Battery discharging method and device, battery management system, storage medium and computer program product

Abstract

The invention relates to the technical field of battery management, and discloses a battery discharging method and device, a battery management system, a storage medium and a computer program product.The method comprises the steps that the current battery temperature and battery coefficients of a battery to be discharged are obtained, and the battery coefficients at least comprise the discharging current coefficient and diffusion activation energy; obtaining the actual safety current of the to-be-discharged battery according to the current battery temperature and the battery coefficient; when the discharge demand sent by the power drive control unit is received, the demand current is determined according to the discharge demand; the required current is compared with the actual safety current of the to-be-discharged battery, and the to-be-discharged battery is controlled to discharge according to the comparison result, so that the actual safety current of the to-be-discharged battery can be obtained according to the current battery temperature and the battery coefficient, and the required current is compared with the actual safety current of the to-be-discharged battery; and controlling the to-be-discharged battery to discharge according to the comparison result, thereby preventing battery over-discharge and ensuring the power performance of the vehicle.

Description

Technical Field

[0001] The present application relates to the field of battery management technology, and in particular to a battery discharging method, device, battery management system, storage medium and computer program product. Background Art

[0002] In modern power systems such as electric vehicles and hybrid vehicles, the power drive control unit has strict requirements on the power output of the battery to ensure the stable operation and power performance of the vehicle. To this end, the power output of the battery can be accurately adjusted by controlling the current of the battery to be discharged to ensure that it meets the real-time power requirements of the power drive control unit.

[0003] In the prior art, when the power of the battery to be discharged is controlled by controlling the current of the battery to be discharged to meet the power demand of the power drive control unit, in order to ensure safety, it is necessary to first calibrate the safe current allowed to be output by the battery to be discharged through the whole vehicle working condition, and the battery to be discharged is allowed to be controlled to discharge with the corresponding current only when the current corresponding to the power demand of the whole vehicle is within the safe current. However, since the battery to be discharged is in some abnormal conditions, such as when the temperature of the battery to be discharged is too low, the actual safe current that the battery to be discharged can withstand will be less than the calibrated safe current. Since the management system of the battery to be discharged performs the discharge operation with reference to the calibrated safe current, there is a situation where the demand current corresponding to the power demand of the power drive control unit is greater than the actual current that the battery to be discharged can withstand but less than the calibrated safe current, resulting in the management system of the battery to be discharged allowing the battery to be discharged, thereby causing over-discharge and shortening the life of the battery to be discharged. Summary of the invention

[0004] The main purpose of the present application is to provide a battery discharging method, device, battery management system, storage medium and computer program product, aiming to solve the problem that the prior art cannot determine the actual safe current of the battery to be discharged according to the real-time working condition of the battery to be discharged, resulting in over-discharge and thus loss of the life of the battery to be discharged.

[0005] To achieve the above object, the present application proposes a battery discharging method, which is applied to a battery management system, wherein the battery management system is connected to a power drive control unit and a battery to be discharged, and the method comprises:

[0006] Acquiring the current battery temperature and battery coefficient of the battery to be discharged, wherein the battery coefficient includes: a discharge current coefficient and a diffusion activation energy;

[0007] Obtaining an actual safe current of the battery to be discharged according to the current battery temperature and the battery coefficient;

[0008] When receiving the discharge requirement sent by the power drive control unit, determining the required current according to the discharge requirement;

[0009] The required current is compared with the actual safe current of the battery to be discharged, and the battery to be discharged is controlled to discharge according to the comparison result.

[0010] In one embodiment, the step of obtaining the actual safe current of the battery to be discharged according to the current battery temperature and the battery coefficient includes:

[0011] Obtaining an ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy;

[0012] The actual safety current of the battery to be discharged is obtained according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient.

[0013] In one embodiment, the diffusion activation energy includes: the diffusion activation energy of the electrolyte of the battery to be discharged, and the discharge current coefficient includes: the discharge current coefficient of the electrolyte of the battery to be discharged;

[0014] The step of obtaining the ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy comprises:

[0015] Obtaining an electrolyte ion diffusion rate of the battery to be discharged according to the current battery temperature and the electrolyte diffusion activation energy;

[0016] The step of obtaining the actual safe current of the battery to be discharged according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient comprises:

[0017] Obtaining an electrolyte safety current of the battery to be discharged according to the electrolyte discharge current coefficient and the electrolyte ion diffusion rate of the battery to be discharged;

[0018] The actual safety current of the battery to be discharged is obtained according to the electrolyte safety current of the battery to be discharged.

[0019] In one embodiment, the diffusion activation energy further includes: the battery positive electrode activation energy and the battery negative electrode activation energy of the battery to be discharged, and the discharge current coefficient further includes: the battery positive electrode discharge current coefficient and the battery negative electrode discharge current coefficient of the battery to be discharged;

[0020] The step of obtaining the ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy further includes:

[0021] Obtaining a battery positive electrode ion diffusion rate of the battery to be discharged according to the current battery temperature and the battery positive electrode diffusion activation energy;

[0022] Obtaining the battery negative electrode ion diffusion rate of the battery to be discharged according to the current battery temperature and the battery negative electrode diffusion activation energy;

[0023] The step of obtaining the actual safe current of the battery to be discharged according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient also includes:

[0024] Obtaining a battery positive electrode safety current of the battery to be discharged according to the battery positive electrode discharge current coefficient and the battery positive electrode ion diffusion rate of the battery to be discharged;

[0025] Obtaining a battery negative electrode safety current of the battery to be discharged according to the battery negative electrode discharge current coefficient and the battery negative electrode ion diffusion rate of the battery to be discharged;

[0026] The actual safety current of the battery to be discharged is obtained based on the battery positive electrode safety current of the battery to be discharged, the battery negative electrode safety current of the battery to be discharged, and the electrolyte safety current of the battery to be discharged.

[0027] In one embodiment, the step of comparing the required current with the actual safe current of the battery to be discharged, and controlling the battery to be discharged to discharge according to the comparison result, includes:

[0028] Comparing the current value of the required current with the current value of the actual safe current of the battery to be discharged;

[0029] When the current value of the required current is not higher than the current value of the actual safety current of the battery to be discharged, the battery to be discharged is controlled to discharge.

[0030] In one embodiment, when the current value of the required current is not higher than the current value of the actual safety current of the battery to be discharged, the step of controlling the battery to be discharged to discharge includes:

[0031] Acquiring the state of charge of the battery to be discharged, and determining the required voltage according to the discharge requirement;

[0032] When the state of charge satisfies a first preset condition, the current battery temperature satisfies a second preset condition, the required voltage satisfies a third preset condition, and the current value of the required current is not higher than the current value of the actual safety current of the battery to be discharged, the battery to be discharged is controlled to discharge.

[0033] In addition, to achieve the above-mentioned purpose, the present application also proposes a battery discharge device, the device comprising:

[0034] A data acquisition module, used to acquire the current battery temperature and battery coefficient of the battery to be discharged, wherein the battery coefficient includes: a discharge current coefficient and a diffusion activation energy;

[0035] A data processing module, used for obtaining an actual safe current of the battery to be discharged according to the current battery temperature and the battery coefficient;

[0036] A demand receiving module, configured to determine a demand current according to a discharge demand when receiving a discharge demand sent by a power drive control unit;

[0037] The discharge control module is used to compare the required current with the actual safe current of the battery to be discharged, and control the battery to be discharged to discharge according to the comparison result.

[0038] In addition, to achieve the above objectives, the present application also proposes a battery management system, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the battery discharging method described above.

[0039] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the battery discharging method described above are implemented.

[0040] In addition, in order to achieve the above-mentioned purpose, the present application also proposes a computer program product, which includes a computer program, and when the computer program is executed by a processor, the steps of the battery discharging method described above are implemented.

[0041] The present application proposes a battery discharging method, device, battery management system, storage medium and computer program product, the method comprising: obtaining the current battery temperature and battery coefficient of a battery to be discharged, the battery coefficient comprising at least: a discharge current coefficient and a diffusion activation energy; obtaining the actual safety current of the battery to be discharged according to the current battery temperature and the battery coefficient; upon receiving a discharge demand sent by a power drive control unit, determining a demand current according to the discharge demand; comparing the demand current with the actual safety current of the battery to be discharged, and controlling the battery to be discharged to discharge according to the comparison result, which means that in the present application, the actual safety current of the battery to be discharged can be obtained according to the current battery temperature and the battery coefficient, and the demand current can be compared with the actual safety current of the battery to be discharged, and the battery to be discharged can be controlled to discharge according to the comparison result, so as to effectively prevent over-discharge of the battery, extend battery life, and ensure the power performance of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0044] Figure 1 This is a flow chart of a first embodiment of the battery discharging method proposed in this embodiment;

[0045] Figure 2 This is a flow chart of a second embodiment of the battery discharging method proposed in this embodiment;

[0046] Figure 3 A diagram of a battery discharge device provided in an embodiment of the present application;

[0047] Figure 4 It is a structural schematic diagram of a battery management system suitable for implementing the embodiment of the present application.

[0048] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0049] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0050] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0051] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0052] It is understandable that in modern power systems such as electric vehicles and hybrid vehicles, the power drive control unit has strict requirements on the power output of the battery to ensure the stable operation and power performance of the vehicle. Therefore, by controlling the current of the battery to be discharged, the power output of the battery can be accurately adjusted to ensure that it meets the real-time power demand of the power drive control unit. This technology not only helps to improve energy utilization efficiency and reduce energy waste, but also prolongs the service life of the battery, while ensuring the reliability and safety of the power system, which is of great significance to promoting the development of new energy vehicle technology.

[0053] In the prior art, when the power of the battery to be discharged is controlled by controlling the current of the battery to be discharged to meet the power demand of the power drive control unit, in order to ensure safety, it is necessary to first calibrate the safe current allowed to be output by the battery to be discharged through the whole vehicle working condition, and the battery to be discharged is allowed to be controlled to discharge with the corresponding current only when the current corresponding to the power demand of the whole vehicle is within the safe current. However, since the battery to be discharged is in some abnormal conditions, such as when the temperature of the battery to be discharged is too low, the actual safe current that the battery to be discharged can withstand will be less than the calibrated safe current. Since the management system of the battery to be discharged performs the discharge operation with reference to the calibrated safe current, there is a situation where the demand current corresponding to the power demand of the power drive control unit is greater than the actual current that the battery to be discharged can withstand but less than the calibrated safe current, resulting in the management system of the battery to be discharged allowing the battery to be discharged, thereby causing over-discharge and shortening the life of the battery to be discharged.

[0054] The following example is used to illustrate that a new energy vehicle is equipped with a lithium battery with a capacity of 100Ah. The nominal voltage of the battery is 3.7V and the discharge rate is 2C, that is, the maximum discharge current is 200A. In the prior art, the battery management system (BMS) may set a fixed maximum discharge current, such as 150A. When the vehicle is driving at high speed, a greater power output is required. At this time, the BMS will control the battery to output a current of 150A according to the vehicle's needs. However, if the ambient temperature is low, such as -20°C, the diffusion rate of lithium ions inside the battery will slow down, resulting in the actual maximum discharge current of the battery being less than 150A. In this case, the battery may be over-discharged, resulting in a shortened battery life.

[0055] Therefore, in order to solve the problem that the prior art cannot determine the actual safety current of the battery to be discharged according to the real-time working condition of the battery to be discharged, resulting in over-discharge and thus loss of the life of the battery to be discharged, the present embodiment proposes a battery discharging method, the method comprising: obtaining the current battery temperature and battery coefficient of the battery to be discharged, the battery coefficient at least comprising: discharge current coefficient and diffusion activation energy; obtaining the actual safety current of the battery to be discharged according to the current battery temperature and the battery coefficient; determining the demand current according to the discharge demand when receiving the discharge demand sent by the power drive control unit; comparing the demand current with the actual safety current of the battery to be discharged, and controlling the battery to be discharged to discharge according to the comparison result. This shows that in the present embodiment, the actual safety current of the battery to be discharged can be obtained according to the current battery temperature and the battery coefficient, and the demand current can be compared with the actual safety current of the battery to be discharged, and the battery to be discharged can be controlled to discharge according to the comparison result, so as to effectively prevent the battery from being over-discharged, extend the battery life, and ensure the power performance of the vehicle.

[0056] For ease of understanding, the following combination Figures 1 to 4 The battery discharging method provided in the embodiment of the present application and the battery discharging method, device, battery management system, storage medium and computer program product provided in the following embodiments are specifically introduced.

[0057] The present application embodiment provides a battery discharging method, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the battery discharging method proposed in this embodiment.

[0058] like Figure 1 As shown, the method includes:

[0059] Step S10: obtaining the current battery temperature and battery coefficient of the battery to be discharged, wherein the battery coefficient includes: discharge current coefficient and diffusion activation energy.

[0060] It should be noted that the execution subject of this embodiment can be a computing service system with battery discharge control, network communication and program running functions, such as a battery management system (Battery Management System, BMS), etc., or an electronic device that can realize the above functions. This embodiment adopts a battery management system (hereinafter referred to as the system), which is equipped on the car as a component of the smart cockpit and can also be applied to other scenarios. This embodiment is illustrated by the battery management system equipped on the car as an example but does not specifically limit this embodiment. The battery management system can be produced by the vehicle itself or installed later, and this embodiment is not limited. In addition, it should be noted that the above system is connected to a power drive unit and a battery to be discharged.

[0061] It should also be noted that the battery to be discharged may be a battery connected to the battery management system for performing functions for an electric vehicle equipped with the battery management system, the current battery temperature may be the temperature of the battery to be discharged collected in real time, and the battery coefficient may be a calibration coefficient obtained when a series of batteries to be discharged are produced based on the basic properties of the batteries to be discharged. In this embodiment, the battery coefficient includes: discharge current coefficient and diffusion activation energy, but this embodiment is not specifically limited.

[0062] At the same time, the above discharge current coefficient can be a parameter describing the relationship between the discharge current and the chemical reaction rate inside the battery, which is used to reflect the sensitivity of the battery to current changes during discharge. The above diffusion activation energy is the energy required for ions inside the battery to move from one side of the electrode to the other side.

[0063] In a specific implementation, the battery management system obtains the real-time temperature value of the battery to be discharged as the current battery temperature through a connected temperature acquisition device or other temperature detection equipment, and retrieves the discharge current coefficient and diffusion activation energy of the battery to be discharged.

[0064] Step S20: obtaining the actual safe current of the battery to be discharged according to the current battery temperature and the battery coefficient.

[0065] It should be noted that the actual safe current of the above-mentioned battery to be discharged may be the maximum current that the above-mentioned battery to be discharged can withstand under the current battery temperature operating conditions. In a specific implementation, the above-mentioned battery management system can obtain the current battery temperature, the discharge current coefficient of the battery to be discharged, and the diffusion activation energy, and obtain the real-time maximum current that the battery to be discharged can withstand through a preset formula.

[0066] It can be understood that since the current of the battery can actually be generated by the diffusion cloud between charged ions in the battery, in this embodiment, the actual safe current of the battery to be discharged can be obtained by the diffusion law of the diffusion rate of ions in the battery to be discharged at a low temperature.

[0067] In order to calculate the diffusion rate and current of the above charged ions at different temperatures, Fick's first law is used in this example:

[0068] Battery current I 扩散 =(D)*A*S=(D0e (-Q0 / RT) )*A*S=I0e (-Q0 / RT) ;

[0069] Among them, A is the maximum volume density gradient, S is the battery cross-sectional area, D0 is the diffusion coefficient constant, and Q0 is the diffusion activation energy. However, this embodiment is not specifically limited.

[0070] Furthermore, in this embodiment, the step of obtaining the actual safe current of the battery to be discharged according to the current battery temperature and the battery coefficient includes:

[0071] Obtaining an ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy;

[0072] The actual safety current of the battery to be discharged is obtained according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient.

[0073] It should be noted that the above diffusion rate can be the rate at which ions inside the battery migrate through the electrode material in the electrochemical reaction. In a specific implementation, the above battery management system first calculates the ion diffusion rate of the battery to be discharged based on the monitored current battery temperature and the obtained diffusion activation energy. Subsequently, the system uses the obtained ion diffusion rate and discharge current coefficient of the battery to be discharged to further determine the actual safe current of the battery to be discharged.

[0074] Step S30: upon receiving the discharge requirement sent by the power drive control unit, determining the required current according to the discharge requirement.

[0075] Step S40: comparing the required current with the actual safe current of the battery to be discharged, and controlling the battery to be discharged to discharge according to the comparison result.

[0076] It should be noted that the above-mentioned discharge demand can be the battery discharge instruction such as the required discharge power or current value issued by the above-mentioned power drive control unit to the battery management system according to the current power demand of the vehicle, and the above-mentioned demand current can be the current that the battery needs to provide calculated based on the discharge demand.

[0077] In a specific implementation, when the battery management system receives the discharge requirement sent by the power drive control unit, the system will immediately obtain the required demand current based on the above discharge requirement, and compare the obtained demand current with the actual safety current of the battery to be discharged determined previously, and control the discharge process of the battery to be discharged according to the comparison result.

[0078] Furthermore, in order to ensure the safety and life of the battery to be discharged, the step of comparing the required current with the actual safety current of the battery to be discharged, and controlling the battery to be discharged to discharge according to the comparison result, includes:

[0079] Comparing the current value of the required current with the current value of the actual safe current of the battery to be discharged;

[0080] When the current value of the required current is not higher than the current value of the actual safety current of the battery to be discharged, the battery to be discharged is controlled to discharge.

[0081] In a specific implementation, the system will obtain the current value of the required demand current according to the discharge demand, and compare the current value of the required current with the current value of the actual safety current of the battery to be discharged determined previously, and control the discharge process of the battery to be discharged according to the comparison result. If the demand current is higher than the actual safety current of the battery to be discharged, the system will not allow discharge or adjust the discharge current to within a safe range to ensure the safe operation of the battery; if the demand current is lower than or equal to the actual safety current of the battery to be discharged, the system will allow the battery to discharge according to the demand current.

[0082] In one example, the BMS monitors the battery temperature in real time. For example, when the battery temperature is -20°C, the BMS calculates the maximum discharge current of the battery, such as 100A, based on the diffusion law. At this time, even if the vehicle requires a higher power output, the BMS will limit the battery discharge current to less than 100A, thereby preventing the battery from over-discharging and protecting the battery life.

[0083] In addition, when the battery temperature returns to normal levels, the BMS will recalculate the maximum discharge current and adjust the battery discharge current according to vehicle needs to ensure the vehicle's power performance.

[0084] This embodiment proposes a battery discharging method, which includes: obtaining a current battery temperature and a battery coefficient of a battery to be discharged, wherein the battery coefficient includes at least a discharge current coefficient and a diffusion activation energy; obtaining an actual safety current of the battery to be discharged according to the current battery temperature and the battery coefficient; determining a demand current according to the discharge demand when a discharge demand sent by a power drive control unit is received; comparing the demand current with the actual safety current of the battery to be discharged, and controlling the battery to be discharged to discharge according to the comparison result. This shows that in this embodiment, the actual safety current of the battery to be discharged can be obtained according to the current battery temperature and the battery coefficient, and the demand current can be compared with the actual safety current of the battery to be discharged, and the battery to be discharged can be controlled to discharge according to the comparison result, thereby effectively preventing over-discharge of the battery, extending the battery life, and ensuring the power performance of the vehicle.

[0085] Based on the first embodiment, in the second embodiment, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be described in detail later. Figure 2 , Figure 2This is a flow chart of a second embodiment of the battery discharging method proposed in this embodiment. Further, the electrolyte diffusion activation energy of the battery to be discharged, the discharge current coefficient includes: the electrolyte discharge current coefficient of the battery to be discharged, and the step of obtaining the ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy includes:

[0086] Step S21: obtaining the electrolyte ion diffusion rate of the battery to be discharged according to the current battery temperature and the electrolyte diffusion activation energy;

[0087] It should be noted that the electrolyte diffusion activation energy may be the energy required for the internal ions of the battery to be discharged to migrate from one end of the battery to the other end through the electrolyte of the battery to be discharged in an electrochemical reaction, and the electrolyte ion diffusion rate of the battery to be discharged may be the rate at which the internal ions of the battery to be discharged migrate through the electrolyte of the battery to be discharged in an electrochemical reaction.

[0088] The step of obtaining the actual safe current of the battery to be discharged according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient comprises:

[0089] Step S22: obtaining the electrolyte safety current of the battery to be discharged according to the electrolyte discharge current coefficient and the electrolyte ion diffusion rate of the battery to be discharged;

[0090] Step S23: obtaining the actual safety current of the battery to be discharged according to the electrolyte safety current of the battery to be discharged.

[0091] It should be noted that the electrolyte safety current of the battery to be discharged may be the maximum current that the electrolyte of the battery to be discharged can withstand under the current battery temperature condition. In a specific implementation, the battery management system calculates the electrolyte ion diffusion rate of the battery to be discharged by monitoring the current battery temperature and the known diffusion activation energy. On this basis, the system further determines the actual safety current of the battery to be discharged in combination with the discharge current coefficient of the electrolyte.

[0092] In this embodiment, the calculation formula of the electrolyte safety current of the battery to be discharged can be obtained by deriving Fick's law as the first preset formula:

[0093] I L =I3e (-Q3 / RT) ;

[0094] Among them, I3 is the electrolyte discharge current coefficient, Q3 is the electrolyte diffusion activation energy, T is the current battery temperature, and R is the battery load.

[0095] Furthermore, in order to more accurately protect the battery to be discharged, in addition to the electrolyte safety current of the battery to be discharged, the positive electrode safety current and negative electrode safety current of the battery to be discharged can also be obtained, and the battery discharge can be more accurately controlled by the electrolyte safety current, positive electrode safety current and negative electrode safety current of the battery to be discharged. Therefore, the diffusion activation energy also includes: the battery positive electrode activation energy and the battery negative electrode activation energy of the battery to be discharged, and the discharge current coefficient also includes: the battery positive electrode discharge current coefficient and the battery negative electrode discharge current coefficient of the battery to be discharged;

[0096] The step of obtaining the ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy further includes:

[0097] Obtaining a battery positive electrode ion diffusion rate of the battery to be discharged according to the current battery temperature and the battery positive electrode diffusion activation energy;

[0098] Obtaining the battery negative electrode ion diffusion rate of the battery to be discharged according to the current battery temperature and the battery negative electrode diffusion activation energy;

[0099] The step of obtaining the actual safe current of the battery to be discharged according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient also includes:

[0100] Obtaining a battery positive electrode safety current of the battery to be discharged according to the battery positive electrode discharge current coefficient and the battery positive electrode ion diffusion rate of the battery to be discharged;

[0101] Obtaining a battery negative electrode safety current of the battery to be discharged according to the battery negative electrode discharge current coefficient and the battery negative electrode ion diffusion rate of the battery to be discharged;

[0102] The actual safety current of the battery to be discharged is obtained based on the battery positive electrode safety current of the battery to be discharged, the battery negative electrode safety current of the battery to be discharged, and the electrolyte safety current of the battery to be discharged.

[0103] It should be noted that the above-mentioned battery positive electrode diffusion activation energy may be the energy required for the internal ions of the above-mentioned battery to be discharged to migrate from one end of the battery to the other end through the battery positive electrode of the above-mentioned battery to be discharged in the electrochemical reaction, and the battery positive electrode ion diffusion rate of the above-mentioned battery to be discharged may be the rate at which the internal ions of the above-mentioned battery to be discharged migrate through the battery positive electrode of the above-mentioned battery to be discharged in the electrochemical reaction. The above-mentioned battery negative electrode diffusion activation energy may be the energy required for the internal ions of the above-mentioned battery to be discharged to migrate from one end of the battery to the other end through the battery negative electrode of the above-mentioned battery to be discharged in the electrochemical reaction, and the battery negative electrode ion diffusion rate of the above-mentioned battery to be discharged may be the rate at which the internal ions of the above-mentioned battery to be discharged migrate through the battery negative electrode of the above-mentioned battery to be discharged in the electrochemical reaction.

[0104] In a specific implementation, the battery management system first calculates the ion diffusion rate of the battery to be discharged at the positive electrode of the battery to be discharged based on the monitored current battery temperature and the diffusion activation energy of the positive electrode of the battery. Next, the system determines the ion diffusion rate of the battery to be discharged at the negative electrode of the battery, also based on the current battery temperature and the diffusion activation energy of the negative electrode of the battery. Subsequently, the system calculates the safe current of the positive electrode of the battery using the discharge current coefficient of the positive electrode of the battery and the ion diffusion rate of the positive electrode battery to be discharged; at the same time, the safe current of the negative electrode of the battery is calculated using the discharge current coefficient of the negative electrode of the battery and the ion diffusion rate of the negative electrode battery to be discharged. Finally, the battery management system determines the actual safe current of the battery to be discharged by combining the safety current of the positive electrode of the battery, the safety current of the negative electrode of the battery, and the safety current of the electrolyte, thereby ensuring the stability and safety of the battery during the discharge process.

[0105] In this embodiment, the calculation formula of the battery positive electrode safety current can be obtained by deriving Fick's law as the second preset formula:

[0106] I + =I1e (-Q1 / RT) ;

[0107] Among them, I1 is the positive electrode discharge current coefficient of the battery, Q1 is the positive electrode diffusion activation energy of the battery, T is the current battery temperature, and R is the battery load.

[0108] In addition, in this embodiment, the calculation formula of the battery negative electrode safety current can be obtained by deriving Fick's law as the third preset formula:

[0109] I - =I2e (-Q2 / RT) ;

[0110] Among them, I2 is the discharge current coefficient of the battery negative electrode, Q2 is the diffusion activation energy of the battery positive electrode, T is the current battery temperature, and R is the battery load.

[0111] In addition, in order to further manage the battery to be discharged in an abnormal state, when the current value of the demand current is not higher than the current value of the actual safety current of the battery to be discharged, the step of controlling the battery to be discharged to discharge includes:

[0112] Acquiring the state of charge of the battery to be discharged, and determining the required voltage according to the discharge requirement;

[0113] When the state of charge satisfies a first preset condition, the current battery temperature satisfies a second preset condition, the required voltage satisfies a third preset condition, and the current value of the required current is not higher than the current value of the actual safety current of the battery to be discharged, the battery to be discharged is controlled to discharge.

[0114] It should be noted that the above-mentioned state of charge can be the ratio of the current remaining capacity of the battery to its total capacity when it is fully charged, the above-mentioned required voltage can be the voltage required by the above-mentioned power control unit to meet the power of the entire vehicle, and the above-mentioned first preset condition can be one of a series of conditions pre-set by the user, which can be a state of charge interval or some state of charge thresholds for judging whether the state of charge of the battery is within the range suitable for discharge. The above-mentioned second preset condition can refer to a safety range pre-set by the user for the battery temperature to ensure that the battery will not be damaged or its performance will not degrade due to excessively high or low temperatures during discharge. The above-mentioned third preset condition can be a condition pre-set by the user for the required voltage to ensure that the battery can provide a voltage level that meets the requirements of the power drive control unit during discharge, while not exceeding the design limit of the battery.

[0115] In a specific implementation, the battery management system first obtains the state of charge of the battery to be discharged, and calculates the required voltage according to the discharge demand of the power drive control unit. The battery management system will control the battery to be discharged to discharge only when the state of charge meets the first preset condition, the current battery temperature meets the second preset condition, the required voltage meets the third preset condition, and the current value of the required current is not higher than the current value of the actual safe current of the battery to be discharged, so as to ensure the safety and efficiency of the battery during the discharge process.

[0116] The following example is used to illustrate, but does not specifically limit this embodiment. Assume that the first preset condition is the highest state of charge SOC min , maximum state of charge SOC max ; The second preset condition is: the lowest current temperature T min , the highest current temperature T max ; Minimum required voltage V min , the maximum required voltage V max ;Minimum required current I min , maximum required current Imax When the battery state of charge SOC, battery temperature T, battery voltage V, PDCU command battery current I, meet SOC min <SOC<SOC max ; T min <T<T max ; V min <V<V max ;I min <I<I max When the discharge is performed.

[0117] This embodiment also provides a battery discharge device, please refer to Figure 3 , Figure 3 A diagram of a battery discharge device provided in an embodiment of the present application, wherein the battery discharge device comprises:

[0118] A data acquisition module, used to acquire the current battery temperature and battery coefficient of the battery to be discharged, wherein the battery coefficient includes: a discharge current coefficient and a diffusion activation energy;

[0119] A data processing module, used for obtaining an actual safe current of the battery to be discharged according to the current battery temperature and the battery coefficient;

[0120] A demand receiving module, configured to determine a demand current according to a discharge demand when receiving a discharge demand sent by a power drive control unit;

[0121] The discharge control module is used to compare the required current with the actual safe current of the battery to be discharged, and control the battery to be discharged to discharge according to the comparison result.

[0122] The data processing module is further used to obtain the ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy, and to obtain the actual safe current of the battery to be discharged according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient.

[0123] The data processing module is further used to obtain the electrolyte ion diffusion rate of the battery to be discharged according to the current battery temperature and the electrolyte diffusion activation energy, and to obtain the electrolyte safety current of the battery to be discharged according to the electrolyte discharge current coefficient and the electrolyte ion diffusion rate of the battery to be discharged; and to obtain the actual safety current of the battery to be discharged according to the electrolyte safety current of the battery to be discharged.

[0124] The data processing module is further used to obtain the battery positive electrode ion diffusion rate of the battery to be discharged according to the current battery temperature and the battery positive electrode diffusion activation energy; obtain the battery negative electrode ion diffusion rate of the battery to be discharged according to the current battery temperature and the battery negative electrode diffusion activation energy; obtain the battery positive electrode safety current of the battery to be discharged according to the battery positive electrode discharge current coefficient and the battery positive electrode ion diffusion rate of the battery to be discharged; obtain the battery negative electrode safety current of the battery to be discharged according to the battery negative electrode discharge current coefficient and the battery negative electrode ion diffusion rate of the battery to be discharged; and obtain the actual safety current of the battery to be discharged based on the battery positive electrode safety current of the battery to be discharged, the battery negative electrode safety current of the battery to be discharged, and the electrolyte safety current of the battery to be discharged.

[0125] The discharge control module is further used to compare the current value of the required current with the current value of the actual safety current of the battery to be discharged; when the current value of the required current is not higher than the current value of the actual safety current of the battery to be discharged, control the battery to be discharged to discharge.

[0126] The discharge control module is further used to obtain the state of charge of the battery to be discharged, and determine the required voltage according to the discharge demand; when the state of charge meets the first preset condition, the current battery temperature meets the second preset condition, the required voltage meets the third preset condition, and the current value of the required current is not higher than the current value of the actual safe current of the battery to be discharged, control the battery to be discharged to discharge.

[0127] The battery discharge device provided in this embodiment adopts the battery discharge method in the above embodiment, which can solve the problem that the prior art cannot determine the actual safe current of the battery to be discharged according to the real-time working condition of the battery to be discharged, resulting in over-discharge and loss of the life of the battery to be discharged. Compared with the prior art, the beneficial effects of the battery discharge device provided in this embodiment are the same as the beneficial effects of the battery discharge method provided in the above embodiment, and other technical features in the battery discharge device are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0128] This embodiment provides a battery management system, which includes: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the battery discharging method in the above-mentioned embodiment 1.

[0129] Reference below Figure 4 , Figure 4The battery management system in the embodiment of the present application may include but is not limited to mobile terminals such as mobile phones, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), battery management systems, etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 4 The battery management system shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0130] like Figure 4 As shown, the battery management system may include a processing device 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM: Read Only Memory) 1002 or a program loaded from a storage device 1003 to a random access memory (RAM: Random Access Memory) 1004. In RAM1004, various programs and data required for the operation of the battery management system are also stored. The processing device 1001, ROM1002, and RAM1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Generally, the following systems can be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD: Liquid Crystal Display), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 can allow the battery management system to communicate wirelessly or wired with other battery management systems to exchange data. Although the figure shows a battery management system with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems can be implemented or have alternatively.

[0131] In particular, according to the present embodiment, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the present embodiment includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through a communication device, or installed from the storage device 1003, or installed from the ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present embodiment are executed.

[0132] The battery management system provided in this embodiment adopts the battery discharging method in the above embodiment, which can solve the problem that the prior art cannot determine the actual safe current of the battery to be discharged according to the real-time working condition of the battery to be discharged, resulting in over-discharging and thus loss of the life of the battery to be discharged. Compared with the prior art, the beneficial effects of the battery management system provided in this embodiment are the same as the beneficial effects of the battery discharging method provided in the above embodiment, and other technical features in the battery management system are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0133] It should be understood that the various parts disclosed in this embodiment can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0134] The above is only a specific implementation of this embodiment, but the protection scope of this embodiment is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in this embodiment, which should be included in the protection scope of this embodiment. Therefore, the protection scope of this embodiment should be based on the protection scope of the claims.

[0135] This embodiment provides a computer-readable storage medium having computer-readable program instructions (ie, computer programs) stored thereon, and the computer-readable program instructions are used to execute the battery discharging method in the above embodiment.

[0136] The computer-readable storage medium provided in this embodiment may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM: Random Access Memory), a read-only memory (ROM: Read Only Memory), an erasable programmable read-only memory (EPROM: Erasable Programmable Read Only Memory or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM: CD-Read Only Memory), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency: Radio Frequency), etc., or any suitable combination of the above.

[0137] The computer-readable storage medium may be included in the device; or may exist independently without being installed in the device.

[0138] The computer-readable storage medium carries one or more programs. When the one or more programs are executed by the device, the device: discharges the battery.

[0139] The computer program code for performing the operation of the present embodiment can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0140] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present embodiment. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0141] The modules involved in the description of this embodiment may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0142] The readable storage medium provided in this embodiment is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned battery discharging method, and can solve the problem that the prior art cannot determine the actual safe current of the battery to be discharged according to the real-time working condition of the battery to be discharged, resulting in over-discharging and thus loss of the life of the battery to be discharged. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this embodiment are the same as the beneficial effects of the battery discharging method provided in the above-mentioned embodiment, and will not be repeated here.

[0143] The above descriptions are only some embodiments, and are not intended to limit the patent scope of this embodiment. All equivalent structural changes made using the contents of the specification and drawings of this application under the technical concept of this application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of this application.

Claims

1. A battery discharging method, characterized in that: The method is applied to a battery management system, wherein the battery management system is connected to a power drive control unit and a battery to be discharged, and the method comprises: Acquiring the current battery temperature and battery coefficient of the battery to be discharged, wherein the battery coefficient includes: a discharge current coefficient and a diffusion activation energy; Obtaining an actual safe current of the battery to be discharged according to the current battery temperature and the battery coefficient; When receiving the discharge requirement sent by the power drive control unit, determining the required current according to the discharge requirement; The required current is compared with the actual safe current of the battery to be discharged, and the battery to be discharged is controlled to discharge according to the comparison result.

2. The method according to claim 1, characterized in that The step of obtaining the actual safe current of the battery to be discharged according to the current battery temperature and the battery coefficient includes: Obtaining an ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy; The actual safety current of the battery to be discharged is obtained according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient.

3. The method according to claim 2, characterized in that The diffusion activation energy includes: the diffusion activation energy of the electrolyte of the battery to be discharged, and the discharge current coefficient includes: the discharge current coefficient of the electrolyte of the battery to be discharged; The step of obtaining the ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy comprises: Obtaining an electrolyte ion diffusion rate of the battery to be discharged according to the current battery temperature and the electrolyte diffusion activation energy; The step of obtaining the actual safe current of the battery to be discharged according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient comprises: Obtaining an electrolyte safety current of the battery to be discharged according to the electrolyte discharge current coefficient and the electrolyte ion diffusion rate of the battery to be discharged; The actual safety current of the battery to be discharged is obtained according to the electrolyte safety current of the battery to be discharged.

4. The method according to claim 3, characterized in that The diffusion activation energy also includes: the battery positive electrode activation energy and the battery negative electrode activation energy of the battery to be discharged, and the discharge current coefficient also includes: the battery positive electrode discharge current coefficient and the battery negative electrode discharge current coefficient of the battery to be discharged; The step of obtaining the ion diffusion rate of the battery to be discharged based on the current battery temperature and the diffusion activation energy further includes: Obtaining a battery positive electrode ion diffusion rate of the battery to be discharged according to the current battery temperature and the battery positive electrode diffusion activation energy; Obtaining the battery negative electrode ion diffusion rate of the battery to be discharged according to the current battery temperature and the battery negative electrode diffusion activation energy; The step of obtaining the actual safe current of the battery to be discharged according to the ion diffusion rate of the battery to be discharged and the discharge current coefficient also includes: Obtaining a battery positive electrode safety current of the battery to be discharged according to the battery positive electrode discharge current coefficient and the battery positive electrode ion diffusion rate of the battery to be discharged; Obtaining a battery negative electrode safety current of the battery to be discharged according to the battery negative electrode discharge current coefficient and the battery negative electrode ion diffusion rate of the battery to be discharged; The actual safety current of the battery to be discharged is obtained based on the battery positive electrode safety current of the battery to be discharged, the battery negative electrode safety current of the battery to be discharged, and the electrolyte safety current of the battery to be discharged.

5. The method according to any one of claims 1 to 4, characterized in that The step of comparing the required current with the actual safe current of the battery to be discharged, and controlling the battery to be discharged to discharge according to the comparison result, comprises: Comparing the current value of the required current with the current value of the actual safe current of the battery to be discharged; When the current value of the required current is not higher than the current value of the actual safety current of the battery to be discharged, the battery to be discharged is controlled to discharge.

6. The method according to claim 5, characterized in that The step of controlling the battery to be discharged to discharge when the current value of the demand current is not higher than the current value of the actual safety current of the battery to be discharged comprises: Acquiring the state of charge of the battery to be discharged, and determining the required voltage according to the discharge requirement; When the state of charge satisfies a first preset condition, the current battery temperature satisfies a second preset condition, the required voltage satisfies a third preset condition, and the current value of the required current is not higher than the current value of the actual safety current of the battery to be discharged, the battery to be discharged is controlled to discharge.

7. A battery discharge device, characterized in that: The device comprises: A data acquisition module, used to acquire the current battery temperature and battery coefficient of the battery to be discharged, wherein the battery coefficient includes: a discharge current coefficient and a diffusion activation energy; A data processing module, used for obtaining an actual safe current of the battery to be discharged according to the current battery temperature and the battery coefficient; A demand receiving module, configured to determine a demand current according to a discharge demand when receiving a discharge demand sent by a power drive control unit; The discharge control module is used to compare the required current with the actual safe current of the battery to be discharged, and control the battery to be discharged to discharge according to the comparison result.

8. A battery management system, characterized in that: The system comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the battery discharging method according to any one of claims 1 to 6.

9. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the battery discharging method according to any one of claims 1 to 6 are implemented.

10. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the steps of the battery discharging method according to any one of claims 1 to 6 are implemented.

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