Battery protection circuit and energy storage device

Abstract

The invention provides a battery protection circuit and energy storage equipment. The battery protection circuit comprises a current sampling module used for obtaining a current detection value of a battery module; the overcurrent detection module is used for comparing the current detection value with a preset current threshold value; when the current detection value is greater than the current threshold value, the over-current detection module generates an over-current signal; the voltage sampling module is used for obtaining a voltage detection value of the battery module; the short circuit detection module is used for comparing the voltage detection value with a preset voltage threshold value, and when the voltage detection value is greater than the voltage threshold value, the short circuit detection module generates a short circuit signal; the driving control module generates a driving control signal when receiving the overcurrent signal and / or the short circuit signal; and when the switch module receives the driving control signal, the switch module turns off the battery module. According to the battery protection circuit, one path of overcurrent detection and one path of short circuit detection are performed respectively, and even if overcurrent fails, the battery module can still be protected through short circuit detection.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery protection circuit and an energy storage device. Background Art

[0002] In a high-voltage battery system, the high-voltage battery module needs to monitor the current in real time during the charging and discharging process. The fault is identified by the collected current, and the battery module is shut down to protect the battery module.

[0003] In the related art, the battery protection circuit uses a shunt to collect current. When the current is relatively large, the relay is controlled to shut down the battery module to protect the battery module.

[0004] However, in actual use, the above battery protection circuit has the problem of failure or malfunction and cannot protect the high-voltage battery module. In this way, the high-voltage battery module can only be protected by blowing the FUSE (fuse), which seriously wastes time and labor maintenance costs and affects customer experience. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the related art.

[0006] To this end, a first aspect of the present application is to provide a battery protection circuit.

[0007] A second aspect of the present application is to provide an energy storage device.

[0008] In view of this, according to the first aspect of the present application, a battery protection circuit is proposed, which is connected to a battery module and includes: a current sampling module, which is connected to the battery module and is used to obtain a current detection value of the battery module; an overcurrent detection module, which is connected to the current sampling module and is used to compare the current detection value with a preset current threshold; when the current detection value is greater than the current threshold, the overcurrent detection module generates an overcurrent signal; a voltage sampling module, which is connected to the battery module and is used to obtain a voltage detection value of the battery module; a short-circuit detection module, which is connected to the voltage sampling module and is used to compare the voltage detection value with a preset voltage threshold, and when the voltage detection value is greater than the voltage threshold, the short-circuit detection module generates a short-circuit signal; a drive control module, which is connected to the overcurrent detection module and the short-circuit detection module and is used to generate a drive control signal; when the drive control module receives an overcurrent signal and / or a short-circuit signal, the drive control module generates a drive control signal; a switch module, which is connected to the battery module and the drive control module; when the drive control signal is received, the switch module turns off the battery module.

[0009] Since when a short circuit occurs, overcurrent occurs first and then short circuit occurs, therefore, in the above technical solution, by setting up a current sampling module and a voltage sampling module respectively, overcurrent detection and short circuit detection are each one way, and the current detection value and voltage detection value are analyzed and processed by the overcurrent detection module and the short circuit detection module respectively. If they exceed the preset threshold, the corresponding overcurrent signal and short circuit signal are generated and sent to the drive control module. After receiving the overcurrent signal and the short circuit signal, the drive control module generates a drive control signal to drive the switch module to shut down the battery module, thereby protecting the battery module. In this way, even if the overcurrent fails, the short circuit detection module can still identify the overcurrent, thereby ensuring that the battery module can be protected in a timely and effective manner.

[0010] In some technical schemes, optionally, the drive control module includes: a drive control unit connected to the overcurrent detection module; a D trigger having a clock input and a data input; the data input is connected to the drive control unit, and the clock input is connected to the short-circuit detection module; a drive unit is connected to the D trigger and the drive control unit, and is used to control the switch module to shut down the battery module.

[0011] In the above technical solution, the setting of the D trigger can maintain stable control over the switch module even when the driving control signal of the driving control unit changes, thereby helping to improve the reliability and stability of the battery protection circuit.

[0012] In some technical schemes, optionally, the short circuit detection module includes: a voltage comparison unit, a first resistor, a second resistor, a third resistor and a MOS tube; wherein the voltage comparison unit is used to compare the voltage detection value and the voltage threshold, and has a fifth input terminal, a sixth input terminal and a third output terminal; the fifth input terminal is used to obtain the voltage threshold, and the sixth input terminal is connected to the second output terminal; the source of the MOS tube is connected to the D trigger; the second resistor is connected to the third output terminal and the gate of the MOS tube; one end of the first resistor is connected between the third output terminal and the second resistor, and the other end is connected to the first power supply; one end of the third resistor is connected to the source of the MOS tube, and the other end is grounded; the drain of the MOS tube is connected to the second power supply; the NOR gate unit includes a seventh input terminal and a fourth output terminal, the seventh input terminal is connected to the source of the MOS tube, and the fourth output terminal is connected to the D trigger.

[0013] In this way, when a short circuit occurs in the battery module, the voltage comparison unit outputs a high level, and after voltage division by the first resistor and the second resistor, the MOS tube is turned on and outputs a high level, and outputs a low level through the NOR gate unit, thereby causing the D trigger to output a drive control signal, forcing the drive unit to control the switch module to shut down the battery module, thereby achieving short circuit protection.

[0014] In some technical schemes, optionally, the short circuit detection module also includes a self-locking unit for locking the output state of the voltage comparison unit; one end of the self-locking unit is connected between the voltage sampling module and the sixth input terminal, and the other end of the self-locking unit is connected between the third output terminal and the second resistor.

[0015] By setting a self-locking unit, the voltage comparison unit continuously outputs a high-level signal until the fault is cleared. In this way, when a short-circuit fault is detected, the battery protection circuit can give a clearer and more lasting indication, thereby facilitating timely measures to clear the fault.

[0016] In the above technical solution, optionally, a digital isolator is further included; the digital isolator is used to isolate the level signal of the MOS tube and the NOR gate unit. In this way, the high and low voltage levels between the MOS tube and the NOR gate unit can be isolated, thereby ensuring the electrical safety between the high and low voltage circuits, so as to improve the safety and reliability of the entire battery protection circuit.

[0017] In some technical solutions, a central control module is also included, which is connected to the overcurrent detection module and the drive control module; when the current detection value is greater than the current threshold, the overcurrent detection module also generates current detection information, and the central control module generates a fault signal after receiving the overcurrent signal and the current detection information; the drive control module generates a drive control signal after receiving the fault signal.

[0018] In the above technical solution, when the overcurrent detection module detects that the current detection value is greater than the current threshold, it preferentially sends an overcurrent signal to the drive control module, so that the drive control module controls the switch module to shut down the battery module, thereby improving the protection response speed; at the same time, the overcurrent detection module will also send the current detection information and the overcurrent signal to the central control module, and the central control module will generate a fault signal when receiving the current detection information and the overcurrent signal and send it to the drive control module; in this way, even if a fault or failure occurs between the overcurrent detection module and the drive control module, the drive control module can also control the switch module to shut down the battery module after receiving the fault signal; the cooperation of these two can improve the reliability and safety of the battery protection circuit.

[0019] The above technical solution also includes a digital isolator, which is used to isolate the fault signal between the central control module and the drive control module and the overcurrent signal between the overcurrent detection module and the drive control module. In this way, the reliability and safety of the entire battery protection circuit can be further improved.

[0020] In some technical solutions, optionally, the battery protection current further includes: a shunt; the shunt is connected to the battery module; wherein the current sampling module and the voltage sampling module are both connected to the shunt.

[0021] In the above technical solution, accurate measurement and rapid response of current are achieved through the combination of the shunt and the first operational amplifier unit, providing a strong guarantee for the safe operation of the battery module.

[0022] In some technical schemes, optionally, the current sampling module includes a first operational amplifier unit having a first input terminal, a second input terminal and a first output terminal; the first input terminal and the second input terminal are respectively connected to the two ends of the shunt, configured to detect a voltage detection value, and generate a current detection value based on the voltage detection value; the first output terminal is connected to the overcurrent detection module; and / or, the voltage sampling module includes a second operational amplifier unit having a third input terminal, a fourth input terminal and a second output terminal; the third input terminal and the fourth input terminal are respectively connected to the two ends of the shunt, configured to detect the voltage detection value.

[0023] In the above technical solution, current and voltage sampling are respectively implemented by the first operational amplifier unit and the second operational amplifier unit, so that the battery protection circuit can quickly detect and respond to the short circuit of the battery module, thereby providing comprehensive protection for the battery module.

[0024] According to the second aspect of the present application, the present application also proposes an energy storage device, including the battery protection circuit provided by any of the above technical solutions. Therefore, the energy storage device has all the beneficial effects of any of the above technical solutions, which will not be repeated here.

[0025] Additional aspects and advantages of the present application will become apparent in the following description or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 A circuit diagram of a battery protection circuit in the related art is shown;

[0028] Figure 2 One of the circuit schematic diagrams of the battery protection circuit in the embodiment of the present application is shown;

[0029] Figure 3 A second circuit schematic diagram of a battery protection circuit in an embodiment of the present application is shown;

[0030] Figure 4 A schematic diagram of the working process of the battery protection circuit in the embodiment of the present application is shown.

[0031] in, Figure 1 The corresponding relationship between the reference numerals and the component names is as follows:

[0032] 100'-shunt; 200'-current comparator; 300'-drive control module; 400'-switch module; 500'-central control module;

[0033] Figure 2 and Figure 3 The corresponding relationship between the reference numerals and the component names is as follows:

[0034] 100-current sampling module; 110-first operational amplifier unit; 111-first input terminal; 112-second input terminal; 113-first output terminal; 200-overcurrent detection module; 300-central control module; 400-drive control module; 410-drive control unit; 420-D trigger; 421-clock input terminal; 422-data input terminal; 430-drive unit; 440-NOR gate unit; 441-seventh input terminal; 442-fourth output terminal; 500-switch module; 600- Voltage sampling module; 610-second operational amplifier unit; 611-third input terminal; 612-fourth input terminal; 613-second output terminal; 700-short circuit detection module; 710-voltage comparison unit; 711-fifth input terminal; 712-sixth input terminal; 713-third output terminal; R1-first resistor; R2-second resistor; R3-third resistor; 720-MOS tube; 730-first power supply; 740-second power supply; 750-self-locking unit; 800-digital isolator; 900-shunt;

[0035] 20-Battery module. DETAILED DESCRIPTION

[0036] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0037] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0038] In the related art, refer to Figure 1In order to improve the protection response speed, the battery protection circuit includes a shunt 100', a current comparator 200', a drive control module 300', a switch module 400' and a central control module 500'. Among them, the shunt 100' is used to collect the current detection value in the battery module, and the current comparator 200' is used to compare the current detection value with the preset current threshold. When it is detected that the current detection value is greater than the current threshold, the drive control module 300' controls the switch module 400' to directly shut down the battery module to protect the battery module.

[0039] However, in actual use, when a fault or failure occurs between the current comparator 200' and the drive control module 300', the battery module cannot be protected. Especially in high-voltage (greater than 400V) battery products, due to the high voltage, once an accident occurs, the consequences are more serious, so the battery protection circuit needs to have higher reliability and response speed. Figures 2 to 4 , the battery protection circuit and energy storage device provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0040] Reference Figure 2 and Figure 3 In an embodiment of the present application, a battery protection circuit is provided, including: a current sampling module 100, an overcurrent detection module 200, a drive control module 400, a switch module 500, a voltage sampling module 600 and a short circuit detection module 700.

[0041] Specifically, the current sampling module 100 is connected to the battery module 20 to obtain the current detection value (I1) of the battery module 20. The overcurrent detection module 200 is connected to the current sampling module 100 to compare the current detection value with a preset current threshold (Iref); when the current detection value is greater than the current threshold, the overcurrent detection module 200 generates an overcurrent signal. The voltage sampling module 600 is connected to the battery module 20 to obtain the voltage detection value (V1) of the battery module 20. The short-circuit detection module 700 is connected to the voltage sampling module 600 to compare the voltage detection value with a preset voltage threshold (Uref); when the voltage detection value is greater than the voltage threshold, the short-circuit detection module 700 generates a short-circuit signal. The drive control module 400 is connected to the overcurrent detection module 200 and the short-circuit detection module 700 to generate a drive control signal; after receiving the overcurrent signal and / or the short-circuit signal, the drive control module 400 generates a drive control signal. The switch module 500 and the battery module 20 are connected to the drive control module 400 ; after receiving the drive control signal, the switch module 500 turns off the battery module 20 .

[0042] Since when a short circuit occurs, overcurrent occurs first and then short circuit occurs, therefore, in the above embodiment, by respectively setting the current sampling module 100 and the voltage sampling module 600, overcurrent detection and short circuit detection are each one way, and the current detection value and the voltage detection value are respectively analyzed and processed by the overcurrent detection module 200 and the short circuit detection module 700. If they exceed the preset threshold, the corresponding overcurrent signal and short circuit signal are generated and sent to the drive control module 400. After receiving the overcurrent signal and the short circuit signal, the drive control module 400 generates a drive control signal to drive the switch module 500 to turn off the battery module 20, thereby protecting the battery module. In this way, even if the overcurrent fails, the short circuit detection module 700 can still identify the overcurrent, thereby ensuring that the battery module 20 can be protected in a timely and effective manner.

[0043] In the above embodiment, redundant acquisition circuits are designed to respectively collect current detection values ​​and voltage detection values, and overcurrent detection and short-circuit detection each report a fault signal, which can back up the overcurrent and short-circuit signals to each other. In this way, even if one of the overcurrent and short-circuit signals fails, the safety of the battery module 20 can be guaranteed.

[0044] In some embodiments, the driving control module 400 includes a driving control unit 410 , a D flip-flop 420 , a driving unit 430 and a NOR gate unit 440 .

[0045] Specifically, the driving control unit 410 is connected to the overcurrent detection module 200, and is used to receive the overcurrent signal and generate the driving control signal. The D trigger 420 has a clock input terminal 421 and a data input terminal 422; the data input terminal 422 is connected to the driving control unit 410, and changes its output state according to the driving control signal output by the driving control unit 410 to output the driving control signal. The NOR gate unit 440 includes a seventh input terminal 441 and a fourth output terminal 442. Among them, the seventh input terminal 441 is connected to the short circuit detection module 700, and the fourth output terminal 442 is connected to the clock input terminal 421 of the D trigger 420. The driving unit 430 is connected to the D trigger 420 and the driving control unit 410, and is used to receive the driving control signal output by the driving control unit 410 and / or the driving control signal of the D trigger 420, and control the switch module 500 to shut down the battery module 20 according to these signals.

[0046] In the above embodiment, when the NOR gate unit 440 receives a short-circuit signal, it outputs a clock signal (CLK, Clock Signal) to the clock input terminal 421 of the D flip-flop 420, so that the output state of the D flip-flop 420 changes, so as to output a drive control signal, thereby forcing the control switch module 500 to shut down the battery module 20, and realizing short-circuit protection, and the short-circuit protection time can reach the microsecond level. At the same time, the setting of the D flip-flop 420 can maintain stable control of the switch module 500 when the drive control signal of the drive control unit 410 changes, thereby helping to improve the reliability and stability of the battery protection circuit.

[0047] In practical applications, the drive unit 430 includes a power electronic switch or a high-side or low-side driver. When the drive control unit 410 receives a fault signal and / or an overcurrent signal, it can disconnect the switch module 500 by controlling the data input terminal 422 of the D trigger 420 and the drive unit 430 to shut down the battery module 20, and the overcurrent protection time can reach milliseconds.

[0048] In the above embodiment, the short circuit detection module 700 includes: a voltage comparison unit 710 (ie, U3 ), a first resistor R1 , a second resistor R2 , a third resistor R3 and a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor) 720 .

[0049] Specifically, the voltage comparison unit 710 is used to compare the voltage detection value with the preset voltage threshold, and has a fifth input terminal 711, a sixth input terminal 712 and a third output terminal 713; the fifth input terminal 711 is used to obtain the voltage threshold, and the sixth input terminal 712 is connected to the second output terminal 613. The source of the MOS tube 720 is connected to the seventh input terminal 441; the second resistor is connected to the third output terminal and the gate of the MOS tube. One end of the first resistor R1 is connected between the third output terminal 713 and the second resistor R2, and the other end is connected to the first power supply 730; one end of the third resistor R3 is connected to the source of the MOS tube 720, and the other end is grounded. The drain of the MOS tube 720 is connected to the second power supply 740.

[0050] In this way, when a short circuit occurs in the battery module 20, the voltage comparison unit 710 outputs a high level, and after voltage division by the first resistor R1 and the second resistor R2, the MOS tube 720 is turned on and outputs a high level, while the NOR gate unit 440 outputs a low level, thereby causing the D trigger 420 to change its output state, forcing the drive unit 430 to control the switch module 500 to turn off the battery module 20, thereby achieving short circuit protection.

[0051] In practical applications, the first power supply 730 and the second power supply 740 are 3.3 V power supplies. It is understandable that the first power supply 730 and the second power supply 740 can also be power supplies with other voltage values, and the present embodiment is not limited thereto.

[0052] In the above embodiment, the short circuit detection module 700 further includes a self-locking unit 750 for locking the output state of the voltage comparison unit 710. One end of the self-locking unit 750 is connected between the second output terminal 613 and the sixth input terminal 712, and the other end is connected between the third output terminal 713 and the second resistor R2.

[0053] By setting the self-locking unit 750, the voltage comparison unit 710 continuously outputs a high level signal until the fault is cleared. In this way, when a short circuit fault is detected, the battery protection circuit can give a clearer and more lasting indication, thereby facilitating timely measures to clear the fault.

[0054] In the above embodiment, a digital isolator 800 is also included; the digital isolator 800 is used to isolate the level signal of the MOS tube 720 and the NOR gate unit 440. In this way, the high and low voltage levels between the MOS tube 720 and the NOR gate unit 440 can be isolated, thereby ensuring the electrical safety between the high and low voltage circuits, so as to improve the safety and reliability of the entire battery protection circuit.

[0055] In some technical solutions, the battery protection circuit further includes a central control module 300. The central control module 300 is connected to the overcurrent detection module 200 and the drive control module 400; when the current detection value is greater than the current threshold, the overcurrent detection module 200 also generates current detection information, which includes the current detection value; after receiving the overcurrent signal and the current detection information, the central control module 300 generates a fault signal; after receiving the fault signal, the drive control module 400 generates a drive control signal.

[0056] In the above embodiment, when the overcurrent detection module 200 detects that the current detection value is greater than the current threshold, the overcurrent signal is preferentially sent to the drive control module 400, so that the drive control module 400 controls the switch module 500 to shut down the battery module 20, thereby improving the protection response speed; at the same time, the overcurrent detection module 200 will also send the current detection information and the overcurrent signal to the central control module 300, and the central control module 300 will generate a fault signal (Fault signal) after receiving the current detection information and the overcurrent signal and send it to the drive control module 400; in this way, even if a fault or failure occurs between the overcurrent detection module 200 and the drive control module 400, the drive control module 400 can also control the switch module 500 to shut down the battery module 20 after receiving the fault signal; the cooperation of these two can improve the reliability and safety of the battery protection circuit.

[0057] When the overcurrent detection module 200 detects that the current detection value is less than the current threshold, the central control module 300 will report the normal current value to the drive control module 400 after receiving the current detection information sent by the overcurrent detection module 200, and the drive control module 400 will work normally.

[0058] It is understandable that, after receiving the current detection information and the overcurrent signal, the central control module 300 can also perform fault analysis and trigger an alarm function or other protection mechanisms.

[0059] In the above embodiment, the central control module 300 is a MCU (Microcontroller Unit). The overcurrent detection module 200 is a 16-bit (binary digit) ADC (Analog-to-Digital Converter). The drive control unit 410 is a BCU (Battery Control Unit).

[0060] In some embodiments, the battery protection circuit further includes a digital isolator 800. The digital isolator 800 is used to isolate the fault signal between the central control module 300 and the drive control module 400 and the overcurrent signal between the overcurrent detection module 200 and the drive control module 400. In this way, the reliability of the entire battery protection circuit can be further improved.

[0061] In some embodiments, the battery protection circuit further includes a shunt 900. Specifically, the shunt 900 is connected to the battery module 20. The current sampling module 100 and the voltage sampling module 600 are both connected to the shunt 900. Thus, when the current passes through the shunt 900, a small voltage drop will be generated due to the resistance of the shunt 900, and this voltage drop is proportional to the current flowing through the shunt 900. By measuring this voltage drop, the current sampling module 100 and the voltage sampling module 600 can accurately calculate the current and voltage of the battery module 20.

[0062] In the above embodiment, the current sampling module 100 includes a first operational amplifier unit 110 (i.e., U1). The first operational amplifier unit 110 has a first input terminal 111, a second input terminal 112, and a first output terminal 113; wherein the first input terminal 111 and the second input terminal 112 are respectively connected to the two ends of the shunt 900, and are configured to detect a voltage detection value and generate a current detection value according to the voltage detection value; the first output terminal 113 is connected to the overcurrent detection module 200.

[0063] In this way, when current flows through the battery module 20, the shunt 900 will generate a voltage drop proportional to the current at both ends. This voltage drop is detected by the first input terminal 111 and the second input terminal 112 of the first operational amplifier unit 110, and an amplified current detection value is generated through the amplification of the operational amplifier. This amplified current detection value is output through the first output terminal 113 and transmitted to the overcurrent detection module 200. The overcurrent detection module 200 determines whether the current in the battery module 20 exceeds the preset current threshold value based on the received current detection value. If it exceeds, the overcurrent protection mechanism will be triggered. The combination of the shunt 900 and the first operational amplifier unit 110 realizes accurate measurement and rapid response of the current, providing a strong guarantee for the safe operation of the battery module 20.

[0064] In some embodiments, the voltage sampling module 600 further includes a second operational amplifier unit 610 (ie, U2 ).

[0065] Specifically, the second operational amplifier unit 610 has a third input terminal 611, a fourth input terminal 612, and a second output terminal 613; the third input terminal 611 and the fourth input terminal 612 are respectively connected to the two ends of the shunt 900, and are configured to detect the voltage detection value (V1). In the above embodiment, by introducing the second operational amplifier unit 610, the battery protection circuit can quickly detect and respond to the short circuit of the battery module 20, thereby providing comprehensive protection for the battery module 20.

[0066] In some embodiments, the switch module 500 includes two relays, which are respectively connected to the positive electrode and the negative electrode of the battery module 20 .

[0067] Reference Figure 4 , the specific working process of the battery protection circuit of the present application is described, which specifically includes the following steps:

[0068] S200, U1 (first op amp unit) collects I1 (current detection value)

[0069] S202, determine whether I1>Iref holds;

[0070] If yes, go to S204; if no, go to S208;

[0071] S204, reporting the overcurrent signal to the drive control module;

[0072] S206, the drive control module controls the switch module to shut down the battery module;

[0073] S208, sending current information to a central control module;

[0074] S210, reporting the current value to the drive control module;

[0075] S212, the drive control module operates normally.

[0076] In the above embodiment, after the overcurrent signal is reported to the drive control module, the method further includes:

[0077] S205, sending current detection information and overcurrent signal to the central control module;

[0078] After receiving the current detection information and the overcurrent signal, the central control module generates a fault signal and sends the fault signal to the drive control module.

[0079] In this way, when the central control module receives the current detection information and the overcurrent signal, it will generate a fault signal (Fault signal) and send it to the drive control module. In this way, even if a fault or failure occurs between the overcurrent detection module and the drive control module, the drive control module can still control the switch module to shut down the battery module after receiving the fault signal, thereby improving the reliability and safety of the battery protection circuit.

[0080] Reference Figure 4 , in some embodiments, further comprising:

[0081] S300, U2 (second operational amplifier unit) collects V1 (voltage detection value);

[0082] S302, determine whether V1>Uref is established;

[0083] If yes, go to step S304; if no, go to step S212;

[0084] S304, outputting a short-circuit signal;

[0085] S306, the NOR gate unit outputs a low level signal to the D flip-flop;

[0086] S308, the switch module turns off the battery module.

[0087] In this way, the short-circuit signal is outputted by the voltage comparison unit, so that the battery protection circuit can quickly detect and respond to the short-circuit condition of the battery module, thereby providing comprehensive protection for the battery module.

[0088] In the above embodiment, after the short-circuit signal is output, the method further includes:

[0089] S305, the self-locking unit works to continuously output the short-circuit signal.

[0090] This enables the battery protection circuit to give a clearer and more persistent indication when a short circuit fault is detected, thereby facilitating timely action to clear the fault.

[0091] In some embodiments, the present application further proposes an energy storage device, including the battery protection circuit provided by any of the above embodiments. Therefore, the energy storage device has all the beneficial effects of any of the above embodiments, which will not be described in detail here.

[0092] It should be clarified that in the claims, specification and drawings of the present application, the term "multiple" refers to two or more than two. Unless otherwise clearly defined, the orientation or position relationship indicated by the terms "upper" and "lower" is based on the orientation or position relationship shown in the drawings, which is only for the purpose of more conveniently describing the present application and making the description process easier, rather than indicating or implying that the device or element referred to must have the specific orientation described, be constructed and operated in a specific orientation, so these descriptions cannot be understood as limitations on the present application; the terms "connect", "install", "fix" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection between multiple objects, or a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects, or an indirect connection between multiple objects through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood based on the specific circumstances of the above data.

[0093] In the claims, specification and drawings of the present application, the description of the terms "one embodiment", "some embodiments", "specific embodiments" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the claims, specification and drawings of the present application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0094] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery protection circuit connected to a battery module, characterized in that: include: A current sampling module, connected to the battery module, for obtaining a current detection value of the battery module; An overcurrent detection module, connected to the current sampling module, and used for comparing the current detection value with a preset current threshold; When the current detection value is greater than the current threshold, the overcurrent detection module generates an overcurrent signal; A voltage sampling module, connected to the battery module, for obtaining a voltage detection value of the battery module; A short circuit detection module, connected to the voltage sampling module, for comparing the voltage detection value with a preset voltage threshold; when the voltage detection value is greater than the voltage threshold, the short circuit detection module generates a short circuit signal; A drive control module, connected to the overcurrent detection module and the short circuit detection module, and used to generate a drive control signal; The drive control module generates the drive control signal when receiving the overcurrent signal and / or the short circuit signal; The switch module is connected to the battery module and the drive control module; when the switch module receives the drive control signal, it turns off the battery module.

2. The battery protection circuit according to claim 1, characterized in that: The drive control module comprises: A drive control unit connected to the overcurrent detection module; A D flip-flop having a clock input terminal and a data input terminal, wherein the data input terminal is connected to the driving control unit; A NOR gate unit, comprising a seventh input terminal and a fourth output terminal, wherein the seventh input terminal is connected to the short circuit detection module, and the fourth output terminal is connected to the clock input terminal of the D flip-flop; The driving unit is connected to the D trigger and the driving control unit, and is used to control the switch module to turn on or off the battery module.

3. The battery protection circuit according to claim 2, characterized in that: The short circuit detection module comprises: a voltage comparison unit, a first resistor, a second resistor, a third resistor and a MOS tube; Wherein, the voltage comparison unit is used to compare the voltage detection value with the voltage threshold, and has a fifth input terminal, a sixth input terminal and a third output terminal; the fifth input terminal is used to obtain the voltage threshold, and the sixth input terminal is connected to the voltage sampling module; The source of the MOS tube is connected to the clock input terminal of the D flip-flop; The second resistor is connected to the third output terminal and the gate of the MOS tube; One end of the first resistor is connected between the third output end and the second resistor, and the other end is connected to the first power supply; One end of the third resistor is connected to the source of the MOS tube, and the other end is grounded; The drain of the MOS tube is connected to the second power supply.

4. The battery protection circuit according to claim 3, characterized in that: The short circuit detection module further includes a self-locking unit for locking the output state of the voltage comparison unit; One end of the self-locking unit is connected between the voltage sampling module and the sixth input end, and the other end of the self-locking unit is connected between the third output end and the second resistor.

5. The battery protection circuit according to claim 3, characterized in that: It also includes a digital isolator; the digital isolator is used to isolate the level signal between the MOS tube and the NOR gate unit.

6. The battery protection circuit according to any one of claims 1 to 4, characterized in that: It also includes a central control module, which is connected to the overcurrent detection module and the drive control module; When the current detection value is greater than the current threshold, the overcurrent detection module also generates current detection information; after receiving the overcurrent signal and the current detection information, the central control module generates a fault signal; after receiving the fault signal, the drive control module generates a drive control signal.

7. The battery protection circuit according to claim 6, characterized in that: It also includes a digital isolator; the digital isolator is used to isolate the fault signal between the central control module and the drive control module and the fault signal between the overcurrent detection module and the drive control module.

8. The battery protection circuit according to any one of claims 1 to 5, characterized in that: Also includes: A shunt; the shunt is connected to the battery module; wherein the current sampling module and the voltage sampling module are both connected to the shunt.

9. The battery protection circuit according to claim 8, characterized in that: The current sampling module includes a first operational amplifier unit having a first input terminal, a second input terminal and a first output terminal; the first input terminal and the second input terminal are respectively connected to the two ends of the shunt, and are configured to detect a voltage detection value and generate a current detection value according to the voltage detection value; the first output terminal is connected to the overcurrent detection module; and / or, The voltage sampling module includes a second operational amplifier unit having a third input terminal, a fourth input terminal and a second output terminal; the third input terminal and the fourth input terminal are respectively connected to the two ends of the shunt and are configured to detect a voltage detection value; the second output terminal is connected to the short circuit detection module.

10. An energy storage device, characterized in that: include: The battery protection circuit according to any one of claims 1 to 9.

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