Battery failure discharge control device and method

Abstract

The invention discloses a battery failure discharge control device and method, which are applied to the technical field of battery safety management and are used for solving the problem of single discharge mode of a battery failure discharge control device in the prior art. Specifically, a multi-stage discharge branch module is connected in parallel between a positive output end and a negative output end of a battery, each stage of discharge branch corresponds to a preset maximum cell voltage interval, and discharge currents corresponding to the stages of discharge branches are different; when the control module determines that the battery is in a failure mode, the control module determines a discharge branch corresponding to a maximum cell voltage interval where the current maximum cell voltage is located as a primary discharge branch; and the primary discharge branch and the post-stage discharge branch are sequentially controlled to be switched on, so that the battery is discharged through the switched-on discharge branches, and all the discharge branches are switched off until the current maximum battery cell voltage meets the battery safety condition. Therefore, the self-adaptive adjustment of the discharge current along with the current maximum cell voltage is realized, and the diversity of the discharge mode is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery safety management, and particularly relates to a battery failure discharge control device and method. BACKGROUND

[0002] With the continuous development and wide application of battery technology, the role of batteries in various electronic devices, energy storage systems and new energy vehicles is increasingly critical. The safety and service life of the battery become important factors that cannot be ignored in the design and use process. When the battery enters the failure mode, there may still be a certain amount of electricity inside. In order to avoid potential safety risks caused by residual electricity, a discharge control device is usually used to control the discharge of the battery so that it reaches below the safety voltage threshold.

[0003] In the prior art, the common discharge control device mainly controls self-discharge through a fixed self-discharge current. Although this discharge method has a simple structure and low cost, it is difficult to adapt to the diversified battery management system requirements and may increase the safety risk in some cases, and even cause unnecessary loss of battery capacity. SUMMARY

[0004] The present application provides a battery failure discharge control device and method to solve the problem of single discharge mode of the existing battery failure discharge control device in the prior art.

[0005] The technical scheme provided by the present application is as follows: On the one hand, the present application provides a battery failure discharge control device, comprising: a voltage detection module, a control module and a multi-stage discharge branch module composed of multiple different levels of discharge branches; The input ends of the voltage detection module are connected with the corresponding battery cells, and the output end of the voltage detection module is connected with the control module; the number of input ends of the voltage detection module is the same as the number of battery cells; the voltage detection module is used to detect the cell voltage of each battery cell in real time; The multi-stage discharge branch module is connected in parallel between the positive output end and the negative output end of the battery, each stage of discharge branch corresponds to a preset maximum cell voltage interval, and the discharge current corresponding to each stage of discharge branch is different; the control ends of the multi-stage discharge branch module are connected with the control module respectively, and the discharge branch is used to be turned on or cut off under the control of the control module; The control module is configured to acquire each cell voltage detected by the voltage detection module; determine a maximum cell voltage in the each cell voltage as a current maximum cell voltage when it is determined that the battery is in the failure mode; determine a discharge branch corresponding to a maximum cell voltage interval in which the current maximum cell voltage is located as a primary discharge branch according to a preset correspondence between the maximum cell voltage interval and the discharge branch; and sequentially control the primary discharge branch and a subsequent discharge branch thereof to be turned on, so that the battery is discharged through the turned-on discharge branch, until all the discharge branches are cut off when the current maximum cell voltage meets a battery safety condition.

[0006] Optionally, the control module is configured to: continuously monitor the current maximum cell voltage during the discharging of the battery through the current stage discharge branch; if the current maximum cell voltage is lower than a lower limit of the maximum cell voltage interval corresponding to the current stage discharge branch, switch to a next stage discharge branch with a lower maximum cell voltage interval threshold, until all the discharge branches are cut off when the current maximum cell voltage is less than a preset safety voltage.

[0007] Optionally, the discharge branch comprises a discharge switch and a discharge resistor. A first end of the discharge resistor is connected to a positive output end of the battery through the discharge switch, and a second end of the discharge resistor is connected to a negative output end of the battery. A control end of the discharge switch is connected to the control module.

[0008] Optionally, the battery failure discharge control device further comprises a temperature acquisition module. The temperature acquisition module is arranged in an interior of the battery, an output end of the temperature acquisition module is connected to the control module, and the temperature acquisition module is configured to acquire a battery temperature. The control module is configured to acquire the battery temperature acquired by the temperature acquisition module, determine a battery voltage according to the each cell voltage detected by the voltage detection module, determine that the battery is in a temporary failure mode in the failure mode when the battery voltage is in a first voltage interval and the battery temperature is in a first temperature interval, and determine that the battery is in a permanent failure mode in the failure mode when the battery voltage is less than a first voltage threshold or the battery temperature is greater than a first temperature threshold, wherein the first voltage threshold is less than a lower limit voltage of the first voltage interval, and the first temperature threshold is greater than an upper limit temperature of the first temperature interval.

[0009] Optionally, the battery failure discharge control device further comprises a first circuit breaking module. A first end of the first circuit breaking module is connected to a positive output end of the battery, a second end of the first circuit breaking module is connected to a positive input end of an external power-consuming device, a control end of the first circuit breaking module is connected to the control module, and the first circuit breaking module is configured to cut off or turn on a connection between the positive output end of the battery and the positive input end of the external power-consuming device. The control module is configured to control the first circuit breaking module to cut off the connection between the positive output terminal of the battery and the positive input terminal of the external power consuming device when the battery is in the temporary failure mode.

[0010] Optionally, the first circuit breaking module comprises a first MOS tube and a second MOS tube. The source of the first MOS tube is connected to the positive output terminal of the battery, the drain of the first MOS tube is connected to the drain of the second MOS tube, and the gate of the first MOS tube is connected to the control module. The source of the second MOS tube is connected to the positive input terminal of the external power consuming device, and the gate of the second MOS tube is connected to the control module.

[0011] Optionally, the battery failure discharge control device further comprises a second circuit breaking module. The first end of the second circuit breaking module is connected to the positive output terminal of the battery, the second end of the second circuit breaking module is connected to the first end of the first circuit breaking module, the third end of the second circuit breaking module is connected to the connection between the negative output terminal of the battery and the negative input terminal of the external power consuming device, and the control end of the second circuit breaking module is connected to the control module; the second circuit breaking module is configured to melt the connection between the positive output terminal of the battery and the positive input terminal of the external power consuming device. The control module is configured to control the second circuit breaking module to melt the connection between the positive output terminal of the battery and the positive input terminal of the external power consuming device when the battery is in the permanent failure mode.

[0012] Optionally, the second circuit breaking module comprises a third MOS tube, a first resistor, a first fuse and a second fuse. The first end of the first fuse is connected to the positive output terminal of the battery, the second end of the first fuse is connected to the first end of the second fuse, and the second end of the second fuse is connected to the first end of the first circuit breaking module. The source of the third MOS tube is connected between the negative output terminal of the battery and the negative input terminal of the external power consuming device, the drain of the third MOS tube is connected between the second end of the first fuse and the first end of the second fuse through the first resistor, and the gate of the third MOS tube is connected to the control module.

[0013] In another aspect, the application provides a battery failure discharge control method applied to the battery failure discharge control device, and the battery failure discharge control method comprises the following steps: Obtaining the cell voltages of the battery cells in the battery; When it is determined that the battery is in the failure mode, determining the maximum cell voltage in the cell voltages as the current maximum cell voltage; According to the correspondence between the preset maximum cell voltage intervals and the discharge branches, determining the discharge branch corresponding to the maximum cell voltage interval where the current maximum cell voltage is located as the primary discharge branch; The primary discharge branch and its subsequent discharge branches are sequentially controlled to discharge the battery through the connected discharge branches until the current maximum cell voltage meets the battery safety conditions, at which point all discharge branches are cut off.

[0014] Optionally, the primary discharge branch and its subsequent discharge branches are sequentially connected, allowing the battery to discharge through the connected discharge branches until the current maximum cell voltage meets the battery safety requirements, at which point all discharge branches are disconnected, including: The maximum cell voltage is continuously monitored during the discharge process of the battery through the current stage discharge branch. If the current maximum cell voltage is lower than the lower limit of the maximum cell voltage range corresponding to the current discharge branch, switch to the next discharge branch with a lower maximum cell voltage range threshold, until the current maximum cell voltage is less than the preset safety voltage and all discharge branches are cut off.

[0015] Optionally, after obtaining the voltage of each cell detected by the voltage detection module, the following steps are included: Obtain the battery temperature; The battery voltage is determined based on the cell voltage of each cell in the battery. When the battery voltage is in the first voltage range and the battery temperature is in the first temperature range, the battery is determined to be in a temporary failure mode within the failure modes; the first circuit breaker module is controlled to disconnect the positive output terminal of the battery from the positive input terminal of the external electrical device; When the battery voltage is less than a first voltage threshold or the battery temperature is greater than a first temperature threshold, the battery is determined to be in a permanent failure mode within the failure modes; wherein, the first voltage threshold is less than the lower limit voltage of the first voltage range and the first temperature threshold is greater than the upper limit temperature of the first temperature range; the second circuit breaker module is controlled to melt and disconnect the connection between the positive output terminal of the battery and the positive input terminal of the external electrical device.

[0016] The beneficial effects of this application are as follows: In this application, the battery failure discharge control device connects multiple discharge branches corresponding to different maximum cell voltage ranges in parallel. The control module intelligently matches and sequentially connects the primary discharge branch and its subsequent branches corresponding to the respective range based on the real-time detected maximum cell voltage. This achieves adaptive adjustment of the discharge current according to the battery voltage state. Initially, a large current is used for rapid discharge to reduce safety risks when the voltage is high; after the voltage drops, it automatically switches to a smaller current for finer discharge. This intelligent graded discharge method can efficiently reduce the cell voltage to a safe range when the battery is in failure mode, thereby reducing safety risks. It achieves intelligent graded adjustable control of the discharge current, enhances the diversity of discharge methods, and provides an active discharge protection mechanism that balances safety and economy.

[0017] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the first structure of the battery failure discharge control device in the embodiments of this application; Figure 2 This is a schematic diagram of a second structure of the battery failure discharge control device in the embodiments of this application; Figure 3 This is a schematic diagram of a third structure of the battery failure discharge control device in the embodiments of this application; Figure 4 This is a schematic diagram of the fourth structure of the battery failure discharge control device in the embodiments of this application; Figure 5 This is a schematic diagram of the fifth structure of the battery failure discharge control device in the embodiments of this application; Figure 6 This is a schematic diagram of the sixth structure of the battery failure discharge control device in the embodiments of this application; Figure 7 This is a schematic diagram of the seventh structure of the battery failure discharge control device in the embodiments of this application; Figure 8 This is a schematic diagram of the overall framework of the battery failure discharge control method in the embodiments of this application; Figure 9 This is a schematic flowchart illustrating the discharge branch switching method in the embodiments of this application. Figure 10 This is a schematic diagram outlining the battery failure identification method in the embodiments of this application.

[0019] Icons: 100 - Battery failure discharge control device; 110 - Voltage detection module; 120 - Control module; 130 - Discharge branch; 131 - Discharge switch; 132 - Discharge resistor; 140 - Temperature acquisition module; 150 - First circuit breaker module; Q1 - First MOSFET; Q2 - Second MOSFET; 160 - Second circuit breaker module; Q3 - Third MOSFET; R1 - First resistor; F1 - First fuse; F2 - Second fuse. Detailed Implementation

[0020] To make the objectives, technical solutions, and beneficial effects of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0022] This application provides a battery failure discharge control device, see below. Figure 1 As shown, the battery failure discharge control device 100 provided in this application embodiment includes at least: a voltage detection module 110, a control module 120, and a multi-level discharge branch module composed of multiple discharge branches 130 of different levels. Each input terminal of the voltage detection module 110 is connected to the corresponding cell in the battery, and the output terminal of the voltage detection module 110 is connected to the control module 120; the number of input terminals of the voltage detection module 110 is the same as the number of cells; the voltage detection module 110 is used to detect the cell voltage of each cell in the battery in real time. The multi-stage discharge branch module is connected in parallel between the positive and negative output terminals of the battery. Each discharge branch 130 corresponds to a preset maximum cell voltage range, and the discharge current corresponding to each discharge branch 130 is different. The control terminals of the multi-stage discharge branch module are connected to the control module 120 respectively. The discharge branch 130 is used to be turned on or off under the control of the control module 120. The control module 120 is used to acquire the voltage of each cell detected by the voltage detection module 110; when the battery is in failure mode, the largest cell voltage among the cell voltages is determined as the current maximum cell voltage; according to the preset correspondence between the maximum cell voltage range and the discharge branch 130, the discharge branch 130 corresponding to the maximum cell voltage range where the current maximum cell voltage is located is determined as the primary discharge branch 130; the primary discharge branch 130 and its subsequent discharge branches 130 are sequentially controlled to be connected, so that the battery discharges through the connected discharge branch 130 until the current maximum cell voltage meets the battery safety conditions and the connected discharge branch 130 is disconnected.

[0023] exist Figure 1In the battery failure discharge control device 100 shown, the battery failure mode refers to the abnormal operating state of the battery caused by factors such as overcharging, high temperature, or mechanical abuse, resulting in abnormal voltage / temperature. This state needs to be restored or suppressed through discharge control. It is divided into two categories: reversible temporary failure modes and irreversible permanent failure modes. Temporary failure modes refer to short-term abnormal modes that do not cause structural damage to the battery and can be restored to a healthy state through graded discharge. Permanent failure modes refer to long-term abnormal modes that cause structural or chemical damage to the battery and cannot be restored through conventional discharge. The voltage detection module 110 can use a high-precision voltage sampling chip to collect the voltage difference between the two ends of each cell in the battery through high-frequency sampling, thus obtaining the voltage of each cell. Each discharge branch 130 in the multi-stage discharge branch module corresponds to a preset maximum cell voltage range, and the discharge branches 130 corresponding to different maximum cell voltage ranges are configured to provide different discharge currents. Based on the range threshold of the maximum cell voltage range corresponding to each discharge branch 130, each discharge branch 130 is set to a corresponding level. The lower the level of the discharge branch 130, the larger the range threshold of the corresponding maximum cell voltage range, and the larger the corresponding discharge current. The maximum cell voltage ranges corresponding to each discharge branch 130 are continuous and do not overlap. Furthermore, the maximum cell voltage range corresponding to each discharge branch 130 can completely cover the voltage range from the cell's safe voltage to its maximum voltage. The control module 120 can sequentially connect each discharge branch 130 until the current maximum cell voltage meets the battery safety conditions, at which point all discharge branches 130 are disconnected.

[0024] In practical applications, the control module 120 first acquires the cell voltages collected by the voltage detection module 110 in real time. When the battery is determined to enter a failure mode, the highest cell voltage is selected from the current cell voltages as the current maximum cell voltage. Subsequently, based on the preset mapping relationship between the maximum cell voltage range and the discharge branch 130, the discharge branch 130 corresponding to the current maximum cell voltage range is located as the primary discharge branch 130. The primary discharge branch 130 and its subsequent levels are connected sequentially from smallest to largest according to the level of the discharge branches 130. The dynamic adjustment of the discharge current and the energy release of the battery are achieved through the step-by-step switching of multiple discharge branches. This staged discharge process continues until the current maximum cell voltage drops and meets the preset battery safety conditions. When the current maximum cell voltage meets the battery safety conditions, the control module 120 immediately cuts off all discharge branches 130, marking the completion of the safe discharge process of the battery in failure mode.

[0025] In this way, the battery failure discharge control device 100 connects multiple discharge branches 130 corresponding to different maximum cell voltage ranges in parallel. The control module 120 intelligently matches and sequentially connects the primary discharge branch 130 and its subsequent branches corresponding to the current maximum cell voltage range based on real-time detection, achieving adaptive adjustment of the discharge current according to the battery voltage state. Initially, a large current is used for rapid discharge to reduce safety risks when the voltage is high; after the voltage drops, it automatically switches to a smaller current for fine discharge. This intelligent graded discharge method can efficiently reduce the cell voltage to a safe range when the battery is in failure mode, thereby reducing safety risks. It achieves intelligent graded adjustable control of the discharge current, enhances the diversity of discharge methods, and provides an active discharge protection mechanism that balances safety and economy.

[0026] Specifically, when sequentially controlling the connection of the primary discharge branch and its subsequent discharge branches, allowing the battery to discharge through the connected discharge branches, until the current maximum cell voltage meets the battery safety conditions and all discharge branches are disconnected, the control module is specifically used for: First, continuously monitor the current maximum cell voltage during the discharge process of the battery through the current stage discharge branch; Then, if the current maximum cell voltage is lower than the lower limit of the maximum cell voltage range corresponding to the current discharge branch, switch to the next discharge branch with a lower maximum cell voltage range threshold, until the current maximum cell voltage is less than the preset safety voltage and all discharge branches are cut off.

[0027] In practical applications, the current-level discharge branch is the discharge branch currently controlled and activated by the control module. Upon initial activation, the current-level discharge branch is the primary discharge branch. Subsequent activations involve a higher number of stages than the primary discharge branch, and a lower threshold value than the primary discharge branch. The control module continuously monitors the change in the current maximum cell voltage as the battery discharges through the current-level discharge branch. The current maximum cell voltage decreases as the battery discharges through the current-level discharge branch. If the current maximum cell voltage drops below the lower limit of the maximum cell voltage range corresponding to the current-level discharge branch (e.g., if the current-level branch corresponds to the 4.3~4.4V range, and the current maximum cell voltage drops to 4.3V), the module automatically switches to the next-level discharge branch with an even lower threshold value (e.g., switching to the discharge branch corresponding to the 4.2~4.3V range). This gradual activation of discharge branches with lower threshold values ​​allows for step-by-step discharge of the battery. This process continues to iterate until the current maximum cell voltage is lower than the preset safe voltage (e.g., 3.8V). At this point, the control module cuts off the currently connected discharge branch to ensure that the battery voltage remains stable within a safe range.

[0028] In practical implementation, the discharge branch in the battery failure discharge control device has various structures to achieve its function; see [reference needed]. Figure 2As shown, the discharge branch 130 may include: a discharge switch 131 and a discharge resistor 132; The first end of the discharge resistor 132 is connected to the positive output terminal of the battery via the discharge switch 131, and the second end of the discharge resistor 132 is connected to the negative output terminal of the battery. The control terminal of the discharge switch 131 is connected to the control module 120.

[0029] exist Figure 2 In the battery failure discharge control device 100 shown, the discharge switch 131 is used to connect or disconnect the discharge branch 130. The on / off state of the discharge switch 131 can be controlled by the control module 120 through a level signal or a PWM signal. The discharge switch 131 can be one of the controllable switches such as MOSFET, relay, and IGBT. The discharge resistor 132, as an energy-consuming element, has its first end connected to the positive terminal of the battery through the discharge switch 131, and its second end directly connected to the negative terminal of the battery, forming a complete discharge circuit. When the control module 120 determines that a certain level of discharge branch 130 needs to be activated, it connects the branch by closing the corresponding discharge switch 131. The battery's electrical energy is converted into heat energy and consumed through the discharge resistor 132, thereby reducing the battery voltage. The resistance value of the discharge resistor 132 varies depending on the level of the discharge branch 130; the smaller the level of the discharge branch 130, the smaller the resistance value of the discharge resistor 132. By switching the discharge branches 130 with different resistance values ​​step by step, the control module 120 can dynamically adjust the discharge current, balancing discharge efficiency and safety.

[0030] In one possible implementation, see [reference] Figure 3 As shown, the battery failure discharge control device 100 also includes a temperature acquisition module 140; The temperature acquisition module 140 is located inside the battery, and its output is connected to the control module 120; the temperature acquisition module 140 is used to acquire the battery temperature. The control module 120 is used to acquire the battery temperature acquired by the temperature acquisition module 140; determine the battery voltage based on the voltage of each cell detected by the voltage detection module 110; determine that the battery is in a temporary failure mode when the battery voltage is in a first voltage range and the battery temperature is in a first temperature range; determine that the battery is in a permanent failure mode when the battery voltage is less than a first voltage threshold or the battery temperature is greater than a first temperature threshold; wherein, the first voltage threshold is less than the lower limit voltage of the first voltage range and the first temperature threshold is greater than the upper limit temperature of the first temperature range.

[0031] exist Figure 3In the battery failure discharge control device 100 shown, the temperature acquisition module 140 may include a temperature sensor. The temperature sensor is integrated into the cell gaps or near the battery tabs inside the battery. The temperature sensor directly monitors the battery temperature, avoiding interference from ambient temperature. The temperature sensor can be an NTC thermistor or a digital temperature acquisition chip. The battery temperature acquired by the temperature sensor is transmitted to the control module 120 in real time. After receiving the battery temperature, the control module 120 combines the battery temperature and battery voltage to determine whether the battery is in a failure mode. The first voltage range is the voltage range within which the battery can fail but recover. The first temperature range is the temperature range within which the battery can fail but recover. The first voltage threshold is the lowest voltage at which the battery fails and cannot recover. The first temperature threshold is the lowest temperature at which the battery fails and cannot recover.

[0032] In practical applications, the control module 120 sums the voltages of each cell detected by the voltage detection module 110 in real time to obtain the battery voltage; the control module 120 also acquires the battery temperature collected by the temperature acquisition module 140 in real time; when the battery voltage and battery temperature are both within a first voltage range and a first temperature range, the control module 120 determines that the battery is in a temporary failure mode, in which discharging the battery can restore its functionality. When the battery voltage is less than a first voltage threshold or the battery temperature is greater than a first temperature threshold, the control module 120 determines that the battery is in a permanent failure mode, in which discharging the battery can ensure circuit safety.

[0033] In one possible implementation, see [reference] Figure 4 As shown, the battery failure discharge control device 100 also includes: a first circuit breaker module 150; The first terminal of the first circuit breaker module 150 is connected to the positive output terminal of the battery, and the second terminal of the first circuit breaker module 150 is connected to the positive input terminal of the external electrical device; the control terminal of the first circuit breaker module 150 is connected to the control module 120; the first circuit breaker module 150 is used to disconnect or connect the connection between the positive output terminal of the battery and the positive input terminal of the external electrical device. The control module 120 is used to control the first circuit breaker module 150 to disconnect the connection between the positive output terminal of the battery and the positive input terminal of the external electrical equipment when the battery is in a temporary failure mode.

[0034] exist Figure 4In the battery failure discharge control device 100 shown, since a battery in a temporary failure mode can be recovered, when the control module 120 determines that the battery is in a temporary failure mode, it controls the first circuit breaker module 150 to disconnect the connection between the positive output terminal of the battery and the positive input terminal of the external electrical device, thereby preventing potential damage to the external electrical device from the battery in a temporary failure mode and protecting the external electrical device. After determining that the current maximum cell voltage of the battery meets the battery safety conditions and disconnecting all discharge branches 130, the control module 120 controls the first circuit breaker module 150 to reconnect the connection between the positive output terminal of the battery and the positive input terminal of the external electrical device, restoring the battery's power supply to the external electrical device and ensuring that the external electrical device can be put back into use when the battery is in a non-failure mode.

[0035] In practical implementation, the first circuit breaker module in the battery failure discharge control device has various structures to achieve its function; see [reference needed]. Figure 5 As shown, the first circuit breaker module 150 may include: a first MOSFET Q1 and a second MOSFET Q2; The source of the first MOSFET Q1 is connected to the positive output terminal of the battery, the drain of the first MOSFET Q1 is connected to the drain of the second MOSFET Q2, and the gate of the first MOSFET Q1 is connected to the control module 120. The source of the second MOSFET Q2 is connected to the positive input terminal of the external electrical device, and the gate of the second MOSFET Q2 is connected to the control module 120.

[0036] exist Figure 5 In the battery failure discharge control device 100 shown, when the control module 120 determines that the battery is in a temporary failure mode, the control module 120 removes the gate voltage of the first MOSFET Q1 and the second MOSFET Q2, causing the first MOSFET Q1 and the second MOSFET Q2 to disconnect, thus cutting off the electrical connection between the battery and the external electrical device. After determining that the current maximum cell voltage of the battery meets the battery safety conditions and cutting off all discharge branches 130, the control module 120 applies a positive drive voltage to the gates of the first MOSFET Q1 and the second MOSFET Q2, causing the first MOSFET Q1 and the second MOSFET Q2 to conduct, thus connecting the positive terminal of the battery to the external electrical device. The back-to-back structure of the first MOSFET Q1 and the second MOSFET Q2 can simultaneously block the current flowing from the positive battery to the external electrical device and from the external device to the battery, preventing reverse voltage generated by parasitic inductance or capacitance from damaging the devices after shutdown.

[0037] In one possible implementation, see [reference] Figure 6 As shown, the battery failure discharge control device 100 also includes: a second circuit breaker module 160; The first terminal of the second circuit breaker module 160 is connected to the positive output terminal of the battery, the second terminal of the second circuit breaker module 160 is connected to the first terminal of the first circuit breaker module 150, the third terminal of the second circuit breaker module 160 is connected to the wiring between the negative output terminal of the battery and the negative input terminal of the external electrical device, and the control terminal of the second circuit breaker module 160 is connected to the control module 120; the second circuit breaker module 160 is used to fuse the connection between the positive output terminal of the battery and the positive input terminal of the external electrical device. The control module 120 is used to control the second circuit breaker module 160 to melt and disconnect the connection between the positive output terminal of the battery and the positive input terminal of the external electrical equipment when the battery is in a permanent failure mode.

[0038] exist Figure 6 In the battery failure discharge control device 100 shown, since a battery in permanent failure mode cannot be recovered, the control module 120, upon determining that the battery is in permanent failure mode, controls the second circuit breaker module 160 to fuse the connection between the positive output terminal of the battery and the positive input terminal of the external electrical equipment. This ensures the safety of the battery when it is in permanent failure mode, prevents the battery from being reconnected, and avoids secondary accidents.

[0039] In practical implementation, the second circuit breaker module in the battery failure discharge control device has various structures to achieve its function; see [reference needed]. Figure 7 As shown, the second circuit breaker module 160 includes: a third MOSFET Q3, a first resistor R1, a first fuse F1, and a second fuse F2; The first end of the first fuse F1 is connected to the positive output terminal of the battery, the second end of the first fuse F1 is connected to the first end of the second fuse F2, and the second end of the second fuse F2 is connected to the first end of the first circuit breaker module 150. The source of the third MOSFET Q3 is connected between the negative output terminal of the battery and the negative input terminal of the external electrical device. The drain of the third MOSFET Q3 is connected between the second terminal of the first fuse F1 and the first terminal of the second fuse F2 via the first resistor R1. The gate of the third MOSFET Q3 is connected to the control module 120.

[0040] exist Figure 7In the battery failure discharge control device 100 shown, the first fuse F1 and the second fuse F2 form a series fuse chain, connected in series between the positive terminal of the battery and the external electrical device. The first resistor R1 is connected in series between the drain of the third MOSFET Q3 and the midpoint between the first fuse F1 and the second fuse F2, serving as a current limiter and voltage divider. When the third MOSFET Q3 is off, the positive terminal of the battery is connected to the external electrical device through the first fuse F1 and the second fuse F2. When the third MOSFET Q3 is on, the negative terminal of the battery forms a bypass current through the third MOSFET Q3 and the first resistor R1, heating the first fuse F1 and the second fuse F2 to melt them, thus cutting off the connection between the positive terminal of the battery and the external electrical device. By generating a bypass current through the third MOSFET Q3 and the first resistor R1, the heating power of the first fuse F1 and the second fuse F2 is precisely controlled, avoiding energy waste and secondary damage caused by traditional direct short-circuit fusing. The first resistor R1 limits the current to prevent excessive current during the fusing process, protecting the third MOSFET Q3. The dual fuse setup with the second fuse F2 ensures that if one fuse fails to completely blow due to a manufacturing defect, the other fuse can still provide isolation, improving fusing reliability. Furthermore, the melting points of the first fuse F1 and the second fuse F2 can be different; the melting point of the first fuse F1 can be lower than that of the second fuse F2. The first fuse F1 is responsible for rapid response to minor overcurrents, while the second fuse F2 handles extreme faults, forming a gradient protection system.

[0041] Based on the above embodiments, this application provides a battery failure discharge control method, applied to the aforementioned battery failure discharge control device, see below. Figure 8 As shown, the general flow of the battery failure discharge control method provided in this application embodiment is as follows: Step 101: Obtain the cell voltage of each cell in the battery.

[0042] Step 102: When it is determined that the battery is in failure mode, the highest cell voltage among all cell voltages is determined as the current maximum cell voltage.

[0043] In practical applications, the control module in the battery failure discharge control device performs the battery failure mode determination operation. Specifically, the control module comprehensively judges the battery's operating status by acquiring and analyzing the voltage of each cell collected by the voltage detection module in real time, and optionally acquiring the battery temperature collected by the temperature acquisition module. The control module has pre-stored judgment conditions for defining failure modes, such as thresholds or ranges related to battery voltage and battery temperature. When the real-time monitored battery voltage and / or battery temperature data meet these preset failure judgment conditions, the control module automatically determines that the battery has entered a failure mode.

[0044] Step 103: Based on the preset correspondence between the maximum cell voltage range and the discharge branch, determine the discharge branch corresponding to the maximum cell voltage range where the current maximum cell voltage is located as the primary discharge branch.

[0045] Step 104: Sequentially control the connection of the primary discharge branch and its subsequent discharge branches, so that the battery discharges through the connected discharge branches until the current maximum cell voltage meets the battery safety conditions, at which point all discharge branches are disconnected.

[0046] In one possible implementation, see [reference] Figure 9 As shown, the steps of sequentially controlling the connection of the primary discharge branch and its subsequent discharge branches, allowing the battery to discharge through the connected discharge branches, until the current maximum cell voltage meets the battery safety conditions and the connected discharge branches are disconnected, include: Step 201: Continuously monitor the current maximum cell voltage during the discharge process of the battery through the current stage discharge branch.

[0047] Step 202: If the current maximum cell voltage is lower than the lower limit of the maximum cell voltage range corresponding to the current discharge branch, switch to the next discharge branch with a lower maximum cell voltage range threshold, until the current maximum cell voltage is less than the preset safety voltage and all discharge branches are cut off.

[0048] In practical applications, each discharge branch corresponds to a preset maximum cell voltage range, defined by its upper and lower threshold values. A lower maximum cell voltage range threshold means that the upper threshold of the maximum cell voltage range corresponding to a discharge branch is numerically lower than the upper threshold of the range corresponding to the preceding discharge branch. For example, if the range corresponding to the first-stage discharge branch is 4.3V to 4.4V, its upper threshold is 4.4V; and the range corresponding to the second-stage discharge branch is 4.2V to 4.3V, its upper threshold is 4.3V. Therefore, the second-stage discharge branch has a lower maximum cell voltage range threshold than the first stage. The control module, based on the decrease in the current maximum cell voltage, sequentially switches from branches corresponding to higher maximum cell voltage range thresholds to branches corresponding to lower maximum cell voltage range thresholds. By progressively lowering the voltage threshold that allows discharge to begin, adaptive control is achieved, where the discharge current decreases progressively as the voltage decreases.

[0049] In one possible implementation, see [reference] Figure 10 As shown, after obtaining the voltage of each cell detected by the voltage detection module, the following is included: Step 301: Obtain the battery temperature.

[0050] Step 302: Determine the battery voltage based on the cell voltage of each cell in the battery.

[0051] Step 303: When the battery voltage is within the first voltage range and the battery temperature is within the first temperature range, determine that the battery is in a temporary failure mode within the failure modes; control the first circuit breaker module to disconnect the positive output terminal of the battery from the positive input terminal of the external electrical device; when the battery voltage is less than the first voltage threshold or the battery temperature is greater than the first temperature threshold, determine that the battery is in a permanent failure mode within the failure modes; wherein, the first voltage threshold is less than the lower limit voltage of the first voltage range, and the first temperature threshold is greater than the upper limit temperature of the first temperature range; control the second circuit breaker module to melt and disconnect the positive output terminal of the battery from the positive input terminal of the external electrical device.

[0052] It should be noted that the principle of the battery failure discharge control method provided in this application embodiment to solve the technical problem is similar to that of the battery failure discharge control device provided in this application embodiment. Therefore, the implementation of the battery failure discharge control method provided in this application embodiment can refer to the implementation of the battery failure discharge control device provided in this application embodiment, and the repeated parts will not be described again.

[0053] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0054] Furthermore, although the operations of the method of this application are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0055] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0056] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A battery failure discharge control device, characterized in that, include: The module includes a voltage detection module, a control module, and a multi-level discharge branch module consisting of multiple discharge branches of different levels. Each input terminal of the voltage detection module is connected to a corresponding cell in the battery, and the output terminal of the voltage detection module is connected to the control module; the number of input terminals of the voltage detection module is the same as the number of cells; the voltage detection module is used to detect the cell voltage of each cell in the battery in real time. The multi-stage discharge branch module is connected in parallel between the positive and negative output terminals of the battery. Each discharge branch corresponds to a preset maximum cell voltage range, and the discharge current corresponding to each discharge branch is different. The control terminals of the multi-stage discharge branch module are respectively connected to the control module, and the discharge branch is used to be turned on or off under the control of the control module. The control module is used to acquire the voltage of each cell detected by the voltage detection module; when it is determined that the battery is in a failure mode, the largest cell voltage among the cell voltages is determined as the current maximum cell voltage; according to the preset correspondence between the maximum cell voltage range and the discharge branch, the discharge branch corresponding to the maximum cell voltage range in which the current maximum cell voltage is located is determined as the primary discharge branch. The primary discharge branch and its subsequent discharge branches are sequentially controlled to be connected, so that the battery discharges through the connected discharge branches until the current maximum cell voltage meets the battery safety conditions, at which point all discharge branches are disconnected.

2. The battery failure discharge control device as described in claim 1, characterized in that, The control module is used for: The current maximum cell voltage is continuously monitored during the discharge process of the battery through the current stage discharge branch. If the current maximum cell voltage is lower than the lower limit of the maximum cell voltage range corresponding to the current discharge branch, switch to the next discharge branch with a lower maximum cell voltage range threshold, until the current maximum cell voltage is less than the preset safety voltage and all discharge branches are cut off.

3. The battery failure discharge control device as described in claim 1, characterized in that, The discharge branch includes: a discharge switch and a discharge resistor; The first end of the discharge resistor is connected to the positive output terminal of the battery via the discharge switch, and the second end of the discharge resistor is connected to the negative output terminal of the battery. The control terminal of the discharge switch is connected to the control module.

4. The battery failure discharge control device according to any one of claims 1-3, characterized in that, Also includes: Temperature acquisition module; The temperature acquisition module is located inside the battery, and its output is connected to the control module; the temperature acquisition module is used to acquire the battery temperature. The control module is used to acquire the battery temperature collected by the temperature acquisition module; determine the battery voltage based on the voltage of each cell detected by the voltage detection module; determine that the battery is in a temporary failure mode when the battery voltage is in a first voltage range and the battery temperature is in a first temperature range; determine that the battery is in a permanent failure mode when the battery voltage is less than a first voltage threshold or the battery temperature is greater than a first temperature threshold; wherein, the first voltage threshold is less than the lower limit voltage of the first voltage range, and the first temperature threshold is greater than the upper limit temperature of the first temperature range.

5. The battery failure discharge control device as described in claim 4, characterized in that, Also includes: First circuit breaker module; The first terminal of the first circuit breaker module is connected to the positive output terminal of the battery, and the second terminal of the first circuit breaker module is connected to the positive input terminal of the external electrical device; the control terminal of the first circuit breaker module is connected to the control module; the first circuit breaker module is used to disconnect or connect the connection between the positive output terminal of the battery and the positive input terminal of the external electrical device. The control module is used to control the first circuit breaker module to disconnect the positive output terminal of the battery from the positive input terminal of the external electrical equipment when the battery is in a temporary failure mode.

6. The battery failure discharge control device as described in claim 5, characterized in that, The first circuit breaker module includes: a first MOSFET and a second MOSFET; The source of the first MOSFET is connected to the positive output terminal of the battery, the drain of the first MOSFET is connected to the drain of the second MOSFET, and the gate of the first MOSFET is connected to the control module. The source of the second MOSFET is connected to the positive input terminal of the external electrical device, and the gate of the second MOSFET is connected to the control module.

7. The battery failure discharge control device as described in claim 5, characterized in that, Also includes: Second circuit breaker module; The first terminal of the second circuit breaker module is connected to the positive output terminal of the battery, the second terminal of the second circuit breaker module is connected to the first terminal of the first circuit breaker module, the third terminal of the second circuit breaker module is connected to the wiring between the negative output terminal of the battery and the negative input terminal of the external electrical device, and the control terminal of the second circuit breaker module is connected to the control module; the second circuit breaker module is used to fuse the connection between the positive output terminal of the battery and the positive input terminal of the external electrical device. The control module is used to control the second circuit breaker module to melt and disconnect the connection between the positive output terminal of the battery and the positive input terminal of the external electrical equipment when the battery is in a permanent failure mode.

8. The battery failure discharge control device as described in claim 7, characterized in that, The second circuit breaker module includes: a third MOSFET, a first resistor, a first fuse, and a second fuse; The first terminal of the first fuse is connected to the positive output terminal of the battery, the second terminal of the first fuse is connected to the first terminal of the second fuse, and the second terminal of the second fuse is connected to the first terminal of the first circuit breaker module. The source of the third MOS transistor is connected between the negative output terminal of the battery and the negative input terminal of the external electrical device. The drain of the third MOS transistor is connected between the second terminal of the first fuse and the first terminal of the second fuse via the first resistor. The gate of the third MOS transistor is connected to the control module.

9. A battery failure discharge control method, characterized in that, The battery failure discharge control method, applied to the battery failure discharge control device as described in any one of claims 1-8, comprises: Obtain the cell voltage of each cell in the battery; When it is determined that the battery is in a failure mode, the largest cell voltage among all the cell voltages is determined as the current maximum cell voltage; Based on the preset correspondence between the maximum cell voltage range and the discharge branch, the discharge branch corresponding to the maximum cell voltage range where the current maximum cell voltage is located is determined as the primary discharge branch. The primary discharge branch and its subsequent discharge branches are sequentially controlled to be connected, so that the battery discharges through the connected discharge branches until the current maximum cell voltage meets the battery safety conditions, at which point all discharge branches are disconnected.

10. The battery failure discharge control method as described in claim 9, characterized in that, The process of sequentially controlling the connection of the primary discharge branch and its subsequent discharge branches, allowing the battery to discharge through the connected discharge branches, until the current maximum cell voltage meets the battery safety conditions, at which point all discharge branches are disconnected, includes: The current maximum cell voltage is continuously monitored during the discharge process of the battery through the current stage discharge branch. If the current maximum cell voltage is lower than the lower limit of the maximum cell voltage range corresponding to the current discharge branch, switch to the next discharge branch with a lower maximum cell voltage range threshold, until the current maximum cell voltage is less than the preset safety voltage and all discharge branches are cut off.

11. The battery failure discharge control method as described in claim 10, characterized in that, After obtaining the voltage of each cell detected by the voltage detection module, the following steps are included: Obtain the battery temperature of the battery; The battery voltage is determined based on the cell voltage of each cell in the battery. When the battery voltage is in the first voltage range and the battery temperature is in the first temperature range, the battery is determined to be in the temporary failure mode of the failure mode; the first circuit breaker module is controlled to disconnect the positive output terminal of the battery from the positive input terminal of the external electrical device; When the battery voltage is less than a first voltage threshold or the battery temperature is greater than a first temperature threshold, the battery is determined to be in a permanent failure mode within the failure modes; wherein the first voltage threshold is less than the lower limit voltage of the first voltage range and the first temperature threshold is greater than the upper limit temperature of the first temperature range; the second circuit breaker module is controlled to melt and disconnect the connection between the positive output terminal of the battery and the positive input terminal of the external electrical device.

Images