Battery pack charging and discharging control method and system

Abstract

The invention discloses a battery pack charging and discharging control method and system, the control method comprises a first method, the first method comprises the following steps: detecting state parameters of a battery pack in a battery pack and environment parameters of the environment in the battery pack in real time, the environment parameters comprising environment humidity and environment temperature; generating current fault parameters related to water immersion in combination with the values of the environment humidity and the environment temperature; generating a first control parameter in combination with the fault parameter and the state parameter; and when the working current of the battery pack is lower than a preset current threshold value, controlling the states of a charging switch and a discharging switch of the battery pack based on the first control parameter. According to the control method, by detecting the multi-element parameters and generating the control parameters, waterproof detection is more comprehensive and higher in accuracy, the water immersion risk can be recognized and processed in the early stage, and the probability of battery short circuit and fire accidents is reduced; in addition, a detection model with a complex structure does not need to be adopted, and the cost of the battery pack is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of rechargeable battery control, and in particular to a battery pack charge and discharge control method and system. Background Art

[0002] The safety and reliability of battery packs are crucial in the use of electric vehicles and energy storage devices. However, during the daily use of battery packs, changes in the external environment, such as rain and vehicle wading, may cause the waterproof performance of the battery pack to deteriorate, or even cause the risk of water immersion. In this case, a short circuit may occur inside the battery pack, causing safety accidents such as fire. Therefore, how to effectively detect and control water immersion in battery packs has become an urgent problem to be solved.

[0003] At present, the waterproof level of battery packs on the market is generally IPX7. Although they have good waterproof performance, their waterproof ability may gradually deteriorate in the face of complex usage environments. Traditional water immersion detection solutions have many shortcomings. Some battery packs lack a complete water immersion detection mechanism, and existing detection technologies often rely on single-element detection circuits or complex detection models. This method not only lacks flexibility and comprehensiveness, but also has problems such as slow response speed and high detection cost. It is difficult to make accurate diagnosis in time at the early stage of battery pack immersion. Summary of the invention

[0004] The object of the present invention is to provide a simple and effective battery pack charge and discharge control method and system for improving the waterproof performance of the battery pack based on multi-factor parameters.

[0005] In order to achieve the above object, the present invention provides a battery pack charge and discharge control method, which includes a first method, wherein the first method includes: Real-time detection of state parameters of the battery pack in the battery pack and environmental parameters of the environment in the battery pack, wherein the environmental parameters include environmental humidity and environmental temperature; generating a current fault parameter related to water intrusion by combining the values ​​of the ambient humidity and the ambient temperature; generating a first control parameter by combining the fault parameter and the state parameter; When the operating current of the battery pack is lower than a preset current threshold, the states of the charging switch and the discharging switch of the battery pack are controlled based on the first control parameter.

[0006] Preferably, when the following first condition and second condition are satisfied at the same time, the content of the first control parameter includes: allowing the charging switch and the discharging switch to be turned on; First condition: the state parameter is within the normal range; Second condition: the ambient humidity is within the first humidity value range.

[0007] Preferably, when the first condition and the following third condition are satisfied at the same time, the content of the first control parameter includes: allowing the discharge switch to be turned on and prohibiting the charge switch from being turned on; Third condition: the ambient humidity is within a second humidity value range, and the ambient temperature is greater than or equal to a preset temperature threshold, and the second humidity value range is greater than the first humidity value range.

[0008] Preferably, when the first condition and the following fourth condition are satisfied at the same time, the content of the first control parameter includes: prohibiting the discharge switch from being turned on, prohibiting the charge switch from being turned on; Fourth condition: the ambient humidity is within a third humidity value interval, and the ambient temperature is greater than or equal to a preset temperature threshold, and the third humidity value interval is greater than the second humidity value interval.

[0009] Preferably, the state parameters include the temperature and voltage of the battery cells in the battery pack.

[0010] Preferably, a second method is further included, wherein the second method comprises: A water immersion detection circuit is provided, the water immersion detection circuit comprising a reference resistor and a reference voltage, the reference resistor is arranged at the bottom of the battery pack, and the reference resistor is electrically connected to the reference voltage through a voltage divider resistor; Detecting the voltage between the reference resistor and the voltage-dividing resistor in real time to obtain a detection voltage; generating a second control parameter according to a relationship between the detection voltage and the reference voltage; When the operating current of the battery pack is lower than a preset current threshold, the states of the charging switch and the discharging switch of the battery pack are controlled based on the first control parameter and / or the second control parameter.

[0011] Preferably, when the ratio of the detection voltage to the reference voltage is within a first ratio numerical interval, the content of the second control parameter includes: allowing the charging switch and the discharging switch to be turned on; when the ratio of the detection voltage to the reference voltage is within a second ratio numerical interval, the content of the second control parameter includes: allowing the discharging switch to be turned on, and prohibiting the charging switch from being turned on; when the ratio of the detection voltage to the reference voltage is within a third ratio numerical interval, the content of the second control parameter includes: prohibiting the charging switch from being turned on, and prohibiting the discharging switch from being turned on; the first ratio numerical interval is greater than the second ratio numerical interval, and the second ratio numerical interval is greater than the third ratio numerical interval.

[0012] The present invention also provides a battery pack charge and discharge control system, which includes a controller and a charging switch and a discharging switch electrically connected to the controller, and the controller controls the states of the charging switch and the discharging switch based on the battery pack charge and discharge control method as described above.

[0013] The present invention also provides a battery pack charge and discharge control system, which includes: one or more processors; Memory; and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the programs include instructions for executing the battery pack charge and discharge control method as described above.

[0014] The present invention also provides a computer-readable storage medium, which includes a computer program, and the computer program can be executed by a processor to implement the battery pack charge and discharge control method as described above.

[0015] Compared with the prior art, the battery pack charge and discharge control method provided by the above technical solution of the present invention generates fault parameters related to water immersion through the ambient humidity and ambient temperature of the environment inside the battery pack, and generates control parameters in combination with the fault parameters and the state parameters of the battery pack. Then, when the battery pack is in a silent state, the charging switch and the discharging switch are controlled based on the control parameters, thereby avoiding safety hazards caused by water immersion. It can be seen that the above control method generates control parameters by detecting multiple factor parameters, making the waterproof detection more comprehensive and more accurate, and the risk of water immersion can be identified and handled at an early stage, reducing the probability of battery short circuit and fire accidents; in addition, there is no need to adopt a complex detection model, which effectively reduces the cost of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Flow chart of the battery pack charging and discharging control method in an embodiment of the present invention.

[0017] Figure 2 It is a principle structure diagram of the battery pack charging and discharging control method in an embodiment of the present invention.

[0018] Figure 3 It is a schematic diagram of the principle structure of the battery pack charge and discharge control system in an embodiment of the invention.

[0019] Figure 4 Schematic diagram of a water immersion detection circuit in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0021] This embodiment discloses a battery pack charge and discharge control method to prevent the battery pack from being started when it is submerged in water, thereby preventing safety hazards. Figure 1 and Figure 2 , the control method comprises a first method: S10: Real-time detection of the state parameters of the battery pack BT in the battery pack and the environmental parameters of the environment in the battery pack, including environmental humidity and ambient temperature. The purpose of detecting the state parameters of the battery pack is to confirm that the battery pack BT is in a normal state, that is, it can safely enter the charging or discharging state.

[0022] S11: Combine the values ​​of ambient humidity and ambient temperature to generate the current fault parameters related to water immersion. When the battery pack is immersed in water or leaking water, the humidity of the internal environment of the battery pack will increase, and the ambient humidity is related to the ambient temperature. Generally, the lower the ambient temperature, the higher the relative humidity. Therefore, if the ambient temperature is also high while the ambient humidity is rising, it indicates that there is a water immersion fault. This improves accuracy. The detection of current (battery status) is added because when the battery is at rest, the environment inside the battery pack is more stable and the detection is more accurate. S12: Generate a first control parameter by combining the fault parameter and the state parameter.

[0023] S13: When the operating current of the battery pack is lower than the preset current threshold, the states of the charging switch K1 and the discharging switch K2 of the battery pack are controlled based on the first control parameter. It should be noted that the monitoring of the above-mentioned state parameters and environmental parameters and the generation of the first control parameter are carried out in real time, and this process covers the static process and the working process of the battery pack. However, the control action of the charging switch K1 and the discharging switch K2 based on the first control parameter can only be performed when the operating current of the battery pack is lower than the preset current threshold, so as to avoid safety hazards due to the forced control of the first control parameter during the normal operation of the battery pack. The theoretical value of the current threshold can be zero. In this embodiment, the current threshold is set to 5A.

[0024] On the other hand, when the following first condition and second condition are satisfied at the same time, the content of the first control parameter includes: allowing the charging switch K1 and the discharging switch K2 to be turned on.

[0025] The first condition: the state parameters are within the normal range, that is, the battery pack is in a healthy state; Second condition: the ambient humidity is within the first humidity value range.

[0026] Specifically, the state parameters include the temperature and voltage of the battery cells in the battery pack BT. Therefore, the health state of the battery pack BT is determined by the temperature and voltage of the battery cells in the battery pack BT.

[0027] In addition, when the first condition and the following third condition are satisfied at the same time, the content of the first control parameter includes: allowing the discharge switch K2 to be turned on, and prohibiting the charge switch K1 from being turned on.

[0028] The third condition: the ambient humidity is within the second humidity value range, and the ambient temperature is greater than or equal to the preset temperature threshold, and the second humidity value range is greater than the first humidity value range.

[0029] Furthermore, when the first condition and the fourth condition described below are satisfied at the same time, the content of the first control parameter includes: prohibiting the discharge switch K2 from being turned on, prohibiting the charge switch K1 from being turned on; Fourth condition: the ambient humidity is within the third humidity value interval, and the ambient temperature is greater than or equal to a preset temperature threshold, and the third humidity value interval is greater than the second humidity value interval.

[0030] Specifically: The first humidity value interval is: [0%, 50%]; The second humidity value interval is: (50%, 75%]; The third humidity value interval is: (75%, 100%].

[0031] Take the temperature threshold TH as 25°C as an example: When RH (ambient humidity) ∈ [0%, 50%], the battery pack is allowed to charge and discharge without reference to the ambient temperature.

[0032] When RH∈(50%, 75%], if TH≥25℃, it indicates that the current fault is level 1 flooding, an alarm signal is issued, discharging is allowed, but charging is prohibited.

[0033] When RH∈(75%, 100%], if TH≥25℃, it indicates that the current fault is level 2 water immersion fault, an alarm signal is issued, charging is prohibited, and discharging is prohibited at the same time.

[0034] For the above control method, the ambient humidity and ambient temperature of the environment inside the battery pack are used to generate fault parameters related to water immersion, and the fault parameters and the state parameters of the battery pack BT are combined to generate control parameters. Then, when the battery pack is in a silent state, the charging switch K1 and the discharging switch K2 are controlled based on the control parameters, thereby avoiding safety hazards caused by water immersion. It can be seen that the above control method generates control parameters by detecting multiple factor parameters, making the waterproof detection more comprehensive and more accurate, and the risk of water immersion can be identified and handled at an early stage, reducing the probability of battery short circuit and fire accidents; in addition, there is no need to adopt a complex detection model, which effectively reduces the cost of the battery pack.

[0035] On the other hand, the battery pack charge and discharge control method of the present invention also includes a second method, which detects whether the battery pack is flooded by a water immersion detection circuit, such as Figure 2 and Figure 4 , the second method comprises: The water immersion detection circuit includes a reference resistor R0 and a reference voltage VC. The reference resistor R0 is arranged at the bottom of the battery pack, and the reference resistor R0 is electrically connected to the reference voltage VC through a voltage divider resistor R1. Real-time detection of the voltage between the reference resistor R0 and the voltage-dividing resistor R1 to obtain a detection voltage VX; Generate a second control parameter according to the relationship between the detection voltage VX and the reference voltage VC; When the operating current of the battery pack is lower than a preset current threshold, the states of the charging switch K1 and the discharging switch K2 of the battery pack are controlled based on the first control parameter and / or the second control parameter.

[0036] It is worth noting that when either the first control parameter or the second control parameter indicates that a flood fault currently occurs and a control action needs to be issued, a corresponding control action can be issued.

[0037] On the other hand, when the ratio of the detection voltage VX to the reference voltage VC is within the first ratio value interval, the second control parameter includes: allowing the charging switch K1 and the discharging switch K2 to be turned on.

[0038] When the ratio of the detection voltage VX to the reference voltage VC is within the second ratio value interval, the second control parameter includes: allowing the discharge switch K2 to be turned on, and prohibiting the charge switch K1 to be turned on.

[0039] When the ratio of the detection voltage VX to the reference voltage VC is within the third ratio value interval, the second control parameter includes: prohibiting the charging switch K1 from being turned on, and prohibiting the discharging switch K2 from being turned on.

[0040] The first ratio numerical interval is greater than the second ratio numerical interval, and the second ratio numerical interval is greater than the third ratio numerical interval.

[0041] Specifically: The first ratio value interval is: (1 / 3, 1 / 2]; The second ratio value interval is: (1 / 4, 1 / 3]; The third ratio value interval is: [0, 1 / 4].

[0042] The working principle of the above water immersion detection circuit is: like Figure 4The reference voltage VC is 3.3V, the reference resistor R0 is 10KΩ, the voltage divider resistor R1 is 10KΩ, there is a collection node J0 between the reference resistor R0 and the voltage divider resistor R1, and the signal collection end is connected to the collection node J0 through a current limiting resistor R2, and the current limiting resistor R2 is 2KΩ.

[0043] When the battery pack is not immersed in water, the detection voltage VX collected by the signal acquisition end is the voltage across the reference resistor R0 (1.65V), which is 1 / 2 of the reference voltage VC.

[0044] When the battery pack is immersed in water, the water will form a conductive path at the bottom of the battery pack, thereby forming a water immersion equivalent resistance RX in parallel with the reference resistor R0 at both ends of the reference resistor R0. Under the influence of the water immersion equivalent resistance RX, the voltage level at both ends of the reference resistor R0 will drop.

[0045] For example, when the battery pack is slightly submerged in water, a parallel equivalent resistance RX of 10KΩ is generated at both ends of the reference resistor R0. After the water equivalent resistance RX is connected in parallel with the reference resistor R0, the detection voltage collected by the signal acquisition end becomes smaller and becomes 1.1V, which is 1 / 3 of the reference voltage VC. Then, when the detection voltage VX drops to 1.1V, an alarm signal is issued, and the discharge switch K2 is allowed to be turned on, and the charging switch K1 is prohibited from being turned on.

[0046] When the battery pack is heavily submerged in water, a parallel equivalent resistance RX of 5KΩ is generated at both ends of the reference resistor R0. After the equivalent resistance RX is connected in parallel with the reference resistor R0, the detection voltage collected by the signal acquisition end becomes smaller and becomes 0.82V, which is 1 / 4 of the reference voltage VC. Then, when the detection voltage VX drops to 0.82V, an alarm signal is issued, and the charging switch K1 is prohibited from being turned on, and the discharge switch K2 is prohibited from being turned on.

[0047] In this embodiment, the change of the collected detection voltage VX is used to determine whether water immersion occurs and the severity of the water immersion. The more water immersion there is, the smaller the detection voltage VX is.

[0048] In another preferred embodiment of the present invention, a battery pack charge and discharge control system is also disclosed. Figure 3 and Figure 4 , which includes a controller and a charging switch K1 and a discharging switch K2 electrically connected to the controller. The controller controls the states of the charging switch K1 and the discharging switch K2 based on the battery pack charging and discharging control method in the above embodiment.

[0049] Specifically, the control system also includes a temperature and humidity sensor, a battery status information collector, a water immersion detection circuit, and a fault alarm connected to the controller. The temperature and humidity sensor is used to detect the ambient humidity and ambient temperature of the environment inside the battery pack. The battery status information collector is used to collect the temperature, voltage, and charge and discharge current of the battery cells of the battery pack in the battery pack. In this embodiment, the battery status information collector includes an AFE (analog front-end acquisition chip).

[0050] The present invention also discloses another battery pack charge and discharge control system, which includes one or more processors, a memory and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the program includes instructions for executing the battery pack charge and discharge control method as described above. The processor can adopt a general central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), or one or more integrated circuits to execute relevant programs to implement the functions required to be executed by the modules in the battery pack charge and discharge control system of the embodiment of the present application, or to execute the battery pack charge and discharge control method of the method embodiment of the present application.

[0051] The present invention also discloses a computer-readable storage medium, which includes a computer program, and the computer program can be executed by a processor to complete the battery pack charge and discharge control method as described above. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium can be a read-only memory (ROM), or a random access memory (RAM), or a magnetic medium, such as a floppy disk, a hard disk, a tape, a magnetic disk, or an optical medium, such as a digital versatile disc (DVD), or a semiconductor medium, such as a solid state disk (SSD), etc.

[0052] The embodiment of the present application also discloses a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the electronic device executes the above-mentioned battery pack charge and discharge control method.

[0053] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A battery pack charge and discharge control method, characterized in that: A first method is included, wherein the first method includes: Real-time detection of state parameters of the battery pack in the battery pack and environmental parameters of the environment in the battery pack, wherein the environmental parameters include environmental humidity and environmental temperature; generating a current fault parameter related to water intrusion by combining the values ​​of the ambient humidity and the ambient temperature; generating a first control parameter by combining the fault parameter and the state parameter; When the operating current of the battery pack is lower than a preset current threshold, the states of the charging switch and the discharging switch of the battery pack are controlled based on the first control parameter.

2. The battery pack charge and discharge control method according to claim 1, characterized in that: When the following first condition and second condition are satisfied at the same time, the content of the first control parameter includes: allowing the charging switch and the discharging switch to be turned on; First condition: the state parameter is within the normal range; Second condition: the ambient humidity is within the first humidity value range.

3. The battery pack charge and discharge control method according to claim 2, characterized in that: When the first condition and the following third condition are met at the same time, the content of the first control parameter includes: allowing the discharge switch to be turned on and prohibiting the charge switch from being turned on; Third condition: the ambient humidity is within a second humidity value range, and the ambient temperature is greater than or equal to a preset temperature threshold, and the second humidity value range is greater than the first humidity value range.

4. The battery pack charge and discharge control method according to claim 3, characterized in that: When the first condition and the following fourth condition are satisfied at the same time, the content of the first control parameter includes: prohibiting the discharge switch from being turned on, prohibiting the charge switch from being turned on; Fourth condition: the ambient humidity is within a third humidity value interval, and the ambient temperature is greater than or equal to a preset temperature threshold, and the third humidity value interval is greater than the second humidity value interval.

5. The battery pack charge and discharge control method according to claim 1, characterized in that: The state parameters include the temperature and voltage of the battery cells in the battery pack.

6. The battery pack charge and discharge control method according to claim 1, characterized in that: Also included is a second method, the second method comprising: A water immersion detection circuit is provided, the water immersion detection circuit comprising a reference resistor and a reference voltage, the reference resistor is arranged at the bottom of the battery pack, and the reference resistor is electrically connected to the reference voltage through a voltage divider resistor; Detecting the voltage between the reference resistor and the voltage-dividing resistor in real time to obtain a detection voltage; generating a second control parameter according to a relationship between the detection voltage and the reference voltage; When the operating current of the battery pack is lower than a preset current threshold, the states of the charging switch and the discharging switch of the battery pack are controlled based on the first control parameter and / or the second control parameter.

7. The battery pack charge and discharge control method according to claim 6, characterized in that: When the ratio of the detection voltage to the reference voltage is within a first ratio numerical interval, the content of the second control parameter includes: allowing the charging switch and the discharging switch to be turned on; when the ratio of the detection voltage to the reference voltage is within a second ratio numerical interval, the content of the second control parameter includes: allowing the discharging switch to be turned on, and prohibiting the charging switch from being turned on; when the ratio of the detection voltage to the reference voltage is within a third ratio numerical interval, the content of the second control parameter includes: prohibiting the charging switch from being turned on, and prohibiting the discharging switch from being turned on; the first ratio numerical interval is greater than the second ratio numerical interval, and the second ratio numerical interval is greater than the third ratio numerical interval.

8. A battery pack charge and discharge control system, characterized in that: It includes a controller and a charging switch and a discharging switch electrically connected to the controller, and the controller controls the states of the charging switch and the discharging switch based on the battery pack charging and discharging control method according to any one of claims 1 to 7.

9. A battery pack charge and discharge control system, characterized in that: include: one or more processors; Memory; and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, the programs including instructions for executing the battery pack charge and discharge control method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: It includes a computer program, which can be executed by a processor to complete the battery pack charge and discharge control method as described in any one of claims 1 to 7.

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