A method for controlling voltage within a battery pack and related apparatus

Abstract

The application discloses a battery pack voltage control method and related device, which is used to improve the charging and discharging capacity of the whole battery. The method comprises the following steps: obtaining the target voltage value set by a user, and determining the maximum value and the minimum value of the voltage values of all the batteries in the battery pack as the current maximum voltage value and the current minimum voltage value respectively; if the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value, performing a mixed voltage adjustment step: charging the batteries with the voltage values less than the target voltage value and discharging the batteries with the voltage values greater than the target voltage value; until the current minimum voltage value reaches the target voltage value, discharging all the batteries and adjusting the discharging current values of all the batteries until the discharging current values of all the batteries are less than or equal to a preset current threshold, so that the voltage values of all the batteries are stabilized to the target voltage value.

Description

Technical Field

[0001] This application relates to the field of battery pack control, and more particularly to a method and related apparatus for controlling voltage within a battery pack. Background Technology

[0002] To meet the high-voltage power consumption and power output requirements of the vehicle, a battery pack consisting of batteries connected in series and parallel is needed. This not only increases the system operating voltage and expands the energy storage capacity, but also ensures the power supply for vehicle start-up and acceleration. Most existing solutions use battery packs connected in series to power the vehicle and ensure its normal operation.

[0003] However, in existing solutions, due to differences in performance and wear among the individual cells in a battery pack, voltage differences exist between them. These voltage differences cause the higher-voltage cells to reach their upper voltage limit first during charging. To prevent overcharging of these cells, charging must be stopped, leaving a significant number of lower-voltage cells uncharged. Conversely, during discharging, the lower-voltage cells again reach their lower voltage limit first. To prevent over-discharging of these cells, discharging must be stopped, again leaving a significant number of higher-voltage cells undischarged. This results in incomplete discharge of the entire battery pack, leading to individual cell variations and an inability to guarantee that all cells maintain a stable voltage at the set value. Consequently, the overall charging and discharging capacity of the battery pack is low. Summary of the Invention

[0004] To address the technical problem of low charge and discharge capacity of the entire battery pack in the background art, embodiments of this application provide a battery pack voltage control method and related apparatus to improve the charge and discharge capacity of the entire battery pack, thereby enhancing the usable capacity and safety of the entire battery pack.

[0005] The first aspect of this application provides a method for controlling voltage within a battery pack, including: Obtain the target voltage value set by the user, and determine the maximum and minimum values ​​among the voltage values ​​of all batteries in the battery pack that are currently collected in real time as the current maximum voltage value and the current minimum voltage value, respectively; If the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value, then perform a hybrid voltage adjustment step: charge the battery with a voltage value less than the target voltage value and discharge the battery with a voltage value greater than the target voltage value; Once the current minimum voltage value reaches the target voltage value, all batteries are discharged, and the discharge current value of all batteries is adjusted until the discharge current value of all batteries is less than or equal to the preset current threshold, so that the voltage value of all batteries stabilizes at the target voltage value.

[0006] Optionally, all batteries are discharged, and the discharge current value of all batteries is adjusted until the discharge current value of all batteries is less than or equal to a preset current threshold, including: For each battery, based on a preset proportional-integral-derivative control algorithm, the corresponding duty cycle is determined according to the difference between the current sampled voltage value and the target voltage value of the battery. Based on pulse width modulation, the switching transistor in the discharge branch where the battery is located is controlled to discharge the battery according to the duty cycle. Calculate the discharge current value of each battery and adjust the battery based on the discharge current value to stabilize the battery voltage value at the target voltage value.

[0007] Optionally, calculate the discharge current value for each battery, including: For each battery, the ratio of the difference between the current collected voltage value and the target voltage value to the discharged time period is determined as the voltage drop rate value, and the ratio of the current collected voltage value to a specified product is determined as the predicted voltage value. The specified product is the product of the voltage drop rate value and the preset discharge time period. Based on the preset relationship between the voltage difference and the discharge current, the corresponding discharge current value is determined according to the difference between the predicted voltage value and the target voltage value.

[0008] Optionally, the battery is adjusted based on the discharge current value to stabilize the battery voltage at a target voltage value, including: If the discharge current value is less than or equal to the preset current threshold, the switch in the discharge branch where the battery is located will be turned off to stop the battery from discharging and stabilize the battery voltage value at the target voltage value. If the discharge current value is greater than the preset current threshold, the first target step and subsequent steps will be executed after a preset time period, until the discharge current value is less than or equal to the preset current threshold. The first target step is to determine the voltage drop rate value as the ratio of the difference between the current collected voltage value and the voltage value to the discharged time period for each battery.

[0009] Optionally, before performing the hybrid voltage regulation step, the following may also be included: The difference between the current maximum voltage value and the current minimum voltage value is determined as the current voltage difference; If the current differential pressure is less than the preset differential pressure threshold, then the mixed voltage adjustment step is executed.

[0010] Optionally, before performing the hybrid voltage regulation step, the following may also be included: The difference between the current maximum voltage value and the current minimum voltage value is determined as the current voltage difference; If the current differential pressure is greater than the preset differential pressure threshold, voltage adjustment is performed until the current differential pressure is less than the preset differential pressure threshold, at which point a mixed voltage adjustment step is executed.

[0011] Optionally, voltage adjustment can be performed, including: Any voltage value within a specified voltage range is defined as the specified voltage value. The minimum value of the specified voltage range is the larger of the current minimum voltage value and the preset lower limit of the battery voltage. The maximum value of the specified voltage range is less than the sum of the current minimum voltage value and the preset differential voltage threshold. Discharge batteries in the battery pack whose initial voltage value is greater than the specified voltage value until the preset conditions are met.

[0012] Optional, satisfying preset conditions, including: The discharge time of batteries in the battery pack whose initial voltage value is greater than the specified voltage value exceeds the preset time. And / or, The voltage of a battery in the battery pack whose initial voltage value is greater than a specified voltage value drops to the specified voltage value after discharge.

[0013] Optionally, the preset differential pressure threshold is 50mV and the preset current threshold is 0.5A.

[0014] A second aspect of this application provides a voltage control device within a battery pack, comprising: The acquisition unit is used to acquire the target voltage value set by the user, and to determine the maximum and minimum values ​​among the voltage values ​​of all batteries in the battery pack that are currently collected in real time as the current maximum voltage value and the current minimum voltage value, respectively. The charging and discharging unit is used to perform a hybrid voltage adjustment step when the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value: charging the battery with a voltage value less than the target voltage value and discharging the battery with a voltage value greater than the target voltage value; The charging and discharging unit is also used to discharge all batteries when the current minimum voltage value reaches the target voltage value, and adjust the discharge current value of all batteries until the discharge current value of all batteries is less than or equal to the preset current threshold, so that the voltage value of all batteries stabilizes to the target voltage value. The control unit, connected to the acquisition unit and the charge / discharge unit, is used to control the operation of the acquisition unit and the charge / discharge unit.

[0015] A third aspect of this application provides a computer program product comprising a computer program stored in a computer-readable storage medium, the computer program being adapted to be read and executed by a processor to cause a computer device having a processor to perform the aforementioned method.

[0016] A fourth aspect of this application provides a computer device including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the aforementioned method.

[0017] A fifth aspect of this application provides a computer-readable storage medium storing a computer program adapted to be loaded by a processor and to execute the steps of the aforementioned method.

[0018] As can be seen from the above technical solutions, the embodiments of this application have the following advantages: First, the target voltage value set by the user is obtained. The maximum and minimum values ​​among the voltage values ​​of all batteries in the battery pack, collected in real-time, are determined as the current maximum and minimum voltage values, respectively. Then, if the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value, a hybrid voltage adjustment step is executed: batteries with voltage values ​​lower than the target voltage value are charged, and batteries with voltage values ​​higher than the target voltage value are discharged. Finally, until the current minimum voltage value reaches the target voltage value, all batteries are discharged, and the discharge current value of all batteries is adjusted until the discharge current value of all batteries is less than or equal to a preset current threshold, thus stabilizing the voltage value of all batteries to the target voltage value. This application, based on the target voltage value, performs charging operations on batteries with voltage values ​​lower than the target voltage value and discharging operations on batteries with voltage values ​​higher than the target voltage value. By adjusting the discharge current value of the batteries, the voltage value of all batteries is stabilized to the target voltage value. This eliminates individual cell differences, prevents overcharging and over-discharging, improves the charging and discharging capacity of the entire battery pack, enhances the usable capacity and safety of the entire battery pack, and provides a better user experience.

[0019] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a hardware schematic diagram of the voltage control device within the battery pack disclosed in this application. Figure 2 This is a schematic diagram of an embodiment of a battery pack voltage control method disclosed in this application; Figure 3 This is a schematic diagram of an embodiment of a voltage control device for a battery pack disclosed in this application; Figure 4This is a schematic diagram of another embodiment of a voltage control device for a battery pack disclosed in this application.

[0022] The realization of the objectives, functional features and advantages of the embodiments of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] To meet the high-voltage power and power output requirements of vehicles, most existing solutions use series-connected battery packs to power the vehicle and ensure normal vehicle operation. However, in existing solutions, due to differences in the performance and wear of the individual batteries within the pack, voltage differences exist between them. These voltage differences cause the battery pack to reach its upper voltage limit first during charging. To prevent overcharging, charging must be stopped, leaving a significant number of lower-voltage batteries uncharged. Similarly, during discharging, lower-voltage batteries reach their lower voltage limit first, again requiring stopping to prevent over-discharge. Again, a considerable number of higher-voltage batteries remain undischarged, resulting in incomplete discharge of the entire battery pack. This leads to individual battery variations and an inability to guarantee that all batteries maintain a stable voltage at the set value, resulting in low overall charging and discharging capacity. This application performs charging operations on batteries with voltage values ​​lower than the target voltage value and discharging operations on batteries with voltage values ​​higher than the target voltage value. By adjusting the discharge current value of the batteries, the voltage values ​​of all batteries are stabilized to the target voltage value. This can eliminate individual differences, prevent overcharging and over-discharging, and improve the charging and discharging capabilities of the entire battery pack, thereby improving the usable capacity and safety of the entire battery pack and providing users with a better experience.

[0024] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the embodiments of this application, and should not be construed as limiting the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of the embodiments of this application.

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0026] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "first," "second," "third," "fourth," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. These terms are used only to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, as used in this application, are intended to cover non-exclusive inclusion. The term "a plurality" as used in this application refers to two or more. The term "and / or" as used in this application refers to one of the embodiments or any combination of multiple embodiments. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0027] The battery pack voltage control method of this application is described in detail below. Please refer to [link / reference]. Figure 1 The method described in this application relies on a battery pack internal voltage control device, including an LPC54 processing chip, relays, MOSFETs, etc. Please refer to... Figure 2 One embodiment of the battery pack voltage control method of this application includes: 201. Obtain the target voltage value set by the user, and determine the maximum and minimum values ​​among the voltage values ​​of all batteries in the battery pack that are currently collected in real time as the current maximum voltage value and the current minimum voltage value, respectively.

[0028] The type of battery can be selected according to actual needs, and is not specifically limited here. Preferably, lithium iron phosphate batteries can be used. The upper limit of the battery voltage is generally 3.65V, and the lower limit of the battery voltage is generally 2.5V. This battery is a safe, durable, and low-cost mainstream lithium battery. A battery pack composed of multiple such batteries connected in series can be controlled by a circuit loop composed of an LPC54 processing chip, relays, MOSFETs, etc. This embodiment uses lithium iron phosphate batteries as an example. The target voltage value is the voltage value that the user sets for all batteries to reach. If lithium iron phosphate batteries are used, the voltage range of the target voltage value is (2.5V, 3.65V), and the preferred target voltage value is close to the upper limit of the battery voltage. Before making a judgment, the maximum value among all the voltage values ​​corresponding to all batteries in the battery pack is the current maximum voltage value, and the minimum value is the current minimum voltage value. It is understandable that the current maximum voltage value and the current minimum voltage value refer to the voltage value at the time of current acquisition. The two values ​​change over time and are not constant. Before the internal equalization adjustment of charging and discharging, the current maximum voltage value is the maximum value among the initial voltage values ​​of all batteries, and the current minimum voltage value is the minimum value among the initial voltage values ​​of all batteries.

[0029] 202. If the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value, then perform the hybrid voltage adjustment step: charge the battery with a voltage value less than the target voltage value and discharge the battery with a voltage value greater than the target voltage value.

[0030] If the current voltage difference is less than the preset voltage difference threshold, all batteries can be charged. If the voltage value of any battery exceeds the target voltage value during charging, that battery will be discharged. Other batteries whose voltage values ​​are still less than the target voltage value will continue to be charged until the current minimum voltage value reaches the target voltage value. At this time, the voltage values ​​of all batteries are greater than or equal to the target voltage value, but will not exceed the upper limit of the battery voltage.

[0031] Furthermore, to ensure accuracy, the difference between the current maximum voltage value and the current minimum voltage value can be detected first. If it is too large, adjustments can be made, and control can be carried out on the basis of a small voltage difference.

[0032] In other words, the following steps may be included before performing the hybrid voltage adjustment step: Before executing the mixed voltage adjustment step: the difference between the current maximum voltage value and the current minimum voltage value is determined as the current voltage difference; if the current difference is less than the preset voltage difference threshold, the mixed voltage adjustment step is executed; if the current voltage difference is greater than the preset voltage difference threshold, voltage adjustment is performed until the current voltage difference is less than the preset voltage difference threshold, and then the mixed voltage adjustment step is executed.

[0033] The step "Voltage Adjustment" specifically involves first determining any voltage value within a specified voltage range as the specified voltage value. The minimum value of the specified voltage range is the larger of the current minimum voltage value and a preset lower limit battery voltage value. The maximum value of the specified voltage range is less than the sum of the current minimum voltage value and a preset differential voltage threshold. The preset differential voltage threshold is preferably 50mV, but can be other values ​​depending on actual needs; no specific limitation is made here. Specifically, the larger of the current minimum voltage value and the lower limit battery voltage value is chosen as the minimum value of the specified voltage range, while the maximum value of the specified voltage range is less than the sum of the current minimum voltage value and the preset differential voltage threshold. This ensures that the target differential voltage is less than the preset differential voltage threshold, and that the actual battery voltage does not fall below the lower limit battery voltage during charging and discharging. Preferably, the specified voltage value is the minimum value of the specified voltage range, i.e., the larger of the minimum voltage value and the lower limit battery voltage. This embodiment uses the minimum value of the specified voltage range as an example. Then, batteries in the battery pack with voltage values ​​greater than the specified voltage value are discharged. Finally, all batteries in the battery pack are charged after the preset conditions are met.

[0034] There are multiple ways to meet the preset conditions, and specific implementations are not limited here. Three implementations are described below as examples. In the first implementation, the preset condition is that the discharge time of batteries with a voltage value greater than a specified voltage value in the battery pack exceeds a preset time. The preset time can be set according to actual conditions; for example, a preset time of 45 minutes is considered safe and ensures that the voltage difference is less than a preset voltage difference threshold, regardless of how low the voltage of batteries with a voltage value greater than the specified voltage value drops. In the second implementation, the preset condition is that the voltage value of batteries with a voltage value greater than the specified voltage value in the battery pack drops to the specified voltage value after discharge adjustment. Specifically, regardless of the discharge time, it is only required that the voltage value of batteries with a voltage value greater than the specified voltage value drops to the specified voltage value after discharge. In the third implementation, it can be a combination of the first and second implementations; simply put, both the time condition and the condition of dropping to the specified voltage value need to be met simultaneously.

[0035] This embodiment illustrates a second implementation method that meets preset conditions.

[0036] For example, a battery pack contains two lithium iron phosphate batteries with an upper voltage limit of 3.65V and a lower voltage limit of 2.5V. The initial voltage of the first battery is 3.55V, and the initial voltage of the second battery is 3.48V. Therefore, the current maximum voltage is 3.55V, the current minimum voltage is 3.48V, the current voltage difference is 0.07V (70mV), the target voltage is 3.5V, and the preset voltage difference threshold is 50mV. Since the current voltage difference is greater than the preset voltage difference threshold, voltage adjustment is required. If the current minimum voltage value is greater than the battery voltage lower limit, then the current minimum voltage value of 3.48V is specified as the minimum value of the specified voltage range, and the maximum value of the specified voltage range is the sum of the current minimum voltage value and the preset voltage difference threshold, i.e., 3.53V. Therefore, the specified voltage range is (3.48V, 3.53V). Then, the first battery is discharged from 3.55V, for example, to 3.52V. At this point, the current voltage difference is 0.04V (i.e., 40mV), which is less than the preset voltage difference threshold. Therefore, a hybrid voltage adjustment step can be executed: discharging the first battery (current voltage value of 3.52V) and charging the second battery (current voltage value of 3.48V). It should be understood that because this application uses a hybrid voltage adjustment step, when the first battery discharges to below 3.5V, it will switch to a charging operation; when the second battery is charged to above 3.5V, it will switch to a discharging operation. If the current minimum voltage value has not yet reached the target voltage value, the charging operation will continue. Finally, once the voltage values ​​of both batteries reach the target voltage value, discharge both batteries and adjust the discharge current value of all batteries until the discharge current value of all batteries is less than or equal to the preset current threshold, so that the voltage value of all batteries stabilizes at the target voltage value of 3.5V.

[0037] 204. Once the current minimum voltage value reaches the target voltage value, discharge all batteries and adjust the discharge current value of all batteries until the discharge current value of all batteries is less than or equal to the preset current threshold, so that the voltage value of all batteries stabilizes at the target voltage value.

[0038] The step "discharge all batteries and adjust the discharge current of all batteries until the discharge current of all batteries is less than or equal to the preset current threshold" specifically involves the following steps: First, for each battery, based on a preset proportional-integral-derivative (PID) control algorithm, the corresponding duty cycle is determined according to the difference between the current sampled voltage value and the target voltage value. Then, based on pulse width modulation (PWM), the switching transistor in the discharge branch of the battery is controlled to turn on and off according to the duty cycle to discharge the battery. Next, the discharge current value of each battery is calculated, and the battery is adjusted based on the discharge current value to stabilize the battery voltage value at the target voltage value. Specifically, the proportional coefficient, integral coefficient, and derivative coefficient in the PID algorithm are preset coefficients according to actual needs. Substituting the difference between the voltage value and the target voltage value yields the duty cycle of the battery. Then, based on pulse width modulation (PWM), the conduction time of the switching transistor (MOS transistor) in the discharge branch of the battery is adjusted using the duty cycle to discharge the battery. The preset current threshold is preferably 0.5A, but it can also be other values, set according to actual needs; no specific limitation is made here.

[0039] The step "calculate the discharge current value for each battery" specifically involves, for each battery, determining the voltage drop rate as the ratio of the difference between the current acquired voltage value and the target voltage value to the already discharged time period, and determining the predicted voltage value as the ratio of the current acquired voltage value to a specified product, where the specified product is the voltage drop rate value multiplied by a preset discharge time period. Based on a preset relationship between the voltage difference and the discharge current, the corresponding discharge current value is determined according to the difference between the predicted voltage value and the target voltage value. Specifically, based on the current voltage drop rate, it is determined whether the predicted voltage value obtained after the preset discharge time period differs significantly from the target voltage value. If the difference is significant, adjustments are made based on the preset relationship to ensure that the final battery voltage value stabilizes at the target voltage value. The preset relationship can be based on proportional-integral-differential algorithms, etc., and is not limited here.

[0040] The step "adjusting the battery based on the discharge current value to stabilize the battery voltage at the target voltage value" specifically involves the following steps: If the discharge current value is less than or equal to a preset current threshold, the switch in the discharge branch containing the battery is turned off to stop the battery from discharging, thus stabilizing the battery voltage at the target voltage value. If the discharge current value is greater than the preset current threshold, the process returns to step "calculating the discharge current value of each battery" after a preset time period. In simpler terms, if the current discharge current value is very small, i.e., less than or equal to the preset current threshold, it means the actual battery voltage is very close to the target voltage, and the battery voltage is considered to be stable at the target voltage. The corresponding switch is then turned off to stop discharging the battery. If the current discharge current value is large, exceeding the preset current threshold, it means there is still a gap between the actual battery voltage and the target voltage, and discharging continues until it approaches the target voltage. The preset current threshold can be set according to actual needs, preferably 0.5A, but this is not specifically limited here.

[0041] This step is based on adjusting the rate of decrease of the discharge current. The closer to the target voltage value, the smaller the discharge current, which allows the voltage values ​​of all batteries to drop smoothly to the target voltage value under safe conditions.

[0042] In this embodiment, the target voltage value set by the user is first obtained. The maximum and minimum values ​​among the voltage values ​​of all batteries in the battery pack currently collected in real time are determined as the current maximum voltage value and the current minimum voltage value, respectively. Then, if the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value, a hybrid voltage adjustment step is executed: batteries with voltage values ​​less than the target voltage value are charged, and batteries with voltage values ​​greater than the target voltage value are discharged. Finally, until the current minimum voltage value reaches the target voltage value, all batteries are discharged, and the discharge current value of all batteries is adjusted until the discharge current value of all batteries is less than or equal to a preset current threshold, so that the voltage value of all batteries stabilizes at the target voltage value. Based on the target voltage value, this application performs charging operations on batteries with voltage values ​​lower than the target voltage value and discharging operations on batteries with voltage values ​​greater than the target voltage value. By adjusting the discharge current value of the batteries, the voltage value of all batteries is stabilized at the target voltage value. This can eliminate individual differences, prevent overcharging and over-discharging, improve the charging and discharging capacity of the entire battery pack, improve the usable capacity and safety of the entire battery pack, and provide users with a better experience. In addition, this application further ensures safety and accuracy by controlling the current voltage difference within the battery pack to be less than a preset voltage difference threshold, thereby ensuring that the voltage of the battery under different conditions can be adjusted on the basis of a small voltage difference.

[0043] The battery pack voltage control method of this application has been described above; the battery pack voltage control device of this application is described below. Please refer to... Figure 3One embodiment of the battery pack voltage control device of this application includes: The acquisition unit 301 is used to acquire the target voltage value set by the user, and to determine the maximum and minimum values ​​among the voltage values ​​of all batteries in the battery pack that are currently collected in real time as the current maximum voltage value and the current minimum voltage value, respectively. The charging and discharging unit 302 is used to perform a hybrid voltage adjustment step when the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value: charging the battery with a voltage value less than the target voltage value and discharging the battery with a voltage value greater than the target voltage value; The charging and discharging unit 302 is also used to discharge all batteries when the current minimum voltage value reaches the target voltage value, and adjust the discharge current value of all batteries until the discharge current value of all batteries is less than or equal to the preset current threshold, so that the voltage value of all batteries stabilizes to the target voltage value. The control unit 303 is connected to the acquisition unit and the charging / discharging unit and is used to control the operation of the acquisition unit and the charging / discharging unit.

[0044] In this embodiment, the acquisition unit 301 first acquires the target voltage value set by the user, and determines the maximum and minimum values ​​among the voltage values ​​of all batteries in the battery pack currently collected in real time as the current maximum voltage value and the current minimum voltage value, respectively. Then, if the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value, the charging and discharging unit 302 performs a mixed voltage adjustment step: charging the batteries with voltage values ​​less than the target voltage value, discharging the batteries with voltage values ​​greater than the target voltage value, and finally discharging all batteries until the current minimum voltage value reaches the target voltage value, and adjusting the discharge current value of all batteries until the discharge current value of all batteries is less than or equal to the preset current threshold, so that the voltage value of all batteries stabilizes to the target voltage value. This application performs charging operations on batteries with voltage values ​​lower than the target voltage value and discharging operations on batteries with voltage values ​​higher than the target voltage value. By adjusting the discharge current value of the batteries, the voltage values ​​of all batteries are stabilized to the target voltage value. This can eliminate individual differences, prevent overcharging and over-discharging, and improve the charging and discharging capabilities of the entire battery pack, thereby improving the usable capacity and safety of the entire battery pack and providing users with a better experience.

[0045] Based on the above embodiments, another embodiment of the battery pack voltage control device of this application further includes: Furthermore, the charging and discharging unit is specifically used for: For each battery, based on a preset proportional-integral-derivative control algorithm, the corresponding duty cycle is determined according to the difference between the current sampled voltage value and the target voltage value of the battery. Based on pulse width modulation, the switching transistor in the discharge branch where the battery is located is controlled to discharge the battery according to the duty cycle. Calculate the discharge current value of each battery and adjust the battery based on the discharge current value to stabilize the battery voltage value at the target voltage value.

[0046] Furthermore, the charging and discharging unit is specifically used for: For each battery, the ratio of the difference between the current collected voltage value and the target voltage value to the discharged time period is determined as the voltage drop rate value, and the ratio of the current collected voltage value to a specified product is determined as the predicted voltage value. The specified product is the product of the voltage drop rate value and the preset discharge time period. Based on the preset relationship between the voltage difference and the discharge current, the corresponding discharge current value is determined according to the difference between the predicted voltage value and the target voltage value.

[0047] Furthermore, the charging and discharging unit is specifically used for: If the discharge current value is less than or equal to the preset current threshold, the switch in the discharge branch where the battery is located will be turned off to stop the battery from discharging and stabilize the battery voltage value at the target voltage value. If the discharge current value is greater than the preset current threshold, the first target step and subsequent steps will be executed after a preset time period, until the discharge current value is less than or equal to the preset current threshold. The first target step is to determine the voltage drop rate value as the ratio of the difference between the current collected voltage value and the voltage value to the discharged time period for each battery.

[0048] Furthermore, the device also includes a determining unit, which is used for: The difference between the current maximum voltage value and the current minimum voltage value is determined as the current voltage difference; If the current differential pressure is less than the preset differential pressure threshold, then the mixed voltage adjustment step is executed.

[0049] Furthermore, the device also includes a determining unit, which is used for: The difference between the current maximum voltage value and the current minimum voltage value is determined as the current voltage difference; If the current differential pressure is greater than the preset differential pressure threshold, voltage adjustment is performed until the current differential pressure is less than the preset differential pressure threshold, at which point a mixed voltage adjustment step is executed.

[0050] Furthermore, the specific use of the unit is as follows: Any voltage value within a specified voltage range is defined as the specified voltage value. The minimum value of the specified voltage range is the larger of the current minimum voltage value and the preset lower limit of the battery voltage. The maximum value of the specified voltage range is less than the sum of the current minimum voltage value and the preset differential voltage threshold. Discharge batteries in the battery pack whose initial voltage value is greater than the specified voltage value until the preset conditions are met.

[0051] Furthermore, the preset conditions must be met, including: The discharge time of batteries in the battery pack whose initial voltage value is greater than the specified voltage value exceeds the preset time. And / or, The voltage of a battery in the battery pack whose initial voltage value is greater than a specified voltage value drops to the specified voltage value after discharge.

[0052] Furthermore, the preset differential pressure threshold is 50mV, and the preset current threshold is 0.5A.

[0053] The functions and processes performed by each unit in the battery pack balancing device in this embodiment are the same as those described above. Figures 1 to 2 The functions and processes performed by the equalization device within the battery pack are similar, and will not be described in detail here.

[0054] Figure 4 This is a schematic diagram of the structure of a voltage control device in a battery pack according to an embodiment of this application. The voltage control device 400 in the battery pack may include one or more central processing units (CPUs) 401 and a memory 405, wherein the memory 405 stores one or more application programs or data.

[0055] The memory 405 can be volatile or persistent storage. The program stored in the memory 405 can include one or more modules, each module including a series of instruction operations on the voltage control device 400 within the battery pack. Furthermore, the central processing unit 401 can be configured to communicate with the memory 405 and execute the series of instruction operations stored in the memory 405 on the voltage control device 400 within the battery pack.

[0056] The battery pack voltage control device 400 may also include one or more power supplies 402, one or more wired or wireless network interfaces 403, one or more input / output interfaces 404, and / or one or more operating systems, such as Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™, etc.

[0057] The central processing unit 401 can perform the aforementioned... Figures 1 to 2The specific operations performed by the voltage control device within the battery pack in the illustrated embodiment will not be described in detail here.

[0058] This application provides a computer program product, which includes a computer program stored in a computer-readable storage medium. The computer program is adapted to be read and executed by a processor so that a computer device having a processor performs the aforementioned method.

[0059] This application provides a computer device including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the aforementioned method.

[0060] This application also provides a computer-readable storage medium including instructions that, when executed on a computer, cause the computer to perform the methods described in the foregoing embodiments.

[0061] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0062] It should be noted that the user information and data involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0063] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0064] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0065] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for controlling voltage within a battery pack, characterized in that, include: Obtain the target voltage value set by the user, and determine the maximum and minimum values ​​among the voltage values ​​of all batteries in the battery pack that are currently collected in real time as the current maximum voltage value and the current minimum voltage value, respectively; If the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value, then a hybrid voltage adjustment step is performed: charging the battery with a voltage value less than the target voltage value and discharging the battery with a voltage value greater than the target voltage value; Once the current minimum voltage value reaches the target voltage value, all batteries are discharged, and the discharge current value of all batteries is adjusted until the discharge current value of all batteries is less than or equal to the preset current threshold, so that the voltage value of all batteries stabilizes at the target voltage value.

2. The battery pack voltage control method according to claim 1, characterized in that, The step of discharging all batteries and adjusting the discharge current value of all batteries until the discharge current value of all batteries is less than or equal to a preset current threshold includes: For each battery, based on a preset proportional-integral-derivative control algorithm, the corresponding duty cycle is determined according to the difference between the current sampled voltage value of the battery and the target voltage value. Based on pulse width modulation, the switching transistor in the discharge branch where the battery is located is controlled to discharge the battery according to the duty cycle. Calculate the discharge current value of each battery, and adjust the battery based on the discharge current value so that the voltage value of the battery is stabilized at the target voltage value.

3. The battery pack voltage control method according to claim 2, characterized in that, The calculation of the discharge current value for each battery includes: For each battery, the ratio of the difference between the current collected voltage value and the target voltage value to the discharged time period is determined as the voltage drop rate value, and the ratio of the current collected voltage value to a specified product is determined as the predicted voltage value, wherein the specified product is the voltage drop rate value multiplied by a preset discharge time period; based on the preset relationship between the voltage difference and the discharge current, the corresponding discharge current value is determined according to the difference between the predicted voltage value and the target voltage value.

4. The battery pack voltage control method according to claim 3, characterized in that, The step of adjusting the battery based on the discharge current value to stabilize the battery voltage at the target voltage value includes: If the discharge current value is less than or equal to the preset current threshold, the switch in the discharge branch where the battery is located is controlled to be turned off to stop the battery from discharging, so that the voltage value of the battery is stabilized at the target voltage value. If the discharge current value is greater than the preset current threshold, then after a preset time period, return to execute the first target step and its subsequent steps until the discharge current value is less than or equal to the preset current threshold. The first target step is to determine the voltage drop rate value as the ratio of the difference between the current collected voltage value and the voltage value to the discharged time period for each battery.

5. The battery pack voltage control method according to claim 1, characterized in that, Prior to performing the hybrid voltage regulation step, the following is also included: The difference between the current maximum voltage value and the current minimum voltage value is determined as the current voltage difference; If the current differential pressure is less than the preset differential pressure threshold, then the hybrid voltage adjustment step is executed.

6. The battery pack voltage control method according to claim 1, characterized in that, Prior to performing the hybrid voltage regulation step, the following is also included: The difference between the current maximum voltage value and the current minimum voltage value is determined as the current voltage difference; If the current differential pressure is greater than the preset differential pressure threshold, voltage adjustment is performed until the current differential pressure is less than the preset differential pressure threshold, at which point a mixed voltage adjustment step is executed.

7. The battery pack voltage control method according to claim 6, characterized in that, The voltage adjustment includes: Any voltage value within a specified voltage range is defined as the specified voltage value. The minimum value of the specified voltage range is the larger of the current minimum voltage value and the preset lower limit of the battery voltage. The maximum value of the specified voltage range is less than the sum of the current minimum voltage value and the preset differential voltage threshold. Discharge the batteries in the battery pack whose initial voltage value is greater than the specified voltage value until the preset conditions are met.

8. The battery pack voltage control method according to claim 7, characterized in that, The conditions for satisfying the preset conditions include: The discharge time of the battery in the battery pack whose initial voltage value is greater than the specified voltage value exceeds the preset time. And / or, The voltage of the battery in the battery pack whose initial voltage value is greater than the specified voltage value drops to the specified voltage value after discharge.

9. The battery pack voltage control method according to any one of claims 5 to 8, characterized in that, The preset differential pressure threshold is 50mV, and the preset current threshold is 0.5A.

10. A voltage control device within a battery pack, characterized in that, include: The acquisition unit is used to acquire the target voltage value set by the user, and to determine the maximum and minimum values ​​among the voltage values ​​of all batteries in the battery pack that are currently collected in real time as the current maximum voltage value and the current minimum voltage value, respectively. A charging and discharging unit is used to perform a hybrid voltage adjustment step when the current minimum voltage value is less than the target voltage value and the current maximum voltage value is greater than the target voltage value: charging the battery with a voltage value less than the target voltage value and discharging the battery with a voltage value greater than the target voltage value; The charging and discharging unit is also used to discharge all batteries when the current minimum voltage value reaches the target voltage value, and adjust the discharge current value of all batteries until the discharge current value of all batteries is less than or equal to a preset current threshold, so that the voltage value of all batteries stabilizes to the target voltage value. A control unit, connected to the acquisition unit and the charging / discharging unit, is used to control the operation of the acquisition unit and the charging / discharging unit.

11. A computer program product, characterized in that, The computer program product includes a computer program stored in a computer-readable storage medium, the computer program being adapted to be read and executed by a processor to cause a computer device having the processor to perform the method of any one of claims 1 to 9.

12. A computer device, characterized in that, It includes a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the method according to any one of claims 1 to 9.

13. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program adapted to be loaded by a processor and to execute the steps of the method according to any one of claims 1 to 9.

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