Short circuit protection circuit and energy storage equipment

Abstract

The embodiment of the invention provides a short circuit protection circuit and energy storage equipment, and the circuit comprises a battery module; the charging and discharging switch tube is connected with the first end of the battery module; the software short-circuit protection loop comprises a micro-control unit, and the micro-control unit turns off or turns on the charging and discharging switch tube through a charging and discharging driving control signal; the hardware short-circuit protection loop comprises a comparator, the output end of the comparator is connected with the charging and discharging switch tube, the loop voltage of the battery module is connected to the first input end of the comparator, and the hardware threshold voltage is connected to the second input end of the comparator; in the hardware short-circuit protection loop, the comparator compares the loop voltage with the hardware threshold voltage, and outputs a high level to turn off the charging and discharging switch tube when the loop voltage is greater than the hardware threshold voltage. According to the scheme, the reliability of overcurrent or short-circuit protection of the low-voltage energy storage battery system is improved.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and more specifically, to a short-circuit protection circuit and an energy storage device. Background Technology

[0002] In current low-voltage energy storage battery systems, overcurrent or short circuits are determined by real-time current monitoring during charging and discharging. Traditional low-voltage battery systems rely on communication between the microcontroller unit (MCU) and the active front end (AFE) via an integrated circuit (IIC) bus to detect overcurrent or short circuits. The AFE then disconnects the charging / discharging metal-oxide-semiconductor (MOS) transistor. However, if the MCU experiences delays or malfunctions during this process, the MOS transistor may not disconnect in time, causing the fuse in the power circuit to blow for protection. Short circuits can lead to product failures that incur significant time and repair costs, resulting in insufficient reliability in low-voltage energy storage battery systems. Summary of the Invention

[0003] The purpose of this invention is to provide a short-circuit protection circuit and energy storage device that can solve the problem that low-voltage energy storage battery systems rely solely on software to detect current to determine whether a short circuit has occurred, resulting in insufficient hardware short-circuit protection capability.

[0004] In view of this, an embodiment of the first aspect of the present invention provides a short-circuit protection circuit.

[0005] An embodiment of the second aspect of the present invention provides an energy storage device.

[0006] To achieve the above objectives, an embodiment of the first aspect of the present invention provides a short-circuit protection circuit, comprising: a battery module; a charge / discharge switch transistor connected to a first terminal of the battery module; a software short-circuit protection circuit including a microcontroller unit, the microcontroller unit turning off or closing the charge / discharge switch transistor via a charge / discharge drive control signal; and a hardware short-circuit protection circuit including a comparator, the output terminal of the comparator being connected to the charge / discharge switch transistor, the first input terminal of the comparator being connected to the loop voltage of the battery module, and the second input terminal of the comparator being connected to a hardware threshold voltage; in the hardware short-circuit protection circuit, the comparator compares the loop voltage with the hardware threshold voltage, and outputs a high level to turn off the charge / discharge switch transistor when the loop voltage is greater than the hardware threshold voltage.

[0007] This invention provides a short-circuit protection circuit based on a hardware and software redundancy architecture. The short-circuit protection circuit establishes two independent and parallel protection paths: one path is implemented through software intelligent control by a microcontroller, and the other path is implemented through hardware fast response by a comparator. Together, they control the charging and discharging switching transistor. This retains the flexibility of the software protection strategy while introducing a completely independent hardware protection channel with extremely fast response speed. This overcomes the delay risk caused by the failure of the microcontroller in pure software protection, and greatly improves the reliability and safety of low-voltage energy storage battery systems against short-circuit faults.

[0008] In some technical solutions, the software short-circuit protection circuit may optionally include: an analog front-end, which is communicatively connected to the microcontroller unit, and the drive control terminal of the analog front-end is connected to the charge / discharge switch.

[0009] In this scheme, based on the original hardware and software redundancy protection architecture, the specific implementation method of the software short circuit protection loop is further defined as a collaborative mode of analog front-end and microcontroller unit. That is, the analog front-end is used as the core hub for high-precision data acquisition and drive execution, and the analog front-end is connected to the microcontroller unit for communication. The drive control terminal of the analog front-end is connected to the charge and discharge switch tube, and the control of the charge and discharge switch tube is realized through the analog front-end.

[0010] In some technical solutions, the short-circuit protection circuit may optionally include an operational amplifier, the output of which is connected to the first input of the comparator for acquiring the loop voltage.

[0011] In this scheme, the operational amplifier, as the signal conditioning unit in the hardware short-circuit protection circuit, differentially amplifies and purifies the extremely weak original circuit voltage signal collected by the shunt, converting it into a stable voltage signal with sufficient amplitude before sending it to the comparator.

[0012] In some technical solutions, the short-circuit protection circuit may optionally include: a shunt, the shunt being connected to the second end of the battery module; a current sampling terminal of the analog front end being connected to both ends of the shunt for acquiring the current signal flowing through the shunt; and an input terminal of the operational amplifier being connected to both ends of the shunt for acquiring the loop voltage flowing through the shunt.

[0013] In this scheme, the current signal generated by the shunt connected in series in the short-circuit protection circuit is fed into two protection paths in parallel and independently. One path is sent to the current sampling end of the analog front end, serving as the data basis for the software short-circuit protection loop to perform high-precision calculations and intelligent judgments; the other path is directly sent to the input end of the operational amplifier, serving as the analog signal source for the hardware short-circuit protection loop to achieve fast comparison and triggering.

[0014] In some technical solutions, optionally, the charge-discharge switch includes a first charge-discharge switch and a second charge-discharge switch; the drain of the first charge-discharge switch and the drain of the second charge-discharge switch are connected; the gate of the first charge-discharge switch is connected to the drive control terminal of the analog front end, and the gate of the second charge-discharge switch is connected to the drive control terminal of the analog front end.

[0015] In this scheme, a back-to-back connection structure is adopted in the configuration of the charging and discharging switching transistors. That is, the drains of the first charging and discharging switching transistor and the second charging and discharging switching transistor are interconnected, and the gates of the first charging and discharging switching transistor and the second charging and discharging switching transistor are connected to the same driving control terminal. By connecting the body diodes of the two MOS transistors in reverse series, the inherent defect that the single-transistor scheme cannot block the reverse current is fundamentally overcome, and bidirectional shutdown of the charging and discharging circuit is realized.

[0016] In some technical solutions, the charge / discharge switch may optionally include: a first resistor, the first end of which is connected to the gate of the first charge / discharge switch, and the second end of which is connected to the drive control terminal of the analog front end; and a second resistor, the first end of which is connected to the gate of the second charge / discharge switch, and the second end of which is connected to the drive control terminal of the analog front end.

[0017] In this scheme, based on the back-to-back MOS transistor structure of the first and second charge-discharge switching transistors, independent first and second resistors are connected in series with the gates of the first and second charge-discharge switching transistors, respectively. These two gate resistors effectively suppress voltage oscillations and peak current surges during the switching process by providing damping for the gate capacitive load, thereby precisely controlling the turn-on and turn-off speeds of the MOS transistors. While improving the stability of switching action and the reliability of the drive circuit, this scheme significantly reduces electromagnetic interference and ensures the accuracy and robustness of the entire short-circuit protection circuit.

[0018] In some technical solutions, optionally, the microcontroller unit turns off or closes the charge / discharge switch transistor via a charge / discharge drive control signal, including: the microcontroller unit sends a control command to the analog front end via an integrated circuit bus; the analog front end outputs a charge / discharge drive control signal through a drive control terminal according to the control command; the charge / discharge drive control signal is transmitted to the gate of the first charge / discharge switch transistor via a first resistor, and to the gate of the second charge / discharge switch transistor via a second resistor, so as to control the charge / discharge switch transistor to turn off or close.

[0019] In this scheme, the microcontroller unit, as the decision-making core in the short-circuit protection circuit, sends digital instructions to the analog front end through the integrated circuit bus. The analog front end, as the intelligent execution interface, converts the digital instructions into specific charge and discharge drive control signals. The charge and discharge drive control signals are then transmitted to the gates of the back-to-back charge and discharge switch transistors through the first resistor and the second resistor, so as to precisely control the first charge and discharge switch transistor and the second charge and discharge switch transistor to turn off or close.

[0020] In some technical solutions, the hardware short-circuit protection circuit may optionally include: a sixth resistor, the first end of which is connected to the first input terminal of the comparator, and the second end of which is connected to the inverting input terminal of the operational amplifier; a seventh resistor, the first end of which is connected to the shunt, and the second end of which is connected to the inverting input terminal; an eighth resistor, the first end of which is connected to the shunt, and the second end of which is connected to the non-inverting input terminal of the operational amplifier; and a ninth resistor, the first end of which is connected to the second end of the eighth resistor, and the second end of which is connected to an external power supply.

[0021] This solution defines a precision differential amplifier circuit consisting of an operational amplifier and a sixth, seventh, eighth, and ninth resistor. The signals at both ends of the shunt are connected through the seventh and eighth resistors, the sixth resistor is used to achieve negative feedback to set the gain, and the ninth resistor is used to match the impedance. Together, they can stably amplify the weak differential voltage signal on the shunt while efficiently suppressing common-mode interference.

[0022] In some technical solutions, the hardware short-circuit protection circuit may optionally include a self-locking unit, which includes a switching transistor, and the output of the comparator is connected to the gate of the switching transistor.

[0023] In this solution, a self-locking unit with a switching transistor as its core is added to the hardware short-circuit protection circuit. The gate of the switching transistor is directly driven by the comparator output. The core function of the self-locking unit is that when the comparator triggers a high-level output due to a short-circuit fault, it will immediately turn on the switching transistor and lock this state, thereby ensuring that the charging and discharging switching transistor remains off until external intervention clears it. This effectively prevents the jitter and repeated impact of the protection circuit under intermittent or transient faults, fundamentally improving the determinism of hardware protection and system reliability.

[0024] In some technical solutions, the self-locking unit may optionally include: a third resistor, the first end of which is connected to the first end of the second resistor, and the second end of which is connected to the drain of the switching transistor; a fourth resistor, the first end of which is connected to the output of the comparator, and the second end of which is connected to the gate of the switching transistor; and a fifth resistor, the first end of which is connected to the second end of the fourth resistor, and the second end of which is connected to the source of the switching transistor.

[0025] In this scheme, the fourth resistor serves as a current-limiting isolation element, connecting the comparator output to the gate of the switching transistor. The fifth resistor provides a pull-down to the gate, ensuring reliable turn-off. The third resistor is connected across the drive terminal of the charge / discharge switching transistor and the drain of the self-locking switching transistor, forming a critical state feedback path. When a short circuit is triggered, the hardware latching circuit composed of the third, fourth, and fifth resistors and the switching transistor can instantly pull down the drive signal and maintain the fault state until an external clear signal intervenes.

[0026] In some technical solutions, optionally, the comparator compares the loop voltage with a hardware threshold voltage, and outputs a high level to turn off the charge / discharge switch when the loop voltage is greater than the hardware threshold voltage. This includes: when the loop voltage is greater than the hardware threshold voltage, the comparator outputs a high-level signal, and the high-level signal drives the switch to turn on via a fourth resistor to turn off the charge / discharge switch.

[0027] In this scheme, when the circuit voltage exceeds the hardware threshold, the comparator outputs a high-level signal instantaneously. After the high-level signal is current-limited and buffered by the fourth resistor, it drives the switch to turn on, thereby forcibly pulling down the gate drive voltage of the charge-discharge switch to achieve rapid turn-off of the first charge-discharge switch and the second charge-discharge switch.

[0028] In some technical solutions, optionally, the microcontroller is configured with a fault clearing signal terminal. The microcontroller outputs a high-level signal to the gate of the switching transistor through the fault clearing signal terminal, so as to turn off the switching transistor, set the level of the drive control terminal of the analog front end to high, and the charge / discharge switching transistor closes again.

[0029] In this scheme, based on the hardware short-circuit protection circuit, a fault safety clearing mechanism led by the microcontroller unit is defined: when the fault is cleared, the microcontroller unit actively outputs a high level to the gate of the self-locking unit switch tube through a dedicated fault clearing signal terminal, forcing it to turn off, thereby releasing the pull-down effect on the charge and discharge switch tube drive signal, restoring the level of the drive control terminal of the analog front end, closing the charge and discharge switch tube again, and restoring the system to normal operation.

[0030] A second aspect of the present invention provides an energy storage device including the short-circuit protection circuit provided by any of the above-described technical solutions. Therefore, the energy storage device possesses all the beneficial effects of any of the above-described technical solutions, which will not be elaborated further here.

[0031] Additional aspects and advantages of the technical solutions of the present invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0032] Figure 1 A circuit diagram of a short-circuit protection circuit in the related art is shown;

[0033] Figure 2One of the circuit diagrams of a short-circuit protection circuit according to this application is shown;

[0034] Figure 3 A second circuit diagram of a short-circuit protection circuit according to this application is shown;

[0035] Figure 4 A schematic block diagram of the energy storage device according to this application is shown;

[0036] Figure 5 A schematic diagram of the operation of the short-circuit protection circuit according to this application is shown.

[0037] Wherein, 100': analog front end; 200': microcontroller unit; 300': switching module; 400': shunt; Q1': first switching transistor; Q2': second switching transistor;

[0038] 100: Short-circuit protection circuit; 102: Charge / discharge switch transistor; 104: Software short-circuit protection circuit; 106: Hardware short-circuit protection circuit; 200: Battery module; 1044: Microcontroller unit; 1042: Analog front end; 300: Shunt unit; 1062: Self-locking unit; 1000: Energy storage device; U2: Comparator; U1: Operational amplifier; Q1: First charge / discharge switch transistor; Q2: Second charge / discharge switch transistor; Q3: Switch transistor; R1: First resistor; R2: Second resistor; R3: Third resistor; R4: Fourth resistor; R5: Fifth resistor; R6: Sixth resistor; R7: Seventh resistor; R8: Eighth resistor; R9: Ninth resistor. Detailed Implementation

[0039] To better understand the above-described objectives, features, and advantages of the embodiments of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, embodiments of the invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0041] In related technologies, refer to Figure 1To improve the protection response speed, the short-circuit protection circuit includes a shunt 400', a microcontroller 200', an analog front-end 100', and a switching module 300'. The shunt 400' is used to collect the current detection value from the battery module. In the instant of overcurrent or short circuit, the analog front-end 100' and the microcontroller 200' communicate via IIC, and the analog front-end 100' then disconnects the switching module 300', specifically the first switch Q1' and the second switch Q2', to protect the battery module.

[0042] In current low-voltage energy storage battery systems, overcurrent or short circuits are determined by real-time current monitoring during charging and discharging. Most low-voltage energy storage battery products on the market lack hardware short-circuit protection and rely on software-based current monitoring to detect overcurrent. Traditional low-voltage battery systems rely on IIC communication between the MCU and AFE (Automatic Current Controller) to detect overcurrent or short circuits, with the AFE then disconnecting the charging / discharging MOSFET. If the MCU malfunctions or malfunctions during this process, the charging / discharging MOSFET may not disconnect in time, causing the FUSE (Fuse in the power circuit) to burn out for protection. Short circuits can lead to product failures that incur significant time and repair costs, severely impacting customer experience and company profits.

[0043] This invention designs a short-circuit protection circuit, which has short-circuit and overcurrent protection functions. When a short circuit or overcurrent occurs in the battery system, the hardware circuit can instantly disconnect the charging and discharging MOS.

[0044] The short-circuit protection circuit and energy storage device provided in this application will be described in detail below with reference to specific embodiments and application scenarios.

[0045] like Figure 2 As shown, this embodiment provides a short-circuit protection circuit 100, including: a battery module 200; a charge / discharge switch 102, the charge / discharge switch 102 being connected to a first terminal of the battery module 200; a software short-circuit protection circuit 104, the software short-circuit protection circuit 104 including a microcontroller unit 1044, the microcontroller unit 1044 turning off or closing the charge / discharge switch 102 via a charge / discharge drive control signal; and a hardware short-circuit protection circuit 106, the hardware short-circuit protection circuit 106 including a comparator U2, the output terminal of the comparator U2 being connected to the charge / discharge switch 102, the first input terminal of the comparator U2 being connected to the loop voltage of the battery module 200, and the second input terminal of the comparator U2 being connected to a hardware threshold voltage; in the hardware short-circuit protection circuit 106, the comparator U2 compares the loop voltage with the hardware threshold voltage, and when the loop voltage is greater than the hardware threshold voltage, it outputs a high level to turn off the charge / discharge switch 102.

[0046] This invention provides a short-circuit protection circuit 100 based on a hardware and software redundancy architecture. The short-circuit protection circuit 100 establishes two independent and parallel protection paths: one path is implemented by software intelligent control through a microcontroller 1044, and the other path is implemented by hardware fast response through a comparator U2. Together, they control the charge / discharge switch 102. This retains the flexibility of the software protection strategy while introducing a completely independent hardware protection channel with extremely fast response speed. This overcomes the delay risk caused by the failure of the microcontroller 1044 in pure software protection, and greatly improves the reliability and safety of the low-voltage energy storage battery system against short-circuit faults.

[0047] The protected object in the short-circuit protection circuit 100 is the battery module 200, which is the core of the short-circuit protection circuit 100. The charge / discharge switch 102 is connected in series in the charge / discharge circuit of the battery module 200, acting as a circuit switch. When the charge / discharge switch 102 is turned on, the battery module 200 can charge and discharge normally; when the charge / discharge switch 102 is turned off, the battery module 200 is disconnected from the external circuit, thus protecting the battery module 200.

[0048] Figure 2 In the diagram, pack+ is the positive terminal of battery module 200, and pack- is the negative terminal of battery module 200, used to connect external devices.

[0049] For example, the charge / discharge switch 102 includes, but is not limited to, a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0050] The microcontroller unit 1044 (MCU) is a digital control loop in the short-circuit protection circuit 100 that senses, calculates, makes decisions, and executes data. The MCU indirectly acquires the signal reflecting the loop current, i.e., the loop voltage, through its peripherals, such as an analog-to-digital converter. The MCU internally runs a program or software algorithm to convert the acquired signal into a current value and compares and judges it against multiple preset, graded overcurrent and short-circuit thresholds. The judgment process of the MCU includes filtering, delay, and debouncing logic to prevent false triggering.

[0051] Once the microcontroller unit 1044 determines that a short circuit has occurred in the short circuit protection circuit 100, it will output a charge / discharge drive control signal to turn off the charge / discharge switch 102, thereby protecting the battery module 200.

[0052] The hardware short-circuit protection circuit 106 is a purely analog signal-triggered hardware circuit without any digital processing. The hardware short-circuit protection circuit 106 includes a comparator U2. The two inputs of comparator U2 are directly connected to two voltage signals, and the output of comparator U2 is connected to the charge / discharge switch 102 to turn it off. Specifically, the first input of comparator U2 is connected to the loop voltage of the battery module 200, i.e., the loop current signal directly acquired from the main circuit, reflecting the real-time current; the second input of comparator U2 is connected to a fixed hardware threshold voltage.

[0053] Comparator U2 continuously compares the hardware threshold voltage and the loop voltage. Under normal circumstances, the loop voltage is less than the hardware threshold voltage, and comparator U2 outputs a low level. Once a short circuit occurs in the short-circuit protection circuit 100, the loop current increases sharply, causing the loop voltage to momentarily exceed the hardware threshold voltage. The output of comparator U2 will immediately flip to a high level, turning off the charge / discharge switch 102 by outputting a high level.

[0054] It should be emphasized that the software short-circuit protection circuit 104 and the hardware short-circuit protection circuit 106 are connected in parallel. The software short-circuit protection circuit 104 and the hardware short-circuit protection circuit 106 share the same protected object, namely the battery module 200, and the same detection signal corresponding to the circuit voltage, but they are completely independent in terms of judgment and execution paths.

[0055] It is understood that the short-circuit protection circuit 100 has two completely independent protection mechanisms. Even if the software protection circuit is completely paralyzed due to the microcontroller unit 1044 program crashing, freezing, or freezing, the hardware short-circuit protection circuit 106 can still work independently and cut off the circuit when a short circuit occurs. Conversely, if the comparator U2 or other components in the hardware short-circuit protection circuit 106 are accidentally damaged, the software short-circuit protection circuit 104 will still continue to operate. Through the dual redundancy design of the software short-circuit protection circuit 104 and the hardware short-circuit protection circuit 106, the reliability and safety of the short-circuit protection circuit 100 are improved.

[0056] In some embodiments, the comparator U2 in the hardware short-circuit protection circuit 106 may optionally be an open-drain output or push-pull output comparator U2.

[0057] In some embodiments, the comparator U2 in the hardware short-circuit protection circuit 106 optionally has a latching function. When a short circuit is triggered, the output state will be maintained until a clear signal is received, at which point the output state will be cleared, so as to provide a more stable fault state maintenance and improve the short-circuit protection reliability of the short-circuit protection circuit 100.

[0058] In some embodiments, optionally, the hardware threshold voltage connected to the second input terminal of comparator U2 is provided by a digital-to-analog converter, which is controlled by a microcontroller unit 1044, thereby realizing a software-programmable hardware protection threshold, improving the flexibility of the short-circuit protection circuit 100, and the hardware threshold voltage can be dynamically adjusted according to the battery status (such as charge and temperature) to achieve the protection point.

[0059] In some embodiments, the microcontroller unit 1044 may optionally implement multi-level delay protection, such as overcurrent protection for 100% for 10 seconds, overcurrent protection for 200% for 1 second, and overcurrent protection for 500% immediately (forming redundancy with hardware protection).

[0060] In some embodiments, optionally, such as Figure 3 As shown, the software short-circuit protection circuit 104 also includes: an analog front-end 1042, which is communicatively connected to the microcontroller unit 1044, and the drive control terminal of the analog front-end 1042 is connected to the charge / discharge switch tube 102.

[0061] In this embodiment, based on the original hardware and software redundancy protection architecture, the specific implementation of the software short-circuit protection loop 104 is further defined as a collaborative mode of analog front-end 1042 and microcontroller 1044. That is, the analog front-end 1042 is used as the core hub for high-precision data acquisition and drive execution. The analog front-end 1042 is connected to the microcontroller 1044 for communication. The drive control terminal of the analog front-end 1042 is connected to the charge-discharge switch tube 102. The control of the charge-discharge switch tube 102 is realized through the analog front-end 1042.

[0062] This not only frees the microcontroller unit 1044 from cumbersome analog signal processing, allowing it to focus on intelligent decision-making, but also enhances the control capability of the charge / discharge switch 102 through the optimized drive circuit built into the analog front-end 1042. Thus, while fulfilling redundant protection, it significantly improves the accuracy and reliability of the software short-circuit protection loop 104 and the overall integration of the short-circuit protection circuit 100.

[0063] Specifically, the Active Front End (AFE) 1042 is a dedicated integrated circuit chip whose core function is to manage battery-related analog signals.

[0064] For example, the analog front end 1042 is used to collect the small voltage difference on the shunt 300, the total voltage of the battery module 200, and the voltage of each cell to ensure the accuracy of current detection.

[0065] Furthermore, the analog front-end 1042 communicates with the microcontroller unit 1044 via an IIC (Interconnect Interface), converting the acquired analog signals into digital data and packaging them for transmission to the microcontroller unit 1044. This method of converting the acquired analog signals into digital data and transmitting them to the microcontroller unit 1044 significantly reduces the operational burden on the microcontroller unit 1044. The microcontroller unit 1044 can acquire the operating data from the short-circuit protection circuit 100 without needing a built-in high-precision analog-to-digital converter, thus improving the stability and reliability of the short-circuit protection circuit 100.

[0066] On the other hand, the analog front-end 1042 also receives instructions from the microcontroller unit 1044 via digital communication, and directly outputs drive signals through the drive control terminal of the analog front-end 1042 to control the gate of the charge / discharge switch 102. The drive circuit of the analog front-end 1042 is typically optimized to provide fast and powerful electrical signals to ensure fast and stable switching of the charge / discharge switch 102.

[0067] In some embodiments, the analog front-end 1042 may optionally communicate with the microcontroller 1044 via an IIC bus or a Serial Peripheral Interface (SPI) to enable the microcontroller 1044 to perform high-speed and frequent configuration or data read / write operations on the analog front-end 1042.

[0068] In some embodiments, the analog front end 1042 is optionally connected to a temperature sensor to collect the temperature of the battery module 200 so that the software protection circuit can implement temperature-related protection measures, such as prohibiting charging at high temperatures, thereby further improving the safety of the short-circuit protection circuit 100.

[0069] In some embodiments, the output of the hardware short-circuit protection circuit 106 can be sent directly to the microcontroller unit 1044 as an interrupt signal, or sent to the analog front-end 1042 as an enable signal. That is, the hardware protection action can not only turn off the charging and discharging switch tube 102, but also promptly notify the microcontroller unit 1044 to record faults and manage the system, thereby realizing more complex fault handling logic.

[0070] In some embodiments, optionally, such as Figure 3 As shown, the hardware short-circuit protection circuit 106 also includes: an operational amplifier U1, the output of which is connected to the first input of the comparator U2, for acquiring the circuit voltage.

[0071] In this embodiment, the operational amplifier U1 serves as the signal conditioning unit in the hardware short-circuit protection circuit 106. It differentially amplifies and purifies the extremely weak original circuit voltage signal collected by the shunt 300, converting it into a stable voltage signal with sufficient amplitude before sending it to the comparator U2.

[0072] Understandably, by using operational amplifier U1 to acquire the weak loop voltage and perform differential amplification, and then transmitting the amplified electrical signal to the first input of comparator U2 through the output terminal, the subsequent comparator U2 can make accurate judgments on a more reliable signal level with stronger anti-interference capabilities. This fundamentally solves the problems of poor accuracy and easy false triggering caused by directly detecting weak signals, and improves the reliability, accuracy and anti-interference capability of the hardware short-circuit protection circuit 106.

[0073] Specifically, although comparator U2 in the hardware short-circuit protection circuit 106 has a fast response speed, it requires high accuracy and stability of the input signal. Directly sending the weak electrical signal from the short-circuit protection circuit 100 into comparator U2 will cause the signal to fluctuate around the threshold due to minor noise interference, leading to malfunction of comparator U2. Furthermore, the input offset voltage of comparator U2 itself may be equivalent to that of the weak electrical signal, resulting in poor comparison accuracy.

[0074] Therefore, the main function of operational amplifier U1 is to process the weak voltage in short-circuit protection circuit 100 and transmit the amplified electrical signal to comparator U2, so that the noise immunity and judgment accuracy of comparator U2 are much higher than those of the original circuit voltage processed directly.

[0075] Furthermore, the operational amplifier U1 acts as a buffer, providing a low-impedance output signal source, making the signal less susceptible to interference from subsequent circuits during transmission to the comparator U2.

[0076] In some embodiments, optionally, such as Figure 3 As shown, the short-circuit protection circuit 100 also includes: a shunt 300, which is connected to the second end of the battery module 200; the current sampling terminal of the analog front-end 1042 is connected to both ends of the shunt 300 to collect the current signal flowing through the shunt 300; and the input terminal of the operational amplifier U1 is connected to both ends of the shunt 300 to collect the loop voltage flowing through the shunt 300.

[0077] In this embodiment, the current signal generated by the shunt 300 connected in series in the short-circuit protection circuit 100 is fed into two protection paths in parallel and independently. One path is sent to the current sampling terminal of the analog front-end 1042, serving as the data basis for the software short-circuit protection circuit 104 to perform high-precision calculations and intelligent judgments. The other path is directly sent to the input terminal of the operational amplifier U1, serving as the analog signal source for the hardware short-circuit protection circuit 106 to achieve fast comparison and triggering.

[0078] It is understandable that by connecting the shunt 300 to the analog front-end 1042 and the operational amplifier U1 respectively, the hardware and software protection loops are truly parallel and independent in terms of physical connection. This ensures that even if one path fails completely, the other path can still perform the complete protection function based on the original shunt 300 signal. Thus, redundant protection without single point of failure is achieved at the root of the system architecture, which greatly improves the overall reliability of the short-circuit protection circuit 100.

[0079] Specifically, the shunt 300 includes at least one precision resistor with extremely low resistance, high accuracy, and high temperature stability. The shunt 300 is connected in series in the short-circuit protection circuit 100, that is, between the battery module 200 and the load. This connection method ensures that all current entering and leaving the battery module 200 must pass through the shunt 300, thereby achieving complete detection of the total current in the circuit.

[0080] When current flows through the shunt 300, a small voltage drop is generated across the shunt 300. This voltage drop is the original signal source for the short-circuit protection circuit 100.

[0081] The current sampling terminal of the analog front-end 1042 is connected to both ends of the shunt 300. The analog front-end 1042 amplifies and filters the weak voltage drop, and converts it into a digital value by the high-resolution analog-to-digital converter inside the analog front-end 1042, so as to provide accurate digital current data for the microcontroller 1044.

[0082] The input terminal of the operational amplifier is connected to both ends of the shunt 300. The voltage drop is amplified by the operational amplifier U1, and a voltage signal with a larger amplitude, greater stability and stronger anti-interference capability is output. The voltage signal is then directly sent to the comparator U2.

[0083] Starting from shunt 300, the two paths corresponding to the software short-circuit protection loop 104 and the hardware short-circuit protection circuit 100 each use independent signal conditioning circuits. There is no signal dependency between the software short-circuit protection loop 104 and the hardware short-circuit protection circuit 100. That is, the judgment logic of the software path runs in the digital domain of the microcontroller 1044, while the judgment logic of the hardware path is completed in the analog domain of the comparator U2. Even if the analog front-end 1042 or the microcontroller 1044 completely fails, the hardware protection path can still completely execute the entire process of current detection, signal conditioning, threshold comparison, and protection triggering, and vice versa.

[0084] In some embodiments, a low-pass filter circuit may be included between the shunt 300 and the analog front-end 1042 to filter out high-frequency noise before the current acquisition signal from the shunt 300 is acquired by the analog front-end 1042, thereby further improving signal quality and enhancing the stability of the system in noisy environments.

[0085] In some embodiments, optionally, such as Figure 3 As shown, the charge / discharge switch 102 includes a first charge / discharge switch Q1 and a second charge / discharge switch Q2; the drain of the first charge / discharge switch Q1 and the drain of the second charge / discharge switch Q2 are connected; the gate of the first charge / discharge switch Q1 is connected to the drive control terminal of the analog front-end 1042, and the gate of the second charge / discharge switch Q2 is connected to the drive control terminal of the analog front-end 1042.

[0086] In this embodiment, a back-to-back connection structure is adopted in the configuration of the charge / discharge switch 102, that is, the drains of the first charge / discharge switch Q1 and the second charge / discharge switch Q2 are interconnected, and the gates of the first charge / discharge switch Q1 and the second charge / discharge switch Q2 are connected to the same drive control terminal. By connecting the body diodes of the two MOS transistors in reverse series, the inherent defect that the single-transistor scheme cannot block the reverse current is fundamentally overcome, and bidirectional shutdown of the charge / discharge circuit is realized.

[0087] Understandably, by connecting the first charge / discharge switch Q1 and the second charge / discharge switch Q2 to form the charge / discharge switch 102, not only are safety hazards caused by reverse battery connection or abnormal charging eliminated, but the series connection of the two switches also forms a hardware redundancy barrier, which significantly improves the fault tolerance capability and overall reliability of the short-circuit protection circuit 100.

[0088] For example, both the first charge / discharge switch Q1 and the second charge / discharge switch Q2 are MOSFETs.

[0089] Since each MOSFET has a parasitic body diode inside, if only one MOSFET is used to control the circuit, when the MOSFET is turned off, a single MOSFET can only block the current in one direction.

[0090] Therefore, the drains of the first charge / discharge switch Q1 and the second charge / discharge switch Q2 are connected together. The sources of the first charge / discharge switch Q1 and the second charge / discharge switch Q2 are connected to the battery and the load / charger, respectively. The gates of the first charge / discharge switch Q1 and the second charge / discharge switch Q2 are connected to the same drive control terminal, receiving a synchronous drive signal and simultaneously turning on or off. Regardless of the current direction, the body diode of one MOSFET is always reverse biased, which can effectively achieve effective blocking.

[0091] Furthermore, MOSFETs are vulnerable components in power circuits. Using two MOSFETs, the first charge / discharge switch Q1 and the second charge / discharge switch Q2, can share the current and heat, reducing the stress on individual devices. Even if one MOSFET fails due to an accident (such as a short circuit), the other may still function, providing a degree of protection and further increasing the system's robustness.

[0092] In some embodiments, multiple pairs of back-to-back MOSFETs may be connected in parallel to share a larger operating current.

[0093] In some embodiments, the charge / discharge switch 102 may optionally include a drain-source voltage monitoring circuit. The microcontroller unit 1044 or the analog front-end 1042 can monitor the voltage drop when the MOSFET is turned on, thereby estimating the on-resistance and temperature rise of the charge / discharge switch 102, and realizing online health status diagnosis and overheat warning.

[0094] In some embodiments, optionally, such as Figure 3 As shown, the charge / discharge switch 102 further includes: a first resistor R1, the first end of which is connected to the gate of the first charge / discharge switch Q1, and the second end of which is connected to the drive control terminal of the analog front-end 1042; and a second resistor R2, the first end of which is connected to the gate of the second charge / discharge switch Q2, and the second end of which is connected to the drive control terminal of the analog front-end 1042.

[0095] In this embodiment, based on the back-to-back MOS transistor structure of the first charge / discharge switch Q1 and the second charge / discharge switch Q2, independent first resistors R1 and second resistors R2 are connected in series with the gates of the first charge / discharge switch Q1 and the second charge / discharge switch Q2, respectively. These two gate resistors effectively suppress voltage oscillations and peak current surges during the switching process by providing damping for the gate capacitive load, thereby precisely controlling the turn-on and turn-off speeds of the MOS transistors. While improving the stability of the switching action and the reliability of the drive circuit, electromagnetic interference is significantly reduced, ensuring the accuracy and robustness of the entire short-circuit protection circuit 100.

[0096] In this circuit, the gate of the MOSFET can be considered a capacitive load. Internally, the MOSFET has gate-source and gate-drain capacitances. When the drive circuit charges or discharges the gate, problems such as parasitic oscillations, peak current surges, and electromagnetic interference can occur. The first resistor R1 connected in series with the gate of the first charge / discharge switch Q1 and the second resistor R2 connected in series with the gate of the second charge / discharge switch Q2 add damping to the gate circuit. The first resistor R1 and the second resistor R2 dissipate the resonant energy, effectively stopping or eliminating ringing of the gate voltage, allowing the gate voltage to rise or fall smoothly, thus ensuring stable switching of the MOSFET state.

[0097] Furthermore, the resistor limits the peak current of the gate capacitor during switching of the driver chip, protecting the internal drive circuit of the analog front-end 1042 from overcurrent stress.

[0098] In some embodiments, optionally, by adjusting the resistance values ​​of the first resistor R1 and the second resistor R2, the gate capacitance and the charging / discharging speed can be controlled, thereby adjusting the rise time and fall time of the MOSFET.

[0099] In some embodiments, optionally, the microcontroller unit 1044 turns off or closes the charge / discharge switch 102 via a charge / discharge drive control signal, including: the microcontroller unit 1044 sends a control command to the analog front-end 1042 via an integrated circuit bus; the analog front-end 1042 outputs a charge / discharge drive control signal through a drive control terminal according to the control command; the charge / discharge drive control signal is transmitted to the gate of the first charge / discharge switch Q1 via a first resistor R1, and to the gate of the second charge / discharge switch Q2 via a second resistor R2, so as to control the charge / discharge switch 102 to turn off or close.

[0100] In this embodiment, the microcontroller unit 1044 serves as the decision-making core in the short-circuit protection circuit 100. It sends digital instructions to the analog front-end 1042 via the integrated circuit bus. The analog front-end 1042, as an intelligent execution interface, converts the digital instructions into specific charge and discharge drive control signals. These signals are then transmitted to the gates of the back-to-back charge and discharge switch transistors 102 via the first resistor R1 and the second resistor R2 to precisely control the first charge and discharge switch transistor Q1 and the second charge and discharge switch transistor Q2 to turn off or close.

[0101] The microcontroller unit 1044 continuously monitors the real-time current data obtained from the analog front-end 1042. When the software algorithm in the microcontroller unit 1044 determines that the current exceeds the preset safety threshold, the microcontroller unit 1044 makes a decision to turn off or close the charge / discharge switch 102.

[0102] The microcontroller unit 1044 sends control commands via the integrated circuit bus, and the control commands contain specific operation commands.

[0103] The analog front-end 1042 receives and parses control commands, and outputs charge and discharge drive control signals through the drive control terminal. When a turn-off command is received, the gate drive circuit integrated inside the analog front-end 1042 will pull down the output voltage of the drive control terminal of the analog front-end 1042; when a turn-on command is received, the gate drive circuit integrated inside the analog front-end 1042 will pull up the output voltage of the drive control terminal of the analog front-end 1042.

[0104] The charge / discharge drive control signal sent by the analog front-end 1042 passes through the first resistor R1 and the second resistor R2, which plays the role of suppressing oscillation, limiting peak current and controlling switching speed, so as to ensure that the drive process of the first charge / discharge switch Q1 and the second charge / discharge switch Q2 is stable and reliable.

[0105] When the gates of the first charge / discharge switch Q1 and the second charge / discharge switch Q2 receive an effective driving voltage, the first charge / discharge switch Q1 and the second charge / discharge switch Q2 are turned on, and the main power circuit corresponding to the battery module 200 is connected; when the gate voltages of the first charge / discharge switch Q1 and the second charge / discharge switch Q2 are pulled low, the first charge / discharge switch Q1 and the second charge / discharge switch Q2 are turned off, and the main power circuit corresponding to the battery module 200 is disconnected.

[0106] Understandably, software protection is a hierarchical intelligent control mechanism based on digital communication. Although its response speed is not as fast as the hardware comparator U2, it realizes programmable multi-level protection, fault diagnosis and system status management, complementing hardware protection and jointly building a redundant security system that combines intelligence and high reliability.

[0107] In some embodiments, the analog front end 1042 is optionally configured to output a drive signal with an adjustable rising or falling slope. By controlling the slope of the drive waveform through software, a finer balance between switching speed and electromagnetic interference can be achieved without changing the external gate resistor.

[0108] In some embodiments, optionally, when the hardware short-circuit protection circuit 106 is activated, an interrupt signal can be generated and sent to the microcontroller unit 1044. The microcontroller unit 1044 records the fault information in the interrupt service routine, and then disables the output drive signal of the analog front-end 1042 through software flow until the fault is cleared, so as to realize the coordination of rapid hardware action and intelligent software management.

[0109] In some embodiments, optionally, such as Figure 3As shown, the hardware short-circuit protection circuit 106 further includes: a sixth resistor R6, the first end of which is connected to the first input terminal of comparator U2, and the second end of which is connected to the inverting input terminal of operational amplifier U1; a seventh resistor R7, the first end of which is connected to shunt 300, and the second end of which is connected to the inverting input terminal; an eighth resistor R8, the first end of which is connected to shunt 300, and the second end of which is connected to the non-inverting input terminal of operational amplifier U1; and a ninth resistor R9, the first end of which is connected to the second end of the eighth resistor R8, and the second end of which is connected to an external power supply.

[0110] In this embodiment, a precision differential amplifier circuit is defined, consisting of an operational amplifier U1 and a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9. The signals at both ends of the shunt 300 are connected through the seventh resistor R7 and the eighth resistor R8. The sixth resistor R6 is used to achieve negative feedback to set the gain, and the ninth resistor R9 is used to match the impedance. Together, they can stably amplify the weak differential voltage signal on the shunt 300, while efficiently suppressing common-mode interference.

[0111] The sixth resistor R6 is connected between the output terminal and the inverting input terminal of the operational amplifier. In conjunction with the seventh resistor R7, it determines the voltage amplification factor of the amplifier for differential signals.

[0112] The seventh resistor R7 is connected between one end of the shunt 300 and the inverting input of the operational amplifier, and the eighth resistor R8 is connected between the other end of the shunt 300 and the non-inverting input of the operational amplifier. The seventh resistor R7 and the eighth resistor R8 first provide high input impedance to the operational amplifier, that is, the current drawn from the shunt 300 by the seventh resistor R7 and the eighth resistor R8 is very small and will not affect the accuracy of the current measurement.

[0113] It should be emphasized that the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 together determine the differential gain of the circuit.

[0114] The ninth resistor R9 is connected between the positive input of the op-amp and the external power supply to suppress common-mode signals.

[0115] Understandably, the precision differential amplifier circuit composed of the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 provides a pure, reliable voltage signal with strong anti-interference capability for the subsequent comparator U2. This ensures the accuracy, stability, and overall anti-interference performance of the hardware short-circuit protection circuit 106 from the source, laying the foundation for the high reliability of the hardware fast protection function.

[0116] In some embodiments, optionally, such as Figure 3As shown, the hardware short-circuit protection circuit 106 also includes a self-locking unit 1062, which includes a switching transistor Q3, and the output terminal of the comparator U2 is connected to the gate of the switching transistor Q3.

[0117] In this embodiment, a self-locking unit 1062 with the switching transistor Q3 as its core is added to the hardware short-circuit protection circuit 106. The gate of the switching transistor Q3 is directly driven by the output of the comparator U2. The core function of the self-locking unit 1062 is that when the comparator U2 triggers a high-level output due to a short-circuit fault, it will immediately turn on the switching transistor Q3 and lock this state, thereby ensuring that the charging and discharging switching transistor 102 remains off until external intervention clears it. This effectively prevents the jitter and repeated impact of the protection circuit under intermittent or transient faults, and fundamentally improves the determinism of hardware protection and system reliability.

[0118] In this circuit, switch Q3 acts as a controlled electronic switch, and its gate is controlled by the output signal of comparator U2. During normal operation, comparator U2 outputs a low level, and switch Q3 is off due to its low gate level. At this time, the self-locking unit 1062 has no effect on the main circuit, and the charge / discharge switch 102 is normally controlled by the analog front-end 1042. When a short circuit occurs in the battery module 200, the output of comparator U2 flips to a high level, driving switch Q3 to conduct. After switch Q3 conducts, it pulls the gate drive voltage of charge / discharge switch 102 down to ground.

[0119] Once switch Q3 is turned on, it will remain on, continuously pulling the drive signal low, thereby forcibly keeping the first charge / discharge switch Q1 and the second charge / discharge switch Q2 off. Even if the short-circuit current disappears, causing the voltage of shunt 300 to drop and the output of comparator U2 to return to a low level, switch Q3 will still remain on through the feedback mechanism.

[0120] The self-locking mechanism can be understood as a fail-safe mechanism. It ensures that once the system detects the most dangerous short-circuit condition, it enters and maintains an absolutely safe state until the microcontroller unit 1044 actively clears the fault. Because the system state is locked, the microcontroller unit 1044 has ample time to read and record various parameters (such as current and voltage values) at the time of the fault, and can report fault information through other interfaces (such as a display screen or communication bus), greatly facilitating subsequent maintenance and fault analysis.

[0121] In some embodiments, optionally, such as Figure 3As shown, the self-locking unit 1062 further includes: a third resistor R3, the first end of which is connected to the first end of the second resistor R2, and the second end of which is connected to the drain of the switching transistor Q3; a fourth resistor R4, the first end of which is connected to the output of the comparator U2, and the second end of which is connected to the gate of the switching transistor Q3; and a fifth resistor R5, the first end of which is connected to the second end of the fourth resistor R4, and the second end of which is connected to the source of the switching transistor Q3.

[0122] In this embodiment, the fourth resistor R4 serves as a current-limiting isolation element, connecting the output of comparator U2 to the gate of switch Q3. The fifth resistor R5 provides current to the gate, pulling it down to ensure reliable turn-off. The third resistor R3 is connected across the drive terminal of charge / discharge switch 102 and the drain of self-locking switch Q3, forming a critical state feedback path. When a short circuit is triggered, the hardware latching circuit composed of the third resistor R3, the fourth resistor R4, the fifth resistor R5, and switch Q3 can instantly pull down the drive signal and maintain the fault state until an external clear signal intervenes.

[0123] Understandably, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 in the self-locking unit 1062 achieve continuous locking of the fault state in a very simple pure hardware manner, effectively preventing power circuit jitter and significantly improving the anti-interference capability and safety redundancy of the short-circuit protection circuit 100.

[0124] The fourth resistor, R4, is connected between the output of comparator U2 and the gate of switching transistor Q3. It limits the peak current flowing from comparator U2 to the gate of switching transistor Q3, protecting the output of comparator U2 from overcurrent damage. Furthermore, it forms a resistor-capacitor circuit with the gate capacitance of switching transistor Q3 to slow down the rise or fall of the gate voltage, suppressing possible high-frequency oscillations and making the switching action smoother.

[0125] The fifth resistor R5 is connected between the gate and source of the switching transistor Q3. When the output of comparator U2 is high impedance or in an uncertain state, it reliably pulls the gate of the switching transistor Q3 low to ground potential, ensuring that the switching transistor Q3 is turned off and preventing false turn-on.

[0126] The third resistor R3 is connected between the drive control terminal of the charge / discharge switch 102 and the drain of the switch Q3. When the switch Q3 is turned on, the high level of the drive control terminal is pulled to ground through the third resistor R3 and the turned-on switch Q3, thereby turning off the charge / discharge switch 102.

[0127] When the drive control terminal is pulled low, this low level will be fed back to the drain of the switching transistor Q3 through the third resistor R3. Although this feedback signal will not directly maintain the gate voltage of the switching transistor Q3, it ensures that as long as the switching transistor Q3 is turned on, the drive signal will be clamped at a low level, thereby maintaining the off state.

[0128] In some embodiments, optionally, a bidirectional Zener diode or transient voltage suppressor diode is connected in parallel between the gate and source of the switching transistor Q3. By clamping the gate-source voltage, the gate oxide layer is prevented from being broken down due to static electricity or voltage spikes, which greatly improves the circuit's anti-static and overvoltage resistance.

[0129] In some embodiments, comparator U2 may optionally compare the loop voltage with a hardware threshold voltage, and output a high level to turn off the charge / discharge switch 102 when the loop voltage is greater than the hardware threshold voltage. This includes: when the loop voltage is greater than the hardware threshold voltage, comparator U2 outputs a high-level signal, and the high-level signal drives switch Q3 to conduct through the fourth resistor R4 to turn off the charge / discharge switch 102.

[0130] In this embodiment, when the circuit voltage exceeds the hardware threshold, the comparator U2 outputs a high-level signal instantaneously. After being current-limited and buffered by the fourth resistor R4, the high-level signal drives the switch Q3 to turn on, thereby forcibly pulling down the gate drive voltage of the charge-discharge switch 102 to quickly turn off the first charge-discharge switch Q1 and the second charge-discharge switch Q2.

[0131] Comparator U2 compares the loop voltage with the hardware threshold voltage to achieve a fault response speed in microseconds. It is completely independent of the software system, which fundamentally ensures the absolute priority and reliability of the protection action under extreme short-circuit conditions, forming the most critical fast-response barrier in the battery system's defense-in-depth system.

[0132] It is understandable that the judgment of comparator U2 is at the nanosecond level, and the conduction of switch Q3 is at the microsecond level. The entire response chain can be completed within a few microseconds. Comparator U2 can quickly cut off the circuit before the short-circuit current rises to a dangerous peak value, which greatly reduces the stress and energy of the short-circuit current, protects power devices such as batteries, MOSFETs, and shunt 300 from irreversible damage, and prevents secondary accidents such as fires caused by arcing or heat generated by huge currents.

[0133] Furthermore, even if the entire software system (including the MCU and AFE) completely fails due to program crashes, system freezes, power failures, or other reasons, the hardware protection circuit can still independently perform its protection mission. This provides ultimate protection against systemic failures, meeting the highest level of safety redundancy requirements in functional safety. It improves the safety and reliability of the short-circuit protection circuit 100.

[0134] In some embodiments, the microcontroller unit 1044 is optionally configured with a fault clearing signal terminal. The microcontroller unit 1044 outputs a high-level signal to the gate of the switching transistor Q3 through the fault clearing signal terminal, so that the switching transistor Q3 is turned off, the level of the drive control terminal of the analog front end 1042 is set high, and the charge / discharge switch 102 is closed again.

[0135] In this embodiment, based on the hardware short-circuit protection circuit 106, a fault safety clearing mechanism dominated by the microcontroller unit 1044 is defined: when the fault is cleared, the microcontroller unit 1044 actively outputs a high level to the gate of the self-locking unit 1062 switch Q3 through a dedicated fault clearing signal terminal, forcing it to turn off, thereby releasing the pull-down effect on the drive signal of the charge-discharge switch 102, restoring the drive control terminal level, closing the charge-discharge switch 102 again, and restoring the system to normal operation.

[0136] Understandably, the design of the fault clearing signal enables the controllable reset of the hardware protection state, ensuring the system remains locked in a safe state until the fault is cleared. At the same time, the programmed clearing process avoids the risk of manual intervention, forming a complete safety closed loop of "trigger-protection-confirmation-recovery", which significantly improves the maintainability and overall intelligence level of the system.

[0137] Specifically, once the hardware protection is triggered, the self-locking unit 1062 will forcibly maintain the charge / discharge switch 102 in the off state. This is a one-time safety mechanism that requires external intervention to reset.

[0138] When the microcontroller unit 1044 learns that it needs to attempt to restore the system through user commands or communication timeout, it outputs a high-level signal through the fault clearing signal terminal configured in the microcontroller unit 1044. This high-level signal is directly sent to the gate of the switching transistor Q3 in the self-locking unit 1062.

[0139] This high-level signal from the microcontroller unit 1044 overrides any signals that maintain the latch-up state, providing a strong pull-up current to the gate of switch Q3. Regardless of the previous state of latch-up unit 1062, this forced drive signal will force switch Q3 to turn off immediately.

[0140] After switch Q3 is turned off, the path between its drain and source is broken. The previously pulled-down drive control terminal no longer has a path to ground, so its level is restored to high level by the pull-up resistor or the internal circuit of the analog front-end 1042, which turns on the first charge / discharge switch Q1 and the second charge / discharge switch Q2 again, and the battery module 200 in the short-circuit protection circuit 100 resumes normal operation.

[0141] In one specific embodiment, optionally, the hardware short-circuit protection design of the low-voltage energy storage system converts the current collected by the shunt into a voltage value. Based on the comparison between the voltage value and a set threshold, if the threshold is exceeded, the hardware short-circuit protection circuit directly pulls down the driving voltage of the charging and discharging MOS, and the charging and discharging MOS quickly disconnects and cuts off the power circuit.

[0142] The hardware overcurrent detection implementation schemes include:

[0143] The current passes through the shunt, and the overcurrent detection circuit detects the voltage value and compares it with the threshold in the hardware short-circuit protection circuit. When the voltage value of the current is higher than the set threshold, the voltage in the drive control circuit of the charge / discharge MOS will be pulled down, thereby disconnecting the charge / discharge MOS and disconnecting the battery circuit.

[0144] Hardware short-circuit protection can be implemented in the following ways:

[0145] When an external load of the battery system short-circuits, a large current is generated in the circuit. The voltage value generated by the shunt is compared with the short-circuit threshold of the comparator. If the voltage value is higher than the set threshold, the voltage in the drive control circuit of the charge / discharge MOS will be pulled down, thereby disconnecting the charge / discharge MOS and forcibly disconnecting the battery circuit.

[0146] The hardware overcurrent or short circuit protection process includes:

[0147] The shunt voltage is fed to the U1 operational amplifier via one path to determine overcurrent or short circuit conditions, which is a hardware protection mechanism. The other path is fed to the AFE to calculate the current, which is a software protection mechanism. Both calculations can protect the battery system, representing a redundant design that increases system reliability. The hardware protection design can more efficiently cut off the charging and discharging MOSFETs in case of software failures, preventing external short circuits from burning out the main circuit fuse (FUSE).

[0148] In one specific embodiment, optionally, when the voltage system is operating normally, the shunt detects a voltage value (V1) and compares it with a threshold value (Uref) in the hardware short-circuit protection circuit. When the voltage value of the current passing through the shunt is higher than the set threshold, the voltage in the drive control circuit of the charging / discharging MOS will be quickly pulled down, and the short-circuit self-locking signal output level will keep Q3 open, thereby locking the state of Q3 and disconnecting the charging / discharging MOS. If the charging / discharging MOS needs to be closed again, the MCU will clear the state of Q3 by sending a fault clear signal to the short-circuit self-locking signal before the charging / discharging MOS can be closed again.

[0149] Among them, such as Figure 5 The following describes the operation of the short-circuit protection circuit of this application. The software overcurrent or short-circuit protection specifically includes the following steps:

[0150] S200: The AFE collects the current and sends it to the MCU. After calculation, the MCU determines whether the current value I1 > the preset current threshold Iref is true in step S202.

[0151] If so, proceed to step S204: The MCU disconnects the charge / discharge MOS signal to the AFE via IIC;

[0152] After step S204, step S206 must also be executed: AFE turns off the charging and discharging MOS, and the power circuit is disconnected;

[0153] If not, proceed to step S208: send the current data to the MCU via IIC;

[0154] After step S208, step S210 also needs to be executed: report the current value to the MCU.

[0155] It is understandable that during overcurrent or short circuit events, the MCU and AFE communicate via IIC, and the AFE then disconnects the charging and discharging MOS. Software protection for the battery module is achieved through software overcurrent or short circuit protection.

[0156] like Figure 5 As shown, in some embodiments, hardware overcurrent or short-circuit protection includes:

[0157] Step S300: U1 collects the voltage of the shunt and calculates the value V1;

[0158] The comparator executes step S302: Determine whether V1 > Uref is true;

[0159] If we proceed to step S304: Q3 MOS transistor turns on, pulling down the charging / discharging MOS drive voltage, and Q1 and Q2 turn off;

[0160] After step S304, step S308 must also be executed: the battery's charge / discharge MOS is turned off, and the power circuit is disconnected;

[0161] Furthermore, after step S304 is executed, there is step S306: the short-circuit self-locking signal continuously outputs voltage, keeping Q3 in the open state;

[0162] If the result of step S302 is negative, then step S310 is executed: Q3 is in the off state, and the power circuit is powered normally.

[0163] After the operational amplifier U1 in the hardware short-circuit protection circuit 106 collects the voltage of the shunt 300, the comparator U2 executes the judgment logic, and the self-locking unit 1062 executes the shutdown of the charge-discharge switch 102. When a short circuit or overcurrent occurs in the battery system, the hardware circuit can instantly disconnect the charge-discharge MOS.

[0164] Understandably, in addition to the software short-circuit protection circuit 104, the present invention also has a designed hardware short-circuit protection circuit 106 to achieve a dual redundancy design; the hardware short-circuit protection circuit 106 serves as passive protection and can disconnect the circuit even under adverse conditions to protect the battery module 200.

[0165] like Figure 4 As shown, this application embodiment also provides an energy storage device 1000, including the short-circuit protection circuit 100 provided in any of the above embodiments. Therefore, the energy storage device 1000 possesses all the beneficial effects of any of the above embodiments, which will not be elaborated further here.

[0166] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0167] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0168] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to specific features, structures, materials, or characteristics described in connection with an embodiment or example that are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0169] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A short-circuit protection circuit, characterized by comprising: The application relates to a short-circuit protection circuit. The short-circuit protection circuit comprises a battery module, a charge-discharge switch tube connected with a first end of the battery module, a software short-circuit protection circuit comprising a micro control unit, the micro control unit being used for turning off or closing the charge-discharge switch tube through a charge-discharge driving control signal, and a hardware short-circuit protection circuit comprising a comparator, an output end of the comparator being connected with the charge-discharge switch tube, a first input end of the comparator being connected with a loop voltage of the battery module, and a second input end of the comparator being connected with a hardware threshold voltage. In the hardware short-circuit protection circuit, the comparator compares the loop voltage with the hardware threshold voltage, and outputs a high level to turn off the charge-discharge switch tube when the loop voltage is greater than the hardware threshold voltage. The software short-circuit protection circuit further comprises an analog front end, the analog front end being connected with the micro control unit in communication, and a driving control end of the analog front end being connected with the charge-discharge switch tube. The short-circuit protection circuit further comprises an operational amplifier, an output end of the operational amplifier being connected with the first input end of the comparator, and the operational amplifier being used for collecting the loop voltage. The short-circuit protection circuit further comprises a shunt, the shunt being connected with a second end of the battery module, a current sampling end of the analog front end being connected with both ends of the shunt, and the current sampling end being used for collecting a current signal flowing through the shunt, and an input end of the operational amplifier being connected with both ends of the shunt, and the input end being used for collecting a loop voltage flowing through the shunt.

2. The short circuit protection circuit according to claim 1, characterized in that The charge-discharge switch tube comprises a first charge-discharge switch tube and a second charge-discharge switch tube. A drain of the first charge-discharge switch tube is connected with a drain of the second charge-discharge switch tube.

3. The short circuit protection circuit of claim 2, wherein A gate of the first charge-discharge switch tube is connected with the driving control end of the analog front end, and a gate of the second charge-discharge switch tube is connected with the driving control end of the analog front end. The charge-discharge switch tube further comprises a first resistor, a first end of the first resistor being connected with the gate of the first charge-discharge switch tube, and a second end of the first resistor being connected with the driving control end of the analog front end, and a second resistor, a first end of the second resistor being connected with the gate of the second charge-discharge switch tube, and a second end of the second resistor being connected with the driving control end of the analog front end.

4. The short circuit protection circuit of claim 3, wherein The micro control unit turns off or closes the charge-discharge switch tube through the charge-discharge driving control signal, and the method comprises the following steps. The micro control unit sends a control instruction to the analog front end through an integrated circuit bus, the analog front end outputs the charge-discharge driving control signal through the driving control end according to the control instruction, the charge-discharge driving control signal is transmitted to the gate of the first charge-discharge switch tube through the first resistor and to the gate of the second charge-discharge switch tube through the second resistor, so as to control the charge-discharge switch tube to be turned off or closed. The hardware short-circuit protection circuit further comprises a sixth resistor, a first end of the sixth resistor being connected with the first input end of the comparator, and a second end of the sixth resistor being connected with a reverse input end of the operational amplifier. ​ 5. The short circuit protection circuit of claim 2, wherein ​ ​ ​ 6. The short circuit protection circuit of claim 5, wherein ​ ​ ​ 7. The short circuit protection circuit of claim 6, wherein ​ ​ 8. The short circuit protection circuit of claim 3, wherein ​ ​ A seventh resistor, a first end of the seventh resistor is connected to the shunt, and a second end of the seventh resistor is connected to the reverse input end; An eighth resistor, a first end of the eighth resistor is connected to the shunt, and a second end of the eighth resistor is connected to the positive input end of the operational amplifier; A ninth resistor, a first end of the ninth resistor is connected to the second end of the eighth resistor, and a second end of the ninth resistor is connected to an external power supply.

9. The short circuit protection circuit of claim 8, wherein, The hardware short-circuit protection circuit further comprises: A self-locking unit, the self-locking unit comprises a switching tube, and an output end of the comparator is connected to a gate of the switching tube.

10. The short circuit protection circuit of claim 9, wherein, The self-locking unit further comprises: A third resistor, a first end of the third resistor is connected to a first end of the second resistor, and a second end of the third resistor is connected to a drain of the switching tube; A fourth resistor, a first end of the fourth resistor is connected to the output end of the comparator, and a second end of the fourth resistor is connected to the gate of the switching tube; A fifth resistor, a first end of the fifth resistor is connected to the second end of the fourth resistor, and a second end of the fifth resistor is connected to a source of the switching tube.

11. The short circuit protection circuit of claim 10, wherein, The comparator compares the loop voltage with the hardware threshold voltage, and outputs a high level to turn off the charge-discharge switching tube when the loop voltage is greater than the hardware threshold voltage, comprising: When the loop voltage is greater than the hardware threshold voltage, the comparator outputs a high level signal, and the high level signal drives the switching tube to be turned on through the fourth resistor, so as to turn off the charge-discharge switching tube.

12. The short circuit protection circuit of claim 10, wherein, The micro control unit is configured with a fault clearing signal end, the micro control unit outputs a high level signal to the gate of the switching tube through the fault clearing signal end, so that the switching tube is turned off, the level of the driving control end of the analog front end is set high, and the charge-discharge switching tube is re-closed.

13. An energy storage device, comprising: Comprise: The short-circuit protection circuit according to any one of claims 1 to 12. The short-circuit protection circuit according to any one of claims 1 to 12.

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