Battery pack over-discharge protection circuit and device

Abstract

The utility model relates to the technical field of battery safety protection, and discloses a battery pack over-discharge protection circuit and a battery pack over-discharge protection device, in the starting operation process of the battery pack over-discharge protection circuit, a low-voltage control module can detect the operation state of a high-voltage discharge module in real time, and when the high-voltage discharge module is detected to be in a dormant state, the battery pack over-discharge protection circuit is started. The low-voltage control module starts safety monitoring for the high-voltage discharge module only if the high-voltage discharge module fails to work, specifically, whether the high-voltage discharge module has an over-current or under-voltage fault or not is monitored, and when the over-current or under-voltage fault exists, the low-voltage control module reversely awakens a battery management system (BMS) arranged in the module, so that the over-current or under-voltage fault of the high-voltage discharge module is monitored. And a battery management system (BMS) generates a corresponding safety control signal in time, so that target control operation including fusing control of a safety device is executed on the high-voltage discharge module in time based on the safety control signal, and a power supply loop of the high-voltage discharge module is disconnected.

Description

Technical Field

[0001] This utility model relates to the field of battery safety protection technology, and in particular to a battery pack over-discharge protection circuit and device. Background Technology

[0002] In the field of new energy vehicles, especially plug-in hybrid electric vehicles (PHEVs) and hybrid electric vehicles (HEVs), battery pack management and protection are crucial. Traditional designs typically employ a combination of a main positive relay and a main negative relay to safely and effectively control the connection and disconnection of the battery pack. This design can quickly disconnect the battery pack from external electrical equipment when needed, thereby preventing continuous discharge under improper conditions and ensuring the stability and safety of the battery system.

[0003] However, due to recent cost pressures, some PHEV and HEV projects have eliminated the main negative relay in their designs, retaining only the main positive relay for connecting and disconnecting the battery pack. While this change reduces costs to some extent, it also introduces significant safety hazards. Specifically, when the main positive relay becomes stuck due to long-term use, aging, or malfunction, it will be unable to properly disconnect the battery pack from external electrical equipment. In this situation, even when the vehicle is parked, the battery pack may continue to supply power to external devices, causing the battery to gradually deplete. Prolonged over-discharge not only severely damages the battery pack, such as shortening battery life and reducing battery capacity, but may also trigger more serious safety issues, such as battery thermal runaway, thereby threatening the safety of the vehicle and its passengers. Utility Model Content

[0004] This invention provides a battery pack over-discharge protection circuit, which can improve the detection speed and processing efficiency of battery pack over-discharge, while also ensuring the safety and reliability of the battery pack.

[0005] To solve the above-mentioned technical problems, the first aspect of this utility model discloses a battery pack over-discharge protection circuit, which includes a low-voltage control module and a high-voltage discharge module, wherein:

[0006] The first terminal of the low-voltage control module is electrically connected to the first terminal of the high-voltage discharge module; the second terminal of the high-voltage discharge module is electrically connected to the high-voltage positive electrode; and the third terminal of the high-voltage discharge module is electrically connected to the high-voltage negative electrode.

[0007] The low-voltage control module is used to perform safety monitoring on the high-voltage discharge module when it is determined that the operating state of the high-voltage discharge module is a dormant state.

[0008] The low-voltage control module is also used to generate a safety control signal when it is determined that the high-voltage discharge module has an overcurrent or undervoltage fault.

[0009] The high-voltage discharge module is used to perform a target control operation based on the safety control signal after detecting the safety control signal; the target control operation includes fuse control of the safety device in the high-voltage discharge module.

[0010] As an optional implementation, in the first aspect of this utility model, the low-voltage control module includes a monitoring submodule, a main chip, and a driver chip; the high-voltage discharge module includes a battery module, the safety device, and a pre-charge protection submodule; wherein:

[0011] The first end of the monitoring submodule is communicatively connected to the first end of the main chip; the second end of the main chip is communicatively connected to the first end of the driver chip; the second end of the driver chip is electrically connected to the first end of the security device.

[0012] The second end of the safety device is electrically connected to the first end of the battery module; the third end of the safety device is electrically connected to the first end of the pre-charge protection submodule; the second end of the battery module is used to be electrically connected to the high-voltage negative electrode; the second end of the pre-charge protection submodule is used to be electrically connected to the high-voltage positive electrode.

[0013] As an optional implementation, in the first aspect of this utility model, the monitoring submodule is used to perform safety monitoring on the high-voltage discharge module when it is determined that the operating state of the high-voltage discharge module is a dormant state. The safety monitoring includes the acquisition and data judgment of target detection parameters. The target detection parameters include at least one of module voltage, module temperature, and module current.

[0014] The monitoring submodule is also used to wake up the main chip and send the target detection parameters to the main chip when it is determined that the safety monitoring result for the high-voltage discharge module indicates that the first processing condition is met.

[0015] Specifically, the security monitoring results satisfying the first processing condition are as follows:

[0016] The safety monitoring results indicate that the battery module in the dormant state has either cell overcurrent or cell undervoltage.

[0017] As an optional implementation, in the first aspect of this utility model, the main chip is used to perform a preset logic diagnosis on the target detection parameters, and when it is determined that the logic diagnosis result for the target detection parameters indicates that the high-voltage discharge module meets the second processing condition, a target control signal is triggered to the drive chip to generate a corresponding drive current signal according to the target control signal, and the drive current signal is used to perform fuse control on the safety device.

[0018] Specifically, the logical diagnostic result indicating that the high-voltage discharge module meets the second processing condition is as follows:

[0019] The logical diagnostic result indicates that the battery management system corresponding to the battery module is in a state of being reverse-wake-up by the monitoring submodule, and the battery module voltage corresponding to the battery module is lower than the set standard module voltage.

[0020] As an optional implementation, in the first aspect of this utility model, the monitoring submodule includes multiple monitoring units, all of which are connected in series. At the same time, different monitoring units are connected in communication, and each monitoring unit can communicate with the main chip.

[0021] The battery module is composed of multiple cells connected in series and parallel; and each monitoring unit is used to monitor the cell operating parameters of one or more of the cells; the cell operating parameters include at least one of cell voltage, cell current and cell temperature.

[0022] As an optional implementation, in the first aspect of this utility model, the pre-charge protection submodule includes a pre-charge unit and a main positive relay, wherein:

[0023] The third terminal of the safety device is electrically connected to the first terminal of the pre-charging unit and the first terminal of the main positive relay, respectively.

[0024] The second terminal of the pre-charging unit and the second terminal of the main positive relay are both used to be electrically connected to the high-voltage positive electrode.

[0025] As an optional implementation, in the first aspect of this utility model, the pre-charging unit includes a pre-charging relay and a pre-charging resistor, wherein:

[0026] The third terminal of the safety device is electrically connected to the first terminal of the precharge relay; the second terminal of the precharge relay is electrically connected to the first terminal of the precharge resistor; the second terminal of the precharge resistor is used to be electrically connected to the high voltage positive electrode.

[0027] As an optional implementation, in the first aspect of this utility model, the safety device is used to detect the drive signal transmitted by the drive chip, and to perform fuse control on the safety device according to the drive signal to cut off the connection circuit between the battery module and the precharge protection submodule.

[0028] The pre-charging resistor is used to perform current limiting on the pre-charging current flowing through it, and simultaneously perform voltage division based on the charging voltage of the battery module.

[0029] The precharge relay is used to perform the current limiting process on the precharge current flowing through the precharge relay;

[0030] The main positive relay is used to detect the pre-charging progress of the battery module and execute target charging control that matches the pre-charging progress.

[0031] As an optional implementation, in the first aspect of this invention, the main positive relay performing target charging control that matches the pre-charging progress includes:

[0032] When the pre-charging progress indicates that the battery module has not completed pre-charging, the main positive relay remains in the off state;

[0033] When the pre-charging progress indicates that the battery module has completed pre-charging, the main positive relay switches from the open state to the closed state to switch the power supply direction of the high voltage positive electrode from flowing through the pre-charging unit to flowing through the main positive relay.

[0034] The second aspect of this utility model discloses a battery pack over-discharge protection device, which includes a device body and a battery pack over-discharge protection circuit as disclosed in any of the first aspects.

[0035] Implementing this utility model has the following beneficial effects:

[0036] This invention provides a battery pack over-discharge protection circuit, which includes a low-voltage control module and a high-voltage discharge module. The first terminal of the low-voltage control module is electrically connected to the first terminal of the high-voltage discharge module; the second terminal of the high-voltage discharge module is electrically connected to the high-voltage positive electrode; and the third terminal of the high-voltage discharge module is electrically connected to the high-voltage negative electrode. The low-voltage control module performs safety monitoring on the high-voltage discharge module when its operating state is determined to be a dormant state. The low-voltage control module also generates a safety control signal when an overcurrent or undervoltage fault is detected in the high-voltage discharge module. The high-voltage discharge module, after detecting the safety control signal, performs a target control operation based on the safety control signal. The target control operation includes fuse control of the safety devices in the high-voltage discharge module. As can be seen, this utility model, through the low-voltage control module, can monitor the operating status of the high-voltage discharge module in real time, distinguishing whether it is in a dormant or non-dormant state. Then, after determining that the high-voltage discharge module has entered a dormant state, the low-voltage control module immediately starts the safety monitoring program, realizing the maintenance of charging / discharging monitoring of the high-voltage discharge module even when the entire system is in a dormant state. This active monitoring mechanism ensures that if the high-voltage discharge module is over-discharged when the entire system is in a dormant state or has been parked for a long time, it can be detected and dealt with in a timely manner. This helps to reduce the probability of system / device / equipment damage caused by the lack of safety monitoring of the high-voltage discharge module in a dormant state and the occurrence of over-discharge faults, thereby improving the safety and reliability of the entire system. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of a battery pack over-discharge protection circuit disclosed in an embodiment of this utility model;

[0039] Figure 2 This is a schematic diagram of another battery pack over-discharge protection circuit disclosed in this utility model embodiment;

[0040] Figure 3 This is a schematic diagram of the structure of a low-voltage control module disclosed in an embodiment of this utility model;

[0041] Figure 4 This is a schematic diagram of the structure of a high-voltage discharge module disclosed in an embodiment of this utility model;

[0042] Figure 5This is a schematic diagram of the structure of a battery pack over-discharge protection device disclosed in an embodiment of this utility model. Detailed Implementation

[0043] To better understand and implement this invention, the technical solutions in the embodiments of this invention 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 invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0044] It should be noted that, unless otherwise expressly specified and limited, the term "electrical connection" in the specification, claims, and accompanying drawings of this utility model should be interpreted broadly. For example, it can be a fixed electrical connection, a detachable electrical connection, or an integral electrical connection; it can be a mechanical electrical connection, an electrical-electrical connection, or a connection that allows for communication; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two elements or an interaction between two elements. Furthermore, the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish different objects, not to describe a specific order. The terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0045] Example 1

[0046] Please see Figure 1 , Figure 1 This is a schematic diagram of a battery pack over-discharge protection circuit disclosed in an embodiment of this utility model. This circuit can be applied to electric vehicles with electrical power supply to perform over-discharge protection during battery charging. This utility model embodiment is not limited in its scope. Figure 1 As shown, the battery pack over-discharge protection circuit includes a low-voltage control module 10 and a high-voltage discharge module 20, wherein:

[0047] The first terminal of the low-voltage control module 10 is electrically connected to the first terminal of the high-voltage discharge module 20; the second terminal of the high-voltage discharge module 20 is electrically connected to the high-voltage positive electrode; and the third terminal of the high-voltage discharge module 20 is electrically connected to the high-voltage negative electrode.

[0048] The low-voltage control module 10 is used to perform safety monitoring on the high-voltage discharge module 20 when it is determined that the operating state of the high-voltage discharge module 20 is a dormant state.

[0049] The low-voltage control module 10 is also used to generate a safety control signal when it is determined that there is an overcurrent or undervoltage fault in the high-voltage discharge module 20;

[0050] The high-voltage discharge module 20 is used to perform target control operations based on the safety control signal after detecting the safety control signal; the target control operations include fuse control of the safety device 202 in the high-voltage discharge module 20.

[0051] It is evident that implementation Figure 1 The described battery pack over-discharge protection circuit can monitor the operating status of the high-voltage discharge module in real time through the low-voltage control module, distinguishing whether it is in a dormant or non-dormant state. After determining that the high-voltage discharge module has entered a dormant state, the low-voltage control module immediately starts the safety monitoring program, realizing the maintenance of charging / discharging monitoring of the high-voltage discharge module even when the whole system is in a dormant state. This active monitoring mechanism ensures that if the high-voltage discharge module is over-discharged in the dormant state or when the whole system is parked for a long time, it can be detected and dealt with in a timely manner. This helps to reduce the probability of system / device / equipment damage caused by the lack of safety monitoring of the high-voltage discharge module in the dormant state and the occurrence of over-discharge faults, thereby improving the safety and reliability of the whole system.

[0052] In an optional embodiment, please refer to Figure 2 , Figure 3 as well as Figure 4 , Figure 2 This is a schematic diagram of another battery pack over-discharge protection circuit disclosed in this utility model embodiment; Figure 3 This is a schematic diagram of the structure of a low-voltage control module disclosed in an embodiment of this utility model; Figure 4 This is a schematic diagram of the structure of a high-voltage discharge module disclosed in an embodiment of this utility model; as shown... Figure 2 , Figure 3 as well as Figure 4 As shown:

[0053] The low-voltage control module 10 includes a monitoring submodule 101, a main chip 102, and a driver chip 103; the high-voltage discharge module 20 includes a battery module 201, a safety device 202, and a pre-charge protection submodule 203; wherein:

[0054] The first terminal of the monitoring submodule 101 is communicatively connected to the first terminal of the main chip 102; the second terminal of the main chip 102 is communicatively connected to the first terminal of the driver chip 103; and the second terminal of the driver chip 103 is electrically connected to the first terminal of the safety device 202.

[0055] The second terminal of the safety device 202 is electrically connected to the first terminal of the battery module 201; the third terminal of the safety device 202 is electrically connected to the first terminal of the pre-charge protection submodule 203; the second terminal of the battery module 201 is used to be electrically connected to the high-voltage negative terminal; the second terminal of the pre-charge protection submodule 203 is used to be electrically connected to the high-voltage positive terminal.

[0056] In this optional embodiment, the monitoring submodule 101 is configured to perform safety monitoring on the high-voltage discharge module 20 when it is determined that the operating state of the high-voltage discharge module 20 is a dormant state. The safety monitoring includes the acquisition and data judgment of target detection parameters. The target detection parameters include at least one of module voltage, module temperature, and module current.

[0057] The monitoring submodule 101 is also used to wake up the main chip 102 and send the target detection parameters to the main chip 102 when it is determined that the safety monitoring result for the high voltage discharge module 20 meets the first processing condition.

[0058] Specifically, the safety monitoring results meeting the first processing condition are as follows:

[0059] Safety monitoring results indicate that battery module 201 has either cell overcurrent or cell undervoltage during dormant state.

[0060] In this optional embodiment, in practical applications, the monitoring submodule 101 can be an AFE circuit; the main chip 102 and the driver chip 103 can be classified as part of a conventional battery management system (BMS); that is, the main chip 102 and the driver chip 103 serve as the management level of the internal functional modules.

[0061] In this optional embodiment, when the high-voltage discharge module 20 is in a non-dormant state, the corresponding overall circuit system is also in a non-dormant state. At this time, the functional module that monitors the high-voltage discharge module 20 can be the monitoring sub-module 101 or other modules with monitoring functions. This utility model does not limit the specific modules.

[0062] In this optional embodiment, when the high-voltage discharge module 20 is in a dormant state, if the monitoring submodule 101 determines that the high-voltage discharge module 20 has an overcurrent or undervoltage fault, the monitoring submodule 101 will wake up the main chip 102 and the driver chip 103 in reverse. That is, the monitoring submodule 101 will wake up the battery management system (BMS) in reverse, and the battery management system will handle the overcurrent or undervoltage fault in the high-voltage discharge module 20.

[0063] As can be seen, in this optional embodiment, the intelligent acquisition and analysis of multiple target detection parameters in the high-voltage discharge module by the monitoring submodule is beneficial to improving the detection speed of abnormal situations such as cell overcurrent or cell undervoltage in the battery module of the high-voltage discharge module; then, for the detected abnormal situation, the main chip can be quickly woken up and the abnormal parameters can be fed back to the main chip, so that the main chip can promptly handle the fault of the abnormal parameters, thereby improving the processing speed of the abnormal situation; this greatly improves the intelligence level of the circuit system, and further enhances the stability and safety of the circuit system.

[0064] In this optional embodiment, the main chip 102 is configured to perform a preset logic diagnosis on the target detection parameters, and when it is determined that the logic diagnosis result for the target detection parameters indicates that the high-voltage discharge module 20 meets the second processing condition, generate a target control signal, so as to trigger the driver chip 103 to generate a corresponding drive current signal according to the target control signal, and the drive current signal is used to perform fuse control on the safety device 202.

[0065] The logic diagnostic result indicates that the high-voltage discharge module 20 meets the second processing condition, specifically:

[0066] The logic diagnostic results indicate that the battery management system corresponding to battery module 201 is in a state of reverse wake-up by the monitored submodule 101, and the voltage of battery module 201 corresponding to battery module 201 is lower than the set standard module voltage.

[0067] As can be seen, in this optional embodiment, a preset logic diagnostic mechanism is introduced at the main chip level. After receiving the target detection parameters sent by the monitoring submodule, the main chip can perform in-depth analysis of these parameters according to the preset logic diagnostic rules. When the logic diagnostic result shows that the high-voltage discharge module meets the specific second processing condition (i.e., the battery management system is reverse-wake-up and the battery module voltage is lower than the preset standard), the main chip will quickly generate a target control signal. This control signal is then transmitted to the driver chip, which generates a corresponding drive current signal based on the signal. This drive current signal directly acts on the safety device, triggering it to execute fuse control. This series of reactions is not only rapid but also accurate, which can effectively prevent the expansion of circuit faults and even avoid potential safety accidents, further improving the safety and stability of the circuit system.

[0068] In yet another alternative embodiment, such as Figure 2 As shown, the pre-charge protection submodule 203 includes a pre-charge unit 2031 and a main positive relay 2032, wherein:

[0069] The third terminal of the safety device 202 is electrically connected to the first terminal of the pre-charge unit 2031 and the first terminal of the main positive relay 2032, respectively.

[0070] The second terminal of the pre-charge unit 2031 and the second terminal of the main positive relay 2032 are both used to be electrically connected to the high voltage positive electrode.

[0071] In this optional embodiment, the pre-charge unit 2031 further includes a pre-charge relay K1 and a pre-charge resistor R1, wherein:

[0072] The third terminal of the safety device 202 is electrically connected to the first terminal of the precharge relay K1; the second terminal of the precharge relay K1 is electrically connected to the first terminal of the precharge resistor R1; the second terminal of the precharge resistor R1 is used to be electrically connected to the high voltage positive terminal.

[0073] In this optional embodiment, the safety device 202 is used to detect the drive signal transmitted by the drive chip 103 and perform fuse control on the safety device 202 according to the drive signal to cut off the connection circuit between the battery module 201 and the precharge protection submodule 203.

[0074] The pre-charge resistor R1 is used to limit the pre-charge current flowing through it and to perform voltage division based on the charging voltage of the battery module 201.

[0075] The precharge relay K1 is used to perform current limiting on the precharge current flowing through the precharge relay K1;

[0076] The main positive relay 2032 is used to detect the pre-charging progress of the battery module 201 and execute target charging control that matches the pre-charging progress.

[0077] As can be seen, in this optional embodiment, the safety device can intelligently detect the drive signal transmitted by the drive chip and perform fuse control according to the drive signal to promptly disconnect the connection circuit between the battery module and the pre-charge protection submodule; this improves the response speed of the safety device to the drive signal and the protection speed of the circuit system; in addition, for the pre-charge unit, the pre-charge resistor and the pre-charge relay work together to perform double current limiting on the current flowing through the pre-charge circuit, ensuring that the pre-charge current is within a safe range and avoiding damage to the battery module due to excessive current during the initial charging of the battery module; at the same time, the pre-charge resistor can also perform voltage division according to the charging voltage of the battery module, further protecting the battery module from high voltage surges.

[0078] In this optional embodiment, the main positive relay 2032 performs target charging control that matches the pre-charging progress, including:

[0079] When the pre-charging progress indicates that the battery module 201 has not completed pre-charging, the main positive relay 2032 remains in the off state.

[0080] When the pre-charging progress indicates that the battery module 201 has completed pre-charging, the main positive relay 2032 switches from the open state to the closed state to switch the power supply direction of the high voltage positive terminal from flowing through the pre-charging unit 2031 to flowing through the main positive relay 2032.

[0081] As can be seen, in this optional embodiment, the main positive relay can detect the pre-charging progress of the battery module and perform operations that match the target charging control according to the pre-charging progress, including circuit breaking for incomplete pre-charging and circuit flow switching for completed pre-charging. This achieves precise protection before the battery module completes pre-charging and normal switching after pre-charging is completed, further improving the operational stability and reliability of the circuit system.

[0082] In yet another alternative embodiment, such as Figure 4 As shown, the monitoring submodule 101 includes multiple monitoring units AFE1-AFEm, all of which are connected in series. At the same time, different monitoring units are connected to each other, and each monitoring unit can communicate with the main chip.

[0083] The battery module 201 is composed of multiple cells connected in series and parallel; and each monitoring unit is used to monitor the cell operating parameters of one or more cells; the cell operating parameters include at least one of cell voltage, cell current and cell temperature.

[0084] In this optional embodiment, different monitoring units communicate with each other via a daisy chain; and each monitoring unit also communicates with the main chip 102 via a daisy chain. Furthermore, the number of monitoring units connected in series and the number of cells connected in series and parallel as mentioned above can be adjusted according to user needs in practical applications, and this embodiment of the present invention does not impose any limitations.

[0085] It is evident that implementation Figure 3 The described battery pack over-discharge protection circuit can connect multiple similar monitoring units and multiple battery cells in series according to actual needs. The number of monitoring units can increase with the number of battery cells, and each monitoring unit monitors at least one battery cell. That is, it can at least ensure accurate monitoring of a single battery cell, thereby improving the precision of monitoring the battery cell's operating parameters.

[0086] The working principle of the battery pack over-discharge protection circuit in this embodiment is as follows:

[0087] In this embodiment of the invention, during the startup and operation of the battery pack over-discharge protection circuit, the low-voltage control module can detect the operating status of the high-voltage discharge module in real time. Specifically, when the high-voltage discharge module is detected to be in a dormant state, the low-voltage control module will initiate safety monitoring of the high-voltage discharge module. This monitoring specifically involves checking for overcurrent or undervoltage faults in the high-voltage discharge module. If such an overcurrent or undervoltage fault is detected, the low-voltage control module will wake up the battery management system (BMS) installed in the module. The BMS will then promptly generate a corresponding safety control signal. Based on this safety control signal, the system will promptly perform target control operations on the high-voltage discharge module, including the fuse control of safety devices, thereby disconnecting the power supply circuit of the high-voltage discharge module.

[0088] Example 2

[0089] Please see Figure 5 , Figure 5 This is a schematic diagram of a battery pack over-discharge protection device disclosed in an embodiment of the present invention. The device includes a main body and any battery pack over-discharge protection circuit as described in Embodiment 1. Furthermore, this battery pack over-discharge protection device includes, but is not limited to, any device / equipment requiring battery charging protection, such as electric vehicles. It should be noted that for a detailed description of the battery pack over-discharge protection device, please refer to the specific description in Embodiment 1; it will not be repeated in this embodiment.

[0090] It is evident that implementation Figure 5 The described battery pack over-discharge protection device can monitor the operating status of the high-voltage discharge module in real time through the low-voltage control module, distinguishing whether it is in a dormant or non-dormant state. After determining that the high-voltage discharge module has entered a dormant state, the low-voltage control module immediately starts the safety monitoring program, realizing the maintenance of charging / discharging monitoring of the high-voltage discharge module even when the entire system is in a dormant state. This active monitoring mechanism ensures that if the high-voltage discharge module is over-discharged in a timely manner when the entire system is in a dormant state or has been parked for a long time, it can be detected and dealt with in a timely manner. This helps to reduce the probability of system / device / equipment damage caused by the lack of safety monitoring of the high-voltage discharge module in a dormant state and the occurrence of over-discharge faults, thereby improving the safety and reliability of the entire system.

[0091] The above provides a detailed description of a battery pack over-discharge protection circuit and device disclosed in the embodiments of this utility model. Specific embodiments have been used to illustrate the principle and implementation of this utility model. However, the above preferred embodiments are not intended to limit this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, based on the idea of ​​this utility model, there will be changes in the specific implementation and application scope without departing from the spirit and scope of this utility model. Therefore, the protection scope of this utility model is determined by the scope defined in the claims.

Claims

1. A battery pack over-discharge protection circuit, characterized in that, The battery pack over-discharge protection circuit includes a low-voltage control module and a high-voltage discharge module, wherein: The first terminal of the low-voltage control module is electrically connected to the first terminal of the high-voltage discharge module; the second terminal of the high-voltage discharge module is electrically connected to the high-voltage positive electrode; and the third terminal of the high-voltage discharge module is electrically connected to the high-voltage negative electrode. The low-voltage control module is used to perform safety monitoring on the high-voltage discharge module when it is determined that the operating state of the high-voltage discharge module is a dormant state. The low-voltage control module is also used to generate a safety control signal when it is determined that the high-voltage discharge module has an overcurrent or undervoltage fault. The high-voltage discharge module is used to perform a target control operation based on the safety control signal after detecting the safety control signal; the target control operation includes fuse control of the safety device in the high-voltage discharge module.

2. The battery pack over-discharge protection circuit according to claim 1, characterized in that, The low-voltage control module includes a monitoring submodule, a main chip, and a driver chip; the high-voltage discharge module includes a battery module, the safety device, and a pre-charge protection submodule; wherein: The first end of the monitoring submodule is communicatively connected to the first end of the main chip; the second end of the main chip is communicatively connected to the first end of the driver chip; the second end of the driver chip is electrically connected to the first end of the security device. The second end of the safety device is electrically connected to the first end of the battery module; the third end of the safety device is electrically connected to the first end of the pre-charge protection submodule; the second end of the battery module is used to be electrically connected to the high-voltage negative electrode; the second end of the pre-charge protection submodule is used to be electrically connected to the high-voltage positive electrode.

3. The battery pack over-discharge protection circuit according to claim 2, characterized in that, The monitoring submodule is used to perform safety monitoring on the high-voltage discharge module when it is determined that the operating state of the high-voltage discharge module is a dormant state. The safety monitoring includes the acquisition and data judgment of target detection parameters. The target detection parameters include at least one of module voltage, module temperature and module current. The monitoring submodule is also used to wake up the main chip and send the target detection parameters to the main chip when it is determined that the safety monitoring result for the high-voltage discharge module indicates that the first processing condition is met. Specifically, the security monitoring results satisfying the first processing condition are as follows: The safety monitoring results indicate that the battery module in the dormant state has either cell overcurrent or cell undervoltage.

4. The battery pack over-discharge protection circuit according to claim 3, characterized in that, The main chip is used to perform preset logic diagnosis on the target detection parameters, and when it is determined that the logic diagnosis result for the target detection parameters indicates that the high-voltage discharge module meets the second processing condition, it generates a target control signal to trigger the driver chip to generate a corresponding drive current signal according to the target control signal. The drive current signal is used to perform fuse control on the safety device. Specifically, the logical diagnostic result indicating that the high-voltage discharge module meets the second processing condition is as follows: The logical diagnostic result indicates that the battery management system corresponding to the battery module is in a state of being reverse-wake-up by the monitoring submodule, and the battery module voltage corresponding to the battery module is lower than the set standard module voltage.

5. The battery pack over-discharge protection circuit according to any one of claims 2-4, characterized in that, The monitoring submodule includes multiple monitoring units, all of which are connected in series. Furthermore, different monitoring units are connected to each other, and each monitoring unit can communicate with the main chip. The battery module is composed of multiple cells connected in series and parallel; and each monitoring unit is used to monitor the cell operating parameters of one or more of the cells; the cell operating parameters include at least one of cell voltage, cell current and cell temperature.

6. The battery pack over-discharge protection circuit according to any one of claims 2-4, characterized in that, The pre-charge protection submodule includes a pre-charge unit and a main positive relay, wherein: The third terminal of the safety device is electrically connected to the first terminal of the pre-charging unit and the first terminal of the main positive relay, respectively. The second terminal of the pre-charging unit and the second terminal of the main positive relay are both used to be electrically connected to the high-voltage positive electrode.

7. The battery pack over-discharge protection circuit according to claim 6, characterized in that, The pre-charge unit includes a pre-charge relay and a pre-charge resistor, wherein: The third terminal of the safety device is electrically connected to the first terminal of the precharge relay; the second terminal of the precharge relay is electrically connected to the first terminal of the precharge resistor; the second terminal of the precharge resistor is used to be electrically connected to the high voltage positive electrode.

8. The battery pack over-discharge protection circuit according to claim 7, characterized in that, The safety device is used to detect the drive signal transmitted by the drive chip, and to perform fuse control on the safety device according to the drive signal to cut off the connection circuit between the battery module and the precharge protection submodule. The pre-charging resistor is used to perform current limiting on the pre-charging current flowing through it, and simultaneously perform voltage division based on the charging voltage of the battery module. The precharge relay is used to perform the current limiting process on the precharge current flowing through the precharge relay; The main positive relay is used to detect the pre-charging progress of the battery module and execute target charging control that matches the pre-charging progress.

9. The battery pack over-discharge protection circuit according to claim 8, characterized in that, The main positive relay performs target charging control that matches the pre-charging progress, including: When the pre-charging progress indicates that the battery module has not completed pre-charging, the main positive relay remains in the off state; When the pre-charging progress indicates that the battery module has completed pre-charging, the main positive relay switches from the open state to the closed state to switch the power supply direction of the high voltage positive electrode from flowing through the pre-charging unit to flowing through the main positive relay.

10. A battery pack over-discharge protection device, characterized in that, The battery pack over-discharge protection device includes a device body, and the battery pack over-discharge protection device includes the battery pack over-discharge protection circuit as described in any one of claims 1-9.

Images