Battery Management System

Abstract

The present application discloses a battery management system, which includes: a battery module, a current sampling circuit, a first resistor, an analog front-end circuit, a relay driving circuit, a control module, and a charge and discharge circuit. The current sampling circuit is used to detect the operating current of the first resistor; the analog front-end circuit is used to collect a plurality of operating parameters of the battery module at the current moment when the operating current does not meet the preset conditions; the control module is used to determine the target operating state of the battery module according to the plurality of operating parameters; when the target operating state is an abnormal state, a control instruction corresponding to the target operating state is generated, and the control instruction is used to control the relay to be closed or opened. By adopting the embodiment of the present application, the safety of battery use can be improved under the condition of large current charge and discharge.

Description

Technical Field

[0001] This application relates to the technical field of battery management, and particularly to a battery management system. Background Art

[0002] In a battery management system, a diode is often used to control the charging and discharging circuit of a battery. However, during the charging and discharging operations of the battery, especially in the case of high-current charging and discharging, the high loss of the diode will generate a large amount of heat. If the heat dissipation condition is not good, the junction temperature of the diode will rise rapidly. The too high junction temperature will affect the performance and lifespan of the diode, and even cause damage to the diode, and further affect the safety of battery use. Therefore, the problem of how to improve the safety of battery use under the condition of high-current charging and discharging needs to be solved urgently. Summary of the Invention

[0003] An embodiment of this application provides a battery management system, which can improve the safety of battery use under the condition of high-current charging and discharging.

[0004] In a first aspect, an embodiment of this application provides a battery management system, which includes: a battery module, a current sampling circuit, a first resistor, an analog front-end circuit, a relay drive circuit, a control module, and a charging and discharging circuit. The charging and discharging circuit includes a relay, a discharge freewheeling circuit, and a charging freewheeling circuit, where:

[0005] The first end of the battery module is connected to the first end of the control module, the second end of the battery module is connected to the first end of the analog front-end circuit, and the third end of the battery module is connected to the second end of the first resistor; the second end of the first resistor is further connected to the fourth end of the current sampling circuit, and the first end of the first resistor is respectively connected to the third end of the current sampling circuit and the third end of the charging and discharging circuit; the first end of the current sampling circuit is connected to the fifth end of the analog front-end circuit, and the second end of the current sampling circuit is connected to the fourth end of the analog front-end circuit; the second end of the analog front-end circuit is connected to the third end of the control module, and the third end of the analog front-end circuit is connected to the first end of the charging and discharging circuit; the second end of the charging and discharging circuit is connected to the second end of the relay drive circuit; the second end of the control module is connected to the first end of the relay drive circuit;

[0006] The current sampling circuit is configured to detect the working current of the first resistor;

[0007] The analog front-end circuit is configured to collect the working parameters of the battery module at the current moment when the working current does not meet the preset condition, and obtain a plurality of working parameters;

[0008] The control module is configured to determine the target working state of the battery module according to the plurality of working parameters;

[0009] When the target operating state is a discharge anomaly state, generate a first control instruction corresponding to the target operating state. The first control instruction is used to control the relay and the discharge freewheeling circuit to disconnect to control the battery module to stop discharging, and to control the charge freewheeling circuit to conduct.

[0010] When the target operating state is a charge anomaly state, generate a second control instruction corresponding to the target operating state. The second control instruction is used to control the relay and the charge freewheeling circuit to disconnect to control the battery module to stop charging, and to control the discharge freewheeling circuit to conduct.

[0011] Through the battery management system provided by the embodiments of the present application, by detecting the operating current of the first resistor, when the operating current does not meet the preset conditions (such as too large or too small current), further collect various operating parameters of the battery module to obtain a plurality of operating parameters, and judge the operating state of the battery module according to these plurality of operating parameters. Once it is found that the operating state of the battery module is abnormal, the control module generates a corresponding control instruction to control the relay and the discharge freewheeling circuit (charge freewheeling circuit) to disconnect, and stop the battery from discharging or charging. Thus, in the case of large current charging and discharging, the safety of battery use is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background art, the following will describe the drawings required to be used in the embodiments of the present application or the background art.

[0013] Figure 1 is a circuit block diagram of a battery management system provided by an embodiment of the present application;

[0014] Figure 2 is a circuit block diagram of another battery management system provided by an embodiment of the present application;

[0015] Figure 3 is a circuit diagram of a charge and discharge circuit provided by an embodiment of the present application;

[0016] Figure 4 is a circuit diagram of another charge and discharge circuit provided by an embodiment of the present application;

[0017] Figure 5 is a circuit diagram of yet another charge and discharge circuit provided by an embodiment of the present application;

[0018] Figure 6 is a flowchart of a battery management method provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] To enable those skilled in the art to better understand the solution of this application, the following will clearly and completely describe the technical solutions in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0020] The terms "first", "second", etc. in the specification, claims and above-mentioned accompanying drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0021] It should be understood that the term "and / or" in this article is only a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article indicates that the associated objects before and after are in an "or" relationship. The "multiple" mentioned in the embodiments of this application means two or more.

[0022] The "connection" that appears in the embodiments of this application refers to various connection methods such as direct connection or indirect connection to achieve communication between devices. This application does not make any limitations on this.

[0023] Referring to "embodiment" in this article means that the specific features, structures or characteristics described in combination with the embodiment can be included in at least one embodiment of this application. The appearance of this phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0024] In all the accompanying drawings of this application, the letters near the module (circuit) connection lines represent port numbers (the port numbers are represented in alphabetical order). For example, Figure 1 the letter a on the upper side of the battery module represents the first end of the battery module, and the letter b on the right side of the battery module represents the second end of the battery module, and so on.

[0025] The following will explain some professional terms involved in this application:

[0026] Duty cycle: The duty cycle is equal to the high-level time divided by the total cycle time. Here, the high-level time refers to the duration of the high level in a complete positive pulse sequence; the total cycle time refers to the total time of a complete positive pulse sequence.

[0027] PWM control algorithm: The English abbreviation of the Pulse Width Modulation control algorithm. It is a technology that adjusts the duty cycle by changing the pulse width at a fixed switching frequency. The basic principle of PWM control is to use an oscillator with a fixed frequency to generate a periodic pulse signal, and then compare this pulse signal with a reference voltage through a comparator to generate a square wave signal with an adjustable duty cycle. The duty cycle of this square wave signal determines the conduction time of the switching transistor, thereby achieving the control of the output voltage or power of the control circuit.

[0028] Please refer to Figure 1 , Figure 1 Figure

[0029] is a circuit block diagram of a battery management system provided by an embodiment of the present application. The system includes: a battery module C1, a current sampling circuit, a first resistor R1, an analog front-end circuit, a relay drive circuit, a control module, and a charge and discharge circuit. The charge and discharge circuit includes a relay K1, a discharge freewheeling circuit, and a charge freewheeling circuit, where:

[0030] It should be explained that B+ in the figure represents the positive electrode of the battery module C1, B- represents the negative electrode of the battery module C1, P+ represents the output positive electrode of the battery management system, and P- represents the output negative electrode of the battery management system.

[0031] The current sampling circuit is used to detect the working current of the first resistor R1. Specifically, since the current sampling circuit is connected to both ends of the first resistor R1, when the battery module C1 is charged and discharged, current will flow through the first resistor R1. The current sampling circuit can measure the voltage drop across the first resistor R1, and then, according to Ohm's law, divide the voltage drop by the resistance value of the first resistor R1 to obtain the working current of the first resistor R1;

[0032] The analog front-end circuit is used to collect the operating parameters of the battery module C1 at the current moment when the operating current does not meet the preset conditions, and obtain multiple operating parameters. It should be noted that the preset conditions can be preset in advance or by default, and are used to determine whether the operating current is within the normal range. When the operating current does not meet the preset conditions, it means that the operating current is not within the normal range, and there may be an abnormality in the battery management system. At this time, the analog front-end circuit can collect the operating parameters of the battery module C1 at the current moment to obtain multiple operating parameters.

[0033] In one embodiment, the analog front-end circuit may include at least one of the following: a temperature detection circuit, a voltage (current) sampling circuit, a voltage equalization circuit, etc., which are not limited herein.

[0034] The control module is used to determine the target operating state of the battery module C1 according to multiple operating parameters. The control module may include at least one of the following: a microcontroller (MCU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), etc., which are not limited herein.

[0035] In one embodiment, the battery module C1 includes at least one battery. The battery type of the at least one battery includes one of the following: lithium iron phosphate battery, lithium manganese iron phosphate battery, lithium cobalt oxide battery, lithium manganese oxide battery, lithium nickel cobalt aluminum oxide battery, lithium titanate battery, lead-acid battery, nickel-cadmium battery, nickel-metal hydride battery, etc., which are not limited herein.

[0036] The voltage range of each battery in the at least one battery can be 2V - 5V, and the voltage range of the battery module C1 can be 2V - 500V.

[0037] Please refer to Figure 2 , Figure 2 FIG. is a circuit block diagram of another battery management system provided by an embodiment of the present application. The system includes: a battery module C1, a current sampling circuit, a first resistor R1, an analog front-end circuit, a relay drive circuit, a control module, a charge and discharge circuit. The charge and discharge circuit includes a relay K1, a discharge freewheeling circuit, a charge freewheeling circuit, as well as a wake-up circuit and a three-terminal fuse, where:

[0038] The first end of the battery module C1 is connected to the first end of the control module, the second end of the battery module C1 is connected to the first end of the analog front-end circuit, and the third end of the battery module C1 is connected to the second end of the first resistor R1; the second end of the first resistor R1 is also connected to the fourth end of the current sampling circuit, and the first end of the first resistor R1 is respectively connected to the third end of the current sampling circuit and the third end of the charge and discharge circuit; the first end of the current sampling circuit is connected to the fifth end of the analog front-end circuit, and the second end of the current sampling circuit is connected to the fourth end of the analog front-end circuit; the second end of the analog front-end circuit is connected to the third end of the control module, and the third end of the analog front-end circuit is connected to the first end of the charge and discharge circuit; the second end of the charge and discharge circuit is connected to the second end of the relay drive circuit; the second end of the control module is connected to the first end of the relay drive circuit;

[0039] The first end of the three-terminal fuse is connected to the first end of the wake-up circuit, the second end of the three-terminal fuse is respectively connected to the third end of the control module and the second end of the analog front-end circuit, and the third end of the three-terminal fuse is connected to the first end of the battery module C1; the second end of the wake-up circuit is connected to the first end of the control module;

[0040] The wake-up circuit is used to wake up the system when the system meets a preset trigger condition. For example, the wake-up circuit can be a power monitoring type wake-up circuit. This kind of circuit is usually used to monitor the power supply (i.e., the battery module C1) state of the system. When the battery module C1 drops to a certain threshold (such as a low battery state), the wake-up circuit will trigger a signal, and this signal can be used to wake up the system, so that the system enters a low-power mode or prompts the user to charge.

[0041] The three-terminal fuse is used to actively fuse when an abnormal situation occurs in the system to cut off the circuit and prevent the battery module C1 from being damaged; the abnormal situation includes at least one of the following: the system is short-circuited, the system is overloaded, and the relay K1 is sintered.

[0042] In one embodiment, please refer to Figure 3 , Figure 3 is the circuit diagram of a charge and discharge circuit provided by an embodiment of the present application, as Figure 3The charging and discharging circuit shown only includes a relay K1 and a discharging freewheeling circuit. The discharging freewheeling circuit includes: a first MOS transistor Q1 and a first diode D1; wherein: the drain of the first MOS transistor Q1 is connected to the negative electrode of the first diode D1, and the source of the first MOS transistor Q1 is connected to the second terminal of the relay K1; the first terminal of the relay K1 is connected to the positive electrode of the first diode D1; the source of the first MOS transistor Q1 serves as the first terminal of the charging and discharging circuit and is connected to the third terminal of the analog front-end circuit, the first terminal of the relay K1 serves as the second terminal of the charging and discharging circuit and is connected to the second terminal of the relay driving circuit, and the second terminal of the relay K1 serves as the third terminal of the charging and discharging circuit and is connected to the first terminal of a first resistor R1.

[0043] The MOS transistor type of the first MOS transistor can be any one of FET (field effect transistor), JFET (junction field effect transistor), BJT (bipolar junction transistor), CMOS (complementary metal oxide semiconductor), VMOS (vertical channel metal oxide semiconductor field effect transistor), TMOS (improved metal oxide semiconductor field effect transistor), vertical DMOS (vertical double-diffused metal oxide semiconductor field effect transistor), and HEXFET (hexagonal field effect transistor).

[0044] In an embodiment, the analog front-end circuit can also be connected to a charging freewheeling circuit. After being connected to the charging freewheeling circuit, the analog front-end circuit can better track the changes in the charging current and voltage in the charging freewheeling circuit. For example, through a high-precision analog-to-digital converter in the analog front-end circuit, the charging voltage and current signals including the freewheeling stage can be obtained in real time, so as to accurately judge the charging state of the battery module C1, such as judging whether the battery is in the constant current charging, constant voltage charging stage or whether it is fully charged.

[0045] In an embodiment, please refer to Figure 4 , Figure 4 is the circuit diagram of another charging and discharging circuit provided by the embodiment of the present application. As Figure 4 shown, the charging and discharging circuit in addition to including the relay K1 and the discharging freewheeling circuit, also includes a charging freewheeling circuit. The charging freewheeling circuit includes: a second MOS transistor Q2 and a second diode D2; wherein: the positive electrode of the second diode D2 is connected to the source of the first MOS transistor Q1, and the negative electrode of the second diode D2 is connected to the drain of the second MOS transistor Q2; the source of the second MOS transistor Q2 is connected to the positive electrode of the first diode D1.

[0046] The MOS transistor type of the second MOS transistor can be any one of FET (Field Effect Transistor), JFET (Junction Field Effect Transistor), BJT (Bipolar Junction Transistor), CMOS (Complementary Metal Oxide Semiconductor), VMOS (Vertical Channel Metal Oxide Semiconductor Field Effect Transistor), TMOS (Improved Metal Oxide Semiconductor Field Effect Transistor), Vertical DMOS (Vertical Double Diffused Metal Oxide Semiconductor Field Effect Transistor), and HEXFET (Hexagonal Field Effect Transistor).

[0047] In one embodiment, please refer to Figure 5 , Figure 5 which is the circuit diagram of another charge and discharge circuit provided by the embodiment of the present application. As shown in Figure 3 the charge and discharge circuit only includes a relay K1 and a charge and discharge freewheeling circuit. The charge and discharge freewheeling circuit includes: a second MOS transistor Q2 and a second diode D2; where: the positive electrode of the second diode D2 is connected to the second end of the relay K1, and the negative electrode of the second diode D2 is connected to the drain of the second MOS transistor Q2; the source of the second MOS transistor Q2 is connected to the first end of the relay K1.

[0048] It should be explained that, as shown in Figure 1 the first resistor R1 and the charge and discharge circuit can be arranged at the negative electrode of the battery module C1. Both the first MOS transistor Q1 and the second MOS transistor Q2 can be NMOS (N-type Metal Oxide Semiconductor). Or, in one embodiment, the first resistor R1 and the charge and discharge circuit can be arranged at the positive electrode of the battery module C1, and the connection relationship of other components of the system remains unchanged. Both the first MOS transistor Q1 and the second MOS transistor Q2 can be PMOS (P-type Metal Oxide Semiconductor).

[0049] In one embodiment, when the battery management system is in a normal state, charge and discharge control can be performed through the relay. For example, when the battery module C1 needs to discharge, the relay is disconnected, and the discharge freewheeling circuit is turned on. The current flows through the first diode D1, the first MOS transistor Q1, and the first resistor R1 in sequence to form a discharge loop. Also, for example, when the battery module C1 needs to be charged, the relay is disconnected, and the charge and discharge freewheeling circuit is turned on. The current flows through the first resistor R1, the second diode D2, and the second MOS transistor Q2 in sequence to form a charging loop.

[0050] It should be explained that in the application scenario of large current, the charge and discharge freewheeling circuit can also adopt the method of parallel connection of multiple pairs of MOS and diodes, and is not limited to the method of only using a pair of MOS and diodes in parallel.

[0051] In one embodiment, the multiple operating parameters include: a first temperature parameter, a first voltage parameter, a first current parameter, and a first current flow direction. In terms of determining the target operating state of the battery module based on the multiple operating parameters, the control module is specifically configured to perform the following steps:

[0052] A1. Determine the target battery operating condition of the battery module according to the first current flow direction; the target battery operating condition includes a discharge condition or a charge condition;

[0053] A2. Obtain the target battery type corresponding to the battery module;

[0054] A3. Determine the reference operating temperature parameter corresponding to the target battery type;

[0055] A4. When the target battery operating condition includes the discharge condition, determine the reference discharge voltage parameter threshold and the reference discharge current parameter threshold corresponding to the target battery type;

[0056] A5. Obtain the target usage duration corresponding to the battery module;

[0057] A6. Determine the first influence coefficient corresponding to the target usage duration;

[0058] A7. Determine the difference between the first temperature parameter and the reference operating temperature parameter to obtain a first temperature difference;

[0059] A8. Determine the second influence coefficient corresponding to the first temperature difference;

[0060] A9. Adjust the reference discharge voltage parameter threshold according to the first influence coefficient and the second influence coefficient to obtain the target discharge voltage parameter threshold;

[0061] A10. Adjust the reference discharge current parameter threshold according to the first influence coefficient and the second influence coefficient to obtain the target discharge current parameter threshold;

[0062] A11. When the first voltage parameter is not greater than the target discharge voltage parameter threshold and the first current parameter is not greater than the target discharge current parameter threshold, determine that the target operating state is a normal state;

[0063] A12. When the first voltage parameter is greater than the target discharge voltage parameter threshold and / or the first current parameter is greater than the target discharge current parameter threshold, determine that the target operating state is the discharge abnormal state.

[0064] In the embodiments of the present application, the target battery type may include one of the following: lead-acid battery type, lithium-ion battery type, nickel-metal hydride battery type, nickel-cadmium battery type, etc., which is not limited herein.

[0065] In a specific embodiment, the target battery condition of the battery module may be determined according to the first current flow direction. When the first current flow direction is that the current flows out from the positive electrode of the battery, the target battery condition is the discharge condition. On the contrary, when the first current flow direction is that the current flows into the positive electrode of the battery from the outside, the target battery condition is the charging condition. Then, the target battery type corresponding to the battery module may be obtained. Specifically, the composition of the battery module may be obtained, and the target battery type may be determined according to these composition components. For example, assuming that the composition components of the battery module include lithium compounds, the target battery type is the lithium-ion battery type. Alternatively, the target battery identifier of the battery module may also be obtained, and the target battery type may be determined according to the target battery identifier. A mapping relationship between the preset battery identifier and the battery type may be pre-stored, and the target battery type corresponding to the target battery identifier may be determined based on this mapping relationship. Then, the reference working temperature parameter corresponding to the target battery type may be determined. The reference working temperature parameter represents the normal working temperature of the battery module. Specifically, a mapping relationship between the preset battery type and the working temperature parameter may be pre-stored, and the reference working temperature parameter corresponding to the target battery type may be determined based on this mapping relationship.

[0066] When the target battery condition includes a discharge condition, the reference discharge voltage parameter threshold and the reference discharge current parameter threshold corresponding to the target battery type can be determined. Specifically, a mapping relationship between the preset battery type and the discharge voltage parameter threshold and the discharge current parameter threshold can be pre-stored, and the reference discharge voltage parameter threshold and the reference discharge current parameter threshold corresponding to the target battery type can be determined based on this mapping relationship. Next, the target usage duration corresponding to the battery module can be obtained. Specifically, the moment when the battery module starts to be put into use can be obtained to get the starting usage moment. Then, the current moment can be obtained, and the target usage duration can be obtained by subtracting the starting usage moment from the current moment. Next, the first influence coefficient corresponding to the target usage duration can be determined. Specifically, a mapping relationship between the preset usage duration and the influence coefficient can be pre-stored, and the first influence coefficient corresponding to the target usage duration can be determined based on this mapping relationship. The value range of the first influence coefficient can be -0.3 - 0.3. Next, the first temperature parameter can be subtracted from the reference working temperature parameter to obtain the first temperature difference. Then, the second influence coefficient corresponding to the first temperature difference can be determined. Specifically, a mapping relationship between the preset temperature difference and the influence coefficient can be pre-stored, and the second influence coefficient corresponding to the first temperature difference can be determined based on this mapping relationship. The value range of the second influence coefficient can be -0.12 - 0.12. Further, the reference discharge voltage parameter threshold can be adjusted according to the first influence coefficient and the second influence coefficient. The specific calculation formula is as follows:

[0067] Target discharge voltage parameter threshold = reference discharge voltage parameter threshold × (1 + first influence coefficient) × (1 + second influence coefficient);

[0068] The target discharge voltage parameter threshold can be obtained according to the above formula. Next, the reference discharge current parameter threshold can be adjusted according to the first influence coefficient and the second influence coefficient. The specific calculation formula is as follows:

[0069] Target discharge current parameter threshold = reference discharge current parameter threshold × (1 + first influence coefficient) × (1 + second influence coefficient);

[0070] The target discharge current parameter threshold can be obtained according to the above formula. When the first voltage parameter is not greater than the target discharge voltage parameter threshold and the first current parameter is not greater than the target discharge current parameter threshold, the target working state is determined to be the normal state;

[0071] When the first voltage parameter is greater than the target discharge voltage parameter threshold and / or the first current parameter is greater than the target discharge current parameter threshold, the target working state is determined to be the discharge abnormal state.

[0072] In this way, by determining whether the battery module is in a discharging condition or a charging condition based on the first current flow direction, subsequent parameter analysis and processing can be accurately performed for different working modes. This helps the system to take targeted measures to manage the battery, avoiding incorrect control strategies caused by incorrect condition judgment. Additionally, by judging whether the working state of the battery is a normal state or an abnormal discharging state based on the adjusted target discharging voltage parameter threshold and target discharging current parameter threshold, the working condition of the battery can be monitored more precisely. This threshold judgment adjusted based on multiple factors (such as temperature, usage duration, etc.) can promptly detect whether the battery is in an abnormal discharging state, such as over-discharging or overloading.

[0073] In one embodiment, when the target battery condition includes the charging condition, the control module is specifically configured to perform the following steps:

[0074] B1. Determine the reference charging voltage parameter threshold and reference charging current parameter threshold corresponding to the target battery type;

[0075] B2. Obtain the target charging rate of the battery module;

[0076] B3. Adjust the reference charging voltage parameter threshold and reference charging current parameter threshold respectively according to the target charging rate to obtain the target charging voltage parameter threshold and target charging current parameter threshold;

[0077] B4. When the first voltage parameter is not greater than the target charging voltage parameter threshold and the first current parameter is not greater than the target charging current parameter threshold, determine that the target working state is the normal state;

[0078] B5. When the first voltage parameter is greater than the target charging voltage parameter threshold and / or the first current parameter is greater than the target charging current parameter threshold, determine that the target working state is the charging abnormal state.

[0079] In the embodiments of the present application, the reference charging voltage parameter threshold and the reference charging current parameter threshold corresponding to the target battery type can be determined first. For example, the mapping relationship between the preset battery type and the charging voltage parameter threshold and the charging current parameter threshold can be stored in advance, and based on this mapping relationship, the reference charging voltage parameter threshold and the reference charging current parameter threshold corresponding to the target battery type can be determined. Then, the target charging rate of the battery module can be obtained. Specifically, the historical charging data of the battery module can be obtained, and the target charging rate can be calculated according to the historical charging data. The duration of each charging cycle of the battery module can be determined from the historical charging data to obtain multiple durations. Then, the initial battery level (which can be the battery level percentage or ampere-hour) at the start of charging and the final battery level at the end of charging of the battery module can also be recorded, and the change in battery level during the charging process can be calculated to obtain multiple changes in battery level. Then, the rated capacity of the battery module is obtained, and according to the definition of the charging rate, the formula is used to calculate the charging rate. The specific calculation formula is as follows:

[0080] C = △Q1 / Qr×t1;

[0081] Wherein, △Q1 is one of the multiple changes in battery level, Qr is the rated capacity of the battery module, t1 is the duration corresponding to △Q1 among the multiple durations, and C is the charging rate. By calculating multiple times according to the above formula, multiple charging rates can be obtained, and the average value of these multiple charging rates is calculated to obtain the target charging rate.

[0082] It should be explained that the charging cycle refers to the time taken for the battery module to be fully charged (or reach a certain set charging termination condition, such as charging to 80% battery level) from the start of charging. In addition, the temperature of the battery module will also affect the magnitudes of the reference charging voltage parameter threshold and the reference charging current parameter threshold. However, the influence of temperature is relatively small compared to the influence of the target charging rate. Therefore, in the embodiments of the present application, only the influence of the target charging rate on the reference charging voltage parameter threshold and the reference charging current parameter threshold is considered. In some embodiments, factors such as temperature and the usage duration of the battery module can also be taken into account.

[0083] Then, the reference charging voltage parameter threshold and the reference charging current parameter threshold can be adjusted respectively according to the target charging rate to obtain the target charging voltage parameter threshold and the target charging current parameter threshold. Specifically, the initial charging rate of the battery module can be obtained, and the deviation degree between the target charging rate and the initial charging rate can be calculated to obtain the target deviation degree. The specific calculation formula is as follows:

[0084] Target deviation degree = (Target charging rate - Initial charging rate) / Initial charging rate×100%;

[0085] According to the above formula, the target deviation degree can be obtained. Then, the target optimization factor corresponding to the target deviation degree can be determined. Suppose there is a pre-stored mapping relationship between the preset deviation degree and the optimization factor, and based on this mapping relationship, the target optimization factor corresponding to the target deviation degree is determined. The value range of this target optimization factor can be -0.3 - 0.3. According to this target optimization factor, the reference charging voltage parameter threshold and the reference charging current parameter threshold are adjusted respectively. The specific calculation formulas are as follows:

[0086] Target charging voltage parameter threshold = reference charging voltage parameter threshold × (1 + target optimization factor);

[0087] Target charging current parameter threshold = reference charging current parameter threshold × (1 + target optimization factor);

[0088] According to the above formula, the target charging voltage parameter threshold and the target charging current parameter threshold can be obtained. When the first voltage parameter is not greater than the target charging voltage parameter threshold and the first current parameter is not greater than the target charging current parameter threshold, the target working state is determined to be the normal state;

[0089] When the first voltage parameter is greater than the target charging voltage parameter threshold and / or the first current parameter is greater than the target charging current parameter threshold, the target working state is determined to be the charging abnormal state.

[0090] In this way, by determining the reference charging voltage parameter threshold and the reference charging current parameter threshold according to the target battery type, it is based on the fact that different battery types (such as lithium-ion batteries, lead-acid batteries, etc.) have different electrochemical characteristics. For example, the charging voltage range of lithium-ion batteries is generally 3.0 - 4.2V, while that of lead-acid batteries is different. By setting the reference threshold for the battery type, it can ensure that the charging process meets the basic electrical and chemical requirements of the battery, providing a basic guarantee for safe and efficient charging. In addition, by obtaining the target charging rate and adjusting the reference charging threshold accordingly to obtain the charging threshold (i.e., the target charging voltage parameter threshold and the target charging current parameter threshold), the diversity of the actual charging scenario is considered. The charging rate reflects the charging speed, and different charging rates will have different impacts on the charging threshold of the battery. Adjusting the reference threshold according to the target charging rate can make the finally obtained charging threshold more accurate and conform to the actual charging scenario. For example, a high charging rate means a faster charging speed, but it may also cause problems such as battery heating and polarization. By adjusting the parameter threshold according to the charging rate, it can better adapt to different charging needs. Appropriately increasing the charging voltage parameter threshold at a high charging rate is because the voltage drop generated by the battery internal resistance increases during high-rate charging, and a higher external voltage is required to ensure that the charging current reaches the requirement. At the same time, the charging current parameter threshold should also be reasonably adjusted to avoid damage to the battery caused by excessive current.

[0091] When the target working state is a discharge abnormal state, a first control instruction corresponding to the target working state is generated. The first control instruction is used to control the relay and the discharge freewheeling circuit to disconnect to control the battery module to stop discharging, and to control the charging freewheeling circuit to conduct. The discharge abnormal state may include at least one of the following: over-discharge state, over-temperature state during discharge, over-current state during discharge, short-circuit state, etc., which are not limited herein.

[0092] In one embodiment, in terms of generating the first control instruction corresponding to the target working state, the control module is specifically configured to perform the following steps:

[0093] C1. Within a second preset time period, sample the current parameters of the charge and discharge circuit to obtain n current parameters; n is an integer greater than 1; each current parameter corresponds to a sampling time; the end moment of the second preset time period is earlier than the current moment;

[0094] C2. Fit according to the n current parameters and the sampling time corresponding to each current parameter to obtain a first current curve;

[0095] C3. Determine the partial current curves in the first current curve that are greater than the target charging current parameter threshold to obtain at least one partial current curve;

[0096] C4. Determine the duration corresponding to each partial current curve in the at least one partial current curve to obtain at least one duration;

[0097] C5. Generate the first control instruction according to the at least one duration and the at least one partial current curve.

[0098] In the embodiments of the present application, the second preset time period can be preset in advance or by default.

[0099] In a specific embodiment, within the second preset time period, the current parameters of the charge and discharge circuit can be sampled to obtain n current parameters. Specifically, the method of equidistant sampling can be used to sample the current parameters of the charge and discharge circuit through a current sampling circuit (or analog front-end circuit). The sampling interval can be a preset interval (for example, 1 millisecond or 1 second) to obtain n current parameters. Then, according to the n current parameters and the sampling time corresponding to each current parameter, a first current curve can be fitted. The horizontal axis of the first current curve is time, and the vertical axis is the current parameter. Specifically, first, the n current parameters and their corresponding sampling times can be combined into coordinate points to obtain n coordinate points. Then, the curve fitting method (for example, polynomial fitting method, spline method, etc.) can be used to fit these n coordinate points to obtain the first current curve.

[0100] Next, the partial current curves in the first current curve that are greater than the target charging current parameter threshold can be determined to obtain at least one partial current curve. Specifically, a first straight line parallel to the x-axis can be drawn according to the target charging current parameter threshold, and the first straight line and the first current curve are placed in the same coordinate system. The first current curve is cut by the first straight line, and the first straight line will divide the first current curve into upper and lower parts. The part above the first straight line is the partial curve greater than the target charging current parameter threshold, that is, at least one partial current curve.

[0101] It should be explained that the method of obtaining at least one partial current curve through the first straight line is only a feasible method. In actual applications, it is also possible to traverse each charging parameter on the first current curve, from the starting point to the ending point. For each charging parameter, it is judged whether it is equal to the target charging current parameter threshold. If the condition is met, the charging parameter and its corresponding time point are recorded, and multiple recording points can be obtained. According to these multiple recording points, the partial curve in the first current curve that is greater than the target charging current parameter threshold is intercepted to obtain at least one partial current curve.

[0102] Next, the duration corresponding to each partial current curve in at least one partial current curve can be determined to obtain at least one duration. Specifically, the starting point and ending point of at least one partial current curve can be determined respectively to obtain at least one starting point and at least one ending point. Then, the time difference between each starting point in at least one starting point and the corresponding ending point can be calculated respectively to obtain at least one time difference, that is, at least one duration. Finally, a first control instruction can be generated according to at least one duration and at least one partial current curve.

[0103] In this way, by sampling the current parameters of the charge and discharge circuit within the second preset time period, n current parameters are obtained. According to these n current parameters, the detailed information of the current change within the second preset time period can be determined. Thus, the dynamic change of the current can be understood more comprehensively, rather than relying only on the current measurement at a certain moment.

[0104] In an embodiment, in terms of generating the first control instruction according to at least one duration and at least one partial current curve, the control module is specifically configured to perform the following steps:

[0105] D1. When the target battery condition includes the discharge condition, obtain the first duty cycle of the first MOS transistor at the current moment;

[0106] D2. Determine the current parameters corresponding to at least one partial current curve among the n current parameters to obtain m current parameters; m is a positive integer less than or equal to n;

[0107] D3. Determine the difference between each of the m current parameters and the target discharge current parameter threshold to obtain m current differences;

[0108] D4. Determine the target mean value corresponding to the m current differences;

[0109] D5. Determine the first anomaly level according to the target mean value;

[0110] D6. Calculate the sum of the at least one duration to obtain the target duration;

[0111] D7. Determine the second anomaly level according to the target duration;

[0112] D8. Determine the target anomaly level according to the first anomaly level and the second anomaly level;

[0113] D9. Determine the first duty cycle change value corresponding to the target anomaly level;

[0114] D10. Determine the second duty cycle according to the first duty cycle change value and the first duty cycle;

[0115] D11. Determine the first control instruction corresponding to the target battery condition according to the second duty cycle;

[0116] D12. When the target battery condition includes the charging condition, obtain the third duty cycle of the second MOS transistor at the current moment;

[0117] D13. Determine the second duty cycle change value corresponding to the second MOS transistor;

[0118] D14. Determine the first control instruction corresponding to the target battery condition according to the third duty cycle and the second duty cycle change value.

[0119] In the embodiments of the present application, the anomaly levels can be divided into the following three types: first-level anomaly, second-level anomaly, third-level anomaly, etc., which are not limited herein. The larger the anomaly level, the more dangerous the abnormal situation of the system.

[0120] In a specific embodiment, when the target battery condition includes the discharge condition, obtain the first duty cycle of the first MOS transistor at the current moment. Specifically, the control module can obtain the PWM signal received by the first MOS transistor at the current moment to obtain the first PWM signal, and determine the duty cycle of the first PWM signal to obtain the first duty cycle.

[0121] It should be noted that in the embodiments of the present application, both the first MOS transistor and the second MOS transistor can be controlled by a PWM control algorithm, that is, driven by a PWM signal.

[0122] Next, it is possible to determine the current parameters corresponding to at least one partial current curve among the n current parameters, obtaining m current parameters. Specifically, it is possible to acquire the sampling time corresponding to each current parameter among the n current parameters, obtaining n acquisition times, determine the acquisition times among these n acquisition times that fall within the above-mentioned at least one duration, obtaining m acquisition times, and determine the current parameters corresponding to these m acquisition times, obtaining m current parameters. Then, it is possible to subtract the target discharge current parameter threshold from each current parameter among the m current parameters, obtaining m current differences. Next, it is possible to calculate the target average value of the m current differences. Further, it is possible to determine the first anomaly level based on the target average value. For example, it is possible to pre-store the mapping relationship between the preset average value and the anomaly level, and determine the first anomaly level corresponding to the target average value based on this mapping relationship. Then, it is possible to add up each duration among the at least one duration, obtaining the target duration. Next, it is possible to determine the second anomaly level based on the target duration. Similarly, it is possible to pre-store the mapping relationship between the preset duration and the anomaly level, and determine the second anomaly level corresponding to the target duration based on this mapping relationship. Then, it is possible to determine the target anomaly level based on the first anomaly level and the second anomaly level. Specifically, it is possible to directly add the first anomaly level and the second anomaly level to obtain the target anomaly level, or it is possible to obtain the first preset weight corresponding to the target average value, the second preset weight corresponding to the target duration, the sum of the first preset weight and the second preset weight being 1, and perform a weighted operation on the first anomaly level and the second anomaly level according to the first preset weight and the second preset weight to obtain the target anomaly level.

[0123] Further, it is possible to determine the first duty cycle change value corresponding to the target anomaly level. Specifically, it is possible to pre-store the mapping relationship between the preset anomaly level and the duty cycle change value, and determine the first duty cycle change value corresponding to the target anomaly level based on this mapping relationship. Then, it is possible to determine the second duty cycle according to the first duty cycle change value and the first duty cycle. The specific calculation formula is as follows:

[0124] ;

[0125] The second duty cycle can be obtained according to the above formula. It should be explained that the first duty cycle and the first duty cycle change value can both be percentages; then, the first control instruction corresponding to the target battery operating condition can be determined according to the second duty cycle. Specifically, the control module can generate a PWM signal with a duty cycle of the second duty cycle to obtain a second PWM signal, and generate a first control instruction according to the second PWM signal. The first control instruction may include the second PWM signal and the signal effective duration of the second PWM signal.

[0126] When the target battery operating condition includes a charging condition, the third duty cycle of the second MOS tube at the current moment can be obtained. Specifically, the method for obtaining the third duty cycle can be the same as the method for obtaining the first duty cycle mentioned above. Determine the second duty cycle change value corresponding to the second MOS tube. Specifically, the method for obtaining the second duty cycle change value can be the same as the method for obtaining the first duty cycle change value mentioned above. Then, the first control instruction corresponding to the target battery operating condition can be determined according to the third duty cycle and the second duty cycle change value. Specifically, the fourth duty cycle can be determined according to the third duty cycle and the second duty cycle change value. The method for obtaining the fourth duty cycle can be the same as the method for obtaining the second duty cycle mentioned above. Then, the first control instruction corresponding to the target battery operating condition can be determined according to the fourth duty cycle.

[0127] In this way, by determining the difference between all current parameters corresponding to at least one partial current curve and the target discharge current parameter threshold, the target mean is calculated to measure the degree of current abnormality, and the information of multiple abnormal current data points is integrated to avoid the accidental error of a single data point, thereby more accurately determining the first abnormality level; in addition, determining the target abnormality level based on the first abnormality level and the second abnormality level can more comprehensively evaluate the abnormal state of the battery, and different abnormality level combinations can reflect problems of different severity, thereby generating corresponding control instructions in a targeted manner.

[0128] When the target working state is the abnormal charging state, a second control instruction corresponding to the target working state is generated, and the second control instruction is used to control the relay and the charging freewheeling circuit to disconnect to control the battery module to stop charging, and to control the discharge freewheeling circuit to turn on. The abnormal charging state includes at least one of the following: overcharge state, charging overtemperature state, charging overcurrent state, short circuit, etc., which are not limited here.

[0129] In one embodiment, when the target operating state is the normal static state, the control module is configured to control the relay to disconnect and the charge-discharge circuit to conduct (i.e., the charge continuation circuit conducts and the discharge continuation circuit conducts): when a charging current is detected, the control module is configured to control the relay to latch and disconnect the charge continuation circuit; when the battery module is fully charged or meets the preset overcharge recovery condition, the control module is configured to control the relay to disconnect and the charge continuation circuit to conduct again; in the normal static state, keeping the charge-discharge circuit conducting enables the voltage of the battery module to be monitored in real time, which helps to promptly detect whether there are abnormal self-discharges in the battery module. The relay is disconnected to avoid unnecessary current paths and prevent unnecessary power consumption in the static state because the relay has a certain contact resistance in the latched state and consumes a certain amount of electrical energy. Disconnecting the relay can reduce this static power consumption.

[0130] In one embodiment, when the target operating state is the normal static state, the control module is configured to control the relay to disconnect and the charge-discharge circuit to conduct: when a discharge current is detected, the control module is configured to control the relay to latch and disconnect the discharge continuation circuit; when the battery module is over-discharged or meets the preset over-discharge recovery condition, the control module is configured to control the relay to disconnect and the discharge continuation circuit to conduct again;

[0131] When the charge and discharge of the battery module are completed and the battery module does not meet the preset overcharge recovery condition or the preset over-discharge recovery condition, the charge and discharge current of the system is detected within a first preset time period. If no charge and discharge current is detected within the first preset time period, the control module is configured to control the relay to disconnect and the charge-discharge circuit to conduct; the start time of the first preset time period is later than the current time. The first preset time period can be preset in advance or by default.

[0132] In one embodiment, the charge and discharge circuit may include one or more relays; the discharge freewheeling circuit may include one or more MOS transistors; the charge freewheeling circuit may include one or more MOS transistors. Specifically, the number of relays or MOS transistors in the charge and discharge circuit can be appropriately increased according to the usage requirements of the system. For example, assuming that the charge and discharge circuit needs to implement multiple different functional modes, such as fast charging mode, trickle charging mode, emergency discharge mode, etc., multiple relays can be used to switch different charging circuits, and charge and discharge parameters suitable for specific functional modes can be configured for each circuit. Another example is that in the charge and discharge circuit, if the current to pass through is relatively large, a single MOS transistor may not be able to withstand such a large current. At this time, multiple MOS transistors can be used in parallel to share the current. For example, in a high-power battery discharge circuit (such as the power system discharge circuit of an electric vehicle), the instantaneous starting current may reach several hundred amperes. At this time, multiple MOS transistors in parallel are required to meet the current-carrying requirements.

[0133] Through the battery management system provided by the embodiments of the present application, by detecting the working current of the first resistor, when the working current does not meet the preset conditions (such as too large or too small current), various working parameters of the battery module are further collected to obtain multiple working parameters. According to these multiple working parameters, the working state of the battery module is judged. Once it is found that the working state of the battery module is abnormal, the control module generates corresponding control instructions to control the relay and the discharge freewheeling circuit (charge freewheeling circuit) to disconnect, stopping the battery from discharging or charging. Thus, in the case of large-current charge and discharge, the safety of battery use is improved.

[0134] Please refer to Figure 6 , Figure 6 which is a flowchart of a battery management method provided by the embodiments of the present application and is applied to any battery management system as described in the above embodiments. The method includes:

[0135] S1. Detect the working current of the first resistor;

[0136] S2. When the working current does not meet the preset conditions, collect the working parameters of the battery module to obtain multiple working parameters;

[0137] S3. Determine the target working state of the battery module according to the multiple working parameters;

[0138] S4. When the target working state is a discharge abnormal state, generate a first control instruction corresponding to the target working state. The first control instruction is used to control the relay and the discharge freewheeling circuit to disconnect to control the battery module to stop discharging, and control the charge freewheeling circuit to conduct;

[0139] S5. When the target operating state is an abnormal charging state, generate a second control instruction corresponding to the target operating state. The second control instruction is used to control the relay and the charging freewheeling circuit to disconnect to control the battery module to stop charging, and to control the discharging freewheeling circuit to conduct.

[0140] The embodiments of the present application also provide a battery management device, wherein the battery management device includes some or all of the battery management systems described in the above embodiments.

[0141] It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0142] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0143] In several embodiments provided by the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the above division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some interfaces, and the indirect coupling or communication connection of the device or unit can be in an electrical or other form.

[0144] The units described above as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or they can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0145] In addition, in each embodiment of the present application, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0146] If the above integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on such an understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in the various embodiments of this application. The aforementioned memory includes various media that can store program codes, such as USB flash drives, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), mobile hard disks, magnetic disks, or optical discs.

[0147] The above has introduced the embodiments of this application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A battery management system, characterized in that, The system includes: a battery module, a current sampling circuit, a first resistor, an analog front-end circuit, a relay driving circuit, a control module, and a charge and discharge circuit. The charge and discharge circuit includes a relay, a discharge freewheeling circuit, and a charge freewheeling circuit, where: The first end of the battery module is connected to the first end of the control module, the second end of the battery module is connected to the first end of the analog front-end circuit, and the third end of the battery module is connected to the second end of the first resistor; the second end of the first resistor is further connected to the fourth end of the current sampling circuit, and the first end of the first resistor is respectively connected to the third end of the current sampling circuit and the third end of the charge and discharge circuit; the first end of the current sampling circuit is connected to the fifth end of the analog front-end circuit, and the second end of the current sampling circuit is connected to the fourth end of the analog front-end circuit; the second end of the analog front-end circuit is connected to the third end of the control module, and the third end of the analog front-end circuit is connected to the first end of the charge and discharge circuit; the second end of the charge and discharge circuit is connected to the second end of the relay driving circuit; the second end of the control module is connected to the first end of the relay driving circuit; The current sampling circuit is configured to detect the operating current of the first resistor; The analog front-end circuit is configured to collect the operating parameters of the battery module at the current moment to obtain a plurality of operating parameters when the operating current does not meet the preset conditions; The control module is configured to determine the target operating state of the battery module according to the plurality of operating parameters; When the target operating state is a discharge abnormal state, generate a first control instruction corresponding to the target operating state, where the first control instruction is used to control the relay and the discharge freewheeling circuit to disconnect to control the battery module to stop discharging, and control the charge freewheeling circuit to conduct; When the target operating state is a charge abnormal state, generate a second control instruction corresponding to the target operating state, where the second control instruction is used to control the relay and the charge freewheeling circuit to disconnect to control the battery module to stop charging, and control the discharge freewheeling circuit to conduct; Wherein, the battery module includes at least one battery; the battery type of the at least one battery includes one of the following: lithium iron phosphate battery, lithium manganese iron phosphate battery, lithium cobalt oxide battery, lithium manganese oxide battery, lithium nickel cobalt aluminum oxide battery, lithium titanate battery, lead-acid battery, nickel-cadmium battery, nickel-metal hydride battery; The voltage range of each battery in the at least one battery is 2V - 5V, and the voltage range of the battery module is 2V - 500V; The system further includes: a wake-up circuit and a three-terminal fuse. The first end of the three-terminal fuse is connected to the first end of the wake-up circuit, the second end of the three-terminal fuse is respectively connected to the third end of the control module and the second end of the analog front-end circuit, and the third end of the three-terminal fuse is connected to the first end of the battery module; the second end of the wake-up circuit is connected to the first end of the control module; The wake-up circuit is configured to wake up the system when the system meets the preset trigger conditions, and the wake-up circuit includes a power supply monitoring type wake-up circuit; The three-terminal fuse is used to actively blow when an abnormal situation occurs in the system, so as to cut off the circuit and prevent damage to the battery module; the abnormal situation includes at least one of the following: system short circuit, system overload, and relay sintering.

2. The system according to claim 1, wherein The discharge freewheeling circuit includes: a first MOS transistor and a first diode; wherein: The drain of the first MOS transistor is connected to the negative electrode of the first diode, and the source of the first MOS transistor is connected to the second terminal of the relay; the first terminal of the relay is connected to the positive electrode of the first diode; The source of the first MOS transistor serves as the first terminal of the charge and discharge circuit and is connected to the third terminal of the analog front-end circuit, the first terminal of the relay serves as the second terminal of the charge and discharge circuit and is connected to the second terminal of the relay drive circuit, and the second terminal of the relay serves as the third terminal of the charge and discharge circuit and is connected to the first terminal of the first resistor; The MOS transistor type of the first MOS transistor includes one of the following: CMOS, VMOS, TMOS, vertical DMOS, HEXFET.

3. The system according to claim 2, characterized in that The charge freewheeling circuit includes: a second MOS transistor and a second diode; wherein: The positive electrode of the second diode is connected to the source of the first MOS transistor, and the negative electrode of the second diode is connected to the drain of the second MOS transistor; the source of the second MOS transistor is connected to the positive electrode of the first diode; The MOS transistor type of the second MOS transistor includes one of the following: CMOS, VMOS, TMOS, vertical DMOS, HEXFET.

4. The system according to claim 1, wherein The charge and discharge circuit includes one or more relays; the discharge freewheeling circuit includes one or more MOS transistors; the charge freewheeling circuit includes one or more MOS transistors.

5. The system according to any one of claims 1-4, characterized in that, When the target operating state is the normal static state, the control module is used to control the relay to disconnect and the charge and discharge circuit to conduct: When a charging current is detected, the control module is used to control the relay to close and disconnect the charge freewheeling circuit. When the battery module is fully charged or meets the preset overcharge recovery condition, the control module is used to control the relay to disconnect and the charge freewheeling circuit to conduct again; Or, When a discharge current is detected, the control module is used to control the relay to close and disconnect the discharge freewheeling circuit. When the battery module is overdischarged or meets the preset overdischarge recovery condition, the control module is used to control the relay to disconnect and the discharge freewheeling circuit to conduct again; When the charge and discharge of the battery module is completed and the battery module does not meet the preset overcharge recovery condition or the preset overdischarge recovery condition, the charge and discharge current of the system is detected within a first preset time period. If no charge and discharge current is detected within the first preset time period, the control module is used to control the relay to disconnect and the charge and discharge circuit to conduct; the starting moment of the first preset time period is later than the current moment.

6. The system according to claim 3, characterized in that The multiple operating parameters include: a first temperature parameter, a first voltage parameter, a first current parameter, and a first current direction. In terms of determining the target operating state of the battery module according to the multiple operating parameters, the control module is specifically configured to: Determine the target battery operating condition of the battery module according to the first current direction; the target battery operating condition includes a discharging condition or a charging condition; Obtain the target battery type corresponding to the battery module; Determine the reference operating temperature parameter corresponding to the target battery type; When the target battery operating condition includes the discharging condition, determine the reference discharging voltage parameter threshold and the reference discharging current parameter threshold corresponding to the target battery type; Obtain the target usage duration corresponding to the battery module; Determine the first influence coefficient corresponding to the target usage duration; Determine the difference between the first temperature parameter and the reference operating temperature parameter to obtain a first temperature difference; Determine the second influence coefficient corresponding to the first temperature difference; Adjust the reference discharging voltage parameter threshold according to the first influence coefficient and the second influence coefficient to obtain the target discharging voltage parameter threshold; Adjust the reference discharging current parameter threshold according to the first influence coefficient and the second influence coefficient to obtain the target discharging current parameter threshold; When the first voltage parameter is not greater than the target discharging voltage parameter threshold and the first current parameter is not greater than the target discharging current parameter threshold, determine that the target operating state is a normal state; When the first voltage parameter is greater than the target discharging voltage parameter threshold and / or the first current parameter is greater than the target discharging current parameter threshold, determine that the target operating state is a discharging abnormal state.

7. The system according to claim 6, wherein When the target battery operating condition includes the charging condition, the control module is specifically configured to: Determine the reference charging voltage parameter threshold and the reference charging current parameter threshold corresponding to the target battery type; Obtain the target charging rate of the battery module; Adjust the reference charging voltage parameter threshold and the reference charging current parameter threshold respectively according to the target charging rate to obtain the target charging voltage parameter threshold and the target charging current parameter threshold; When the first voltage parameter is not greater than the target charging voltage parameter threshold and the first current parameter is not greater than the target charging current parameter threshold, determine that the target operating state is the normal state; When the first voltage parameter is greater than the target charging voltage parameter threshold and / or the first current parameter is greater than the target charging current parameter threshold, determine that the target operating state is a charging abnormal state.

8. The system according to claim 7, wherein In terms of generating the first control instruction corresponding to the target operating state, the control module is specifically configured to: Sample the current parameters of the charge and discharge circuit within a second preset time period to obtain n current parameters; n is an integer greater than 1; each current parameter corresponds to a sampling time; The end moment of the second preset time period is earlier than the current moment; Fitting is performed according to the n current parameters and the sampling time corresponding to each current parameter to obtain a first current curve; Determine the partial current curves in the first current curve that are greater than the target charging current parameter threshold to obtain at least one partial current curve; Determine the duration corresponding to each partial current curve in the at least one partial current curve to obtain at least one duration; Generate the first control instruction according to the at least one duration and the at least one partial current curve.

9. The system according to claim 8, wherein In terms of generating the first control instruction according to the at least one duration and the at least one partial current curve, the control module is specifically configured to: When the target battery condition includes the discharging condition, obtain the first duty cycle of the first MOS transistor at the current moment; Determine the current parameters corresponding to the at least one partial current curve among the n current parameters to obtain m current parameters; m is a positive integer less than or equal to n; Determine the difference between each current parameter in the m current parameters and the target discharging current parameter threshold to obtain m current differences; Determine the target mean value corresponding to the m current differences; Determine a first abnormality level according to the target mean value; Calculate the sum of the at least one duration to obtain a target duration; Determine a second abnormality level according to the target duration; Determine a target abnormality level according to the first abnormality level and the second abnormality level; Determine the first duty cycle change value corresponding to the target abnormality level; Determine a second duty cycle according to the first duty cycle change value and the first duty cycle; Determine the first control instruction corresponding to the target battery condition according to the second duty cycle; When the target battery condition includes the charging condition, obtain the third duty cycle of the second MOS transistor at the current moment; Determine the second duty cycle change value corresponding to the second MOS transistor; Determine the first control instruction corresponding to the target battery condition according to the third duty cycle and the second duty cycle change value.

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