Thermal runaway protection circuit of storage battery pack

Abstract

The utility model provides a thermal runaway protection circuit for a storage battery pack, and the protection circuit comprises a detection module which is disposed on a storage battery sub-pack so as to obtain the information of the storage battery sub-pack; the shunting module is connected in parallel to the storage battery sub-group so as to shunt the charging current of the storage battery sub-group; the voltage reduction module is connected in series between the positive electrode of the storage battery pack and the positive electrode of the charger so as to control the charging current of the charger to the storage battery pack; the protection module is connected to the voltage reduction module in parallel so as to disconnect the connection between the charger and the storage battery pack; and the first control module is respectively connected with the detection module, the shunting module, the voltage reduction module and the protection module, and can send a control signal to control the actions of the shunting module, the voltage reduction module and the protection module according to the information of the storage battery sub-group. The thermal runaway protection circuit of the storage battery pack can improve the use safety of the storage battery pack.

Description

Technical Field

[0001] This utility model relates to the field of battery pack technology, and in particular to a battery pack thermal runaway protection circuit. Background Technology

[0002] In critical systems within the power industry, the stable operation of DC systems is crucial for ensuring uninterrupted power transmission, distribution, and communication command functions. To achieve this, series-connected battery banks are widely used as primary or backup power sources, especially in key areas such as communication power supplies and DC dispatch control systems. These systems utilize meticulously designed battery bank configurations; for example, communication power supplies may employ 24 individual 2V batteries connected in series, while DC dispatch control systems may utilize an even larger configuration of 104 individual 2V batteries connected in series, to provide ample and reliable backup power support.

[0003] However, in series-connected battery banks, problems such as uneven initial performance of individual battery cells, different degrees of degradation during use, or internal defects in individual battery cells can lead to accelerated heating. When the heating rate of a battery cell exceeds its natural cooling rate, the battery will enter a state of thermal runaway. When the cell temperature reaches the deformation limit of the casing, the battery casing may deform and crack. Without the protection of the casing, the electrolyte will flow out rapidly, causing the battery cell to open circuit. The outflowing electrolyte may cause corrosion, poisoning, and fire hazards. When the cell temperature reaches the deformation limit of the internal insulation devices and plate grids, it may cause an internal short circuit, which may lead to rapid short-circuit discharge or even explosion of the battery, thus compromising the safety of the battery bank. Utility Model Content

[0004] In view of this, the present invention aims to provide a thermal runaway protection circuit for a battery pack to improve the safety of battery pack use.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] A thermal runaway protection circuit for a battery pack is provided for thermal runaway protection during battery pack charging. The battery pack includes several battery sub-packs, and the positive and negative terminals of the battery sub-packs are respectively connected to the positive and negative terminals of a charger. The protection circuit includes:

[0007] A detection module is provided on the battery sub-group to acquire information about the battery sub-group.

[0008] A current shunt module is connected in parallel to the battery sub-group to shunt the charging current of the battery sub-group.

[0009] A step-down module is connected in series between the positive terminal of the battery pack and the positive terminal of the charger to control the charging current of the charger to the battery pack.

[0010] A protection module, connected in parallel to the step-down module, is provided to disconnect the charger from the battery pack.

[0011] The first control module is connected to the detection module, the current shunt module, the voltage reduction module, and the protection module, respectively, and can send control signals to control the operation of the current shunt module, the voltage reduction module, and the protection module according to the information of the battery sub-group.

[0012] Furthermore, the detection module includes several temperature detection units respectively disposed on the battery sub-groups, and each temperature detection unit is connected to the first control module to transmit the temperature information of each battery sub-group to the first control module.

[0013] Furthermore, the temperature detection unit includes a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is located at the positive terminal of the battery sub-group and the second temperature sensor is located at the negative terminal of the battery sub-group.

[0014] Furthermore, the shunt module includes a second control module, and several sets of first IGBT transistors and resistors connected in parallel across the battery sub-group, wherein the first IGBT transistors and the resistors are connected in series; the collector of the first IGBT transistor is connected to the positive terminal of the battery sub-group, the emitter of the first IGBT transistor is connected to the first terminal of the resistor, the gate of the first IGBT transistor is connected to the second control module, and the second terminal of the resistor is connected to the negative terminal of the battery sub-group; the second control module is connected to the first control module and is configured to receive control signals from the control module to control the on / off state of the first IGBT transistors.

[0015] Furthermore, the protection module includes a second IGBT and a first diode connected in parallel; the collector of the second IGBT is connected to the positive terminal of the battery pack, the emitter of the second IGBT is connected to the positive terminal of the charger, the gate of the second IGBT is connected to the first control module, the anode of the first diode is connected to the positive terminal of the battery pack, and the cathode of the first diode is connected to the negative terminal of the charger.

[0016] Furthermore, the first control module includes a data acquisition unit, a processing unit, a control unit, and a communication interface; the data acquisition unit can receive the battery sub-group information acquired by the detection module and send it to the processing unit; the processing unit can process and analyze the battery sub-group information and send the processed information to the control unit; the control unit can generate control information based on the processed information and send the control information to the shunt module, the step-down module, and the protection module through the communication interface to control the operation of the shunt module, the step-down module, and the protection module.

[0017] Furthermore, an ammeter is connected in series between the negative terminal of the battery pack and the negative terminal of the charger, and the ammeter is connected to the control module to transmit the current signal to the acquisition unit.

[0018] Compared with the prior art, this utility model has the following advantages:

[0019] The battery pack thermal runaway protection circuit of this utility model, through the setting of the detection module, can collect information of the battery sub-pack and send the information to the first control module. Through the setting of the first control module, it can issue control signals according to the information collected by the detection module, and control the operation of the shunt module, the step-down module and the protection module. This helps to control the protection module to disconnect the charger from the battery pack when an abnormal temperature rise of the battery sub-pack is detected. Furthermore, through the setting of the step-down module and the shunt module, it can control the voltage and current of the charger charging the battery pack, which helps to manage the voltage and current of the charger charging the battery pack before thermal runaway occurs, thus contributing to the thermal runaway protection of the battery pack during charging and improving the safety of the battery pack in use.

[0020] Furthermore, the temperature detection unit enables the detection of temperature signals from each battery sub-group and transmits them to the first control module, facilitating more intuitive acquisition of temperature information from each sub-group. By installing a first temperature sensor and a second temperature sensor at the positive and negative terminals of each battery sub-group, accurate temperature data acquisition is achieved, leading to better detection of temperature changes. The configuration of the second control module, the first IGBT, and resistors allows for controlled current shunting of the battery sub-groups, facilitating control by the first control module and simplifying the design and implementation.

[0021] Furthermore, the placement of the second IGBT and the first diode allows the charger to be disconnected from the battery pack under the control of the first control module without affecting the battery pack's discharge to the load, facilitating design implementation. This simplifies the design by including a data acquisition unit, processing unit, control unit, and communication interface in the first control module, resulting in a simple structure that also aids in design implementation. The inclusion of a current meter facilitates the acquisition of current signals between the battery pack and the charger, enabling the first control module to issue control signals, thus improving battery safety and further facilitating design implementation. Attached Figure Description

[0022] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0023] Figure 1 This is a circuit diagram of the battery pack thermal runaway protection circuit described in an embodiment of the present invention;

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Battery pack; 2. Battery sub-pack; 3. Charger;

[0026] 4. Detection module;

[0027] 401. Temperature detection unit;

[0028] 5. Distributor module;

[0029] 501. Second control module;

[0030] 6. Step-down module; 7. Protection module; 8. First control module; 9. Ammeter; 10. Load. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0032] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] Furthermore, in the description of this utility model, unless otherwise explicitly defined, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model in light of the specific circumstances.

[0034] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] Example 1

[0036] This embodiment relates to a thermal runaway protection circuit for a battery pack, aiming to improve the safety of the battery pack by optimizing the circuit structure.

[0037] In terms of overall structure, such as Figure 1 As shown, the battery pack thermal runaway protection circuit in this embodiment is used for thermal runaway protection during charging of the battery pack 1. The battery pack 1 includes several battery sub-packs 2. The positive and negative terminals of the battery pack 1 are respectively connected to the positive and negative terminals of the charger 3. The protection circuit includes a detection module 4, a shunt module 5, a step-down module 6, a protection module 7, and a first control module 8.

[0038] The detection module 4 is located on the battery sub-group 2 to acquire information about the battery sub-group 2. The shunt module 5 is connected in parallel to the battery sub-group 2 to shunt the charging current of the battery sub-group 2. The step-down module 6 is connected in series between the positive terminal of the battery group 1 and the positive terminal of the charger 3 to control the charging current of the charger 3 to the battery group 1. The protection module 7 is connected in parallel to the step-down module 6 to disconnect the charger 3 from the battery group 1. The first control module 8 is connected to the detection module 4, the shunt module 5, the step-down module 6 and the protection module 7 respectively, and can send control signals to control the operation of the shunt module 5, the step-down module 6 and the protection module 7 according to the information of the battery sub-group 2.

[0039] As configured above, the battery pack thermal runaway protection circuit in this embodiment, through the setting of the detection module 4, can collect information of the battery sub-pack 2 and send the information to the first control module 8. Through the setting of the first control module 8, it can issue control signals according to the information collected by the detection module 4, and control the operation of the shunt module 5, the step-down module 6 and the protection module 7. This helps to control the protection module 7 to disconnect the charger 3 from the battery pack 1 when an abnormal temperature rise of the battery sub-pack 2 is detected. Furthermore, through the setting of the step-down module 6 and the shunt module 5, it can control the voltage and current of the charger 3 when charging the battery pack 1, which helps to manage the voltage and current of the charger 3 when charging the battery pack 1 before thermal runaway occurs, which helps to protect the battery pack 1 from thermal runaway during charging and improves the safety of the battery pack 1.

[0040] Based on the above overview, combined with Figure 1 As shown, as an exemplary structure, the detection module 4 of the battery pack thermal runaway protection circuit in this embodiment includes several temperature detection units 401 respectively disposed on the battery sub-pack 2. Each temperature detection unit 401 is connected to the first control module 8 to transmit the temperature information of each battery sub-pack 2 to the first control module 8. Through the setting of the temperature detection unit 401, the temperature signal of each battery sub-pack 2 can be detected and transmitted to the first control module 8, which is conducive to more intuitive acquisition of the temperature information of each battery sub-pack 2.

[0041] Specifically, the temperature detection unit 401 includes a first temperature sensor and a second temperature sensor. The first temperature sensor is located at the positive terminal of the battery sub-group 2, and the second temperature sensor is located at the negative terminal of the battery sub-group 2. By setting the first temperature sensor at the positive terminal and the second temperature sensor at the negative terminal of the battery sub-group 2 respectively, it is helpful to collect the temperature information of the battery sub-group 2 more accurately, thereby enabling better detection of temperature changes in the battery sub-group 2. Of course, the temperature of the negative terminal of the battery is generally higher during use, so it is also possible to detect the temperature of the battery sub-group 2 by setting a temperature sensor only at the negative terminal of the battery sub-group 2.

[0042] To better shunt the current between the charger 3 and the battery pack 1 during charging, the shunt module 5 in this embodiment includes a second control module 501, and several sets of first IGBT transistors Q1 and resistors R1 connected in parallel across the two ends of the battery sub-pack 2. The first IGBT transistors Q1 and resistors R1 are connected in series. The collector of the first IGBT transistor Q1 is connected to the positive terminal of the battery sub-pack 2, the emitter of the first IGBT transistor Q1 is connected to the first end of the resistor R1, the gate of the first IGBT transistor Q1 is connected to the second control module 501, and the second end of the resistor R1 is connected to the negative terminal of the battery sub-pack 2. The second control module 501 is connected to the first control module 8 and is configured to receive control signals from the control module to control the on / off state of the first IGBT transistor Q1. Through the configuration of the second control module 501, the first IGBT transistor Q1, and the resistor R1, the shunt current of the battery sub-pack 2 can be controlled by the resistor R1, which is convenient for the control of the first control module 8 and facilitates design and implementation.

[0043] It is worth mentioning that both the charger 3 and the load 10 can be considered as being connected in parallel across the two ends of the battery pack 1, and the charger 3 is also considered as being connected in parallel across the two ends of the load 10. In this embodiment, the number of batteries included in the battery pack 1 can be, for example, one, two, three, four, etc. When the number of batteries is two or more, the batteries are connected in series.

[0044] To better disconnect the charger 3 from the battery pack 1 while ensuring the battery supplies power to the load 10, the protection module 7 in this embodiment includes a second IGBT Q2 and a first diode D1 connected in parallel. The collector of the second IGBT Q2 is connected to the positive terminal of the battery pack 1, the emitter of the second IGBT Q2 is connected to the positive terminal of the charger 3, and the gate of the second IGBT Q2 is connected to the first control module 8. The anode of the first diode D1 is connected to the positive terminal of the battery pack 1, and the cathode of the first diode D1 is connected to the negative terminal of the charger 3. Through the arrangement of the second IGBT Q2 and the first diode D1, the connection between the charger 3 and the battery pack 1 can be disconnected under the control of the first control module 8 without affecting the discharge of the battery pack 1 to the load 10, which is beneficial for design and implementation.

[0045] Furthermore, to better control the aforementioned modules, the first control module 8 in this embodiment includes a data acquisition unit, a processing unit, a control unit, and a communication interface. The data acquisition unit can receive the information of the battery sub-group 2 collected by the detection module 4 and send it to the processing unit. The processing unit can process and analyze the information of the battery sub-group 2 and send the processed information to the control unit. The control unit can generate control information based on the processed information and send the control information to the shunt module 5, the step-down module 6, and the protection module 7 through the communication interface to control the actions of the shunt module 5, the step-down module 6, and the protection module 7. Thus, the first control module 8 includes a data acquisition unit, a processing unit, a control unit, and a communication interface, which has a simple structure and is easy to design and implement.

[0046] Furthermore, to facilitate the control of the first control module 8, in this embodiment, a galvanometer 9 is connected in series between the negative terminal of the battery pack 1 and the negative terminal of the charger 3, and the galvanometer 9 is connected to the control module to transmit the current signal to the acquisition unit. The setting of the galvanometer 9 facilitates the acquisition of the current signal between the battery pack 1 and the charger 3, which facilitates the issuance of the control signal by the first control module 8, helps to improve the safety of battery use, and is conducive to design and implementation.

[0047] In this embodiment, when the detection module 4 detects the temperature information of the battery sub-group 2 and determines that the temperature information is abnormal, the first control module 8 turns on the step-down module 6 and controls the second control module 501 to turn on the resistor R1 to shunt the current to the battery sub-group 2, and disconnects the second IGBT tube Q2 of the protection module 7. While ensuring that the battery group 1 supplies power to the load 10, the step-down module 6 reduces the charging voltage of the charger 3, and fully charges the battery group 1 while avoiding potential thermal runaway risks.

[0048] The battery thermal runaway protection circuit in this embodiment can ensure the charging of battery pack 1 and the discharge of battery pack 1 to load 10 while detecting the risk of thermal runaway of battery sub-pack 2. By setting up step-down module 6 and shunt module 5, the potential risk of thermal runaway when charging battery pack 1 can be avoided, which helps to improve the safety of battery pack 1.

[0049] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A thermal runaway protection circuit for a battery pack, used for thermal runaway protection during charging of a battery pack (1), wherein the battery pack (1) includes a plurality of battery sub-packs (2), and the positive and negative terminals of the battery packs (1) are respectively connected to the positive and negative terminals of a charger (3), characterized in that, The protection circuit includes: The detection module (4) is located on the battery sub-group (2) to obtain information about the battery sub-group (2); The current shunt module (5) is connected in parallel to the battery sub-group (2) to shunt the charging current of the battery sub-group (2); A step-down module (6) is connected in series between the positive terminal of the battery pack (1) and the positive terminal of the charger (3) to control the charging current of the charger (3) to the battery pack (1). Protection module (7), which is connected in parallel to the step-down module (6) to disconnect the charger (3) from the battery pack (1); The first control module (8) is connected to the detection module (4), the current shunt module (5), the voltage reduction module (6) and the protection module (7) respectively, and can send control signals to control the operation of the current shunt module (5), the voltage reduction module (6) and the protection module (7) according to the information of the battery subgroup (2).

2. The battery pack thermal runaway protection circuit according to claim 1, characterized in that: The detection module (4) includes several temperature detection units (401) respectively disposed on the battery sub-group (2). Each temperature detection unit (401) is connected to the first control module (8) to transmit the temperature information of each battery sub-group (2) to the first control module (8).

3. The battery pack thermal runaway protection circuit according to claim 2, characterized in that: The temperature detection unit (401) includes a first temperature sensor and a second temperature sensor. The first temperature sensor is located at the positive terminal of the battery sub-group (2), and the second temperature sensor is located at the negative terminal of the battery sub-group (2).

4. The battery pack thermal runaway protection circuit according to claim 1, characterized in that: The current shunt module (5) includes a second control module (501), and several sets of first IGBT tubes and resistors connected in parallel across the two ends of the battery subgroup (2), wherein the first IGBT tubes and the resistors are connected in series. The collector of the first IGBT is connected to the positive terminal of the battery sub-group (2), the emitter of the first IGBT is connected to the first end of the resistor, the gate of the first IGBT is connected to the second control module (501), and the second end of the resistor is connected to the negative terminal of the battery sub-group (2). The second control module (501) is connected to the first control module (8) and is configured to receive control signals from the control module to control the on / off state of the first IGBT tube.

5. The battery pack thermal runaway protection circuit according to claim 1, characterized in that: The protection module (7) includes a second IGBT and a first diode connected in parallel; The collector of the second IGBT is connected to the positive terminal of the battery pack (1), the emitter of the second IGBT is connected to the positive terminal of the charger (3), the gate of the second IGBT is connected to the first control module (8), the anode of the first diode is connected to the positive terminal of the battery pack (1), and the cathode of the first diode is connected to the negative terminal of the charger (3).

6. The battery pack thermal runaway protection circuit according to any one of claims 1-5, characterized in that: The first control module (8) includes a data acquisition unit, a processing unit, a control unit, and a communication interface; The acquisition unit can receive the battery subgroup (2) information acquired by the detection module (4) and send it to the processing unit; The processing unit is capable of processing and analyzing the information of the battery subgroup (2) and sending the processing information to the control unit; The control unit can generate control information based on the processing information and send the control information to the shunt module (5), the step-down module (6) and the protection module (7) through the communication interface to control the operation of the shunt module (5), the step-down module (6) and the protection module (7).

7. The battery pack thermal runaway protection circuit according to claim 6, characterized in that: A galvanometer (9) is connected in series between the negative terminal of the battery pack (1) and the negative terminal of the charger (3), and the galvanometer (9) is connected to the control module to transmit the current signal to the acquisition unit.

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