Overheat protection circuit of lithium battery cell and lithium battery energy storage inverter

Abstract

The utility model relates to the technical field of cell overheat protection, and discloses a lithium battery cell overheat protection circuit and a lithium battery energy storage inverter, and the circuit comprises a cooling fan, a control module, a first cell power supply module, a second cell power supply module and a plurality of temperature detectors. The temperature detector is located between two adjacent battery cells, and the temperature detector is used for detecting a temperature value between the two adjacent battery cells; the control module is used for driving the cooling fan to operate when determining that one temperature value exceeds a preset temperature threshold value; the first battery cell power supply module is connected with the power supply ends of the at least two battery cells, and the first battery cell power supply module is connected with the power supply end of the control module; and the second battery cell power supply module is connected with the power supply ends of the at least two battery cells, and the second battery cell power supply module is connected with the power supply ends of the plurality of temperature detectors. And the battery core of the lithium battery directly supplies power, so that the dependence on an external power supply is reduced, multi-point detection is realized, and the stability and the safety of the lithium battery energy storage inverter are improved.

Description

Technical Field

[0001] This utility model relates to the field of battery cell overheat protection technology, and in particular to an overheat protection circuit for lithium battery cells and a lithium battery energy storage inverter. Background Technology

[0002] A lithium-ion battery energy storage inverter is a power system that uses lithium batteries as energy storage devices to convert direct current (DC) to alternating current (AC). Lithium-ion battery energy storage inverters use lithium batteries to provide longer power supply times, making them suitable for scenarios requiring continuous power supply.

[0003] In the existing technology, some power protection boards use an external power supply to power modules such as overheat protection. The external power supply may be affected by factors such as load changes, and overheat protection usually adopts a single-point detection method, which may lead to unstable output voltage or overheating of the power protection board or power supply module, affecting the accuracy of overheat protection and the service life of the protection board. Utility Model Content

[0004] The purpose of this utility model is to provide an overheat protection circuit for a lithium battery cell and a lithium battery energy storage inverter, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0005] The solution to the technical problem of this utility model is to provide an overheat protection circuit for a lithium battery cell and a lithium battery energy storage inverter.

[0006] In a first aspect of this utility model, an overheat protection circuit for a lithium battery cell is provided, wherein the lithium battery is composed of multiple battery cells connected in series; the overheat protection circuit includes:

[0007] Cooling fan;

[0008] Multiple temperature detectors are provided, wherein the temperature detectors are disposed between two adjacent battery cells, and the temperature detectors are used to detect the temperature value between two adjacent battery cells;

[0009] The control module has its input terminal connected to multiple temperature detectors and its output terminal connected to the cooling fan. The control module is used to drive the cooling fan to run when it determines that one of the temperature values ​​exceeds a preset temperature threshold.

[0010] A first cell power supply module, wherein the input terminal of the first cell power supply module is connected to the power supply terminals of at least two of the battery cells, and the output terminal of the first cell power supply module is connected to the power supply terminal of the control module;

[0011] The second battery cell power supply module has its input terminal connected to the power supply terminals of at least two of the battery cells, and its output terminal connected to the power supply terminals of a plurality of the temperature detectors.

[0012] Furthermore, the second battery cell power supply module includes:

[0013] A drive-on unit, wherein the input terminal of the drive-on unit is connected to the power supply terminals of at least two of the battery cells, and the drive terminal of the drive-on unit is connected to the output terminal of the control module;

[0014] The first voltage regulator unit has its input terminal connected to the output terminal of the drive conduction unit, and its output terminal connected to the power supply terminals of the plurality of temperature detectors.

[0015] Furthermore, the first battery cell power supply module includes:

[0016] The second voltage regulator unit has its input terminal connected to the power supply terminals of at least two of the battery cells, and its output terminal connected to the power supply terminal of the control module.

[0017] Furthermore, the drive conduction unit includes:

[0018] A MOSFET switching circuit, wherein the input terminal of the MOSFET switching circuit is connected to the power supply terminals of at least two of the battery cells, and the output terminal of the MOSFET switching circuit is connected to the input terminal of the first voltage regulator unit;

[0019] The transistor driving circuit has its input terminal connected to the output terminal of the control module, and its output terminal connected to the driving terminal of the MOS transistor switching circuit.

[0020] Furthermore, the drive conduction unit also includes:

[0021] A battery voltage detection circuit is provided, wherein the input terminal of the battery voltage detection circuit is connected to the output terminal of the MOS transistor switching circuit, and the output terminal of the battery voltage detection circuit is connected to the input terminal of the control module.

[0022] Furthermore, an overheat protection circuit for a lithium battery cell also includes:

[0023] An AC monitoring module is provided, wherein the power supply terminal of the AC monitoring module is connected to the output terminal of the first voltage regulator unit and the power supply terminals of at least two of the battery cells respectively, and the monitoring port of the AC monitoring module is connected to the control module.

[0024] An interface is provided, which is connected to the communication monitoring module.

[0025] Furthermore, an overheat protection circuit for a lithium battery cell also includes:

[0026] The LCD module has its input terminal connected to the control module and its power supply terminal connected to the output terminal of the first voltage regulator unit.

[0027] Furthermore, the second battery cell power supply module also includes:

[0028] The third voltage regulator unit has its input terminal connected to the output terminal of the drive conduction unit, and its output terminal connected to the power supply terminal of the LCD module.

[0029] Furthermore, the AC monitoring module includes:

[0030] An optocoupler, wherein the input terminal of the optocoupler is connected to the AC interface, the output terminal of the optocoupler is connected to the control module, and the power supply terminal of the optocoupler is connected to the first voltage regulator unit;

[0031] An AC status display unit is provided, which is connected to the control module. The power supply terminal of the AC status display unit is connected to the power supply terminals of at least two of the battery cells.

[0032] In a second aspect of this utility model, a charging device includes an overheat protection circuit for a lithium battery cell as described in the first aspect of this utility model.

[0033] The beneficial effects of this utility model are: by directly powering the lithium battery cells, the dependence on external power sources is reduced, the risk of failure due to unstable external power sources or environmental changes is reduced, and the service life of the protection board is improved. By setting a temperature detector between two adjacent battery cells, which is in direct contact with the battery cells, the heat generated by the circuit board is reduced, which affects the accuracy of the temperature detector. This enables multi-point detection, improves detection accuracy and response speed, saves installation space, and improves the stability and safety of the lithium battery energy storage inverter. Attached Figure Description

[0034] Figure 1 This is a partial circuit diagram of an overheat protection circuit for a lithium battery cell provided in one embodiment of the present invention;

[0035] Figure 2 This is a partial circuit diagram of an overheat protection circuit for a lithium battery cell provided in another embodiment of this utility model;

[0036] Figure 3 This is a circuit diagram of an LCD module for an overheat protection circuit of a lithium battery cell provided in one embodiment of this utility model.

[0037] Figure 4 This is a circuit diagram of the current monitoring module of an overheat protection circuit for a lithium battery cell provided in another embodiment of the present invention.

[0038] Reference numerals: 100, First cell power supply module; 110, Second voltage regulator unit; 200, Second cell power supply module; 210, Drive conduction unit; 211, MOSFET switching circuit; 212, Transistor drive circuit; 213, Battery voltage detection circuit; 220, First voltage regulator unit; 230, Third voltage regulator unit; 300, Temperature detector; 400, Control module; 500, Cooling fan; 600, AC monitoring module; 610, AC status display unit; U4, Optocoupler; 700, LCD module. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and should not be construed as limiting the scope of this invention.

[0040] It should be noted that although functional modules are divided in the diagram, in some cases, the modules can be divided differently from those in the system.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" and "second" may explicitly or implicitly include one or more features.

[0042] In the description of this utility model, it should be noted that, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0043] To ensure the safety and efficiency of lithium batteries during charging and to extend their lifespan, most products use lithium batteries with a power protection board (also known as a battery protection board).

[0044] In the existing technology, some power protection boards use an external power supply to power modules such as overheat protection. The external power supply may be affected by factors such as load changes, and overheat protection usually adopts a single-point detection method, which may lead to unstable output voltage or overheating of the power protection board or power supply module, affecting the accuracy of overheat protection and the service life of the protection board.

[0045] Reference Figure 1 and Figure 2 In some embodiments of the first aspect of this utility model, an overheat protection circuit for a lithium battery cell includes: a cooling fan 500, a control module 400, a first cell power supply module 100, a second cell power supply module 200, and multiple temperature detectors 300.

[0046] A temperature detector 300 is installed in the gap between two adjacent battery cells so that the temperature detector 300 can directly contact the battery cell, saving installation space and reducing the impact of heat generated by the circuit board on the accuracy of the temperature detector 300.

[0047] Temperature detector 300 can detect the temperature between adjacent battery cells and obtain the temperature value. In other words, temperature detector 300 can detect the temperature of two battery cells simultaneously. Based on the principle of heat transfer, when the temperature of one battery cell rises above the normal operating temperature, it will also cause the temperature of the other battery cell to rise. Therefore, by detecting the temperature between adjacent battery cells, it is possible to determine whether the battery cells are overheating, thereby achieving multi-point detection to improve detection accuracy and response speed.

[0048] exist Figure 1 In this application, a circuit diagram corresponding to an embodiment with three temperature detectors 300 is provided. In practical applications, multiple temperature detectors 300 can be set according to actual needs, and the number of temperature detectors 300 can be one less than the number of battery cells.

[0049] The input terminal of the control module 400 is connected to multiple temperature detectors 300, and the control module 400 can receive multiple temperature values ​​output by the multiple temperature detectors 300. The output terminal of the control module 400 is connected to the cooling fan 500.

[0050] The control module 400 can receive multiple temperature values, and when one of the temperature values ​​exceeds a preset temperature threshold, it is considered that a battery cell is overheating. The control module 400 drives the cooling fan 500 to run in order to control the temperature of the protection circuit board.

[0051] In one embodiment, the control module 400 can also drive a corresponding relay or other switching device to cut off the power supply to the battery cell or switch the power supply of the battery cell to the outside.

[0052] The power supply terminals of at least two battery cells are connected to the input terminal of the first battery cell power supply module 100. The output terminal of the first battery cell power supply module 100 is connected to the power supply terminal of the control module 400. The first battery cell power supply module 100 can process the battery voltage output by at least two battery cells to supply power to the control module 400.

[0053] The power supply terminals of at least two battery cells are connected to the input terminal of the second battery cell power supply module 200, and the power supply terminals of multiple temperature detectors 300 are connected to the output terminal of the second battery cell power supply module 200. The second battery cell power supply module 200 can process the battery voltage output by at least two battery cells to power multiple temperature detectors 300.

[0054] In one embodiment, the second cell power supply module 200 can also process the battery voltage output by the two battery cells to supply power to the other modules.

[0055] Since a lithium battery is formed by connecting multiple battery cells in series, the battery cells connected to the battery cell power supply module are also connected in series. In other words, the battery cells connected to the battery cell power supply module can be some of the battery cells or all of the battery cells in the lithium battery, but at least two battery cells must be connected.

[0056] By directly powering the battery cells, dependence on external power sources is reduced, lowering the risk of failure due to unstable external power sources or environmental changes. Internal power supply via lithium batteries provides more stable voltage and current, reduces voltage fluctuations caused by external factors, extends the lifespan of the protection board, and improves the stability and safety of the lithium battery energy storage inverter.

[0057] Reference Figure 1 and Figure 2 In some embodiments of the first aspect of this utility model, the first battery cell power supply module 100 includes: a second voltage regulator unit 110.

[0058] The input terminal of the second voltage regulator unit 110 is connected to the power supply terminal of at least two battery cells, and the output terminal of the second voltage regulator unit 110 is connected to the power supply terminal of the control module 400. The second voltage regulator unit 110 can regulate and reduce the battery voltage output by at least two battery cells to provide a 3.3V DC voltage to the control module 400.

[0059] The second voltage regulator unit 110 includes an HT7533-2 linear regulator.

[0060] Reference Figures 1 to 3 In some embodiments of the first aspect of this utility model, the second battery cell power supply module 200 includes: a drive conduction unit 210, a first voltage regulator unit 220, and a third voltage regulator unit 230.

[0061] The input terminal of the drive-on unit 210 is connected to the power supply terminals of at least two battery cells, and the output terminal of the drive-on unit 210 is connected to the input terminals of the first voltage regulator unit 220 and the third voltage regulator unit 230, respectively. The drive terminal of the drive-on unit 210 is connected to the output terminal of the control module 400. That is to say, the first voltage regulator unit 220 and the third voltage regulator unit 230 are connected in parallel.

[0062] For example, the drive conduction unit 210 can conduct the power supply terminals of at least two battery cells to the input terminal of the first voltage regulator unit 220 and the power supply terminals of at least two battery cells to the input terminal of the third voltage regulator unit 230 according to the control signal output by the control module 400, so as to supply the battery voltage of at least two battery cells to the first voltage regulator unit 220 and the third voltage regulator unit 230.

[0063] The output terminal of the first voltage regulator unit 220 is connected to the power supply terminal of the multiple temperature detectors 300. The first voltage regulator unit 220 can regulate and reduce the battery voltage output by at least two battery cells to provide a 3.3V voltage to the multiple temperature detectors 300.

[0064] Reference Figure 1 and Figure 3 The output terminal of the third voltage regulator unit 230 is connected to the power supply terminal of the LCD module 700. The third voltage regulator unit 230 can regulate and reduce the battery voltage output by at least two battery cells to provide 5V voltage to the LCD module 700.

[0065] The second voltage regulator unit 110 includes an HT7533-2 linear regulator, and the third voltage regulator unit 230 includes an HT7550-2 linear regulator.

[0066] In some embodiments, the drive conduction unit 210 includes: a MOSFET switching circuit 211, a transistor driving circuit 212, and a battery voltage detection circuit 213.

[0067] The input terminal of the MOSFET switching circuit 211 is connected to the power supply terminals of at least two battery cells, and the output terminal of the MOSFET switching circuit 211 is connected to the battery voltage detection circuit 213, the first voltage regulator unit 220 and the third voltage regulator unit 230.

[0068] In other words, the battery voltage detection circuit 213, the first voltage regulator unit 220, and the third voltage regulator unit 230 are connected in parallel.

[0069] The driving terminal of the MOSFET switching circuit 211 is connected to the output terminal of the transistor driving circuit 212, and the input terminal of the transistor driving circuit 212 is connected to the output terminal of the control module 400. The transistor driving circuit 212 can receive the driving signal sent by the control module 400 and drive the MOSFET switching circuit 211 to conduct.

[0070] For example, the control module 400 outputs a drive signal to the transistor drive circuit 212, the transistor in the transistor drive circuit 212 is turned on, the transistor drive circuit 212 outputs a conduction signal to the MOSFET switch circuit 211, the MOSFET in the MOSFET switch circuit 211 is turned on, so that the voltage and current of at least two battery cells can be supplied to the first voltage regulator unit 220 and the third voltage regulator unit 230 for processing, and power the corresponding modules.

[0071] In this circuit, the MOS transistor in the MOS transistor switching circuit 211 is a PMOS transistor, and the transistor in the transistor driving circuit 212 is an NPN transistor. The base of the transistor is connected to the output terminal of the control module 400, the collector of the transistor is connected to the gate of the NMOS transistor, the emitter of the transistor is grounded, the source of the MOS transistor is connected to the power supply terminals of at least two battery cells, and the drain of the MOS transistor is connected to the battery voltage detection circuit 213, the first voltage regulator unit 220, and the third voltage regulator unit 230.

[0072] The input terminal of the battery voltage detection circuit 213 is connected to the power supply terminal of at least two battery cells through the MOSFET switching circuit 211. When the MOSFET of the MOSFET switching circuit 211 is turned on, the battery voltage detection circuit 213 can detect the voltage output by at least two battery cells, obtain the battery voltage value, and output it to the control module 400.

[0073] Since the power supply voltage required by the LCD module 700 is different from that required by other modules, based on the specifications of the lithium battery cells, the battery voltage supplied by at least two battery cells needs to be processed by the first voltage regulator unit 220 and the third voltage regulator unit 230 to enable power supply to different modules.

[0074] In addition, a shutdown circuit composed of MOSFET switching circuit 211 and transistor driving circuit 212 is used to control the on / off of the battery voltage supplied by at least two battery cells, thereby making the internal power supply controllable and improving the stability and safety of the overheat protection circuit.

[0075] Reference Figures 1 to 4 In some embodiments of the first aspect of this utility model, the overheat protection circuit further includes: an AC interface, an AC monitoring module 600, and an LCD module 700.

[0076] Reference Figure 4 The AC interface can be connected to the AC power supply terminal in the energy storage inverter, and it can also be connected to the AC monitoring module 600. That is, the AC power supply terminal is connected to the AC monitoring module 600 through the AC interface.

[0077] The power supply terminal of the AC monitoring module 600 is connected to the output terminal of the first voltage regulator unit 220. The power supply terminal of the AC monitoring module 600 is also connected to the power supply terminals of at least two battery cells. The monitoring port of the AC monitoring module 600 is connected to the input terminal of the control module 400.

[0078] The AC monitoring module 600 includes an AC status display unit 610 and an optocoupler U4.

[0079] The power supply terminals of at least two battery cells are connected to the power supply terminal of the AC status display unit 610, the input terminal of the AC status display unit 610 is connected to the output terminal of the control module 400, and the output terminal of the AC status display unit 610 is connected to the AC interface.

[0080] The power supply terminal (i.e., the fourth pin of optocoupler U4) is connected to the output terminal of the first voltage regulator unit 220.

[0081] The input terminals of optocoupler U4 (i.e., the first and second pins of optocoupler U4) are connected to the AC interface.

[0082] The output terminal of optocoupler U4 (i.e., the third pin of optocoupler U4) is connected to the input terminal of control module 400 to realize the connection between the monitoring port and the input terminal of control module 400.

[0083] For example, when an AC power source is connected to the AC interface, the LED of the optocoupler U4 will turn on and emit light, the phototransistor will turn on, and the phototransistor will generate a signal, which will be output to the control module 400 to indicate the connection of the AC power source, thereby realizing the monitoring of the AC power source.

[0084] Reference Figure 3 The input terminal of the LCD module 700 is connected to the output terminal of the control module 400, and the power supply terminal of the LCD module 700 is connected to the output terminals of the first voltage regulator unit 220 and the third voltage regulator unit 230, respectively. The LCD module 700 can display the working status of the lithium battery.

[0085] In some embodiments of the second aspect of this utility model, a lithium battery energy storage inverter includes the overheat protection circuit for the lithium battery cell in the embodiments of the first aspect of this utility model.

[0086] By directly powering the battery cells, dependence on external power sources is reduced, lowering the risk of failure due to unstable external power sources or environmental changes. Internal power supply via lithium batteries provides more stable voltage and current, reduces voltage fluctuations caused by external factors, extends the lifespan of the protection board, and improves the stability and safety of the lithium battery energy storage inverter.

[0087] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. An overheat protection circuit for a lithium battery cell, characterized by, The lithium battery is composed of a plurality of battery cores in series; the overheat protection circuit comprises: a cooling fan; a plurality of temperature detectors arranged between adjacent two battery cores, the temperature detectors being used to detect the temperature value between adjacent two battery cores; a control module, an input end of the control module being connected with the plurality of temperature detectors, an output end of the control module being connected with the cooling fan, the control module being used to drive the cooling fan to operate when it is determined that one of the temperature values exceeds a preset temperature threshold; a first battery core power supply module, an input end of the first battery core power supply module being connected with the power supply ends of at least two battery cores, an output end of the first battery core power supply module being connected with the power supply end of the control module; a second battery core power supply module, an input end of the second battery core power supply module being connected with the power supply ends of at least two battery cores, an output end of the second battery core power supply module being connected with the power supply ends of the plurality of temperature detectors.

2. The overheat protection circuit of a lithium battery cell according to claim 1, wherein, The second battery core power supply module comprises: a drive conduction unit, an input end of the drive conduction unit being connected with the power supply ends of at least two battery cores, a drive end of the drive conduction unit being connected with the output end of the control module; a first voltage stabilizing unit, an input end of the first voltage stabilizing unit being connected with the output end of the drive conduction unit, an output end of the first voltage stabilizing unit being connected with the power supply ends of the plurality of temperature detectors.

3. The overheat protection circuit of a lithium battery cell according to claim 1, wherein, The first battery core power supply module comprises: a second voltage stabilizing unit, an input end of the second voltage stabilizing unit being connected with the power supply ends of at least two battery cores, an output end of the second voltage stabilizing unit being connected with the power supply end of the control module.

4. The overheat protection circuit of a lithium battery cell according to claim 2, wherein, The drive conduction unit comprises: a MOS tube switch circuit, an input end of the MOS tube switch circuit being connected with the power supply ends of at least two battery cores, an output end of the MOS tube switch circuit being connected with the input end of the first voltage stabilizing unit; a triode drive circuit, an input end of the triode drive circuit being connected with the output end of the control module, an output end of the triode drive circuit being connected with the drive end of the MOS tube switch circuit.

5. The overheat protection circuit of a lithium battery cell according to claim 4, wherein, The drive conduction unit further comprises: a battery voltage detection circuit, an input end of the battery voltage detection circuit being connected with the output end of the MOS tube switch circuit, an output end of the battery voltage detection circuit being connected with the input end of the control module.

6. The overheat protection circuit of a lithium battery cell according to claim 2, wherein, Further comprising: an alternating current monitoring module, a power supply end of the alternating current monitoring module being connected with the output end of the first voltage stabilizing unit and the power supply ends of at least two battery cores respectively, a monitoring port of the alternating current monitoring module being connected with the control module; an alternating current interface, the alternating current interface being connected with the alternating current monitoring module.

7. The overheat protection circuit of a lithium battery cell according to claim 2, wherein, Further comprising: an LCD module, an input end of the LCD module being connected with the control module, a power supply end of the LCD module being connected with the output end of the first voltage stabilizing unit.

8. The overheat protection circuit of a lithium battery cell according to claim 7, wherein, The second battery core power supply module further comprises: a third voltage stabilizing unit, an input end of the third voltage stabilizing unit being connected with the output end of the drive conduction unit, an output end of the third voltage stabilizing unit being connected with the power supply end of the LCD module.

9. The overheat protection circuit of a lithium battery cell according to claim 6, wherein, The AC monitoring module comprises: An optoelectronic coupler, an input end of the optoelectronic coupler being connected with the AC interface, an output end of the optoelectronic coupler being connected with the control module, and a power supply end of the optoelectronic coupler being connected with the first voltage stabilizing unit; An AC state display unit, the AC state display unit being connected with the control module, and a power supply end of the AC state display unit being connected with the power supply ends of the at least two battery cores.

10. A lithium battery energy storage inverter, characterized by, The overheat protection circuit of the lithium battery core comprises the overheat protection circuit of the lithium battery core according to any one of claims 1 to 9.

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