch is separated from the battery cell series circuit, the access of the battery cell series circuit can be ensured; therefore, the fault removal of the single battery cell can be realized based on the electronic switch, namely, the pressure data of the battery pack and the voltage, current and temperature data of each battery cell are firstly acquired; then, judging whether each battery cell has a fault or not according to the data, and when the fault is judged, controlling the electronic switch of the battery cell with the fault to disconnect the connection between the battery cell and the battery cell series circuit; on the basis, the faulted battery cell can be separated from the circuit, so that the normal power supply of the normal battery cell to the equipment is ensured; therefore, the battery pack can continuously and normally work; therefore, the maintenance cost is reduced while the working stability and sustainability are improved.

Description

Technical Field

[0001] The 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; currently, 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 mostly impossible to replace the cells individually, and the maintenance method is usually to replace the entire battery pack; in this case, 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 a problem that needs to be solved urgently. 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, causing the battery pack to be 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 the electronic switches is the same as the number of cells in the battery pack, each cell corresponds to an electronic switch, and any electronic switch 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 to 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, and is used to determine whether each battery cell has a fault based on the pressure data, the voltage data, the current data and the temperature data of each battery cell, and when it is determined that any battery cell has a fault, control the electronic switch corresponding to any battery cell to disconnect the connection between 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 is equipped with an electronic switch for each battery cell in the battery pack, wherein the electronic switch of any battery cell is used to control the connection or disconnection of any battery cell to the battery pack's battery cell series circuit, and when disconnected, the passage of the entire battery cell series circuit can still be guaranteed; in this way, the fault elimination of a single battery cell can be realized based on the aforementioned electronic switch, that is: the present invention collects the pressure data of the battery pack and the voltage, current and temperature data of each battery cell through the battery monitoring module; then, through the aforementioned data, it is judged whether each battery cell has a fault, and when the fault is judged, the electronic switch of the faulty battery cell is controlled to disconnect the battery cell from the battery cell series circuit; based on this, the faulty battery cell can be disconnected from the circuit, thereby ensuring the normal power supply of the remaining normal batteries to the equipment; thus, the present invention realizes the fault detection of a single battery cell and the disconnection processing of the faulty battery cell, which can enable the battery pack to continue to work normally and uninterruptedly; therefore, while improving the working stability and sustainability, it also reduces the maintenance cost, which is very suitable for large-scale application and promotion.

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

[0011] It is used to judge whether each battery cell has a physical fault based on the pressure data, the voltage data and the 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 any battery cell to disconnect the connection between any battery cell and the battery cell series circuit.

[0012] In one possible design, the chemical fault includes: an electrolyte decomposition 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;

[0013] The main control module is used to obtain voltage data of each battery cell in any battery block when it is determined that the pressure data of any battery block exceeds a 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 battery cell in any of the battery blocks whose voltage change value exceeds the 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 a possible design, the chemical fault also 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 according to 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 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 any battery cell to disconnect the connection between any battery cell and the battery cell series circuit;

[0020] The main control module is also used to judge whether each battery cell has a battery SEI film growth fault at any sampling moment according to the sampled 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 sampled voltage of any battery cell at any sampling moment is higher than the voltage threshold, it is judged that any battery cell has the battery SEI film growth fault.

[0021] In a 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 used to determine that any of the battery cells has a short circuit fault 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, a 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 a voltage increase threshold and the temperature change data exceeds a second temperature change threshold, it is determined that any of the battery cells has a connection fault.

[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 used 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 is 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 disconnects the battery pack from the external device.

[0029] In a possible design, 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;

[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 a 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, used for judging whether a target battery cell exists in the battery pack based on the voltage data of each battery cell, wherein the target battery cell is a battery 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, 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 capacity of the battery pack at the current moment according to the charging capacity of each battery cell;

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

[0037] If so, the main control module disconnects the battery pack from 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 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;

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

[0040] In one possible design, the main control module is used to determine the 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 path battery strings to the main control module based on the alarm prompt, so that the main control module can control the operation of the battery pack based on the number of path battery strings after receiving the number of path battery strings.

[0041] In a possible design, it also 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 separation processing of the faulty battery cell, which can enable the battery pack to continue to work normally and uninterruptedly; 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, combined 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 burning and exploding due to battery cell failure, thereby avoiding harm and loss to people and property.

[0045] (3) The present invention manages the charging and discharging of the battery pack according to the power and voltage data of each battery cell. During charging, the management is performed on a cell-by-cell basis, i.e., when the voltage of any battery cell is greater than the maximum voltage, the electronic switch of the battery cell is controlled to disconnect the battery cell from the battery cell series circuit, thereby preventing overcharging. At the same time, the charging voltage of the charging pile is reduced, and 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 a preset power, the connection between the battery pack and the charging pile is disconnected (if the aforementioned conditions are not met, monitoring continues, and after a battery cell reaches the maximum voltage, the charging voltage continues to be reduced until the aforementioned conditions are met). Of course, the same is true for discharge management. Based on this, the charging method provided by the present invention completely avoids overcharging of the battery cell, prevents heating and thermal runaway of the battery cell, and the discharge process completely avoids over-discharging of the battery cell, preventing excessive loss of the battery cell life. Thus, the battery pack can be filled 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 failures, that is, after the main control module detects a faulty battery cell, it generates a corresponding alarm prompt 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 the alarm prompt; based on this, the battery pack can be disassembled and opened, and the faulty battery cell can be manually cut and welded to disconnect the circuit and connect the broken circuit, and at the same time, the number of cell strings in the path of the main control module can be manually changed and rewritten. At this time, the main control module can adjust the number of battery cell strings based on the number of cell strings in the path, thereby restoring the normal operation of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0048] Figure 2 A diagram showing the connection structure between a battery cell and an electronic switch provided in an embodiment of the present invention;

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

[0050] Figure 4 A schematic diagram of a discharge process provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0052] It should be understood that although the terms first, second, etc. 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 unit. For example, a first unit can be referred to as a second unit, and similarly, a second unit can be referred to as a first unit without departing from the scope of the exemplary embodiments of the present invention.

[0053] It should be understood that the term "and / or" that may appear in this article is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, B exists alone, and A and B exist at the same time. The term " / and" that may appear in this article describes another type of association object relationship, indicating that two relationships may exist. For example, A / and B can represent two situations: A exists alone, and A and B exist alone. In addition, the character " / " that may appear in this article generally indicates that the previous and next associated objects are in an "or" relationship.

[0054] Example:

[0055] See also Figure 1 As shown, the battery fault management system provided in this embodiment may include but is not limited to 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 be connected to or disconnected from the cell series circuit of the battery pack, so that when a cell fails, the faulty cell can be disconnected from the cell series circuit based on the cell switch module, thereby ensuring 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 perform cell fault diagnosis based on the data transmitted by the aforementioned battery monitoring module, and control the cell switch module to disconnect the faulty cell from the cell series circuit.

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

[0057] In a specific application, the following discloses a connection circuit between a battery cell and an electronic switch.

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

[0059] by Figure 2 Taking the second cell in as an example, when the second terminal 2 and the third terminal 3 of the electronic switch are turned off, and the second terminal 2 and the first terminal 1 are turned on, the positive electrode of the second cell is turned on by the negative electrode of the first cell, and the cell is connected to the cell series circuit; conversely, when the first terminal 1 and the second terminal 2 are turned off, and the second terminal 2 and the third terminal 3 are turned on, the positive electrode of the second cell is disconnected, so the cell is disconnected from the cell series circuit. At the same time, since the second terminal 2 and the third terminal 3 are turned on, 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 turned on, the first cell and the third cell are connected in series, so the entire cell series circuit will not be disconnected; thereby, it can be ensured that after the faulty cell is disconnected from the circuit, the entire cell series circuit is still connected, so that the remaining normal cells can continue to supply power to the outside.

[0060] Optionally, the electronic switch may be, but is not limited to, a relay; of course, other switching devices may also be used as long as they can achieve the aforementioned functions, and are not limited to the aforementioned examples.

[0061] Therefore, through the above design, based on the circuit structure, combined with the above battery monitoring module and main control module, the faulty battery cell can be separated; specifically, the specific working process of the battery monitoring module and the main control module is 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; and the main control module is electrically connected to the battery monitoring module and each electronic switch, respectively, and is used to determine whether each battery cell has a fault according to the pressure data, the voltage data, current data and temperature data of each battery cell, and when it is determined that any battery cell has a fault, control the electronic switch corresponding to any battery cell to disconnect the connection between any battery cell and the battery cell series circuit; in this way, the battery monitoring module and the electronic switch module can be combined to disconnect the faulty battery cell in the battery pack from the battery cell series circuit of the entire battery pack, thereby ensuring that the normal battery cells in the entire battery pack continue to supply power to the load.

[0063] Therefore, through the above explanation, the battery fault management system provided in this embodiment realizes the fault detection of a single battery cell and the disconnection processing of the faulty battery cell. In this way, the battery pack can continue to work normally and uninterruptedly, thereby improving the working stability and sustainability while reducing the maintenance cost. Therefore, it is very suitable for large-scale application and promotion.

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

[0065] Optionally, this embodiment can implement chemical fault detection and physical fault detection of each battery cell based on 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 determine whether each battery cell has a chemical fault based on the pressure data and the voltage data and current data of each battery cell, and when it is determined that any battery cell has a chemical fault, control the electronic switch corresponding to any battery cell to disconnect the connection between any battery cell and the battery cell series circuit; and is used to determine whether each battery cell has a physical fault based on the pressure data, the voltage data and the temperature data of each battery cell, and when it is determined that any battery cell has a physical fault, control the electronic switch corresponding to any battery cell to disconnect the connection between 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 the electrode, reducing the number of available lithium ions, thereby causing the battery cell capacity to decrease) 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 not limited to as shown below.

[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 pressure data of multiple battery blocks. Therefore, the expansion of the battery cells in each battery block (i.e., expansion caused by decomposition of electrolyte) can be detected 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, according to 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 according to 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 values ​​exceed the change threshold; wherein, if there are batteries whose voltage change values ​​exceed the change threshold, it can be determined that the aforementioned batteries whose voltage change values ​​exceed 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 aforementioned battery cell with the electrolyte decomposition fault, thereby cutting off the connection between the battery cell with the electrolyte decomposition fault and the battery cell series circuit, and then making the aforementioned faulty battery cell disconnect from the battery cell series circuit.

[0070] Similarly, as explained above, the voltage data of each battery cell includes the sampling circuits at multiple sampling moments, and therefore, the current data is also the same, that is, it includes the sampling currents at multiple sampling moments; 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 sampling voltages and sampling currents.

[0071] In specific implementation, this embodiment performs active material loss fault detection (i.e., capacity reduction due to active material loss) by calculating the power of each battery cell; wherein, the detection process is as follows: the main control module is used to calculate the power of each battery cell at each sampling moment according to the sampled voltage and sampled current of each battery cell at multiple sampling moments; then, according to the power of each battery cell at each sampling moment, it is determined whether each battery cell has a battery active material loss fault, and when it is determined that any battery cell has a battery active material loss fault, the electronic switch corresponding to any battery cell is controlled to disconnect the connection between any battery cell and the battery cell series circuit.

[0072] In this embodiment, the method for calculating the power of any battery cell at each sampling moment is: use sampling moment × sampling voltage × sampling current (of course, if each sampling window is a period of time during sampling, then the sampling moment can be replaced with the corresponding sampling duration); in this way, based on the above method, the power of each battery cell at each sampling moment can be calculated; then, by summing the power of each battery cell at each sampling moment, the power of any battery cell can be obtained, and then, for any battery cell, the power of any battery cell is integrated to obtain an integral value (this value is used for standard storage or release of power); finally, if the integral value is less than the set value, it is determined that the capacity of 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 action of the electronic switch corresponding to any battery cell, so that any battery cell is disconnected from the battery cell series circuit.

[0073] Furthermore, for the detection of SET film growth failure, the main control module determines whether each battery cell has a battery SEI film growth failure at any sampling moment based on the sampled voltage of each battery cell at the sampling moment, and when it is determined that any battery cell has a battery SEI film growth failure, controls the electronic switch corresponding to the any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit; wherein, in the present embodiment, if the sampled voltage of any battery cell at the sampling moment is higher than the voltage threshold, it is determined that any battery cell has the battery SEI film growth failure; 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] Thus, based on the above explanation, chemical fault detection of each battery cell can be realized; similarly, physical fault detection is realized based on the pressure data of each battery block, and 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, which 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 instantly rise. 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 is determined 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 loosens or disconnects 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 concluded whether any battery cell has a connection fault.

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

[0078] Furthermore, for the detection of mechanical damage failures, the present 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 any battery block exceeds the second pressure threshold; if so, the main control module determines whether the voltage data of each battery cell in any battery block are the same; if they are the same, the main control module determines that any battery block has a mechanical damage failure, and when it is determined that any battery block has a mechanical damage failure, controls the electronic switches corresponding to each battery cell in any battery block to disconnect each battery cell 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 failure caused by electrolyte decomposition through the voltage of each battery cell in the battery block; among them, when the voltages of each battery cell in the battery pack are the same or in the same voltage range (such as the voltage difference between each battery cell is within a preset difference range), at this time, it means that the battery pack has been squeezed or impacted and mechanical damage has occurred. Based on this, in order to ensure safety, it is necessary to disconnect each battery cell from the battery cell series circuit, and at the same time, disconnect the battery pack from external equipment; of course, the connection between all battery cells in the battery pack and the battery cell series circuit can be disconnected.

[0080] Therefore, through the above explanation, the battery fault management system provided in this embodiment can complete all physical and chemical fault detection of battery cells through the pressure data of each battery block in the battery pack, and the voltage, current and temperature data of each battery cell, and automatically eliminate the corresponding fault after detecting it; based on this, the safe use of the battery can be guaranteed.

[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 each battery cell, 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, the battery pack is charged and discharged.

[0082] See also Figure 3 As shown, the following provides the charging 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, wherein the target battery cell is a battery cell in the battery pack whose voltage data is greater than or equal to the maximum voltage; in the present embodiment, when the voltage data of any battery cell reaches the maximum voltage at a certain moment, it indicates that the any battery cell has been fully charged. At this time, it is necessary to disconnect the connection between the any battery cell and the battery series circuit, that is, the main control module controls 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.

[0084] Next, the 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; in this embodiment, it is equivalent to subtracting the voltage of the fully charged battery cell from the charging voltage of the charging pile for each fully charged battery cell, thereby reducing the charging voltage; at this time, it is necessary to combine the power of the battery pack and the charging voltage of the charging pile at this time (that is, the aforementioned updated charging voltage) to determine whether the charging of the entire battery pack can be stopped, that is:

[0085] The main control module is used to obtain the total charging capacity of the battery pack at the current moment according to the charging capacity of each battery cell; in the present embodiment, the charging capacity of each battery cell has been described above, and the total charging capacity of the battery pack at the current moment is obtained by summing up the charging capacity of each battery cell; at this time, it is determined whether the updated charging voltage is less than or equal to the minimum charging voltage, and whether the total charging capacity reaches the preset capacity; wherein, if the above 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 the voltage data of the battery cells one by one to see whether they reach the maximum voltage, and monitor continuously until the above-mentioned total charging capacity reaches the preset capacity 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 battery 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 above conditions are met, the battery pack can be disconnected from the charging pile to stop charging the battery pack.

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

[0088] When it is collected that a certain battery cell is charged to the highest voltage (that is, the collected voltage data is greater than or equal to the maximum 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. At the same time, the main control module controls the charging pile through the CAN bus to reduce the charging voltage (that is, reduce the voltage data of the battery cell), and continues to monitor in a cycle until the charging voltage reaches the minimum voltage of the charging pile and the total electrical energy of the battery pack reaches the preset electrical energy. The main control module controls the total charging relay through the CAN bus to stop charging. In this way, this charging process completely avoids the problem of overcharging of the battery cell, prevents the heating and thermal runaway of the battery cell, and thus greatly improves the charging safety.

[0089] Similarly, the discharge process is the same as the charging process, that is, during the discharge process, the power of each battery cell is the discharge power, and the process is:

[0090] See also 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, wherein the specified battery cell is a 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 any battery cell has been discharged. At this time, it is necessary to disconnect the connection between any battery cell and the battery series circuit, that is: if so, the main control module is used to control the electronic switch corresponding to the specified battery cell, disconnect the specified battery cell from the series circuit, so as to stop discharging the specified battery cell.

[0091] Next, the main control module is used to obtain the minimum load voltage of the load corresponding to the battery pack (for example, in an electric vehicle, it is the minimum voltage set by the motor controller), and reduce the total voltage of the entire battery pack to obtain an updated total voltage, wherein 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 it is determined that the power of a battery cell is fully 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 the discharge of the entire battery pack can be stopped, and the process is as follows:

[0092] The main control module is used to obtain the total discharge power of the battery pack at the current moment according to the discharge power of each battery cell; in this embodiment, the discharge power of each battery cell is summed to obtain the total discharge power of the battery pack at the current moment; at this time, it can be determined whether the updated total voltage is less than or equal to the minimum load voltage (i.e. Figure 4 ), and judge whether the total discharged electricity reaches the preset discharge amount; wherein, if the above conditions are met, the connection between the battery pack and the load is disconnected to stop the discharge of the battery pack; otherwise, it is necessary to continue to monitor whether the voltage data of the battery cells one by one is less than or equal to the minimum voltage, and monitor continuously until the above-mentioned total discharged electricity reaches the preset discharge amount and the total voltage of the battery pack is less than or equal to the minimum voltage of the load; of course, when there is no designated battery cell in the battery pack, it is directly judged whether the total voltage of the battery pack is less than or equal to the minimum voltage of the load, and whether the total discharged electricity reaches the preset discharge amount, 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:

[0094] When it is detected that a certain battery cell is discharged 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 to monitor in a cycle until the discharge voltage reaches the minimum load voltage set by the motor controller and the total discharge amount of the entire battery pack reaches the preset discharge amount, the main control module controls the total discharge relay through the CAN bus to stop discharging; in this way, this discharge process completely avoids the problem of over-discharge of the battery cell and prevents excessive loss of the battery cell's life, thereby greatly improving the battery's service life.

[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, and a current sensor, etc., so that 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, the entire system may also include, but is not limited to, a serial bus, wherein 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, 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 may also be specifically set according to actual use, and is not limited to the aforementioned examples.

[0097] In one possible design, the second aspect of this embodiment provides another battery management method, which differs from the first aspect of the embodiment in that no cell switch module is provided, that is, no electronic switch is provided in the circuit of the battery pack. Instead, when a faulty cell is detected, the system outputs an alarm prompt, thereby allowing the operation and maintenance personnel to physically cut off the faulty cell.

[0098] Specifically, its working process is:

[0099] The main control module is also used to determine the 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 battery cell strings to the main control module based on the alarm prompt, so that the main control module can control the operation of the battery pack based on the number of battery cell strings after receiving the number of battery cell strings.

[0100] In the present embodiment, when the main control module detects a faulty battery cell, it will read the number of the faulty battery cell, and then generate an alarm prompt based on the number of the faulty battery cell and send it to the operation and maintenance terminal; in this way, the operation and maintenance personnel will know the number of the faulty battery cell based on the alarm prompt; based on this, the battery pack can be disassembled and opened, and the faulty battery cell can be disconnected from the circuit by manual cutting and welding, and the broken circuit can be turned on; at the same time, the number of cell strings in 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 the number of battery cell strings based on the number of cell strings 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, and the manual only needs to re-enter the number of cell strings in the path to match it with the algorithm to control the battery pack; and in actual 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 separation processing of the faulty battery cell, which can enable the battery pack to continue to work normally and uninterruptedly; therefore, while improving the working stability and sustainability, it also reduces the maintenance cost, and is very suitable for large-scale application and promotion.

[0103] (2) Compared with traditional technologies, it can automatically eliminate all physical and chemical faults in the battery cells, thereby preventing the battery pack from burning and exploding due to battery cell failure, thus avoiding harm and loss to people and property.

[0104] (3) The charging method provided by the invention completely avoids overcharging of the battery cells, prevents heating and thermal runaway of the battery cells, while the discharge process completely avoids overdischarging of the battery cells, prevents excessive loss of the life of the battery cells; thereby, 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.

[0105] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended 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: include: A cell switch module, wherein the cell switch module includes a plurality of electronic switches, wherein the number of the electronic switches is the same as the number of cells in the battery pack, each cell corresponds to an electronic switch, and any electronic switch 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 to maintain the passage of the cell series circuit after disconnecting from 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 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; The main control module is electrically connected to the battery monitoring module and each electronic switch, and is used to determine whether each battery cell has a fault based on the pressure data, the voltage data, the current data and the temperature data of each battery cell, and when it is determined that any battery cell has a fault, control the electronic switch corresponding to any battery cell to disconnect the connection between any battery cell and the battery cell series circuit.

2. A battery fault management system according to claim 1, characterized in that: The main control module is used to judge whether each battery cell has a chemical fault 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 any battery cell to disconnect the connection between any battery cell and the battery cell series circuit; as well as It is used to judge whether each battery cell has a physical fault based on the pressure data, the voltage data and the 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 any battery cell to disconnect the connection between any battery cell and the battery cell series circuit.

3. A battery fault management system according to claim 2, characterized in that: The chemical fault includes: an electrolyte decomposition 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; The main control module is used to obtain voltage data of each battery cell in any battery block when it is determined that the pressure data of any battery block exceeds a first pressure threshold; 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; The main control module is used to determine whether there is a battery cell in any of the battery blocks whose voltage change value exceeds the change threshold; If so, the main control module determines that the battery cell whose voltage change value exceeds the change threshold has an electrolyte decomposition fault.

4. A battery fault management system according to claim 2, characterized in that: The chemical faults also include: battery active material loss fault and 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; The main control module is used to calculate the power of each battery cell at each sampling moment according to the sampled voltage and sampled current of each battery cell at multiple sampling moments; The main control module is used to determine whether each battery cell has a battery active material loss fault 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 any battery cell to disconnect the connection between the any battery cell and the battery cell series circuit; The main control module is further used to judge whether each battery cell has a battery SEI film growth fault at any sampling moment according to the sampled 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 sampled voltage of any battery cell at any sampling moment is higher than the voltage threshold, it is judged that any battery cell has the battery SEI film growth fault.

5. A battery fault management system according to claim 2, characterized in that: The physical faults include: short circuit faults and connection faults; 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; The main control module is used to determine that any of the battery cells has a short circuit fault 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 Based on the voltage data of any of the battery cells, a 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 a voltage increase threshold and the temperature change data exceeds a second temperature change threshold, it is determined that any of the battery cells has a connection fault.

6. A battery fault management system according to claim 2, characterized in that: The physical fault also 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; For any battery block among the plurality of battery blocks, the main control module is used to determine whether the pressure data of the any battery block exceeds a second pressure threshold; If so, the main control module determines whether the voltage data of each battery cell in any battery block is the same; 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 disconnects the battery pack from the external device.

7. A battery fault management system according to claim 1, characterized in that: 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; 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.

8. A battery fault management system according to claim 7, characterized in that: When the battery pack is in a charging state, the power of each battery cell is the charging power; A main control module, used for judging whether a target battery cell exists in the battery pack based on the voltage data of each battery cell, wherein the target battery cell is a battery cell in the battery pack whose voltage data is greater than or equal to the maximum voltage; 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; A main control module, 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; The main control module is used to obtain the total charging capacity of the battery pack at the current moment according to the charging capacity of each battery cell; A main control module, used to determine whether the updated charging voltage is less than or equal to the minimum charging voltage, and to determine whether the total charging power reaches a preset power; If so, the main control module disconnects the battery pack from the charging pile to stop charging the battery pack.

9. A battery fault management system according to claim 8, characterized in that: If the main control module determines that there is no target battery 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 battery pack from the charging pile to stop charging the battery pack.

10. A battery fault management system according to claim 1, characterized in that: The main control module is also used to determine the 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 battery cell strings to the main control module based on the alarm prompt, so that the main control module can control the operation of the battery pack based on the number of battery cell strings after receiving the number of battery cell strings.

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