Short circuit protection circuit and energy storage power supply

Abstract

The utility model provides a short circuit protection circuit and an energy storage power supply. The short-circuit protection circuit comprises a subtraction module and a comparison output module. The input end of the subtraction module is respectively connected with the input end and the output end of the main circuit, the output end of the subtraction module is connected with the comparison output module, the comparison output module is also respectively connected with a first reference voltage and a second reference voltage, the first reference voltage is a negative voltage, and the second reference voltage is a positive voltage; the subtraction module is used for receiving an input voltage of the main circuit and an output voltage of the main circuit and calculating a difference value between the input voltage and the output voltage so as to output a target voltage; and the comparison output module is used for outputting a short-circuit fault signal when detecting that the target voltage is within the range from the first reference voltage to the second reference voltage. According to the application, when the main circuit is short-circuited, the short-circuit fault signal can be accurately output, so that the short-circuit condition can be accurately identified.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of electronic circuit, in particular to a short-circuit protection circuit and an energy storage power supply. BACKGROUND

[0002] In the era of wide popularization of intelligent devices such as mobile phones and notebooks, the importance of PD (Power Delivery) circuit is increasingly prominent. It operates according to the USB-PD (USB Power Delivery) protocol, accurately allocates voltage and current to meet the fast charging needs of different devices, greatly improves the charging efficiency, and provides strong support for the convenient use of users.

[0003] However, the problem of circuit short circuit is always a major safety hazard. The international standard IEC 62368-1 has strict specifications for the short circuit of PD circuit, which highlights the key significance of short circuit protection circuit. CONTENT OF THE INVENTION

[0004] The embodiment of the present application provides a short-circuit protection circuit and an energy storage power supply, which can detect short circuit to reduce the short circuit risk of the main circuit and improve the safety of the circuit.

[0005] In a first aspect, the embodiment of the present application provides a short-circuit protection circuit, which is applied to a main circuit, wherein the input voltage and the output voltage of the main circuit are different when the main circuit is normally working; the short-circuit protection circuit comprises a subtraction operation module and a comparison output module; the input end of the subtraction operation module is connected with the input end and the output end of the main circuit respectively, the output end of the subtraction operation module is connected with the comparison output module, and the comparison output module is further connected with a first reference voltage and a second reference voltage respectively, wherein the first reference voltage is a negative voltage and the second reference voltage is a positive voltage; the subtraction operation module is used for receiving the input voltage of the main circuit and the output voltage of the main circuit, calculating the difference between the input voltage and the output voltage to output a target voltage; and the comparison output module is used for outputting a short-circuit fault signal when the target voltage is within the range of the first reference voltage to the second reference voltage.

[0006] In some embodiments, the comparison output module comprises a first comparison unit and a second comparison unit; the first comparison unit is connected with the second comparison unit, the first comparison unit is also connected with the subtraction operation module, and the second comparison unit is also connected with the subtraction operation module; the first comparison unit is configured to output a first target level signal when the target voltage is greater than the first reference voltage; the second comparison unit is configured to output a second target level signal when the target voltage is less than the second reference voltage; and the comparison output module outputs the short-circuit fault signal when the first comparison unit outputs the first target level signal and the second comparison unit outputs the second target level signal.

[0007] In some embodiments, the first comparison unit comprises a comparator U1A and a diode D1; the inverting input terminal of the comparator U1A is connected with the subtraction operation module, the output terminal of the comparator U1A is connected with the anode of the diode D1, the cathode of the diode D1 is connected with the second comparison unit, the non-inverting input terminal of the comparator U1A is configured to receive the first reference voltage, and the cathode of the diode D1 is configured to output the first target level signal.

[0008] In some embodiments, the second comparison unit comprises a comparator U1B and a diode D2; the non-inverting input terminal of the comparator U1B is connected with the subtraction operation module, the output terminal of the comparator U1B is connected with the anode of the diode D2, the cathode of the diode D2 is connected with the first comparison unit, the inverting input terminal of the comparator U1B is configured to receive the second reference voltage, and the cathode of the diode D2 is configured to output the second target level signal.

[0009] In some embodiments, the subtraction operation module comprises an amplifier U2A, a resistor R1, a resistor R3, a resistor R4, and a resistor R5; the first terminal of the resistor R3 is connected with the main circuit, the first terminal of the resistor R4 is connected with the main circuit, the second terminal of the resistor R3 is connected with the inverting input terminal of the amplifier U2A and the first terminal of the resistor R1, the second terminal of the resistor R4 is connected with the non-inverting input terminal of the amplifier U2A and the first terminal of the resistor R5, the second terminal of the resistor R5 is grounded, the output terminal of the amplifier U2A is connected with the second terminal of the resistor R1 and the comparison output module, and the first terminal of the resistor R3 is configured to receive the output voltage of the main circuit and the first terminal of the resistor R4 is configured to receive the input voltage of the main circuit.

[0010] In some embodiments, the short-circuit protection circuit further comprises a voltage generation module; the voltage generation module is connected with the comparison output module; and the voltage generation module is configured to generate the first reference voltage and the second reference voltage.

[0011] In some embodiments, the voltage generation module comprises an amplifier U2B, a resistor R9, a resistor R11, a resistor R12, a resistor R13; a first end of the resistor R11 is connected with a power supply, a second end of the resistor R11 is connected with a first end of the resistor R12, a first end of the resistor R13 and the comparison output module respectively, a second end of the resistor R12 is connected with a first end of the resistor R9 and an inverting input terminal of the amplifier U2B, a second end of the resistor R13 and a non-inverting input terminal of the amplifier U2B are grounded, an output terminal of the amplifier U2B is connected with a second end of the resistor R9 and the comparison output module, the second end of the resistor R11 is used for outputting the second reference voltage, and the output terminal of the amplifier U2B is used for outputting the first reference voltage.

[0012] In some embodiments, the short-circuit protection circuit further comprises a protection module; the protection module is connected with the comparison output module; the protection module is used for outputting a target enable signal based on the short-circuit fault signal to make a control chip in the main circuit stop working based on the target enable signal when the short-circuit fault signal is received.

[0013] In some embodiments, the protection module comprises a resistor R6, a resistor R7, a resistor R8, a resistor R10, a voltage stabilizing diode DZ1 and a switch tube Q1; a first end of the resistor R7 is connected with the comparison output module, a second end of the resistor R7 is connected with a first end of the resistor R10, a negative electrode of the voltage stabilizing diode DZ1 and a control terminal of the switch tube Q1 respectively, a first end of the switch tube Q1 is connected with a second end of the resistor R6 and a first end of the resistor R8 respectively, a first end of the resistor R6 is connected with a power supply, a second end of the resistor R10, a positive electrode of the voltage stabilizing diode DZ1, a second end of the switch tube Q1 and a second end of the resistor R8 are grounded, and the first end of the switch tube Q1 is used for outputting the target enable signal.

[0014] In a second aspect, the embodiments of the present application provide a storage power supply, which comprises the short-circuit protection circuit as described above.

[0015] The short-circuit protection circuit and the energy storage power supply are different from the prior art. The short-circuit protection circuit is applied to a main circuit. The input voltage of the main circuit is different from the output voltage of the main circuit when the main circuit is in normal operation. The short-circuit protection circuit comprises a subtraction operation module and a comparison output module. The input end of the subtraction operation module is connected with the input end and the output end of the main circuit respectively. The output end of the subtraction operation module is connected with the comparison output module. The comparison output module is further connected with a first reference voltage and a second reference voltage respectively. The first reference voltage is a negative voltage, and the second reference voltage is a positive voltage. The subtraction operation module is used for receiving the input voltage of the main circuit and the output voltage of the main circuit, calculating the difference between the input voltage and the output voltage to output a target voltage, and outputting a short-circuit fault signal when the target voltage is within the range of the first reference voltage to the second reference voltage. The input voltage and the output voltage of the main circuit are obtained by the subtraction operation module, the difference is calculated to output the target voltage, and the comparison output module is judged according to the set positive and negative reference voltage range. Under normal circumstances, the target voltage will not be in this specific interval, and once the main circuit is short-circuited, the output voltage will quickly approach the input voltage, so that the target voltage falls into the specified interval, and then the short-circuit fault signal is accurately output. This voltage difference comparison method can accurately identify the short-circuit condition, effectively reduce the misjudgment, and ensure that the main circuit can be stably operated without being disturbed by the false protection action. BRIEF DESCRIPTION OF DRAWINGS

[0016] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are schematic and not intended to be limiting of the embodiments, and in which like reference numerals refer to like elements in the various figures. The figures in the drawings are not necessarily to scale, with emphasis being placed on illustrating the principles of the embodiments.

[0017] Figure 1 is a structural block diagram of a short-circuit protection circuit provided by an embodiment of the application;

[0018] Figure 2 is a structural block diagram of a comparison output module provided by an embodiment of the application;

[0019] Figure 3 is a structural block diagram of another short-circuit protection circuit provided by an embodiment of the application;

[0020] Figure 4 is a circuit structure schematic diagram of a short-circuit protection circuit provided by an embodiment of the application. DETAILED DESCRIPTION

[0021] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for clear and detailed description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0022] The technical features involved in the various embodiments of the present application described below can be combined with each other without conflict and can be combined with each other.

[0023] When an element is described as "connected to" another element, it can be directly connected to the other element, or one or more intermediate elements can be present therebetween.

[0024] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually a class, not limited to the number of objects, for example, the first object can be one or more.

[0025] Please refer to Figure 1 , Figure 1 is a structural block diagram of a short-circuit protection circuit 100 provided by the embodiments of the present application.

[0026] The embodiments of the present application provide a short-circuit protection circuit 100, which is applied to a main circuit 200, wherein the input voltage of the main circuit 200 is different from the output voltage when the main circuit 200 is normally working. The short-circuit protection circuit 100 comprises a subtraction operation module 11 and a comparison output module 12. The input end of the subtraction operation module 11 is connected with the input end and the output end of the main circuit 200 respectively, and the output end of the subtraction operation module 11 is connected with the comparison output module 12. The comparison output module 12 is also connected with a first reference voltage and a second reference voltage respectively, wherein the first reference voltage is a negative voltage and the second reference voltage is a positive voltage.

[0027] Specifically, the subtraction operation module 11 is used for receiving the input voltage of the main circuit 200 and the output voltage of the main circuit 200, and calculating the difference between the input voltage and the output voltage to output a target voltage. The comparison output module 12 is used for outputting a short-circuit fault signal when the target voltage is within the range of the first reference voltage to the second reference voltage.

[0028] The short-circuit fault signal is an indicating signal output by the comparison output module 12, which indicates that a short-circuit fault occurs in the main circuit 200. It can be an electrical signal with a specific level (such as high or low), or a specific pulse signal, etc., depending on the circuit design of the comparison output module 12 and the requirements of the subsequent circuit receiving the signal for signal type. The function of this signal is to inform the relevant control circuit or monitoring system that the main circuit 200 has a short-circuit fault, so as to take appropriate protective measures, such as cutting off the power supply of the main circuit, issuing an alarm, etc.

[0029] In actual application, the input voltage and the output voltage of the main circuit 200 are different when it is working normally, that is, there is a certain voltage difference.

[0030] Firstly, the input end of the subtraction operation module 11 is connected to the input end and the output end of the main circuit 200, so that it can obtain the input voltage value and the output voltage value of the main circuit 200 in real time. The subtraction operation module 11 uses its internal circuit structure (such as a subtraction operation circuit composed of operational amplifiers and other elements) to perform subtraction operation on the obtained input voltage and output voltage, calculates the difference between the two, obtains the target voltage, and outputs the target voltage to the comparison output module 12.

[0031] Then, after receiving the target voltage output from the subtraction operation module 11, the comparison output module 12 is also connected to the first reference voltage (negative voltage) and the second reference voltage (positive voltage). In the normal working state, the difference between the input voltage and the output voltage of the main circuit 200 makes the target voltage calculated by the subtraction operation module 11 outside the range of the first reference voltage to the second reference voltage. For example, the target voltage may be a large positive or negative value in normal times, depending on the specific voltage characteristics and design of the main circuit 200.

[0032] However, when the main circuit 200 has a short-circuit fault, its output voltage will tend to approach the input voltage, and the difference between the two will decrease sharply. Once the target voltage calculated from this difference enters the range of the first reference voltage to the second reference voltage, the comparison output module 12 will detect this situation, and according to the judgment of its internal logic circuit, output a short-circuit fault signal to prompt that the main circuit 200 has a short-circuit fault, triggering the subsequent corresponding protection action.

[0033] Please refer to Figure 2 , Figure 2 is a structural block diagram of the comparison output module 12 provided by the embodiment of the application.

[0034] In some embodiments, the comparison output module 12 comprises a first comparison unit 121 and a second comparison unit 122. The first comparison unit 121 is connected to the second comparison unit 122, and is also connected to the subtraction operation module 11. The second comparison unit 122 is also connected to the subtraction operation module 11.

[0035] Specifically, the first comparison unit 121 is configured to output a first target level signal when the target voltage is greater than the first reference voltage. The second comparison unit 122 is configured to output a second target level signal when the target voltage is less than the second reference voltage. When the first comparison unit 121 outputs the first target level signal and the second comparison unit 122 outputs the second target level signal, the comparison output module 12 outputs a short-circuit fault signal.

[0036] The first target level signal is a level state signal output by the first comparison unit 121, and its specific level value (such as high or low) depends on the circuit design of the first comparison unit 121 and the comparison logic used. When the target voltage is greater than the first reference voltage, the first comparison unit 121 will output the first target level signal.

[0037] The second target level signal is also a level state signal output by the second comparison unit 122. When the target voltage is less than the second reference voltage, the second comparison unit 122 will output the signal, and its level value (high or low, etc.) is also determined by its own circuit design and comparison logic. The second target level signal is also an intermediate link signal for short-circuit fault judgment, and plays a role in the overall judgment mechanism.

[0038] In actual application, the first comparison unit 121 receives the target voltage output by the subtraction operation module 11, and compares the received target voltage with the first reference voltage (negative voltage). When the target voltage is greater than the first reference voltage, the first comparison unit 121 will output the first target level signal.

[0039] The second comparison unit 122 also receives the target voltage output by the subtraction operation module 11, and compares the target voltage with the second reference voltage. Once the target voltage is less than the second reference voltage, the second comparison unit 122 will output the second target level signal.

[0040] The whole comparison output module 12 needs to output the short-circuit fault signal, and needs to meet two conditions that the first comparison unit 121 outputs the first target level signal and the second comparison unit 122 outputs the second target level signal. That is, only when the target voltage is greater than the first reference voltage and less than the second reference voltage (that is, within the range of the first reference voltage to the second reference voltage), it means that the voltage condition that meets the short-circuit fault judgment occurs. At this time, based on the internal logic circuit of the whole comparison output module 12, the short-circuit fault signal is outputted, so as to indicate to the outside that the short-circuit fault occurs in the main circuit, so as to trigger the corresponding protection action or notify the related monitoring system.

[0041] Please refer to Figure 3 , Figure 3 is another structural block diagram of a short-circuit protection circuit 100 provided by the embodiment of the application.

[0042] In some embodiments, the short-circuit protection circuit 100 further comprises a voltage generation module 13. Wherein, the voltage generation module 13 is connected with the comparison output module 12. Specifically, the voltage generation module 13 is used to generate the first reference voltage and the second reference voltage.

[0043] In some embodiments, the short-circuit protection circuit 100 further comprises a protection module 14. Wherein, the protection module 14 is connected with the comparison output module 12. Specifically, the protection module 14 is used to output a target enable signal based on the short-circuit fault signal when receiving the short-circuit fault signal, so as to make the control chip in the main circuit 200 stop working based on the target enable signal.

[0044] Wherein, the target enable signal is a signal outputted by the protection module 14, which is used to control the working state of the control chip in the main circuit 200. It can be a level signal (such as high level or low level) or a pulse signal and the like, and the specific signal form and parameters depend on the circuit design of the protection module 14 and the requirements of the control chip in the main circuit 200 for the enable signal. The main function of the target enable signal is to act as an instruction to inform the control chip in the main circuit 200 to stop working, so as to avoid further damage caused by the short-circuit fault, and to play a role in protecting the circuit.

[0045] Please refer to Figure 4 , Figure 4 is a circuit structure schematic diagram of a short-circuit protection circuit 100 provided by the embodiment of the application.

[0046] In some embodiments, the first comparison unit 121 comprises a comparator U1A and a diode D1. Wherein, the inverting input terminal of the comparator U1A is connected with the subtraction module 11, the output terminal of the comparator U1A is connected with the anode of the diode D1, the cathode of the diode D1 is connected with the second comparison unit 122, the non-inverting input terminal of the comparator U1A is used for receiving the first reference voltage, and the cathode of the diode D1 is used for outputting the first target level signal.

[0047] In some embodiments, the second comparison unit 122 comprises a comparator U1B and a diode D2. Wherein, the non-inverting input terminal of the comparator U1B is connected with the subtraction module 11, the output terminal of the comparator U1B is connected with the anode of the diode D2, the cathode of the diode D2 is connected with the first comparison unit 121, the inverting input terminal of the comparator U1B is used for receiving the second reference voltage, and the cathode of the diode D2 is used for outputting the second target level signal.

[0048] In some embodiments, the subtraction module 11 comprises an amplifier U2A, a resistor R1, a resistor R3, a resistor R4, a resistor R5. Wherein, the first terminal of the resistor R3 is connected with the main circuit 200, the first terminal of the resistor R4 is connected with the main circuit 200, the second terminal of the resistor R3 is connected with the inverting input terminal of the amplifier U2A and the first terminal of the resistor R1, the second terminal of the resistor R4 is connected with the non-inverting input terminal of the amplifier U2A and the first terminal of the resistor R5, the second terminal of the resistor R5 is grounded, the output terminal of the amplifier U2A is connected with the second terminal of the resistor R1 and the comparison output module 12, and the first terminal of the resistor R3 is used for receiving the output voltage of the main circuit 200, and the first terminal of the resistor R4 is used for receiving the input voltage of the main circuit 200.

[0049] In some embodiments, the voltage generation module 13 comprises an amplifier U2B, a resistor R9, a resistor R11, a resistor R12, a resistor R13. Wherein, the first terminal of the resistor R11 is connected with the power supply (VCC), the second terminal of the resistor R11 is connected with the first terminal of the resistor R12, the first terminal of the resistor R13 and the comparison output module 12 respectively, the second terminal of the resistor R12 is connected with the first terminal of the resistor R9 and the inverting input terminal of the amplifier U2B, the second terminal of the resistor R13 and the non-inverting input terminal of the amplifier U2B are both grounded, the output terminal of the amplifier U2B is connected with the second terminal of the resistor R9 and the comparison output module 12, the second terminal of the resistor R11 is used for outputting the second reference voltage, and the output terminal of the amplifier U2B is used for outputting the first reference voltage.

[0050] In some embodiments, the protection module 14 includes a resistor R6, a resistor R7, a resistor R8, a resistor R10, a zener diode DZ1 and a switch tube Q1. Among them, the first end of the resistor R7 is connected with the comparison output module 12, the second end of the resistor R7 is connected with the first end of the resistor R10, the negative electrode of the zener diode DZ1 and the control end of the switch tube Q1 respectively, the first end of the switch tube Q1 is connected with the second end of the resistor R6 and the first end of the resistor R8 respectively, the first end of the resistor R6 is connected with the power supply (V_IN), the second end of the resistor R10, the positive electrode of the zener diode DZ1, the second end of the switch tube Q1 and the second end of the resistor R8 are all grounded, and the first end of the switch tube Q1 is used to output the target enable signal.

[0051] Among them, the switch tube Q1 can be a PMOS tube or any other suitable switch tube. Figure 4 Taking the switch tube Q1 as a PMOS tube as an example, the gate of the PMOS tube is the control end of the switch tube Q1, the source of the PMOS tube is the first end of the switch tube Q1, and the drain of the PMOS tube is the second end of the switch tube Q1.

[0052] The following will be described in combination with Figure 4 The working principle of the short circuit protection circuit 100 will be briefly described.

[0053] Firstly, the input voltage (V_IN) and the output voltage (V_OUT) of the main circuit 200 are connected to the non-inverting input end and the inverting input end of the amplifier U2A respectively, and a difference value signal (target voltage) is obtained by subtraction operation.

[0054] At the same time, the amplifier U2B acts as a voltage inverter, and its input end is a voltage level signal +Vref (i.e. the second reference voltage, which is a positive voltage) obtained by voltage division from the power supply VCC. Its size is: VCC*R13 / (R11+R13), wherein VCC is the voltage value of the power supply VCC, R13 is the resistance value of the resistor R13, and R11 is the resistance value of the resistor R11. After passing through the amplifier U2B, a reverse voltage -Vref (i.e. the first reference voltage, which is a negative voltage) is obtained, and its size is: -VCC*R13*R9 / [(R11+R13)*(R9+R12)], wherein VCC is the voltage value of the power supply VCC, R13 is the resistance value of the resistor R13, R11 is the resistance value of the resistor R11, R9 is the resistance value of the resistor R9, and R12 is the resistance value of the resistor R12.

[0055] Then, the comparator U1A and the comparator U1B constitute a window comparator (both are connected to the power supply VCC by pull-up resistors, for example, the comparator U1A is connected to the power supply VCC by the pull-up resistor R2). When the input target voltage is greater than the second reference voltage +Vref, it must be greater than the first reference voltage -Vref, that is, the comparator U1A outputs a low-level signal (the first target level signal), and the comparator U1B outputs a high-level signal pulled up by the power supply VCC, so that the output voltage of the final window comparator is a high-level signal. When the input target voltage is less than the first reference voltage -Vref, it must be less than the second reference voltage +Vref, that is, the comparator U1A outputs a high-level signal pulled up by the power supply VCC, and the comparator U1B outputs a low-level signal (the second target level signal), so that the output voltage of the final window comparator is a high-level signal; when the input target voltage is between the first reference voltage -Vref and the second reference voltage +Vref, the comparator U1A outputs a low-level signal (the first target level signal), and the comparator U1B simultaneously outputs a low-level signal (the second target level signal), at this time, the output of the window comparator (the comparison output module 12) is a low-level signal (the short-circuit fault signal).

[0056] When the main circuit 200 is short-circuited, the difference signal (the target voltage) output by the amplifier U2A is between the first reference voltage -Vref and the second reference voltage +Vref of the window comparator composed of the comparator U1A and the comparator U1B, and the low-level signal (the short-circuit fault signal) output by the window comparator is divided by the resistors R7 and R10, so that a low-level signal is obtained to shut off the input voltage of the main circuit 200 to the external device (for example, the MCU). At the same time, the low-level signal makes the switch tube Q1 (the PMOS tube) conduct, and pulls down the EN signal (the target enable signal) of the control chip in the main circuit 200, so that the control chip is enabled to be turned off.

[0057] In the embodiment of the application, when the main circuit is normally working, there is a difference between the input and output voltages, the subtraction operation module obtains the difference between the two voltages and outputs a target voltage, and the comparison output module judges according to the set positive and negative reference voltage range. Under normal circumstances, the target voltage will not be in this specific interval, and once the main circuit is short-circuited, the output voltage will quickly approach the input voltage, so that the target voltage falls into the specified interval, and then the short-circuit fault signal is accurately output. This voltage difference comparison method can accurately identify the short-circuit condition, effectively reduce the misjudgment, and ensure that the main circuit can be stably operated without being disturbed by the false protection action.

[0058] In addition, when the comparison output module outputs the short-circuit fault signal, the subsequent related protection mechanism can be triggered rapidly, such as linkage control switch to shut down the main circuit or make the control chip stop working, etc. In the moment of short-circuit, the action is taken to block the impact of the abnormal large current on various elements in the main circuit, such as transistors, capacitors, inductors, etc., to avoid the damage of the elements due to overload, greatly prolong the service life of the elements, reduce the maintenance cost and downtime caused by the fault, and maintain the efficient operation of the whole system.

[0059] The embodiment of the present application provides a kind of energy storage power supply, and energy storage power supply includes short-circuit protection circuit 100 as described above.

[0060] The specific structure and working principle of short-circuit protection circuit 100 can refer to the above embodiment, which will not be repeated here.

[0061] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; under the idea of the present application, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes of the different aspects of the present application as described above, for the sake of simplicity, they are not provided in details; although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A short-circuit protection circuit, characterized by comprising: The short-circuit protection circuit is applied to a main circuit, wherein the input voltage of the main circuit is different from the output voltage when the main circuit is in normal operation; The short-circuit protection circuit comprises a subtraction operation module and a comparison output module; The input end of the subtraction operation module is connected with the input end and the output end of the main circuit respectively, the output end of the subtraction operation module is connected with the comparison output module, and the comparison output module is further connected with a first reference voltage and a second reference voltage respectively, wherein the first reference voltage is a negative voltage and the second reference voltage is a positive voltage; The subtraction operation module is used for receiving the input voltage of the main circuit and the output voltage of the main circuit, and calculating the difference between the input voltage and the output voltage to output a target voltage; The comparison output module is used for outputting a short-circuit fault signal when the target voltage is within the range of the first reference voltage to the second reference voltage.

2. The short circuit protection circuit according to claim 1, characterized in that The comparison output module comprises a first comparison unit and a second comparison unit; The first comparison unit is connected with the second comparison unit, the first comparison unit is further connected with the subtraction operation module, and the second comparison unit is further connected with the subtraction operation module; The first comparison unit is used for outputting a first target level signal when the target voltage is greater than the first reference voltage; The second comparison unit is used for outputting a second target level signal when the target voltage is less than the second reference voltage; When the first comparison unit outputs the first target level signal and the second comparison unit outputs the second target level signal, the comparison output module outputs the short-circuit fault signal.

3. The short circuit protection circuit of claim 2, wherein The first comparison unit comprises a comparator U1A and a diode D1; The non-inverting input end of the comparator U1A is connected with the subtraction operation module, the output end of the comparator U1A is connected with the positive electrode of the diode D1, the negative electrode of the diode D1 is connected with the second comparison unit, the inverting input end of the comparator U1A is used for receiving the first reference voltage, and the negative electrode of the diode D1 is used for outputting the first target level signal.

4. The short circuit protection circuit of claim 2, wherein The second comparison unit comprises a comparator U1B and a diode D2; The inverting input end of the comparator U1B is connected with the subtraction operation module, the output end of the comparator U1B is connected with the positive electrode of the diode D2, the negative electrode of the diode D2 is connected with the first comparison unit, the non-inverting input end of the comparator U1B is used for receiving the second reference voltage, and the negative electrode of the diode D2 is used for outputting the second target level signal.

5. The short circuit protection circuit of claim 1, wherein The subtraction operation module comprises an amplifier U2A, a resistor R1, a resistor R3, a resistor R4 and a resistor R5. The first end of the resistor R3 is connected with the main circuit, the first end of the resistor R4 is connected with the main circuit, the second end of the resistor R3 is connected with the inverting input terminal of the amplifier U2A and the first end of the resistor R1, the second end of the resistor R4 is connected with the non-inverting input terminal of the amplifier U2A and the first end of the resistor R5, the second end of the resistor R5 is grounded, the output terminal of the amplifier U2A is connected with the second end of the resistor R1 and the comparison output module, the first end of the resistor R3 is used for receiving the output voltage of the main circuit, and the first end of the resistor R4 is used for receiving the input voltage of the main circuit.

6. The short circuit protection circuit of claim 1, wherein The short-circuit protection circuit further comprises a voltage generation module; The voltage generation module is connected with the comparison output module; The voltage generation module is used for generating the first reference voltage and the second reference voltage.

7. The short circuit protection circuit of claim 6, wherein The voltage generation module comprises an amplifier U2B, a resistor R9, a resistor R11, a resistor R12 and a resistor R13. The first end of the resistor R11 is connected with a power supply, the second end of the resistor R11 is connected with the first end of the resistor R12, the first end of the resistor R13 and the comparison output module respectively, the second end of the resistor R12 is connected with the first end of the resistor R9 and the inverting input terminal of the amplifier U2B, the second end of the resistor R13 and the non-inverting input terminal of the amplifier U2B are both grounded, the output terminal of the amplifier U2B is connected with the second end of the resistor R9 and the comparison output module, the second end of the resistor R11 is used for outputting the second reference voltage, and the output terminal of the amplifier U2B is used for outputting the first reference voltage.

8. The short-circuit protection circuit according to any one of claims 1 to 7, characterized in that The short-circuit protection circuit further comprises a protection module; The protection module is connected with the comparison output module; The protection module is used for, when the short-circuit fault signal is received, outputting a target enable signal based on the short-circuit fault signal, so that a control chip in the main circuit stops working based on the target enable signal.

9. The short circuit protection circuit of claim 8, wherein, The protection module comprises a resistor R6, a resistor R7, a resistor R8, a resistor R10, a voltage stabilizing diode DZ1 and a switch tube Q1. The first end of the resistor R7 is connected with the comparison output module, the second end of the resistor R7 is connected with the first end of the resistor R10, the negative electrode of the voltage stabilizing diode DZ1 and the control end of the switch tube Q1 respectively, the first end of the switch tube Q1 is connected with the second end of the resistor R6 and the first end of the resistor R8 respectively, the first end of the resistor R6 is connected with a power supply, the second end of the resistor R10, the positive electrode of the voltage stabilizing diode DZ1, the second end of the switch tube Q1 and the second end of the resistor R8 are all grounded, and the first end of the switch tube Q1 is used for outputting the target enable signal.

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

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