A forklift lithium battery module control method, system, device and medium

Abstract

The present application relates to the technical field of battery control, and in particular to a forklift lithium battery module control method, system, device and medium. The present application first obtains the current state of the lithium battery module and the operating state of the forklift, analyzes the module discharge according to these states, and obtains the discharge analysis result; then, according to the discharge analysis result, performs a directional power-off analysis on the target lithium battery module in the micro-current discharge state, and obtains directional power-off parameters such as power-off time parameters and power-off mode; finally, according to these parameters, controls the connection state of the target lithium battery module and the system, and realizes targeted power-off protection, thereby solving the problems caused by micro-current discharge, maximizing the service life of the lithium battery, and improving the overall working reliability.

Description

Technical Field

[0001] The present application relates to the technical field of battery control, and in particular to a forklift lithium battery module control method, system, device and medium. Background Art

[0002] With the rapid development of the new energy vehicle industry, lithium batteries are widely used as the main power batteries in electric vehicles, forklifts and other fields. Lithium batteries have the advantages of high energy density, no memory effect, and low self-discharge rate, but they also have safety hazards and service life problems. Sophisticated battery management strategies are needed to ensure safe and reliable operation.

[0003] In the prior art, a battery management system (BMS) is usually used to monitor and manage lithium batteries. BMS can obtain battery parameters such as voltage, current, and temperature, and perform operations such as balancing management and overcharge and over-discharge protection according to preset strategies. However, most BMS systems only focus on the instantaneous working status of the battery, ignoring the impact of long-term micro-current discharge on battery life when the forklift is stationary.

[0004] However, when lithium batteries are in a state of micro-current discharge for a long time, the structural changes of the positive and negative electrodes and the decomposition of the electrolyte will be accelerated, resulting in irreversible capacity loss and reduced life. Existing technologies fail to effectively detect and manage this state, resulting in the inability to maximize battery performance and increasing potential safety hazards. This situation needs to be further improved. Summary of the invention

[0005] In order to solve the problem that the existing battery management system ignores the long-term micro-current discharge when the forklift is stationary, resulting in capacity loss and reduced life, the present application provides a forklift lithium battery module control method, system, device and medium, which adopts the following technical solutions:

[0006] In a first aspect, the present application provides a forklift lithium battery module control method, comprising the following steps:

[0007] Obtain the current status of the lithium battery module and the operating status of the forklift;

[0008] Analyze the discharge status of the lithium battery module according to the current status and the operating status to obtain a discharge analysis result;

[0009] According to the discharge analysis result, a directional power-off analysis is performed on the target lithium battery module in a micro-current discharge state to obtain corresponding directional power-off parameters;

[0010] The connection state of the target lithium battery module is controlled according to the directional power-off parameter.

[0011] By adopting the above technical solution, since the lithium battery is in a micro-current discharge state for a long time when the forklift is stationary, it will accelerate the structural changes of the positive and negative electrodes and the decomposition of the electrolyte, thereby causing irreversible capacity loss and reduced life. The present application first obtains the current state of the lithium battery module and the operating state of the forklift, and analyzes the discharge of the module according to these states to obtain the discharge analysis results; then, according to the discharge analysis results, a directional power-off analysis is performed on the target module in the micro-current discharge state to obtain directional power-off parameters such as power-off time parameters and power-off mode; finally, according to these parameters, the connection state of the target module and the system is controlled to achieve targeted power-off protection, thereby solving the problems caused by micro-current discharge, maximizing the service life of the lithium battery, and improving the overall working reliability.

[0012] Optionally, the discharge condition of the lithium battery module is analyzed according to the current state and the operating state to obtain a discharge analysis result, which specifically includes the following steps:

[0013] determining an operating mode of the forklift according to the operating state;

[0014] When the operation mode is the static mode, the real-time output current value of each module in the lithium battery is detected according to the current state;

[0015] Determine whether the real-time output current value is less than a preset micro-current threshold and the duration exceeds a preset time threshold;

[0016] If so, it is determined that the corresponding lithium battery module is in a micro-current discharge state; otherwise, it is in a normal state.

[0017] By adopting the above technical solution, the present application first determines the current operating mode of the forklift according to its operating state, such as driving, stationary, etc.; when the operating mode is stationary, the real-time output current value of each module in the lithium battery is detected, and then it is determined whether these real-time output current values ​​are less than the preset micro-current threshold and the duration exceeds the preset time threshold. If these two conditions are met, the corresponding module is determined to be in a micro-current discharge state, otherwise it is in a normal state. It can eliminate the interference of current fluctuations during the operation of the forklift, accurately capture the micro-current discharge module in a stationary state, and set a time threshold at the same time to avoid misjudgment of short-term small currents.

[0018] Optionally, according to the discharge analysis result, a directional power-off analysis is performed on the target lithium battery module in the micro-current discharge state to obtain corresponding directional power-off parameters, which specifically includes the following steps:

[0019] According to the discharge analysis result, the power value, temperature value and aging value of the target lithium battery module in the micro-current discharge state are obtained;

[0020] If any parameter among the power value, the temperature value and the aging value exceeds the corresponding preset threshold, determining the power-off time parameter and the power-off mode of the target lithium battery module as the directional power-off parameter;

[0021] Otherwise, the current connection state of the target lithium battery module is maintained.

[0022] By adopting the above technical solution, simply judging the micro-current discharge state is not enough to determine whether it is necessary to disconnect the battery from the system. It is necessary to further evaluate the specific working state and health of the battery. This application first obtains the parameters such as the power value, temperature value and aging value of the target module based on the discharge analysis results, and then determines whether these parameters are lower than / higher than the preset power threshold, temperature threshold, and aging threshold respectively. If any parameter exceeds the threshold, it is considered that there is a potential safety hazard, and it is necessary to determine the power-off time and power-off method as directional power-off parameters to perform targeted power-off protection; otherwise, the current connection state of the target module is maintained.

[0023] Optionally, determining the power-off time parameter and the power-off mode of the target lithium battery module specifically comprises the following steps:

[0024] Obtaining a power difference between the power value and a preset power threshold, a temperature difference between a temperature value and a preset temperature threshold, and an aging degree difference between an aging value and a preset aging threshold;

[0025] A comprehensive score is obtained by calculating the power difference, temperature difference and aging degree difference according to preset weights;

[0026] According to the preset power-off time interval corresponding to the comprehensive score value, the power-off time parameter and the power-off mode of the target lithium battery module are determined.

[0027] By adopting the above technical scheme, since the power level, temperature and aging degree have different effects on battery safety, determining the power-off strategy based solely on a certain parameter exceeding the threshold may lead to over-protection or under-protection. The present application first obtains the difference between the power value of the target module and the preset threshold, the difference between the temperature value and the preset threshold, and the difference between the aging value and the preset threshold; then, based on these three differences, a comprehensive score value is calculated according to a pre-set weight coefficient. The higher the score value, the more unsafe the working state of the target module. Then, based on the preset power-off time interval corresponding to this comprehensive score value, the specific time length and power-off method for the target module to be powered off are determined as power-off parameters, which can more comprehensively and accurately evaluate the working condition of the battery and make the power-off strategy more refined.

[0028] Optionally, the method further comprises the following steps:

[0029] Obtaining the voltage value, temperature value and internal resistance value of each single cell in the lithium battery module;

[0030] Calculating the voltage difference, temperature difference and internal resistance difference between each single cell and the average value;

[0031] Judging whether there is an unbalanced monomer according to the voltage difference, temperature difference and internal resistance difference;

[0032] If there is an unbalanced monomer, a monomer balancing operation is performed to adjust the charge and discharge of the unbalanced monomer;

[0033] The preset power threshold, the preset temperature threshold and the preset aging threshold are dynamically adjusted according to the balancing conditions of the single cells.

[0034] By adopting the above technical solution, since there are parameter differences and imbalances between the single cells in the battery module, if they are not monitored and adjusted, the overall working performance and service life of the module will be affected. This application monitors the voltage, temperature, internal resistance and other parameters of each single cell in the battery module, calculates their difference with the average value, and determines whether there is an unbalanced single cell. If so, a single cell balancing operation is performed to adjust the charge and discharge of the abnormal single cell to restore it to a balanced state. At the same time, according to the balancing situation, the power, temperature and aging thresholds at the module level can also be dynamically adjusted to improve the adaptability of the management strategy.

[0035] Optionally, the method further comprises the following steps:

[0036] Obtaining an ambient temperature value, and determining whether the ambient temperature value is lower than a preset low temperature threshold;

[0037] If the ambient temperature value is lower than the preset low temperature threshold, charging the lithium battery module is prohibited, and the maximum discharge power of the lithium battery module is limited to a preset safety value range;

[0038] The preset power threshold, preset temperature threshold and preset aging threshold of the lithium battery module are adjusted according to the ambient temperature value to relax the triggering conditions of directional power off.

[0039] By adopting the above technical solution, since the internal electrochemical reaction activity of lithium batteries will decrease, the charging and discharging efficiency will deteriorate, and even safety hazards may occur when working in a low-temperature environment, the present application first obtains the current ambient temperature value to determine whether it is lower than the preset low-temperature threshold. If the temperature is lower than the threshold, any charging operation on the lithium battery module is prohibited to prevent affecting the internal reaction of the battery. At the same time, the maximum discharge power of the module is limited to a pre-set safety value range to avoid dynamic thermal runaway of excessive discharge current, thereby ensuring the safe and reliable operation of the battery under various temperature conditions to a greater extent, while avoiding efficiency loss caused by over-protection.

[0040] In a second aspect, the present application provides a forklift lithium battery module control system, comprising:

[0041] An operating status acquisition module is used to obtain the current status of the lithium battery module and the operating status of the forklift;

[0042] A discharge analysis module, used to analyze the discharge status of the lithium battery module according to the current status and the operating status, and obtain a discharge analysis result;

[0043] A directional power-off parameter acquisition module is used to perform a directional power-off analysis on the target lithium battery module in a micro-current discharge state according to the discharge analysis result to obtain corresponding directional power-off parameters;

[0044] A connection status control module is used to control the connection status of the target lithium battery module according to the directional power-off parameter.

[0045] In a third aspect, the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the forklift lithium battery module control method when executing the computer program.

[0046] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the forklift lithium battery module control method are implemented.

[0047] In summary, the present application includes at least one of the following beneficial technical effects:

[0048] 1. When the forklift is stationary, the lithium battery will accelerate the structural changes of the positive and negative electrodes and the decomposition of the electrolyte when it is in a micro-current discharge state for a long time, thereby causing irreversible capacity loss and reduced life. The present application first obtains the current state of the lithium battery module and the operation state of the forklift, and analyzes the module discharge according to these states to obtain the discharge analysis results; then, according to the discharge analysis results, a directional power-off analysis is performed on the target module in the micro-current discharge state to obtain directional power-off parameters such as power-off time parameters and power-off methods; finally, according to these parameters, the connection state of the target module and the system is controlled to achieve targeted power-off protection, thereby solving the problems caused by micro-current discharge, maximizing the service life of the lithium battery, and improving the overall working reliability;

[0049] 2. This application first determines the current operation mode of the forklift according to its operation state, such as driving, stationary, etc.; when the operation mode is stationary, detect the real-time output current value of each module in the lithium battery, and then determine whether these real-time output current values ​​are less than the preset micro-current threshold value, and the duration exceeds the preset time threshold value. If these two conditions are met, the corresponding module is determined to be in a micro-current discharge state, otherwise it is a normal state, which can eliminate the interference of current fluctuations during the operation of the forklift, accurately capture the micro-current discharge module in the stationary state, and set the time threshold at the same time to avoid misjudgment of short-term small currents;

[0050] 3. Since the power level, temperature and aging degree have different effects on battery safety, determining the power-off strategy based solely on a certain parameter exceeding a threshold may lead to over-protection or under-protection. The present application first obtains the difference between the power value of the target module and the preset threshold, the difference between the temperature value and the preset threshold, and the difference between the aging value and the preset threshold; then, based on these three differences, a comprehensive score is calculated according to a pre-set weight coefficient. The higher the score, the less safe the working state of the target module. Then, based on the preset power-off time interval corresponding to this comprehensive score, the specific length of time and method of power-off that the target module should be powered off are determined as power-off parameters, which can more comprehensively and accurately evaluate the working condition of the battery and make the power-off strategy more refined. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a flow chart of a forklift lithium battery module control method according to an embodiment of the present application;

[0052] Figure 2 It is a flow chart of step S120 in a forklift lithium battery module control method according to an embodiment of the present application;

[0053] Figure 3 It is a flow chart of step S130 in a forklift lithium battery module control method according to an embodiment of the present application;

[0054] Figure 4 It is a flow chart of step S132 in a forklift lithium battery module control method according to an embodiment of the present application;

[0055] Figure 5 It is a flow chart of adjusting the threshold value according to the balancing situation in a forklift lithium battery module control method according to an embodiment of the present application;

[0056] Figure 6 It is a schematic diagram of a flow chart of adjusting a threshold value according to ambient temperature in a forklift lithium battery module control method according to an embodiment of the present application;

[0057] Figure 7 This is a module schematic diagram of a forklift lithium battery module control system according to an embodiment of the present application;

[0058] Figure 8 It is a diagram of the internal structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0059] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to be used as limitations to the present application. As used in the specification and appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear indication to the contrary in the context. It should also be understood that the term "and / or" used in the present application refers to any or all possible combinations comprising one or more listed items.

[0060] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features, and in the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0061] The embodiments of the present application are further described in detail below in conjunction with the drawings in the specification.

[0062] In the first aspect, the present application provides a forklift lithium battery module control method, referring to Figure 1 , including the following steps:

[0063] S110, obtaining the current state of the lithium battery module and the operating state of the forklift.

[0064] In this embodiment, the current state refers to the output current value of the lithium battery module within a specific time period; the operating state refers to the current operating mode of the forklift, such as driving, braking or stationary.

[0065] Specifically, the real-time output current value of the lithium battery module is periodically obtained through the battery management system as the current state. For the forklift operation state, the current operation mode can be determined according to the preset state judgment algorithm through the sensor data collected by the forklift controller.

[0066] S120: Analyze the discharge status of the lithium battery module according to the current status and the operation status to obtain a discharge analysis result.

[0067] In this embodiment, the discharge analysis refers to determining whether the lithium battery module is in a micro-current discharge state. Micro-current discharge refers to long-term discharge with a very small current, which will accelerate battery aging.

[0068] Specifically, the current state is compared with a preset micro-current threshold. When the forklift is in a stationary state, if the current state of a module is lower than the micro-current threshold and lasts for more than a preset time, the module is determined to be in a micro-current discharge state and is marked as a target module that needs further analysis.

[0069] S130. According to the discharge analysis result, a directional power-off analysis is performed on the target lithium battery module in a micro-current discharge state to obtain corresponding directional power-off parameters.

[0070] In this embodiment, a power threshold is preset to obtain the current power value of the target module. If it is less than 20%, it is determined that power-off protection needs to be performed. The power-off duration is determined proportionally according to the difference between the power value and the threshold. The larger the difference, the longer the power-off duration, so as to avoid permanent damage to the battery due to excessive discharge. The power-off method can be uniformly hard power-off, that is, directly cutting off the electrical connection between the module and the load.

[0071] S140, controlling the connection state of the target lithium battery module according to the directional power-off parameters.

[0072] In this embodiment, the connection status refers to the connection and disconnection status between the target module and the vehicle power supply system.

[0073] Specifically, a disconnect relay is set in the battery management system, and the electrical connection state between the target module and the vehicle power supply system is controlled by the relay. According to the power-off duration parameter determined previously, the battery management system controls the relay to disconnect for a period of time to cut off the power supply of the target module; after the time is up, the relay closes again and reconnects the power supply.

[0074] In one embodiment, referring to Figure 2 In step S120, the discharge condition of the lithium battery module is analyzed according to the current state and the operation state to obtain the discharge analysis result, which specifically includes the following steps:

[0075] S121. Determine an operation mode of the forklift according to the operation status.

[0076] In this embodiment, the operating mode refers to the current motion state of the forklift, including a driving mode, a braking mode, and a stationary mode.

[0077] Specifically, the forklift controller collects various sensor data, such as speed sensor, brake sensor, direction sensor, etc., and comprehensively determines the current operation mode of the forklift according to a preset judgment algorithm. For example, when the speed is 0 and the brake state is not braked, it is determined to be in stationary mode.

[0078] S122. When the operation mode is the static mode, the real-time output current value of each module in the lithium battery is detected according to the current state.

[0079] In this embodiment, the real-time output current value refers to the instantaneous current value output by the lithium battery module to the load at that time point.

[0080] Specifically, a high-precision current sensor is installed on the current detection circuit of the battery management system to sample and digitally process the current value of each module output in real time. Alternatively, the voltage difference between the two ends of each module is measured and calculated based on the known load resistance value, and then the corresponding real-time output current value is derived.

[0081] S123, determining whether the real-time output current value is less than a preset micro-current threshold and whether the duration exceeds a preset time threshold.

[0082] In this embodiment, the micro-current threshold and the time threshold are used to determine the magnitude and duration of the output current, respectively.

[0083] Specifically, a micro-current threshold, such as 50mA, is pre-set according to the battery model and parameters. At the same time, a time threshold, such as 2 hours, is also required. Only when the real-time output current value is lower than 50mA and lasts for more than 2 hours, it is regarded as micro-current discharge, avoiding some transient small currents from being misjudged.

[0084] S124, if yes, determine that the corresponding lithium battery module is in a micro-current discharge state; otherwise, it is in a normal state.

[0085] In this embodiment, the micro-current discharge state refers to a working state in which the battery is discharged slowly with an extremely small current, which will accelerate the aging of the battery.

[0086] Specifically, if a lithium battery module meets the conditions of step S123, that is, the real-time output current is continuously lower than 50mA for more than 2 hours, the BMS will determine it as being in a micro-current discharge state and further directional power-off analysis and adjustment will be required. For other modules, if the current value is not continuously lower than the threshold, it is considered to be in a normal working state and no special treatment is required.

[0087] In one embodiment, referring to Figure 3 In step S130, according to the discharge analysis result, a directional power-off analysis is performed on the target lithium battery module in the micro-current discharge state to obtain the corresponding directional power-off parameters, which specifically includes the following steps:

[0088] S131. According to the discharge analysis result, the power value, temperature value and aging value of the target lithium battery module in the micro-current discharge state are obtained.

[0089] In this embodiment, the power value refers to the current remaining power percentage of the target lithium battery module; the temperature value refers to the real-time temperature of the module; and the aging value indicates the degree of cycle aging experienced by the module.

[0090] The power and temperature values ​​are directly read from the battery management system (BMS), which has built-in circuits and algorithms for detecting power and temperature. The aging value is calculated by the BMS based on the historical usage data of the target module and combined with the preset aging model.

[0091] Specifically, the historical number of charge and discharge cycles of the module is counted, and then the rated cycle life of the battery is checked, and the cycle aging value is calculated based on the historical number of charge and discharge cycles and the rated cycle life; the average operating temperature of the module over a period of time is obtained, the ideal operating temperature of the battery is checked, and the temperature aging value is calculated based on the preset temperature aging model function; the number of deep discharges of the module is counted, the rated deep discharge cycle life of the battery is checked, and the deep discharge aging value is calculated; then, according to the preset weights, the cycle aging value, temperature aging value and deep discharge aging value are weighted and summed to obtain a comprehensive aging score value.

[0092] S132: If any parameter among the power value, temperature value and aging value exceeds the corresponding preset threshold, determine the power-off time parameter and power-off mode of the target lithium battery module as the directional power-off parameter.

[0093] In this embodiment, the power-off time parameter is used to control the duration of the power-off of the target module, and the power-off mode refers to the specific method of power-off such as hard power-off or soft power-off.

[0094] Specifically, the power threshold (such as 20%), temperature threshold (such as 55°C) and aging threshold (such as 80%) are pre-set. If the power value obtained is lower than 20%, or the temperature value is higher than 55°C, or the aging value exceeds 80%, it is determined that the module needs to be powered off. At this time, a comprehensive score can be calculated based on the deviation of each parameter from the threshold, and different weights can be given. A high score corresponds to a long power-off time (such as 5 minutes). At the same time, depending on the score, choose hard power-off (directly cut off the power supply) or soft power-off (current-limited discharge) mode.

[0095] By cutting off power for a certain period of time, the module can be temporarily cut off to prevent it from continuous micro-current discharge and aging, but the power supply of the entire vehicle will not be completely interrupted, which can prevent excessive discharge and damage to the battery. In this process, some internal parameters of the battery may improve. If the situation is good, it can work normally after reconnection, extending the battery life. Through multiple cycles of disconnection and reconnection, the module's status changes can be continuously monitored, and whether it can still be used can be dynamically evaluated based on the latest data.

[0096] S133: Otherwise, maintain the current connection state of the target lithium battery module.

[0097] In this embodiment, the current connection state is maintained, that is, the target module is still electrically connected to the vehicle power supply system, and no power-off operation is performed.

[0098] In one embodiment, referring to Figure 4 In step S132, the power-off time parameter and the power-off mode of the target lithium battery module are determined, which specifically includes the following steps:

[0099] S1321. Obtain a power difference between a power value and a preset power threshold, a temperature difference between a temperature value and a preset temperature threshold, and an aging degree difference between an aging value and a preset aging threshold.

[0100] In this embodiment, these differences reflect the extent to which various parameters of the target module deviate from the normal working range.

[0101] Specifically, the power value, temperature value and aging value obtained in step S131 are respectively subtracted from the preset power threshold (such as 20%), temperature threshold (such as 55°C) and aging threshold (such as 80%) to obtain three difference values. For example, if the module power is 15%, the power difference is 20%-15%=5%. It is worth noting that the difference of the parameter is only calculated when it exceeds the corresponding preset threshold.

[0102] S1322. Calculate a comprehensive score according to preset weights based on the power difference, temperature difference and aging degree difference.

[0103] In this embodiment, the comprehensive score value incorporates the effects of three parameter deviations.

[0104] Specifically, three weighted scores are pre-set, such as a power difference weight of 0.5, a temperature difference weight of 0.3, and an aging degree difference weight of 0.2. The three differences are then multiplied by the corresponding weights and added together to form a comprehensive score for the module.

[0105] S1323: Determine the power-off time parameters and the power-off method of the target lithium battery module according to the preset power-off time interval corresponding to the comprehensive score value.

[0106] In this embodiment, a mapping relationship table between the score value and the power outage time interval is pre-established, and a high score corresponds to a long power outage time.

[0107] Specifically, the score is divided into several levels, each level corresponds to a power-off time interval, such as 0-2 points for 1-3 minutes, 2-5 points for 2-5 minutes, 5-8 points for 3-8 minutes, etc. At the same time, each level also sets a corresponding power-off mode, such as hard power-off or soft power-off.

[0108] In one embodiment, referring to Figure 5 , the method further comprises the steps of:

[0109] S510, obtaining the voltage value, temperature value and internal resistance value of each single cell in the lithium battery module.

[0110] In this embodiment, the voltage value, temperature value and internal resistance value reflect the degree of imbalance between the monomers inside the module and are the basis for performing a balancing operation.

[0111] S520, calculating the voltage difference, temperature difference and internal resistance difference between each single cell and the average value.

[0112] In this embodiment, the size of the difference directly reflects the degree of deviation between the monomer and the whole.

[0113] Specifically, the BMS calculates the average values ​​of the obtained voltage value, temperature value and internal resistance value respectively, and then subtracts them from the actual value of each monomer to obtain a series of voltage difference values, temperature difference values ​​and internal resistance difference values.

[0114] S530: Determine whether there is an unbalanced monomer according to the voltage difference, temperature difference and internal resistance difference.

[0115] In this embodiment, the judgment is based on the preset voltage difference threshold, temperature difference threshold and internal resistance difference threshold.

[0116] Specifically, when a certain difference of any monomer exceeds the corresponding threshold (such as voltage difference ±0.05V, temperature difference ±5℃, internal resistance difference ±10%), the monomer is judged as an unbalanced monomer. For example, if the temperature of a node is 45℃, the average temperature is 40℃, and the temperature difference of 5℃ does not exceed the threshold, but the voltage difference of -0.1V exceeds the threshold, it is judged as an unbalanced monomer.

[0117] S540: If there is an unbalanced monomer, perform a monomer balancing operation to adjust the charge and discharge of the unbalanced monomer.

[0118] In this embodiment, the source of the imbalance is eliminated by actively adjusting the charge and discharge state of the monomer.

[0119] Specifically, the BMS can control the balancing circuit to perform a small amount of discharge on unbalanced monomers such as those with high voltage, high temperature, and low internal resistance, and to perform a small amount of charge on unbalanced monomers such as those with low voltage, low temperature, and high internal resistance, so that their voltage, temperature, and internal resistance values ​​gradually approach the average value, thereby achieving dynamic balance between monomers.

[0120] S550: Dynamically adjust a preset power threshold, a preset temperature threshold, and a preset aging threshold according to the balancing conditions of each single battery.

[0121] In this embodiment, various preset threshold parameters are adjusted according to the balance status of the cells inside the module.

[0122] Specifically, if the consistency between cells in the module is greatly improved after the balancing operation, the power threshold, temperature threshold and aging threshold can be appropriately increased to extend the service life of the module; conversely, if the cell imbalance is serious, these thresholds need to be lowered and more conservative protection measures need to be taken in a timely manner.

[0123] In one embodiment, referring to Figure 6 , the method further comprises the steps of:

[0124] S610: Obtain an ambient temperature value, and determine whether the ambient temperature value is lower than a preset low temperature threshold.

[0125] In this embodiment, the ambient temperature is taken into consideration because of the adverse effects of low temperature on lithium batteries.

[0126] Specifically, the ambient temperature value around the battery is obtained through the temperature sensor and compared with a preset low temperature threshold (such as -10°C). If the ambient temperature is too low, a corresponding protection strategy needs to be activated.

[0127] S620: If the ambient temperature is lower than a preset low temperature threshold, charging of the lithium battery module is prohibited, and the maximum discharge power of the lithium battery module is limited to a preset safety value.

[0128] In this embodiment, under low temperature conditions, the charging operation can easily cause irreversible damage to the lithium battery, such as metal lithium deposition and polarization, while high-power discharge may cause problems such as cracking of the plate material.

[0129] Specifically, when the ambient temperature is lower than the threshold, the BMS automatically cuts off the charging circuit of the module and prohibits any charging behavior; at the same time, the maximum allowable discharge power is limited according to the actual temperature value, such as limiting it to 0.2C rate at -5℃ and 0.1C rate at -15℃, etc., to avoid damage caused by excessive discharge current.

[0130] S630: Adjust the preset power threshold, preset temperature threshold, and preset aging threshold of the lithium battery module according to the ambient temperature value to relax the triggering conditions of the directional power-off.

[0131] In this embodiment, various thresholds are appropriately lowered in a low temperature environment, so as to minimize the number of unnecessary power outages and avoid frequent charge and discharge cycles that exacerbate battery aging.

[0132] Specifically, a correction relationship between the ambient temperature threshold and each protection threshold is established in advance. For example, when the temperature decreases by 10°C, the power threshold decreases by 5%, the temperature threshold decreases by 3°C, and the aging threshold decreases by 10%. During actual operation, these threshold parameters are dynamically adjusted according to the measured value of the ambient temperature.

[0133] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0134] In a second aspect, the present application provides a forklift lithium battery module control system. The forklift lithium battery module control system of the present application is described below in combination with the above-mentioned forklift lithium battery module control method.

[0135] Reference Figure 7 , a forklift lithium battery module control system, comprising:

[0136] An operating status acquisition module is used to obtain the current status of the lithium battery module and the operating status of the forklift;

[0137] The discharge analysis module is used to analyze the discharge status of the lithium battery module according to the current status and the operating status to obtain the discharge analysis results;

[0138] A directional power-off parameter acquisition module is used to perform a directional power-off analysis on the target lithium battery module in a micro-current discharge state according to the discharge analysis result, and obtain the corresponding directional power-off parameters;

[0139] The connection status control module is used to control the connection status of the target lithium battery module according to the directional power-off parameters.

[0140] In one embodiment, the present application provides an electronic device, which may be a server, and its internal structure diagram may be as follows: Figure 8 As shown. The electronic device includes a processor, a memory and a network interface connected through a system bus. Among them, the processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the electronic device is used to store data. The network interface of the electronic device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a forklift lithium battery module control method is implemented.

[0141] Those skilled in the art will understand that Figure 8 The structure shown in the figure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the electronic device to which the scheme of the present application is applied. The specific electronic device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0142] In one embodiment, an electronic device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0143] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the above-mentioned computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0144] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A forklift lithium battery module control method, characterized in that: The steps include: Obtain the current status of the lithium battery module and the operating status of the forklift; Analyze the discharge status of the lithium battery module according to the current status and the operating status to obtain a discharge analysis result; According to the discharge analysis result, a directional power-off analysis is performed on the target lithium battery module in a micro-current discharge state to obtain corresponding directional power-off parameters; Controlling the connection state of the target lithium battery module according to the directional power-off parameter; According to the current state and the operating state, the discharge condition of the lithium battery module is analyzed to obtain the discharge analysis result, which specifically includes the following steps: determining an operating mode of the forklift according to the operating state; When the operation mode is the static mode, the real-time output current value of each module in the lithium battery is detected according to the current state; Determine whether the real-time output current value is less than a preset micro-current threshold and the duration exceeds a preset time threshold; If yes, it is determined that the corresponding lithium battery module is in a micro-current discharge state; otherwise, it is in a normal state; According to the discharge analysis result, a directional power-off analysis is performed on the target lithium battery module in a micro-current discharge state to obtain corresponding directional power-off parameters, which specifically includes the following steps: According to the discharge analysis result, the power value, temperature value and aging value of the target lithium battery module in the micro-current discharge state are obtained; If any parameter among the power value, the temperature value and the aging value exceeds the corresponding preset threshold, determining the power-off time parameter and the power-off mode of the target lithium battery module as the directional power-off parameter; Otherwise, maintaining the current connection state of the target lithium battery module; Determining the power-off time parameters and the power-off mode of the target lithium battery module specifically comprises the following steps: Obtaining a power difference between the power value and a preset power threshold, a temperature difference between a temperature value and a preset temperature threshold, and an aging degree difference between an aging value and a preset aging threshold; According to the power difference, temperature difference and aging degree difference, a comprehensive score value is calculated according to preset weights; According to the preset power-off time interval corresponding to the comprehensive score value, the power-off time parameter and the power-off mode of the target lithium battery module are determined.

2. The forklift lithium battery module control method according to claim 1, characterized in that: The method further comprises the steps of: Obtaining the voltage value, temperature value and internal resistance value of each single cell in the lithium battery module; Calculating the voltage difference, temperature difference and internal resistance difference between each single cell and the average value; Judging whether there is an unbalanced monomer according to the voltage difference, temperature difference and internal resistance difference; If there is an unbalanced monomer, a monomer balancing operation is performed to adjust the charge and discharge of the unbalanced monomer; The preset power threshold, the preset temperature threshold and the preset aging threshold are dynamically adjusted according to the balancing conditions of the single cells.

3. The forklift lithium battery module control method according to claim 1, characterized in that: The method further comprises the steps of: Obtaining an ambient temperature value, and determining whether the ambient temperature value is lower than a preset low temperature threshold; If the ambient temperature is lower than the preset low temperature threshold, charging the lithium battery module is prohibited, and the maximum discharge power of the lithium battery module is limited to a preset safety value range; The preset power threshold, preset temperature threshold and preset aging threshold of the lithium battery module are adjusted according to the ambient temperature value to relax the triggering conditions of directional power off.

4. A forklift lithium battery module control system, characterized in that: include: An operating status acquisition module is used to obtain the current status of the lithium battery module and the operating status of the forklift; A discharge analysis module, used to analyze the discharge status of the lithium battery module according to the current status and the operating status, and obtain a discharge analysis result; A directional power-off parameter acquisition module is used to perform a directional power-off analysis on the target lithium battery module in a micro-current discharge state according to the discharge analysis result to obtain corresponding directional power-off parameters; A connection state control module, used to control the connection state of the target lithium battery module according to the directional power-off parameter; Wherein, the discharge analysis module performs the following steps: determining an operating mode of the forklift according to the operating state; When the operation mode is the static mode, the real-time output current value of each module in the lithium battery is detected according to the current state; Determine whether the real-time output current value is less than a preset micro-current threshold and the duration exceeds a preset time threshold; If yes, it is determined that the corresponding lithium battery module is in a micro-current discharge state; otherwise, it is in a normal state; The directional power-off parameter acquisition module performs the following steps: According to the discharge analysis result, the power value, temperature value and aging value of the target lithium battery module in the micro-current discharge state are obtained; If any parameter among the power value, the temperature value and the aging value exceeds the corresponding preset threshold, determining the power-off time parameter and the power-off mode of the target lithium battery module as the directional power-off parameter; Otherwise, maintaining the current connection state of the target lithium battery module; Determining the power-off time parameters and the power-off mode of the target lithium battery module specifically comprises the following steps: Obtaining a power difference between the power value and a preset power threshold, a temperature difference between a temperature value and a preset temperature threshold, and an aging degree difference between an aging value and a preset aging threshold; According to the power difference, temperature difference and aging degree difference, a comprehensive score value is calculated according to preset weights; According to the preset power-off time interval corresponding to the comprehensive score value, the power-off time parameter and the power-off mode of the target lithium battery module are determined.

5. An electronic device, characterized in that: It comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the forklift lithium battery module control method described in any one of claims 1 to 3 are implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the forklift lithium battery module control method described in any one of claims 1-3 are implemented.

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