Protection circuit and energy storage power supply

Abstract

The utility model provides a protection circuit and an energy storage power supply. The protection circuit comprises a sampling module, a positive and negative comparison module and an overcurrent memory module. The sampling module, the positive and negative comparison module and the overcurrent memory module are sequentially connected, and the sampling module is used for being connected with a main circuit. The sampling module is used for collecting sampling current of the main circuit and generating sampling voltage based on the sampling current; the positive and negative comparison module is used for outputting an overcurrent signal when the sampling voltage is greater than a first preset voltage or less than a second preset voltage; wherein the first preset voltage is greater than the second preset voltage; and the overcurrent memory module is used for outputting a protection signal when the overcurrent signal meets a preset condition. The possibility that electronic components in the main circuit are damaged due to overcurrent can be reduced, and the reliability and the stability of the circuit are improved.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a protection circuit and an energy storage power supply. Background Technology

[0002] With the development of power electronics, electronic devices are becoming increasingly prevalent in daily life. Typically, each electronic device has a specific rated current, a crucial parameter for its normal operation. From a professional perspective, the internal circuit structure and component selection of electronic devices are based on the rated current during design and manufacturing. When the equipment is operating normally, the current remains within the rated range, allowing each component to operate within its safe operating area, ensuring stable and reliable equipment performance.

[0003] However, if an overload or malfunction occurs during use, causing the current to exceed the rated value for an extended period, it will exacerbate the heating of components, exceeding their heat dissipation capacity. This will lead to a decline in component performance and a shortened lifespan, and in severe cases, it can directly burn out the equipment or even cause safety accidents such as fires. Therefore, ensuring that electronic equipment operates within its rated current range is crucial and is a fundamental requirement for ensuring the safe and stable operation of equipment. Utility Model Content

[0004] This application provides a protection circuit and an energy storage power supply, which can reduce the possibility of electronic components in the main circuit being damaged by overcurrent and improve the reliability and stability of the circuit.

[0005] In a first aspect, embodiments of this application provide a protection circuit, which includes a sampling module, a positive-negative comparison module, and an overcurrent memory module. The sampling module, the positive-negative comparison module, and the overcurrent memory module are connected sequentially. The sampling module is used to connect to a main circuit. The sampling module is used to acquire the sampling current of the main circuit and generate a sampling voltage based on the sampling current. The positive-negative comparison module is used to output an overcurrent signal when the sampling voltage is greater than a first preset voltage or less than a second preset voltage; wherein the first preset voltage is greater than the second preset voltage. The overcurrent memory module is used to output a protection signal when the overcurrent signal meets a preset condition.

[0006] In some embodiments, the overcurrent memory module includes a memory unit and an overcurrent comparison unit. The memory unit is connected to both the overcurrent comparison unit and the positive / negative comparison module. The memory unit is used to output a memory voltage based on the overcurrent signal; wherein the memory voltage is positively correlated with the time of the overcurrent signal; the overcurrent comparison unit is used to output the protection signal when the memory voltage is greater than a third preset voltage.

[0007] In some embodiments, the memory unit includes a switch Q1, a capacitor C5, resistors R12, R13, and R14, and a diode D1. The first terminal of resistor R12 is connected to the positive / negative comparison module, and the second terminal of resistor R12 is connected to the control terminal of switch Q1. The first terminal of switch Q1 is connected to the second terminal of resistor R13, the first terminal of resistor R14, and the anode of diode D1. The first terminal of resistor R13 is connected to a power supply. The cathode of diode D1 is connected to the second terminal of resistor R14, the first terminal of capacitor C5, and the overcurrent comparison unit. The second terminals of capacitor C5 and switch Q1 are both grounded.

[0008] In some embodiments, the memory cell further includes a diode D2 and a resistor R15. The anode of the diode D2 is connected to the cathode of the diode D1, the second terminal of the resistor R14, and the first terminal of the capacitor C5, respectively. The cathode of the diode D2 is connected to the first terminal of the resistor R15 and the overcurrent comparator, respectively. The second terminal of the resistor R15 is grounded.

[0009] In some embodiments, the overcurrent comparison unit includes a comparator U4, resistors R16, R17, R18, R19, and R20. The inverting input of comparator U4 is connected to the memory unit via resistor R16. The non-inverting input of comparator U4 is connected to the second terminal of resistor R17 and the first terminal of resistor R18. The first terminal of resistor R17 is connected to a power supply, and the second terminal of resistor R18 is grounded. The output of comparator U4 is connected to the first terminal of resistor R19, and the second terminal of resistor R19 is connected to the second terminal of resistor R20. The first terminal of resistor R20 is connected to a power supply. The second terminal of resistor R19 is used to output the protection signal.

[0010] In some embodiments, the overcurrent signal includes a first overcurrent level signal and a second overcurrent level signal, and the positive / negative comparison module includes a first comparison unit and a second comparison unit. The first comparison unit is connected to both the sampling module and the overcurrent memory module, and the second comparison unit is connected to both the sampling module and the overcurrent memory module. The first comparison unit is used to output the first overcurrent level signal when the sampled voltage is greater than the first preset voltage; the second comparison unit is used to output the second overcurrent level signal when the sampled voltage is less than the second preset voltage.

[0011] In some embodiments, the positive and negative comparison module further includes a voltage divider unit. The voltage divider unit is connected to the first comparison unit, the second comparison unit, and the overcurrent memory module, respectively, and is also connected to a power supply. The voltage divider unit is used to divide the voltage of the power supply to provide a divided voltage to the overcurrent memory module.

[0012] In some embodiments, the sampling module includes an amplifier U1, resistors R1, R2, R3, and R4. The first end of resistor R1 is connected to the main circuit; the second end of resistor R1 is connected to the second end of resistor R3 and the non-inverting input of amplifier U1; the first end of resistor R3 is connected to a power supply; the first end of resistor R2 is grounded; the second end of resistor R2 is connected to the first end of resistor R4 and the inverting input of amplifier U1; and the output of amplifier U1 is connected to the second end of resistor R4 and the positive / negative comparison module.

[0013] In some embodiments, the sampling module further includes a capacitor C1, the first terminal of which is connected in parallel with the resistor R3.

[0014] Secondly, embodiments of this application provide an energy storage power supply, which includes the protection circuit described above.

[0015] This application provides a protection circuit and an energy storage power supply. The protection circuit includes a sampling module, a positive / negative comparison module, and an overcurrent memory module. The sampling module can collect the sampled current of the main circuit in real time and convert it into a sampled voltage, allowing the protection circuit to obtain the magnitude and changes of the main circuit current in a timely and accurate manner. The positive / negative comparison module, by setting two preset voltage thresholds (first and second preset voltages), can monitor not only whether the main circuit current is too high (sampled voltage greater than the first preset voltage) but also whether abnormal situations such as reverse overcurrent or insufficient current occur (sampled voltage less than the second preset voltage), achieving comprehensive monitoring of multiple overcurrent conditions. The overcurrent memory module sets preset conditions, and only outputs a protection signal when the overcurrent signal meets these conditions. This effectively reduces false triggering of protection actions caused by accidental factors such as instantaneous current fluctuations, improving the reliability and stability of the circuit. It also reduces the possibility of damage to electronic components in the main circuit due to overcurrent, extending the service life of the equipment in the main circuit. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 This is a structural block diagram of the protection circuit provided in the embodiments of this application;

[0018] Figure 2 This is a structural block diagram of the positive and negative comparison module provided in the embodiments of this application;

[0019] Figure 3 This is a structural block diagram of the overcurrent memory module provided in the embodiments of this application;

[0020] Figure 4 This is a schematic diagram of the circuit structure of the sampling module provided in the embodiments of this application;

[0021] Figure 5 This is a schematic diagram of the circuit structure of the positive and negative comparison module provided in the embodiments of this application;

[0022] Figure 6 This is a schematic diagram of the circuit structure of the overcurrent memory module provided in the embodiments of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0024] The technical features involved in the various embodiments of this application described below do not conflict with each other and can be combined with each other.

[0025] When an element is described as "connected" to another element, it can be directly connected to the other element, or there may be one or more intervening elements between them.

[0026] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and are not limited in number; for example, a first object can be one or more.

[0027] Please see Figure 1 , Figure 1 This is a structural block diagram of the protection circuit 100 provided in the embodiments of this application.

[0028] This application provides a protection circuit 100, which includes a sampling module 10, a positive-negative comparison module 20, and an overcurrent memory module 30. The sampling module 10, the positive-negative comparison module 20, and the overcurrent memory module 30 are connected in sequence, and the sampling module 10 is used to connect to the main circuit (not shown).

[0029] Specifically, sampling module 10 is used to acquire the sampling current (I-test) of the main circuit and generate a sampling voltage based on the sampling current. Positive and negative comparison module 20 is used to output an overcurrent signal when the sampling voltage is greater than a first preset voltage or less than a second preset voltage; wherein the first preset voltage is greater than the second preset voltage. Overcurrent memory module 30 is used to output a protection signal (V-cop2) when the overcurrent signal meets preset conditions.

[0030] The sampling current refers to the current collected from the main circuit for monitoring and analysis. It is a part of the actual operating current in the main circuit or has a specific proportional relationship with the main circuit current, reflecting the magnitude and changes of the current in the main circuit, so as to monitor and judge the operating status of the main circuit.

[0031] The sampling voltage is a voltage signal generated by the sampling module based on the acquired sampling current through a certain conversion relationship. For example, the sampling current can be converted into a corresponding voltage signal through a current-to-voltage conversion circuit for processing and comparison in subsequent circuits.

[0032] The first preset voltage is the standard for judging whether the sampling voltage is too high. When the sampling voltage generated by the sampling module 10 is greater than the first preset voltage, it indicates that there is an overcurrent situation in the main circuit (such as positive overcurrent), which has reached the upper limit voltage value that requires protection action. The positive and negative comparison module 20 will output an overcurrent signal based on this.

[0033] The second preset voltage is the standard for judging whether the sampling voltage is too low. When the sampling voltage is less than the second preset voltage, it is considered that there is an overcurrent in the main circuit (such as reverse overcurrent), and the positive and negative comparison module 20 will output an overcurrent signal accordingly.

[0034] The overcurrent signal is the signal output by the positive / negative comparison module when the sampled voltage is greater than a first preset voltage or less than a second preset voltage. It is an electrical signal, such as a low-level signal.

[0035] Preset conditions refer to specific requirements or states that the overcurrent signal needs to meet, such as the overcurrent signal lasting for a certain duration or the overcurrent signal reaching a preset number of times within a certain time. When the overcurrent signal meets these preset conditions, the overcurrent memory module 30 will output a protection signal.

[0036] The protection signal is the signal output by the overcurrent memory module 30 when the overcurrent signal meets the preset conditions. It is used to trigger the protection circuit to perform corresponding protection actions, such as cutting off the main circuit power supply, reducing the main circuit operating current, and issuing an alarm signal.

[0037] In practical applications, firstly, the sampling module 10 acquires the sampling current in the main circuit. After acquiring the sampling current, it converts the sampling current into a sampling voltage. Then, the positive and negative comparison module 20 receives the sampling voltage from the sampling module 10 and compares it with a first preset voltage and a second preset voltage. The first preset voltage is the upper limit threshold for determining whether the current is too large (abnormalities such as forward overcurrent), and the second preset voltage is the lower limit threshold for determining whether the current is too small (abnormalities such as reverse overcurrent), and the first preset voltage is greater than the second preset voltage. When the sampling voltage is greater than the first preset voltage or less than the second preset voltage, the positive and negative comparison module 20 outputs an overcurrent signal. Next, the overcurrent memory module 30 receives the overcurrent signal output by the positive and negative comparison module 20. When the overcurrent signal meets preset conditions (e.g., the duration of the overcurrent signal reaches a certain length, the overcurrent signal reaches a preset number of times within a certain time, etc.), the overcurrent memory module 30 outputs a protection signal.

[0038] Please see Figure 2 , Figure 2 This is a structural block diagram of the positive and negative comparison module 20 provided in the embodiments of this application.

[0039] In some embodiments, the overcurrent signal includes a first overcurrent level signal and a second overcurrent level signal. The positive / negative comparison module 20 includes a first comparison unit 21 and a second comparison unit 22. The first comparison unit 21 is connected to both the sampling module 10 and the overcurrent memory module 30, and the second comparison unit 22 is also connected to both the sampling module 10 and the overcurrent memory module 30. Specifically, the first comparison unit 21 outputs a first overcurrent level signal when the sampled voltage is greater than a first preset voltage. The second comparison unit 22 outputs a second overcurrent level signal when the sampled voltage is less than a second preset voltage.

[0040] Wherein, the first preset voltage is greater than the second preset voltage. The first overcurrent level signal can be a low-level signal. The second overcurrent level signal can be a low-level signal.

[0041] The first preset voltage is the standard for judging whether the sampling voltage is too high. When the sampling voltage generated by the sampling module 10 is greater than the first preset voltage, it indicates that there is an overcurrent in the main circuit (such as forward overcurrent), which has reached the upper limit voltage value that requires protection action. The first comparison unit 21 will output the first overcurrent level signal based on this.

[0042] The second preset voltage is the standard for judging whether the sampling voltage is too low. When the sampling voltage is less than the second preset voltage, it is considered that there is an overcurrent in the main circuit (such as reverse overcurrent), and the second comparison unit 22 will output a second overcurrent level signal accordingly.

[0043] The first and second preset voltages can be reasonably set according to the actual application scenario and the tolerance of the main circuit, so as to flexibly adjust the conditions for the protection circuit to trigger the protection action and improve the adaptability and reliability of the protection circuit.

[0044] In this embodiment, when the positive and negative comparison module 20 outputs a first overcurrent level signal and / or a second overcurrent level signal, it is considered that the positive and negative comparison module 20 outputs an overcurrent signal.

[0045] In some embodiments, the positive and negative comparison module 20 further includes a voltage divider unit 23. The voltage divider unit 23 is connected to the first comparison unit 21, the second comparison unit 22, and the overcurrent memory module 30, respectively. The voltage divider unit 23 is also connected to a power supply (not shown, typically a DC power supply, such as +5V DC, +3.3V DC, etc.). Specifically, the voltage divider unit 23 divides the voltage of the power supply to provide a divided voltage to the overcurrent memory module 30.

[0046] The voltage divider can be considered a reference voltage used to match subsequent circuits. When the first comparison unit 21 does not output the first overcurrent level signal and the second comparison unit 22 does not output the second overcurrent level signal (that is, when the sampled voltage is less than or equal to the first preset voltage and greater than or equal to the second preset voltage), the signal output by the positive and negative comparison module 20 can be considered as the voltage divider.

[0047] Please see Figure 3 , Figure 3 This is a structural block diagram of the overcurrent memory module 30 provided in the embodiments of this application.

[0048] In some embodiments, the overcurrent memory module 30 includes a memory unit 31 and an overcurrent comparison unit 32. The memory unit 31 is connected to both the overcurrent comparison unit 32 and the positive / negative comparison module 20. Specifically, the memory unit 31 outputs a memory voltage based on an overcurrent signal; wherein the memory voltage is positively correlated with the time of the overcurrent signal. The overcurrent comparison unit 32 outputs a protection signal when the memory voltage exceeds a third preset voltage.

[0049] The memory voltage is a voltage signal output by the memory unit 31 based on the overcurrent signal. It is positively correlated with the duration of the overcurrent signal, meaning that the longer the overcurrent signal lasts, or the more frequently it occurs within a certain time, the higher the memory voltage output by the memory unit. In terms of working principle, when the positive / negative comparison module 20 outputs an overcurrent signal, the memory unit 31 begins to respond to and process the signal. For example, the memory unit 31 may contain components with storage characteristics, such as capacitors. The overcurrent signal can charge the capacitor; as the duration of the overcurrent signal increases, the charge accumulated on the capacitor increases, and the voltage across it (i.e., the memory voltage) increases accordingly. The memory voltage quantifies and records the duration of the overcurrent signal, reflecting the severity and duration of the overcurrent in the main circuit.

[0050] The third preset voltage is used as the threshold for the overcurrent comparison unit 32 to determine whether to output a protection signal. The overcurrent comparison unit 32 compares the memory voltage output by the memory unit 21 with the third preset voltage. When the memory voltage is greater than the third preset voltage, it indicates that the overcurrent situation in the main circuit has lasted for a long time and is relatively serious, reaching the level that requires triggering protection action. At this time, the overcurrent comparison unit 32 will output a protection signal to trigger subsequent protection measures.

[0051] Among them, the third preset voltage can be reasonably set according to the actual application scenario and the tolerance of the main circuit, and the conditions for the protection circuit to trigger the protection action can be flexibly adjusted to improve the adaptability and reliability of the protection circuit.

[0052] Please see Figure 4 , Figure 4 This is a schematic diagram of the circuit structure of the sampling module 10 provided in the embodiment of this application.

[0053] In some embodiments, the sampling module 10 includes an amplifier U1, resistors R1, R2, R3, and R4. The first end of resistor R1 is connected to the main circuit, the second end of resistor R1 is connected to the second end of resistor R3 and the non-inverting input terminal of amplifier U1, and the first end of resistor R3 is connected to the power supply (…). Figure 4 (Taking a +1.5V DC power supply as an example) The first end of resistor R2 is grounded, the second end of resistor R2 is connected to the first end of resistor R4 and the inverting input of amplifier U1, and the output of amplifier U1 is connected to the second end of resistor R4 and the positive and negative comparison module 20.

[0054] In some embodiments, the sampling module 10 further includes a capacitor C1, the first terminal of which is connected in parallel with a resistor R3. The capacitor C1 is used for filtering.

[0055] In some embodiments, the resistance values ​​of resistor R1, resistor R2, resistor R3, and resistor R4 are equal.

[0056] The following is Figure 4 The working principle of sampling module 10 is briefly explained.

[0057] like Figure 4 As shown, taking a +1.5V DC power supply as an example, when the current on the power line of the main circuit is zero, the voltage of the sampling current I-test is 1.5V. According to the superposition theorem, the voltage at point A (i.e., the sampling voltage) is 1.5V, which is the reference voltage. When the current on the power line of the main circuit is positive (positive and negative are opposite), VA (i.e., the voltage at point A) > the reference voltage (e.g., 1.5V). When the current on the power line of the main circuit is negative, VA < the reference voltage (e.g., 1.5V).

[0058] Please see Figure 5 , Figure 5 This is a schematic diagram of the circuit structure of the positive and negative comparison module 20 provided in the embodiments of this application.

[0059] In some embodiments, the first comparison unit 21 includes a comparator U2, resistors R5, R8, and R9, and a capacitor C2. The inverting input of comparator U2 is connected to the sampling module 10, and the non-inverting input of comparator U2 is connected to the second terminal of resistor R5, the first terminal of resistor R8, and the first terminal of capacitor C2. The first terminal of resistor R5 is used to connect to the power supply (…). Figure 5 (Taking a +3.3V DC power supply as an example) The second end of resistor R8 and the second end of capacitor C2 are both grounded. The output of comparator U2 is connected to the overcurrent memory module 30 through resistor R9.

[0060] In some embodiments, the second comparison unit 22 includes a comparator U3, resistors R6, R7, and R10, and a capacitor C3. The non-inverting input of comparator U3 is connected to the sampling module 10, and the inverting input of comparator U3 is connected to the second terminal of resistor R6, the first terminal of resistor R7, and the first terminal of capacitor C3. The first terminal of resistor R6 is used to connect to the power supply (…). Figure 5 (Taking a +3.3V DC power supply as an example) The second end of resistor R7 and the second end of capacitor C3 are both grounded, and the output of comparator U3 is connected to overcurrent memory module 30 through resistor R10.

[0061] In some embodiments, the voltage divider unit 23 includes a resistor R11 and a capacitor C4. The first terminal of the resistor R11 is used to connect to the power supply (…). Figure 5The VCC of the resistor R11 can be connected to a +5V DC power supply, a +3.3V DC power supply, etc. The second end of the resistor R11 is connected to the first end of the capacitor C4, the first comparison unit 21, the second comparison unit 22 and the overcurrent memory module 30 respectively. The second end of the capacitor C4 is grounded.

[0062] The following is Figure 5 The working principle of the positive and negative comparison module 20 is briefly explained.

[0063] like Figure 5 As shown, in the first comparison unit 21, resistors R5 and R8 divide the voltage, and VC (voltage at point C) can be set to > reference voltage (e.g., 1.5V), representing the current-limiting threshold when the current direction of the main circuit is positive. In the second comparison unit 22, resistors R6 and R7 divide the voltage, and VD (voltage at point D) can be set to < reference voltage (e.g., 1.5V), representing the current-limiting threshold when the current direction of the main circuit is negative. That is, VC > reference voltage (e.g., 1.5V) > VD.

[0064] Specifically, when VB (voltage at point B) ≤ VC and VB ≥ VD, it indicates that the current in the main circuit does not exceed the current limiting threshold in both the positive and negative directions. At this time, comparators U2 and U3 both output high levels, and V-ocp1 is at a high level.

[0065] When VB > VC or VB < VD, it indicates that the current in the main circuit exceeds the current limiting threshold in the positive or negative direction. At this time, comparator U2 (when VB > VC) or comparator U3 (when VB < VD) outputs a low level, and V-ocp1 is at a low level (i.e., an overcurrent signal).

[0066] The overcurrent signal can be used as a trigger signal or an alarm signal to be sent to the MCU (Microcontroller Unit) or other circuits, so that the overcurrent signal can be responded to immediately, such as cutting off the power supply to the main circuit or reducing the operating current of the main circuit.

[0067] Please see Figure 6 , Figure 6 This is a schematic diagram of the circuit structure of the overcurrent memory module 30 provided in the embodiments of this application.

[0068] In some embodiments, the memory unit 31 includes a switch Q1, a capacitor C5, resistors R12, R13, and R14, and a diode D1. The first end of resistor R12 is connected to the positive / negative comparison module 20, and the second end of resistor R12 is connected to the control terminal of switch Q1. The first end of switch Q1 is connected to the second end of resistor R13, the first end of resistor R14, and the anode of diode D1. The first end of resistor R13 is connected to a power supply (VCC, which can be a +5V DC power supply, a +3.3V DC power supply, etc.). The cathode of diode D1 is connected to the second end of resistor R14, the first end of capacitor C5, and the overcurrent comparison unit 32. The second ends of capacitor C5 and switch Q1 are both grounded.

[0069] In this circuit, the switching transistor Q1 can be an NPN transistor or any other suitable switching transistor. Taking an NPN transistor as an example, the base of the NPN transistor is the control terminal of the switching transistor Q1, the collector of the NPN transistor is the first terminal of the switching transistor Q1, and the emitter of the NPN transistor is the second terminal of the switching transistor Q1.

[0070] In some embodiments, the memory unit 31 further includes a diode D2 and a resistor R15. The anode of diode D2 is connected to the cathode of diode D1, the second terminal of resistor R14, and the first terminal of capacitor C5, respectively. The cathode of diode D2 is connected to the first terminal of resistor R15 and the overcurrent comparator unit 32, respectively. The second terminal of resistor R15 is grounded.

[0071] Specifically, diode D2 and resistor R15 are used to provide a discharge path for capacitor C5.

[0072] In some embodiments, the overcurrent comparison unit 32 includes a comparator U4, resistors R16, R17, R18, R19, and R20. The inverting input of comparator U4 is connected to the memory unit 31 via resistor R16. The non-inverting input of comparator U4 is connected to the second terminal of resistor R17 and the first terminal of resistor R18. The first terminal of resistor R17 is connected to the power supply, and the second terminal of resistor R18 is grounded. The output of comparator U4 is connected to the first terminal of resistor R19, and the second terminal of resistor R19 is connected to the second terminal of resistor R20. The first terminal of resistor R20 is connected to the power supply. Figure 6 (Using a +3.3V DC power supply as an example) The connection is as follows. The second terminal of resistor R19 is used to output a protection signal.

[0073] In some embodiments, the overcurrent comparator unit 32 further includes capacitors C6 and C7. The first terminal of capacitor C6 is connected to the non-inverting input of comparator U4, and the second terminal of capacitor C6 is grounded. The first terminal of capacitor C7 is connected to the second terminal of resistor R20, and the second terminal of capacitor C7 is grounded. Capacitor C6 is used for filtering, and capacitor C7 is used for buffering, filtering, etc.

[0074] The following is Figure 6 The working principle of the overcurrent memory module 30 is briefly explained.

[0075] like Figure 6 As shown, in memory cell 31, when V-ocp1 is low (i.e., when the positive / negative comparison module 20 outputs an overcurrent signal), the switching transistor Q1 is turned off. The power supply at VCC charges capacitor C5 through resistor R13 and diode D1. When the voltage of capacitor C5 is charged to the point where VE (the voltage at point E, i.e., the memory voltage) > VF (the voltage at point F, i.e., the third preset voltage), comparator U4 outputs a low level, and the signal at V-ocp2 at this time is the protection signal.

[0076] If the overcurrent signal V-ocp1 is low for a very short duration, insufficient to charge capacitor C5 to a point where VE > VF, then resistor C5 discharges through resistor R14 and switch Q1 when the overcurrent signal briefly disappears. Therefore, resistor R14 can be set relatively large to slow down the discharge rate of capacitor C5 and the voltage drop of capacitor C5, allowing the previous overcurrent signal to be remembered. If an overcurrent occurs again before capacitor C5 is fully discharged, capacitor C5 continues to charge until the number of overcurrent signals or the duration of the overcurrent signal causes the voltage of capacitor C5 to reach a point where VE > VF, triggering the overcurrent comparator unit 32 to output a protection signal.

[0077] If the overcurrent signal V-ocp1 is low for a very short period, insufficient to charge capacitor C5 to the point where VE > VF, and no further overcurrent occurs for a relatively long period afterward (meaning the time it takes for capacitor C5 to fully discharge), then the voltage of capacitor C5 will be reduced to zero, and the memory of the previous overcurrent will be cleared. In other words, capacitor C5 has the function of remembering a short period of previous overcurrent conditions.

[0078] This application provides a protection circuit 100, which includes a sampling module 10, a positive / negative comparison module 20, and an overcurrent memory module 30. The sampling module 10 can collect the sampled current of the main circuit in real time and convert it into a sampled voltage, enabling the protection circuit to obtain the magnitude and changes of the main circuit current in a timely and accurate manner. The positive / negative comparison module 20, by setting two threshold values—a first preset voltage and a second preset voltage—can monitor not only whether the main circuit current is too high (sampled voltage greater than the first preset voltage) but also whether abnormal situations such as reverse overcurrent or insufficient current occur (sampled voltage less than the second preset voltage), achieving comprehensive monitoring of various overcurrent conditions. The overcurrent memory module 30 is set with preset conditions; a protection signal is only output when the overcurrent signal meets these conditions. This effectively reduces false triggering of protection actions caused by accidental factors such as instantaneous current fluctuations, improving the reliability and stability of the protection circuit. Once the overcurrent memory module 30 outputs a protection signal, it can trigger corresponding protection actions, such as cutting off the main circuit power supply or reducing the main circuit operating current, thereby reducing the possibility of damage to electronic components in the main circuit due to overcurrent and extending the service life of the equipment in the main circuit.

[0079] This application embodiment also provides an energy storage power supply, which includes the protection circuit 100 as described above.

[0080] The specific structure and working principle of the protection circuit 100 can be referred to the above embodiments, and will not be repeated here.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; under the concept of this utility model, the technical features of the above embodiments or different embodiments can also be combined, and there are many other variations of different aspects of this utility model as described above. For the sake of brevity, they are not provided in detail; although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A protection circuit, characterized by, The protection circuit comprises a sampling module, a positive-negative comparison module and an overcurrent memory module; The sampling module, the positive-negative comparison module and the overcurrent memory module are connected in sequence, and the sampling module is configured to be connected with the main circuit; The sampling module is configured to collect a sampling current of the main circuit and generate a sampling voltage based on the sampling current; The positive-negative comparison module is configured to output an overcurrent signal when the sampling voltage is greater than a first preset voltage or less than a second preset voltage; the first preset voltage is greater than the second preset voltage; The overcurrent memory module is configured to output a protection signal when the overcurrent signal meets a preset condition.

2. The protection circuit of claim 1, wherein, The overcurrent memory module comprises a memory unit and an overcurrent comparison unit; The memory unit is connected with the overcurrent comparison unit and the positive-negative comparison module respectively; The memory unit is configured to output a memory voltage based on the overcurrent signal; the memory voltage is positively correlated with the time of the overcurrent signal; The overcurrent comparison unit is configured to output the protection signal when the memory voltage is greater than a third preset voltage.

3. The protection circuit of claim 2, wherein, The memory unit comprises a switch tube Q1, a capacitor C5, a resistor R12, a resistor R13, a resistor R14 and a diode D1; A first end of the resistor R12 is connected with the positive-negative comparison module, a second end of the resistor R12 is connected with a control end of the switch tube Q1, a first end of the switch tube Q1 is connected with a second end of the resistor R13, a first end of the resistor R14 and a positive electrode of the diode D1, a first end of the resistor R13 is configured to be connected with a power supply, a negative electrode of the diode D1 is connected with a second end of the resistor R14, a first end of the capacitor C5 and the overcurrent comparison unit respectively, and a second end of the capacitor C5 and a second end of the switch tube Q1 are both grounded.

4. The protection circuit of claim 3, wherein, The memory unit further comprises a diode D2 and a resistor R15; A positive electrode of the diode D2 is connected with a negative electrode of the diode D1, a second end of the resistor R14 and a first end of the capacitor C5 respectively, a negative electrode of the diode D2 is connected with a first end of the resistor R15 and the overcurrent comparison unit respectively, and a second end of the resistor R15 is grounded.

5. The protection circuit of claim 2, wherein, The overcurrent comparison unit comprises a comparator U4, a resistor R16, a resistor R17, a resistor R18, a resistor R19 and a resistor R20; An inverting input end of the comparator U4 is connected with the memory unit through the resistor R16, a non-inverting input end of the comparator U4 is connected with a second end of the resistor R17 and a first end of the resistor R18 respectively, a first end of the resistor R17 is configured to be connected with a power supply, a second end of the resistor R18 is grounded, an output end of the comparator U4 is connected with a first end of the resistor R19, a second end of the resistor R19 is connected with a second end of the resistor R20, and a first end of the resistor R20 is configured to be connected with a power supply; wherein the second end of the resistor R19 is configured to output the protection signal.

6. The protection circuit of claim 1, wherein, The overcurrent signal comprises a first overcurrent level signal and a second overcurrent level signal, and the positive-negative comparison module comprises a first comparison unit and a second comparison unit; The first comparison unit is connected with the sampling module and the overcurrent memory module respectively, and the second comparison unit is connected with the sampling module and the overcurrent memory module respectively; The first comparison unit is configured to output the first overcurrent level signal when the sampling voltage is greater than the first preset voltage; The second comparison unit is configured to output the second overcurrent level signal when the sampling voltage is less than the second preset voltage.

7. The protection circuit of claim 6, wherein, The positive and negative comparison module further comprises a voltage dividing unit; The voltage dividing unit is connected with the first comparison unit, the second comparison unit and the overcurrent memory module respectively, and the voltage dividing unit is further connected with a power supply; The voltage dividing unit is configured to divide the voltage of the power supply to provide a divided voltage for the overcurrent memory module.

8. The protection circuit according to any one of claims 1 to 7, characterized in that, The sampling module comprises an amplifier U1, a resistor R1, a resistor R2, a resistor R3 and a resistor R4; A first end of the resistor R1 is configured to be connected with the main circuit, a second end of the resistor R1 is connected with a second end of the resistor R3 and a non-inverting input terminal of the amplifier U1 respectively, a first end of the resistor R3 is configured to be connected with a power supply, a first end of the resistor R2 is grounded, a second end of the resistor R2 is connected with a first end of the resistor R4 and an inverting input terminal of the amplifier U1 respectively, and an output terminal of the amplifier U1 is connected with a second end of the resistor R4 and the positive and negative comparison module respectively.

9. The protection circuit of claim 8, wherein, The sampling module further comprises a capacitor C1, and a first end of the capacitor C1 is connected with the resistor R3 in parallel.

10. An energy storage power supply, characterized by, The energy storage power supply comprises the protection circuit according to any one of claims 1 to 9.

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