Overcurrent protection circuit and energy storage power supply

Abstract

The utility model provides an overcurrent protection circuit and an energy storage power supply. The overcurrent protection circuit comprises a detection module, a comparison module and a protection module, the detection module is connected with a battery sampling resistor in the main circuit, the detection module is also connected with the comparison module, the comparison module is also connected with the protection module, and the protection module is also connected with a control end of a driving switch in the main circuit; the detection module is used for collecting a current signal of a battery sampling resistor and converting the current signal into a voltage signal; the comparison module is used for outputting a first level signal when the voltage signal 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 protection module is used for outputting a first control signal when receiving the first level signal, so that the driving switch is turned off, and the parallel package input port in the main circuit is turned off. According to the invention, the possibility of damage to the battery pack and other circuit elements caused by overcurrent can be reduced, and the stability and safety of the circuit are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power electronics, and particularly relates to an overcurrent protection circuit and an energy storage power supply. BACKGROUND

[0002] An inverter is an electronic device that converts direct current into alternating current. In some application scenarios, multiple battery packs may be connected in parallel (parallel connection) to increase the total capacity or improve the reliability of the system. In normal circumstances, the ideal parallel connection state is that the current output by each battery pack should be evenly distributed to ensure stable operation of the entire system. However, due to differences in the production and manufacturing process, the internal resistance, capacity, voltage and other parameters of different battery packs may not be completely consistent. For example, the internal resistance of some battery packs may be slightly larger, while the internal resistance of some other battery packs may be slightly smaller. When connected in parallel, according to Ohm's law, the current tends to flow through the battery packs with smaller internal resistance, resulting in uneven current distribution. In addition, there may be impedance differences in the lines connecting the battery packs and the inverter. If the resistance of some connection lines is larger, the current output by the battery packs connected through the lines will be relatively smaller, while the battery packs connected to the lines with smaller impedance will output larger current, thereby causing uneven current sharing.

[0003] When the current sharing is unbalanced, some battery packs output larger current, and the corresponding parallel connection driving tube needs to bear higher current, which may damage the parallel connection driving tube through mechanisms such as overheating and electrical stress. CONTENT OF THE UTILITY MODEL

[0004] The application embodiment provides an overcurrent protection circuit and an energy storage power supply, which reduces the possibility of damage to battery packs and other circuit elements caused by overcurrent, and improves the stability and safety of the circuit.

[0005] In a first aspect, the application embodiment provides an overcurrent protection circuit, which comprises a detection module, a comparison module and a protection module. The detection module is connected with a battery sampling resistor in a main circuit, the detection module is further connected with the comparison module, the comparison module is further connected with the protection module, and the protection module is further connected with a control end of a driving switch in the main circuit. The detection module is used to collect a current signal of the battery sampling resistor and convert the current signal into a voltage signal. The comparison module is used to output a first level signal when the voltage signal is greater than a first preset voltage or smaller than a second preset voltage. The first preset voltage is greater than the second preset voltage. The protection module is used to output a first control signal when the first level signal is received, so that the driving switch is turned off and the parallel connection input port in the main circuit is disconnected.

[0006] In some embodiments, the protection module comprises a first switch unit, an isolation switch unit, a second switch unit, a third switch unit; the control end of the first switch unit is connected with the comparison module, the first switch unit is also connected with the isolation switch unit, the control end of the second switch unit is connected with the isolation switch unit, the control end of the third switch unit is connected with the second switch unit, and the control end of the third switch unit is also connected with the control end of the drive switch; the first switch unit is used to turn off when receiving the first level signal; the isolation switch unit is used to turn off when the first switch unit turns off; the second switch unit is used to turn on when the isolation switch unit turns off; and the third switch unit is used to output the first control signal when the second switch unit turns on.

[0007] In some embodiments, the first switch unit comprises a switch tube Q5, a resistor R11, a resistor R12, a resistor R14, a resistor R20, and a resistor R22; the control end of the switch tube Q5 is connected with the comparison module through the resistor R20, the control end of the switch tube Q5 is also connected with the first end of the resistor R22, the second end of the switch tube Q5 is connected with the second end of the resistor R22 and grounded, the third end of the switch tube Q5 is connected with the first power supply in sequence through the resistor R14, the resistor R12, and the resistor R11, and the isolation switch unit is connected with both ends of the resistor R12.

[0008] In some embodiments, the isolation switch unit comprises an optical coupler U3 and a resistor R7; the first end of the optical coupler U3 and the second end of the optical coupler U3 are connected with the first switch unit respectively, the third end of the optical coupler U3 is grounded, the fourth end of the optical coupler U3 is connected with the first power supply through the resistor R7, and the fourth end of the optical coupler U3 is also connected with the control end of the second switch unit.

[0009] In some embodiments, the second switch unit comprises a switch tube Q3, a resistor R4, and a resistor R9; the control end of the switch tube Q3 is connected with the isolation switch unit, the second end of the switch tube Q3 is grounded, the third end of the switch tube Q3 is connected with the second end of the resistor R4 and the first end of the resistor R9 respectively, the first end of the resistor R4 is connected with the first power supply, and the second end of the resistor R9 is connected with the control end of the third switch unit.

[0010] In some embodiments, the third switch unit comprises a switch tube Q2, a switch tube Q4 and a resistor R8; a control end of the switch tube Q2 and a control end of the switch tube Q4 are connected with the second switch unit; a third end of the switch tube Q2 is connected with a first power supply; a second end of the switch tube Q2 is connected with a second end of the switch tube Q4 through the resistor R8; a third end of the switch tube Q4 is grounded; and the second end of the switch tube Q4 is further connected with a control end of the drive switch.

[0011] In some embodiments, the comparison module comprises a first comparison unit and a second comparison unit; the first comparison unit and the second comparison unit are respectively connected with the detection module, and the first comparison unit and the second comparison unit are respectively connected with the protection module; the first comparison unit is configured to output the first level signal when the voltage signal is greater than the first preset voltage; and the second comparison unit is configured to output the first level signal when the voltage signal is less than the second preset voltage.

[0012] In some embodiments, the first comparison unit comprises a comparator U2A, a resistor R15 and a resistor R23; a non-inverting input end of the comparator U2A is connected with the detection module; a same-phase input end of the comparator U2A is connected with a second power supply through the resistor R15; the same-phase input end of the comparator U2A is further grounded through the resistor R23; and an output end of the comparator U2A is connected with the protection module.

[0013] In some embodiments, the second comparison unit comprises a comparator U2B, a resistor R24 and a resistor R25; a same-phase input end of the comparator U2B is connected with the detection module; a non-inverting input end of the comparator U2B is connected with a second power supply through the resistor R24; the non-inverting input end of the comparator U2B is further grounded through the resistor R25; and an output end of the comparator U2B is connected with the protection module.

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

[0015] Different from the related technical solutions, the application embodiment provides a kind of overcurrent protection circuit and energy storage power supply, the overcurrent protection circuit includes detection module, comparison module, protection module;The detection module is connected with the battery sampling resistor in main circuit, the detection module is also connected with the comparison module, the comparison module is also connected with the protection module, the protection module is also connected with the control end of the driving switch in the main circuit;The detection module is used to collect the current signal of the battery sampling resistor, and the current signal is converted into voltage signal;The comparison module is used to output first level signal when the voltage signal is greater than first preset voltage or less than second preset voltage;Wherein, the first preset voltage is greater than second preset voltage;The protection module is used to output first control signal when receiving the first level signal, to make the driving switch be closed, so that the parallel package input port in main circuit is disconnected.In the application embodiment, once comparison module detects voltage signal anomaly, i.e. output first level signal.This signal is rapidly transmitted to protection module, and triggers protection action.Protection module receives first level signal, and immediately outputs first control signal, so that driving switch is closed, to disconnect the parallel package input port in main circuit, i.e. disconnect battery package.The whole process responds quickly, can cut off battery package in the very short time after overcurrent occurs, effectively reduces the possibility of damage caused by overcurrent to battery package and other circuit elements, improves the stability and safety of circuit. 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 of the drawings in which: the figures are not to scale.

[0017] Figure 1 is the circuit structure schematic diagram of main circuit;

[0018] Figure 2 is the structure block diagram of overcurrent protection circuit provided by the application embodiment;

[0019] Figure 3 is the structure block diagram of comparison module provided by the application embodiment;

[0020] Figure 4 is the structure block diagram of protection module provided by the application embodiment;

[0021] Figure 5 is the circuit structure schematic diagram of detection module provided by the application embodiment;

[0022] Figure 6 is the circuit structure schematic diagram of comparison module provided by the application embodiment;

[0023] Figure 7 is a circuit structure schematic diagram of the protection module provided by the embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and in detail below with reference to the drawings 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 should not be used to limit the present application.

[0025] The technical features involved in the various embodiments of the present application described below do not conflict with each other and can be combined with each other.

[0026] 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.

[0027] 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 exchanged 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 generally a class, and do not limit the number of objects, for example, the first object can be one or more.

[0028] Please refer to Figure 1 , Figure 1 is a circuit structure schematic diagram of the main circuit 200.

[0029] As shown in Figure 1 , the main circuit 200 includes a parallel input port CN1, a fuse F1, a fuse F2, a driving switch Q1, a resistor R61, a resistor R62, a battery sampling resistor R63, a resistor R64, a resistor R65, a resistor R66, a capacitor C1, and a capacitor C2.

[0030] The positive terminal of the parallel input port CN1 is connected to the second end of the drive switch Q1 through a fuse F1 and a fuse F2 connected in parallel. The third end of the drive switch Q1 is connected to the BAT+ side and grounded. The second end of the drive switch Q1 is also connected to the BAT+ side through a resistor R65 and a capacitor C1. The control end of the drive switch Q1 is connected to the overcurrent protection circuit 100 provided in an embodiment of the present application through a resistor R64, and the control end of the drive switch Q1 is also grounded through a resistor R66. The negative terminal of the parallel input port CN1 is grounded through a battery sampling resistor R63. Capacitor C2 is connected in parallel with the battery sampling resistor R63. The first end of the battery sampling resistor R63 is connected to the overcurrent protection circuit 100 through a resistor R61, and the second end of the battery sampling resistor R63 is connected to the overcurrent protection circuit 100 through a resistor R62.

[0031] Among them, the parallel pack input port CN1 is the parallel terminal, and the battery pack is connected to the BAT+ side through this terminal.

[0032] The battery sampling resistor R63 is a current sensing resistor.

[0033] The driving switch Q1 is an NMOS tube, the gate of the NMOS tube is the control terminal of the driving switch Q1 , the drain of the NMOS tube is the second terminal of the driving switch Q1 , and the source of the NMOS tube is the third terminal of the driving switch Q1 .

[0034] See also Figure 2 , Figure 2 1 is a structural block diagram of the overcurrent protection circuit 100 provided in an embodiment of the present application.

[0035] An embodiment of the present application provides an overcurrent protection circuit 100 , which includes a detection module 10 , a comparison module 20 , and a protection module 30 .

[0036] The detection module 10 is connected to the battery sampling resistor R63 in the main circuit 200 , and is also connected to the comparison module 20 . The comparison module 20 is also connected to the protection module 30 , and the protection module 30 is also connected to the control end of the drive switch Q1 in the main circuit 200 .

[0037] Specifically, the detection module 10 is configured to collect the current signal from the battery sampling resistor R63 and convert it into a voltage signal. The comparison module 20 is configured to output a first level signal when the voltage signal 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 protection module 30 is configured to output a first control signal upon receiving the first level signal to turn off the drive switch Q1, thereby disconnecting the parallel packet input port CN1 in the main circuit 200.

[0038] When the current of the battery pack is normal (i.e. not overcurrent), the voltage signal is between the first preset voltage and the second preset voltage. In practical applications, the first preset voltage is a value greater than the reference voltage (the reference voltage can be 1.65V), and the second preset voltage is a value less than the reference voltage.

[0039] The first level signal is a signal output by the comparison module 20. When the converted voltage signal of the detection module 10 is greater than the first preset voltage or less than the second preset voltage, the comparison module 20 outputs the first level signal. The first level signal is usually a digital level signal, such as a high level or a low level. In some embodiments, the first level signal is a low level signal.

[0040] The first control signal is a signal output by the protection module 30 after receiving the first level signal, for controlling the turn-off of the driving switch Q1 in the main circuit 200. In some embodiments, the first control signal is a low level signal.

[0041] Please see Figure 1 and Figure 2 In practical applications, the battery pack (not shown in the figure) is connected to the parallel pack input port CN1 in the main circuit 200. When the battery pack is successfully connected in parallel, the machine works normally, and at this time the driving switch Q1 is turned on. The battery pack after being connected in parallel can be charged or discharged.

[0042] At this time, the detection module 10 in the overcurrent protection circuit 100 collects the voltage between the battery sampling resistor R63 in real time to obtain the voltage signal. The comparison module 20 compares the voltage signal with the first preset voltage and the second preset voltage. When the voltage of the voltage signal is greater than the first preset voltage, or the voltage of the voltage signal is less than the second preset voltage, the comparison module 20 outputs the first level signal (for example, a low level signal). At this time, the protection module 30 outputs the first control signal according to the received first level signal, and the first control signal can control the turn-off of the driving switch Q1, so that the parallel pack input port CN1 in the main circuit 200 is disconnected, thereby disconnecting the battery pack.

[0043] On the contrary, if the voltage of the voltage signal is less than or equal to the first preset voltage, and the voltage of the voltage signal is greater than or equal to the second preset voltage, the comparison module 20 outputs the second level signal (for example, a high level signal). At this time, the protection module 30 outputs the second control signal according to the received second level signal, and the second control signal can control the turn-on of the driving switch Q1, so that the parallel pack input port CN1 in the main circuit 200 is connected. At this time, the normal connection of the battery pack to the main circuit 200 is realized.

[0044] Because, the existence of the overcurrent protection circuit 100, when the battery pack is connected through the parallel pack input port CN1, if the overcurrent occurs when the battery pack charges and discharges, the control end of the driving switch Q1 of the main circuit 200 (namely, Ext2_DrvG) will be pulled down, at this time, the driving switch Q1 is immediately disconnected, and the parallel pack is disconnected, and the overcurrent protection is rapidly realized.

[0045] Please refer to Figure 3 , Figure 3 is a structural block diagram of the comparison module 20 provided by the embodiment of the application.

[0046] In some embodiments, the comparison module 20 includes a first comparison unit 21 and a second comparison unit 22.

[0047] Among them, the first comparison unit 21 and the second comparison unit 22 are respectively connected with the detection module 10, and the first comparison unit 21 and the second comparison unit 22 are also respectively connected with the protection module 30.

[0048] Specifically, the first comparison unit 21 is configured to output a first level signal (for example, a low level signal) when the voltage signal is greater than a first preset voltage. The second comparison unit 22 is configured to output the first level signal when the voltage signal is less than a second preset voltage.

[0049] In addition, the first comparison unit 21 is configured to output a second level signal (for example, a high level signal) when the voltage signal is less than or equal to the first preset voltage. The second comparison unit 22 is configured to output the second level signal when the voltage signal is greater than or equal to the second preset voltage.

[0050] It should be noted that when one of the first comparison unit 21 and the second comparison unit 22 outputs the first level signal, the output of the comparison module 20 is the first level signal. That is, only when the first comparison unit 21 outputs the second level signal and the second comparison unit 22 outputs the second level signal, the output of the comparison module 20 is the second level signal.

[0051] Please refer to Figure 4 , Figure 4 is a structural block diagram of the protection module 30 provided by the embodiment of the application.

[0052] In some embodiments, the protection module 30 includes a first switch unit 31, an isolation switch unit 32, a second switch unit 33, and a third switch unit 34.

[0053] Among them, the control end of the first switch unit 31 is connected with the comparison module 20, the first switch unit 31 is also connected with the isolation switch unit 32, the control end of the isolation switch unit 32 is also connected with the second switch unit 33, the control end of the second switch unit 33 is also connected with the third switch unit 34, and the control end of the third switch unit 34 is also connected with the control end of the driving switch Q1.

[0054] Specifically, the first switch unit 31 is configured to be turned off when the first level signal is received; the isolation switch unit 32 is configured to be turned off when the first switch unit 31 is turned off; the second switch unit 33 is configured to be turned on when the isolation switch unit 32 is turned off; and the third switch unit 34 is configured to output the first control signal when the second switch unit 33 is turned on.

[0055] Referring to Figure 5 , Figure 5 is a circuit structure schematic diagram of the detection module 10 provided by the embodiment of the present application.

[0056] In some embodiments, the detection module 10 includes a resistor R13, a resistor R16, a resistor R17, a resistor R19, a resistor R21, a capacitor C5, a capacitor C6, and an operational amplifier U1B.

[0057] The non-inverting input terminal of the operational amplifier U1B is connected to the first end of the battery sampling resistor R63 in the main circuit 200 through the resistor R16, and is also connected to the third power supply (for example, +1.65V) through the resistor R13, and the capacitor C5 is connected in parallel with the resistor R13. The inverting input terminal of the operational amplifier U1B is connected to the second end of the battery sampling resistor R63 through the resistor R19, and is also connected to the output terminal of the operational amplifier U1B through the resistor R21, and the capacitor C6 is connected in parallel with the resistor R21. The output terminal of the operational amplifier U1B is also connected to the comparison module 20 through the resistor R17.

[0058] Referring to Figure 6 , Figure 6 is a circuit structure schematic diagram of the comparison module 20 provided by the embodiment of the present application.

[0059] In some embodiments, the first comparison unit 21 includes a comparator U2A, a resistor R15, and a resistor R23. The inverting input terminal of the comparator U2A is connected to the detection module 10, the non-inverting input terminal of the comparator U2A is connected to the second power supply through the resistor R15, the non-inverting input terminal of the comparator U2A is also grounded through the resistor R23, and the output terminal of the comparator U2A is connected to the protection module 30.

[0060] In some embodiments, the second comparison unit 22 includes a comparator U2B, a resistor R24, and a resistor R25. The non-inverting input terminal of the comparator U2B is connected to the detection module 10, the inverting input terminal of the comparator U2B is connected to the second power supply through the resistor R24, the inverting input terminal of the comparator U2B is also grounded through the resistor R25, and the output terminal of the comparator U2B is connected to the protection module 30.

[0061] Referring to Figure 7 ,Figure 7 Fig. 1 is a schematic diagram of a circuit structure of a protection module 30 provided by an embodiment of the present application.

[0062] In some embodiments, the first switch unit 31 comprises a switch tube Q5, a resistor R11, a resistor R12, a resistor R14, a resistor R20, and a resistor R22. The control end of the switch tube Q5 is connected to the comparison module 20 through the resistor R20, and is also connected to the first end of the resistor R22. The second end of the switch tube Q5 is connected to the second end of the resistor R22 and grounded. The third end of the switch tube Q5 is connected to the first power supply in sequence through the resistor R14, the resistor R12, and the resistor R11. The disconnection switch unit 32 is connected to both ends of the resistor R12.

[0063] The switch tube Q5 can be an NPN triode or any other suitable switching device, which is not limited herein. If the switch tube Q5 is an NPN triode, the control end of the switch tube Q5 is the base of the NPN triode, the second end of the switch tube Q5 is the emitter of the NPN triode, and the third end of the switch tube Q5 is the collector of the NPN triode.

[0064] In some embodiments, the disconnection switch unit 32 comprises an optical coupler U3 and a resistor R7. The first end of the optical coupler U3 and the second end of the optical coupler U3 are respectively connected to the first switch unit 31. The third end of the optical coupler U3 is grounded. The fourth end of the optical coupler U3 is connected to the first power supply through the resistor R7, and is also connected to the control end of the second switch unit 33.

[0065] In some embodiments, the second switch unit 33 comprises a switch tube Q3, a resistor R4, and a resistor R9. The control end of the switch tube Q3 is connected to the disconnection switch unit 32. The second end of the switch tube Q3 is grounded. The third end of the switch tube Q3 is respectively connected to the second end of the resistor R4 and the first end of the resistor R9. The first end of the resistor R4 is connected to the first power supply. The second end of the resistor R9 is connected to the control end of the third switch unit 34.

[0066] The switch tube Q3 can be an NPN triode or any other suitable switching device, which is not limited herein. If the switch tube Q3 is an NPN triode, the control end of the switch tube Q3 is the base of the NPN triode, the second end of the switch tube Q3 is the emitter of the NPN triode, and the third end of the switch tube Q3 is the collector of the NPN triode.

[0067] In some embodiments, the third switch unit 34 includes a switch tube Q2, a switch tube Q4, and a resistor R8. The control terminals of the switch tubes Q2 and Q4 are both connected to the second switch unit 33. The third terminal of the switch tube Q2 is connected to the first power supply. The second terminal of the switch tube Q2 is connected to the second terminal of the switch tube Q4 via the resistor R8. The third terminal of the switch tube Q4 is grounded. The second terminal of the switch tube Q4 is also connected to the control terminal of the driving switch Q1.

[0068] The switch Q2 can be an NPN transistor or any other suitable switching device, and is not limited here. If the switch Q2 is an NPN transistor, the control terminal of the switch Q2 is the base of the NPN transistor, the second terminal of the switch Q2 is the emitter of the NPN transistor, and the third terminal of the switch Q2 is the collector of the NPN transistor.

[0069] The switch Q4 can be a PNP transistor or any other suitable switching device, and is not limited here. If the switch Q4 is a PNP transistor, the control terminal of the switch Q4 is the base of the PNP transistor, the second terminal of the switch Q4 is the emitter of the PNP transistor, and the third terminal of the switch Q2 is the collector of the PNP transistor.

[0070] The following combination Figure 1 、 Figure 5 、 Figure 6 、 Figure 7 The working principle of the overcurrent protection circuit 100 is briefly described.

[0071] In actual application, first, the battery pack (not shown) is connected to the parallel input port CN1 in the main circuit 200. When the battery pack is successfully paralleled, the machine works normally and the drive switch Q1 is turned on. The paralleled battery pack can be charged or discharged. Figure 5 As shown, I_EXB2+ and I_EXB2- are the current signals of the battery pack after being packed together, and the voltage signal V1 is obtained after passing through the operational amplifier U1B. Figure 6 As shown, the voltage signal V1 is compared with the first preset voltage V2 and the second preset voltage V3.

[0072] If the battery pack is successfully combined and there is no overcurrent during charging and discharging of the battery pack, that is, the voltage signal V1 is less than or equal to the first preset voltage V2, and the voltage signal V1 is greater than or equal to the second preset voltage V3. Figure 6 Pin 1 in the output is an open drain output (i.e., a second level signal), and the output of the comparator U2B ( Figure 6 Pin 7 in the output is also an open drain output (i.e., the second level signal). At this time, the outputs of the two comparators are pulled high by the pull-up resistor R18, so that the output of point A is the second level signal (high level signal). Figure 7As shown, the output of point A is high, and the point V4 is also high, at this time, the switch tube Q5 is turned on. At this time, the current flows as follows: +12V, R11, R12, R14, Q5, GND. At this time, the optocoupler U3 is turned on, so that the control end (1 pin) of the switch tube Q3 is short-circuited with the second end (2 pin) of the switch tube Q3. Through the third end (3 pin) and the fourth end (4 pin) of the optocoupler U3 connected to the ground GND_ISO2, therefore, the switch tube Q3 cannot be turned on. The first power supply (+12V1) is an isolated power supply, which is driven through the optocoupler U3 isolation. At this time, the current flows as follows: +12V1, R4, R9, the base of the switch tube Q2 and the base of the switch tube Q4, so that the switch tube Q2 is turned on, and the switch tube Q4 cannot be turned on. The current flows as follows: +12V1, Q2, R8, Ext2_DrvG. Therefore, the Ext2_DrvG is high (the second control signal), at this time, the driving switch Q1 on the main circuit is maintained closed, and the battery pack after the battery pack is still normally charged and discharged.

[0073] If the parallel packing is successful, the overcurrent of the battery pack during charging and discharging, that is, the voltage signal V1 is greater than the first preset voltage V2, or the voltage signal V1 is less than the second preset voltage V3. In the first aspect, if the overcurrent is discharged, for example, Figure 6 As shown, the voltage signal V1 is greater than the first preset voltage V2, and the output end (1 pin) of the comparator U2A outputs low (the first level signal). Since the first preset voltage V2 is greater than the second preset voltage V3, the voltage signal V1 is also greater than the second preset voltage V3, and the output end (7 pin) of the comparator U2B is an open drain output (high, the second level signal). At this time, the two comparators finally output low (the first level signal). In the second aspect, if the overcurrent is charged, for example, Figure 6 As shown, the voltage signal V1 is less than the second preset voltage V3, and the output end (7 pin) of the comparator U2B outputs low (the first level signal). Since the first preset voltage V2 is greater than the second preset voltage V3, the voltage signal V1 is also less than the first preset voltage V2, and the output end (1 pin) of the comparator U2A is an open drain output (high, the second level signal). At this time, the two comparators finally output low (the first level signal). As shown, Figure 7 As shown, the output of point A is low, and the point V4 is also low, at this time, the switch tube Q5 cannot be turned on. Therefore, the optocoupler U3 is not turned on. At this time, the current flows as follows: +12V1, R7, the base of the switch tube Q3, so that the switch tube Q3 is turned on. In turn, the switch tube Q2 is not turned on and the switch tube Q4 is turned on. Therefore, the Ext2_DrvG is low (the first control signal), at this time, the driving switch Q1 on the main circuit is turned off, thereby quickly disconnecting the parallel packing input port CN1 in the main circuit 200, disconnecting the battery pack, and protecting the machine from being damaged.

[0074] In the embodiment of the present application, once the comparison module detects the abnormal voltage signal, a first level signal is output. This signal is rapidly transmitted to the protection module to trigger the protection action. After receiving the first level signal, the protection module immediately outputs a first control signal to make the driving switch be turned off, thereby disconnecting the parallel pack input port in the main circuit, that is, disconnecting the battery pack. The whole process responds quickly and can cut off the battery pack in a very short time after the overcurrent occurs, effectively reducing the possibility of damage to the battery pack and other circuit elements caused by overcurrent, and improving the stability and safety of the circuit.

[0075] The embodiment of the present application provides a kind of energy storage power supply, and energy storage power supply includes overcurrent protection circuit 100 as described above.

[0076] Wherein, the structure and principle of overcurrent protection circuit 100 can refer to the foregoing description, and will not be repeated here.

[0077] 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. An overcurrent protection circuit, characterized in that: The overcurrent protection circuit includes a detection module, a comparison module, and a protection module; The detection module is connected to the battery sampling resistor in the main circuit, the detection module is also connected to the comparison module, the comparison module is also connected to the protection module, and the protection module is also connected to the control end of the drive switch in the main circuit; The detection module is used to collect the current signal of the battery sampling resistor and convert the current signal into a voltage signal; The comparison module is configured to output a first level signal when the voltage signal 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 protection module is configured to output a first control signal upon receiving the first level signal, so that the driving switch is turned off, thereby disconnecting the parallel packet input port in the main circuit.

2. The overcurrent protection circuit according to claim 1, characterized in that: The protection module includes a first switch unit, an isolating switch unit, a second switch unit, and a third switch unit; The control end of the first switch unit is connected to the comparison module, the first switch unit is also connected to the isolation switch unit, the isolation switch unit is also connected to the control end of the second switch unit, the second switch unit is also connected to the control end of the third switch unit, and the third switch unit is also connected to the control end of the drive switch; The first switch unit is configured to be turned off upon receiving the first level signal; The isolating switch unit is configured to be turned off when the first switch unit is turned off; The second switch unit is configured to be turned on when the isolation switch unit is turned off; The third switch unit is configured to output the first control signal when the second switch unit is turned on.

3. The overcurrent protection circuit according to claim 2, wherein: The first switch unit includes a switch tube Q5, a resistor R11, a resistor R12, a resistor R14, a resistor R20, and a resistor R22; The control end of the switch tube Q5 is connected to the comparison module through the resistor R20. The control end of the switch tube Q5 is also connected to the first end of the resistor R22. The second end of the switch tube Q5 is connected to the second end of the resistor R22 and is grounded. The third end of the switch tube Q5 is connected to the first power supply through the resistor R14, the resistor R12, and the resistor R11 in sequence. The isolation switch unit is connected to both ends of the resistor R12.

4. The overcurrent protection circuit according to claim 2, wherein: The isolation switch unit includes an optical coupler U3 and a resistor R7; The first end of the optocoupler U3 and the second end of the optocoupler U3 are respectively connected to the first switch unit, the third end of the optocoupler U3 is grounded, the fourth end of the optocoupler U3 is connected to the first power supply through the resistor R7, and the fourth end of the optocoupler U3 is also connected to the control end of the second switch unit.

5. The overcurrent protection circuit according to claim 2, wherein: The second switch unit includes a switch tube Q3, a resistor R4, and a resistor R9; The control end of the switch tube Q3 is connected to the isolation switch unit, the second end of the switch tube Q3 is grounded, and the third end of the switch tube Q3 is respectively connected to the second end of the resistor R4 and the first end of the resistor R9. The first end of the resistor R4 is connected to the first power supply, and the second end of the resistor R9 is connected to the control end of the third switch unit.

6. The overcurrent protection circuit according to claim 2, characterized in that: The third switch unit includes a switch tube Q2, a switch tube Q4, and a resistor R8; The control end of the switch tube Q2 and the control end of the switch tube Q4 are both connected to the second switch unit, the third end of the switch tube Q2 is connected to the first power supply, the second end of the switch tube Q2 is connected to the second end of the switch tube Q4 through the resistor R8, the third end of the switch tube Q4 is grounded, and the second end of the switch tube Q4 is also connected to the control end of the drive switch.

7. The overcurrent protection circuit according to claim 1, wherein: The comparison module includes a first comparison unit and a second comparison unit; The first comparison unit and the second comparison unit are respectively connected to the detection module, and the first comparison unit and the second comparison unit are also respectively connected to the protection module; The first comparison unit is configured to output the first level signal when the voltage signal is greater than the first preset voltage; The second comparison unit is configured to output the first level signal when the voltage signal is less than the second preset voltage.

8. The overcurrent protection circuit according to claim 7, characterized in that: The first comparison unit includes a comparator U2A, a resistor R15, and a resistor R23; The inverting input terminal of the comparator U2A is connected to the detection module, the non-inverting input terminal of the comparator U2A is connected to the second power supply through the resistor R15, the non-inverting input terminal of the comparator U2A is also grounded through the resistor R23, and the output terminal of the comparator U2A is connected to the protection module.

9. The overcurrent protection circuit according to claim 7, characterized in that: The second comparison unit includes a comparator U2B, a resistor R24, and a resistor R25; The non-inverting input terminal of the comparator U2B is connected to the detection module, the inverting input terminal of the comparator U2B is connected to the second power supply through the resistor R24, the inverting input terminal of the comparator U2B is also grounded through the resistor R25, and the output terminal of the comparator U2B is connected to the protection module.

10. An energy storage power supply, characterized in that: The energy storage power supply includes the overcurrent protection circuit according to any one of claims 1 to 9.

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