Undervoltage protection circuit and energy storage power supply

Abstract

The embodiment of the utility model provides an under-voltage protection circuit and an energy storage power supply. The under-voltage protection circuit comprises a switch module, a selection module, a first indication module and a second indication module, the switch module is used for conducting when the battery voltage is larger than a first threshold value and conducting when the battery voltage is smaller than or equal to the first threshold value; the selection module is used for establishing the connection between the positive electrode of the battery and the first indication module and disconnecting the connection between the positive electrode of the battery and the second indication module when the switch module is switched on; when the switch module is cut off, the connection between the positive electrode of the battery and the second indication module is established, and the connection between the positive electrode of the battery and the first indication module is cut off; the first indication module is used for being electrified when being connected with the positive electrode of the battery and sending out a first indication signal; the second indication module is used for obtaining electricity when being connected with the positive electrode of the battery and sending out a second indication signal. By cutting off the connection between the load and the battery in time, the battery is prevented from continuously discharging in an under-voltage state.

Description

Technical Field

[0001] The present application belongs to the field of power electronics technology, and specifically relates to an undervoltage protection circuit and an energy storage power supply. Background Art

[0002] Lead-acid batteries often over-discharge during actual use, especially during discharge. Under conventional discharge conditions, the discharge process of lead-acid batteries is often difficult to accurately control due to the lack of effective control mechanisms.

[0003] However, prolonged, uncontrolled discharge has a profoundly negative impact on lead-acid batteries. From a battery lifespan perspective, excessive discharge gradually destroys the battery's internal chemical structure. This chemical change is irreversible, and each overdischarge damages the battery's lifespan, significantly shortening its overall service life. Furthermore, frequent overdischarge increases the battery's susceptibility to failure, such as a sharp drop in capacity and increased internal resistance. Utility Model Content

[0004] The embodiments of the present application provide an undervoltage protection circuit and an energy storage power supply, which can improve the safety and stability of a battery during discharge.

[0005] In a first aspect, an embodiment of the present application provides an undervoltage protection circuit, comprising a switch module, a selection module, a first indication module, and a second indication module; the switch module is respectively connected to the selection module and the positive electrode of a battery, the selection module is also respectively connected to the positive electrode of the battery, the first indication module, and the second indication module, the first indication module and the second indication module are also respectively connected to the negative electrode of the battery, and the first indication module is connected in parallel with a load; the switch module is configured to be turned on when the battery voltage is greater than a first threshold value, and to be turned off when the battery voltage is less than or equal to the first threshold value; the selection module is configured to establish a connection between the positive electrode of the battery and the first indication module, and to disconnect the positive electrode of the battery from the second indication module, when the switch module is turned on; to establish a connection between the positive electrode of the battery and the second indication module, and to disconnect the positive electrode of the battery from the first indication module, when the switch module is turned off; the first indication module is configured to be powered on and to send a first indication signal when connected to the positive electrode of the battery; the second indication module is configured to be powered on and to send a second indication signal when connected to the positive electrode of the battery.

[0006] In some embodiments, the switch module includes a voltage divider unit and a first switch unit; the first end of the voltage divider unit is connected to the positive pole of the battery, the second end of the voltage divider unit is connected to the control end of the first switch unit, the third end of the first switch unit is connected to the selection module, and the third end of the voltage divider unit and the second end of the first switch unit are both connected to the negative pole of the battery; the voltage divider unit is used to make the voltage of the voltage divider unit greater than a second threshold when the battery voltage is greater than the first threshold; and make the voltage of the voltage divider unit less than or equal to the second threshold when the battery voltage is less than or equal to the first threshold; wherein the second threshold is less than the first threshold; the first switch unit is used to turn on when the voltage of the voltage divider unit is greater than the second threshold, and to turn off when the voltage of the voltage divider unit is less than or equal to the second threshold.

[0007] In some embodiments, the voltage dividing unit includes a resistor R2, a resistor R7, and a resistor R10; the first end of the resistor R2 is connected to the positive electrode of the battery, the second end of the resistor R2 is connected to the first end of the resistor R7, the second end of the resistor R7 is connected to the first end of the resistor R10 and the control end of the first switching unit, and the second end of the resistor R10 is connected to the negative electrode of the battery.

[0008] In some embodiments, the first switching unit includes a voltage regulator tube DZ1, a resistor R6, and a switch tube Q2; the cathode of the voltage regulator tube DZ1 is connected to the second end of the voltage divider unit, the anode of the voltage regulator tube DZ1 is connected to the first end of the resistor R6 and the control end of the switch tube Q2, the third end of the switch tube Q2 is connected to the selection module, and the second end of the resistor R6 and the second end of the switch tube Q2 are both connected to the negative electrode of the battery.

[0009] In some embodiments, the selection module includes a relay RLY1, a resistor R1, and a voltage regulator tube TVS1; the relay RLY1 includes a coil, a common contact, a normally closed contact, and a normally open contact; the second end of the coil is connected to the positive pole of the battery through the resistor R1, and the second end of the coil is also connected to the first end of the voltage regulator tube TVS1, the first end of the coil is connected to the second end of the voltage regulator tube TVS1 and the switch module, the common contact is connected to the positive pole of the battery, the normally open contact is connected to the first indication module, and the normally closed contact is connected to the second indication module.

[0010] In some embodiments, the first indication module includes a light-emitting diode LED2 and a resistor R9; the positive electrode of the light-emitting diode LED2 is connected to the selection module and the first end of the load, the negative electrode of the light-emitting diode LED2 is connected to the first end of the resistor R9, and the second end of the resistor R9 is connected to the negative electrode of the battery and the second end of the load.

[0011] In some embodiments, the second indication module includes a second switch unit, a third switch unit, and an indication unit; the control end and the first end of the second switch unit are both connected to the selection module, the second end of the second switch module is connected to the negative pole of the battery, the output end of the second switch module is connected to the control end of the third switch unit, the third end of the third switch unit is connected to the selection module through the indication unit, and the second end of the third switch unit is connected to the negative pole of the battery; the second switch unit is used to be turned on when connected to the positive pole of the battery; the third switch unit is used to be turned on when the second switch unit is turned on; the indication unit is used to be powered on when the third switch unit is turned on and to send the second indication signal.

[0012] In some embodiments, the second switch unit includes a resistor R3, a resistor R4, a resistor R11, a capacitor C11, and a switch tube Q1; a first end of the resistor R3 is connected to the selection module, a second end of the resistor R3 is connected to the first end of the capacitor C11 and the control end of the switch tube Q1, a third end of the switch tube Q1 is connected to the selection module through the resistor R4, a second end of the switch tube Q1 is connected to the first end of the resistor R11 and the control end of the third switch unit, and a second end of the capacitor C11 and a second end of the resistor R11 are both connected to the negative electrode of the battery.

[0013] In some embodiments, the third switch unit includes a resistor R8, a resistor R12, and a switch tube Q3; the first end of the resistor R8 is connected to the output end of the second switch unit, the second end of the resistor R8 is connected to the control end of the switch tube Q1 and the first end of the resistor R12, the third end of the switch tube Q3 is connected to the selection module through the indication unit, and the second end of the switch tube Q3 and the second end of the resistor R12 are both connected to the negative electrode of the battery.

[0014] In a second aspect, an embodiment of the present application provides an energy storage power supply, which includes the undervoltage protection circuit as described above.

[0015] Different from the related technical solutions, the embodiment of the present application provides an undervoltage protection circuit and an energy storage power supply, which is configured to cut off the switch module when the battery voltage is less than or equal to the first threshold value, and then the selection module promptly cuts off the connection between the battery and the load. This can prevent the load from operating in a battery undervoltage state, because undervoltage operation may cause the load to not work properly and may even cause permanent damage to the load device. Only when the battery voltage is greater than the first threshold value will the switch module be turned on, thereby ensuring that the load obtains a stable power supply within the normal voltage range, which is conducive to the load device maintaining good performance and stable operating state. By energizing the second indication module to send a second indication signal when the battery is undervoltage (the switch module is cut off), the user can intuitively know that the battery is in an undervoltage state and promptly understand the battery power status so as to take corresponding measures such as charging. When the battery voltage is normal (the switch module is turned on), the first indication module is energized to send a first indication signal, which allows the user to clearly understand that the current battery can supply power to the load normally, without having to worry about the load malfunctioning due to power problems. In summary, the embodiments of the present application prevent the battery from continuing to discharge in an undervoltage state by promptly cutting off the connection between the load and the battery, thereby protecting the internal structure of the battery, extending the battery life, reducing battery failures and safety hazards caused by excessive discharge, and improving the safety and stability of the battery during discharge. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

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

[0018] Figure 2 is a structural block diagram of an undervoltage protection circuit provided by another embodiment of the present application;

[0019] Figure 3 1 is a schematic diagram of the circuit structure of an undervoltage protection circuit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0021] 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.

[0022] When an element is referred to as being “connected to” another element, it can be directly connected to the other element, or one or more intervening elements may be present therebetween.

[0023] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "first," "second," and the like generally distinguish objects of a class and do not limit the number of objects. For example, the first object may be one or more.

[0024] See also Figure 1 , Figure 1 1 is a structural block diagram of an undervoltage protection circuit 100 provided in an embodiment of the present application.

[0025] The undervoltage protection circuit 100 provided in the embodiment of the present application includes a switch module 11 , a selection module 12 , a first indication module 13 , and a second indication module 14 .

[0026] Among them, the switch module 11 is respectively connected to the selection module 12 and the positive pole of the battery 200, the selection module 12 is also respectively connected to the positive pole of the battery 200, the first indication module 13, and the second indication module 14, the first indication module 13 and the second indication module 14 are also respectively connected to the negative pole of the battery 200, and the first indication module 13 is connected in parallel with the load 300.

[0027] Specifically, the switch module 11 is configured to be turned on when the battery voltage is greater than a first threshold value, and to be turned off when the battery voltage is less than or equal to the first threshold value. The selection module 12 is configured to establish a connection between the positive electrode of the battery 200 and the first indication module 13, and to disconnect the positive electrode of the battery 200 from the second indication module 14, when the switch module 11 is turned on. When the switch module 11 is turned off, the selection module 12 is configured to establish a connection between the positive electrode of the battery 200 and the second indication module 14, and to disconnect the positive electrode of the battery 200 from the first indication module 13. The first indication module 13 is configured to be powered when connected to the positive electrode of the battery 200 and to issue a first indication signal. The second indication module 14 is configured to be powered when connected to the positive electrode of the battery 200 and to issue a second indication signal.

[0028] In practical applications, the undervoltage protection circuit 100 can be applied to scenarios where the voltage of the battery 200 is monitored. First, when the battery voltage is greater than a first threshold, the switch module 11 turns on. Then, with the switch module 11 turned on, the selection module 12 establishes a connection between the positive terminal of the battery 200 and the first indication module 13. This energizes the first indication module 13 and the load 300. At this point, the first indication module 13 issues a first indication signal, indicating that the battery voltage of the battery 200 is normal and that the battery 200 is discharging for the load 300.

[0029] Conversely, when the battery voltage is less than or equal to the first threshold, the switch module 11 is turned off. Then, with the switch module 11 turned off, the selection module 12 establishes a connection between the positive electrode of the battery 200 and the second indication module 14. This energizes the second indication module 14. At this point, the second indication module 14 issues a second indication signal, indicating that the battery voltage of the battery 200 is less than or equal to the first threshold and that the battery 200 is not discharging for the load 300.

[0030] The battery voltage is the voltage difference between the positive electrode and the negative electrode of the battery 200 .

[0031] The first threshold value is the boundary value that distinguishes whether the battery is in a normal power supply state and an undervoltage state. The first threshold value can be set according to actual application conditions and is not specifically limited in this embodiment of the application. The first threshold value is related to the components in the undervoltage protection circuit 100 and the connection relationship between the components.

[0032] The first indication signal may be a light signal, a sound signal, etc., for example, it may be a green light signal.

[0033] The second indication signal may be a light signal, a sound signal, etc., for example, it may be a red light signal.

[0034] In a specific application scenario, if the load 300 requires a stable voltage to operate normally, the first threshold can be set to the minimum voltage value that can ensure the normal operation of the load 300. In this way, when the battery voltage drops to a level close to that which may affect the load performance, the undervoltage protection circuit 100 can disconnect the load 300 from the battery 200 and issue a second indication signal to issue a warning, allowing the user sufficient time to take countermeasures, such as charging or replacing the battery. In addition, the possibility of over-discharge of the battery 200 can be reduced, thereby improving the safety and lifespan of the battery 200.

[0035] See also Figure 2 , Figure 2 1 is a structural block diagram of an undervoltage protection circuit 100 provided in another embodiment of the present application.

[0036] In some embodiments, the switch module 11 includes a voltage dividing unit 111 and a first switch unit 112 .

[0037] Among them, the first end of the voltage divider unit 111 is connected to the positive electrode of the battery 200, the second end of the voltage divider unit 111 is connected to the control end of the first switch unit 112, the third end of the first switch unit 112 is connected to the selection module 12, and the third end of the voltage divider unit 111 and the second end of the first switch unit 112 are both connected to the negative electrode of the battery 200.

[0038] Specifically, the voltage divider unit 111 is configured to have a voltage greater than a second threshold when the battery voltage is greater than a first threshold; and to have a voltage less than or equal to a second threshold when the battery voltage is less than or equal to the first threshold, wherein the second threshold is less than the first threshold. The first switch unit 112 is configured to be turned on when the voltage of the voltage divider unit 111 is greater than the second threshold, and to be turned off when the voltage of the voltage divider unit 111 is less than or equal to the second threshold.

[0039] The voltage divider unit 111 divides the battery voltage and obtains the voltage of the voltage divider unit 111 (i.e., the voltage output by the voltage divider unit 111 to the first switch unit 112). The second threshold is set to the critical voltage value output by the voltage divider unit 111 that causes the first switch unit 112 to switch from on to off when a battery enters an undervoltage state. The second threshold can be set according to actual application conditions and is not specifically limited in this embodiment of the present application.

[0040] Specifically, when the battery voltage is greater than a first threshold, the voltage divider unit 111 performs its voltage dividing function, causing the voltage of the voltage divider unit 111 to exceed a second threshold. In this case, the voltage divider unit 111 appropriately divides the battery voltage to meet the control requirements of the first switch unit 112. When the battery voltage is less than or equal to the first threshold, the voltage of the voltage divider unit 111 will also be less than or equal to the second threshold. The first switch unit 112 is configured to turn on when the voltage of the voltage divider unit 111 is greater than the second threshold. When the voltage output by the voltage divider unit 111 meets the turn-on condition of the first switch unit 112, the first switch unit 112 will be in the on state, allowing current to flow smoothly through the first switch unit 112 to the subsequent circuit modules. Conversely, when the voltage of the voltage divider unit 111 is less than or equal to the second threshold, the first switch unit 112 will be turned off. At this point, the first switch unit 112 acts like a closed valve, preventing the passage of current, thereby changing the operating state of the entire circuit.

[0041] In some embodiments, the second indication module 14 includes a second switch unit 141 , a third switch unit 142 , and an indication unit 143 .

[0042] Among them, the control end and the first end of the second switch unit 141 are both connected to the selection module 12, the second end of the second switch module 11 is connected to the negative pole of the battery 200, the output end of the second switch module 11 is connected to the control end of the third switch unit 142, the third end of the third switch unit 142 is connected to the selection module 12 through the indication unit 143, and the second end of the third switch unit 142 is connected to the negative pole of the battery 200.

[0043] Specifically, the second switch unit 141 is used to be turned on when connected to the positive pole of the battery 200; the third switch unit 142 is used to be turned on when the second switch unit 141 is turned on; the indication unit 143 is used to be powered when the third switch unit 142 is turned on and to send a second indication signal.

[0044] In actual application, when the battery voltage is less than or equal to the first threshold, the switch module 11 is turned off, and the selection module 12 establishes a connection between the positive electrode of the battery 200 and the second indication module 14 in this case.

[0045] First, the control terminal and first terminal of the second switch unit 141 are both connected to the selection module 12. At this time, due to the connection with the positive electrode of the battery 200, the second switch unit 141 is turned on. The turning on of the second switch unit 142 causes its output terminal to output a control signal. Next, this control signal acts on the control terminal of the third switch unit 142. Since the second switch unit 141 is turned on, the third switch unit 142 is also turned on. When the third switch unit 142 is turned on, current can flow from the selection module 12 to the negative electrode of the battery 299 through the indication unit 143, forming a loop. At this time, the indication unit 143 is energized and sends a second indication signal to indicate that the battery voltage is less than or equal to the first threshold and that the battery 200 is not discharging the load 300.

[0046] In general, when the battery 200 is in an undervoltage state, the second switch unit 141 and the third switch unit 142 are turned on in sequence, so that the indication unit 143 can accurately send a second indication signal to remind the user of the current status of the battery, so that the user can take corresponding measures in time, such as charging or replacing the battery, thereby ensuring the stable operation of the entire system.

[0047] In some embodiments, the undervoltage protection circuit 100 further includes an undervoltage blocking module 15 .

[0048] The selection module 12 is connected to the second indication module 14 via the undervoltage blocking module 15 .

[0049] Specifically, the undervoltage blocking module 15 is configured to be cut off when the battery voltage is less than or equal to a third threshold value, so as to disconnect the positive electrode of the battery 200 from the second indication module 14 ; wherein the third threshold value is less than the first threshold value.

[0050] The third threshold is lower than the first threshold and is used to further refine the determination of a battery undervoltage condition. When the battery voltage is less than or equal to the third threshold, the undervoltage blocking module 15 is turned off, thereby disconnecting the positive electrode of the battery 200 from the second indicator module 14. This means that when the battery voltage drops to a level more severe than a typical undervoltage condition (determined by the first threshold), the circuit takes more stringent measures to prevent the second indicator module 14 from receiving power. The third threshold can be set according to actual application conditions and is not specifically limited in this embodiment of the present application.

[0051] For example, the first threshold might be set to a voltage at which the battery can still sustain a certain load but requires attention, while the third threshold might be set to indicate that the battery voltage is dangerously low and continued use could cause irreversible damage. In this case, the third threshold can be used to avoid unnecessary circuit operation and possible erroneous indications when the battery voltage is extremely low, while also protecting the battery and connected loads from damage caused by excessively low voltage.

[0052] See also Figure 3 , Figure 3 FIG. 1 is a schematic diagram of the circuit structure of an undervoltage protection circuit 100 provided in an embodiment of the present application.

[0053] In some embodiments, the voltage dividing unit 111 includes a resistor R2 , a resistor R7 , and a resistor R10 .

[0054] Among them, the first end of the resistor R2 is connected to the positive electrode of the battery 200, the second end of the resistor R2 is connected to the first end of the resistor R7, the second end of the resistor R7 is connected to the first end of the resistor R10 and the control end of the first switch unit 112, and the second end of the resistor R10 is connected to the negative electrode of the battery 200.

[0055] Specifically, the resistors R2 , R7 , and R10 are used to divide the battery voltage output by the battery 200 and generate a voltage of the voltage dividing unit 111 at the second end of the resistor R7 .

[0056] In some embodiments, the first switch unit 112 includes a voltage regulator DZ1 , a resistor R6 , and a switch Q2 .

[0057] Among them, the negative electrode of the voltage regulator tube DZ1 is connected to the second end of the voltage divider unit 111, the positive electrode of the voltage regulator tube DZ1 is connected to the first end of the resistor R6 and the control end of the switch tube Q2, the third end of the switch tube Q2 is connected to the selection module 12, and the second end of the resistor R6 and the second end of the switch tube Q2 are both connected to the negative electrode of the battery 200.

[0058] Specifically, the minimum voltage that causes the voltage regulator diode DZ1 to be turned on is the second threshold.

[0059] In this embodiment, the switch tube Q2 is an NPN transistor. The base of the NPN transistor is the control terminal of the switch tube Q2, the emitter of the NPN transistor is the second terminal of the switch tube Q2, and the collector of the NPN transistor is the third terminal of the switch tube Q2.

[0060] In addition, the switch tube Q2 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon-controlled rectifier (SCR) device, a junction-gate field-effect transistor (JFET) device, a MOS-controlled thyristor (MCT) device, etc.

[0061] In some embodiments, the selection module 12 includes a relay RLY1, a resistor R1, and a voltage regulator tube TVS1; the relay RLY1 includes a coil, a common contact ( Figure 3 The contact numbered 4 next to the relay RLY1 in the middle), the normally closed contact ( Figure 3 The contact numbered 3 next to the relay RLY1 in the middle), the normally open contact ( Figure 3 (contact number 5 next to relay RLY1).

[0062] Among them, the second end of the coil ( Figure 3 The end of the coil (numbered 2 next to the relay RLY1) is connected to the positive electrode of the battery 200 through the resistor R1, and the second end of the coil is also connected to the first end of the voltage regulator tube TVS1. Figure 3 The end numbered 1 next to the middle relay RLY1 is connected to the second end of the voltage regulator tube TVS1 and the switch module 11, the common contact is connected to the positive electrode of the battery 200, the normally open contact is connected to the first indication module 13, and the normally closed contact is connected to the second indication module 14.

[0063] The voltage regulator tube TVS1 is used to prevent the charging current from being too large when the relay RLY1 is closed, so as to protect the relay RLY1.

[0064] In some embodiments, the first indication module 13 includes a light emitting diode LED2 and a resistor R9.

[0065] The positive electrode of the light-emitting diode LED2 is connected to the selection module 12 and the first end of the load 300 , the negative electrode of the light-emitting diode LED2 is connected to the first end of the resistor R9 , and the second end of the resistor R9 is connected to the negative electrode of the battery 200 and the second end of the load 300 .

[0066] The light emitting diode LED2 can be a green light emitting diode or a light emitting diode of other colors. The resistor R9 is a current limiting resistor.

[0067] In some embodiments, the second switch unit 141 includes a resistor R3 , a resistor R4 , a resistor R11 , a capacitor C11 , and a switch Q1 .

[0068] Among them, the first end of the resistor R3 is connected to the selection module 12, the second end of the resistor R3 is connected to the first end of the capacitor C11 and the control end of the switch tube Q1, the third end of the switch tube Q1 is connected to the selection module 12 through the resistor R4, the second end of the switch tube Q1 is connected to the first end of the resistor R11 and the control end of the third switch unit 142, and the second end of the capacitor C11 and the second end of the resistor R11 are both connected to the negative electrode of the battery 200.

[0069] In this embodiment, the switch tube Q1 is an NPN transistor, for example, wherein the base of the NPN transistor is the control terminal of the switch tube Q1, the emitter of the NPN transistor is the second terminal of the switch tube Q1, and the collector of the NPN transistor is the third terminal of the switch tube Q1.

[0070] In addition, the switch tube Q1 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon-controlled rectifier (SCR) device, a junction-gate field-effect transistor (JFET) device, a MOS-controlled thyristor (MCT) device, etc.

[0071] In some embodiments, the third switch unit 142 includes a resistor R8 , a resistor R12 , and a switch Q3 .

[0072] Among them, the first end of the resistor R8 is connected to the output end of the second switch unit 141, the second end of the resistor R8 is connected to the control end of the switch tube Q1 and the first end of the resistor R12, the third end of the switch tube Q3 is connected to the selection module 12 through the indication unit 143, and the second end of the switch tube Q3 and the second end of the resistor R12 are both connected to the negative electrode of the battery 200.

[0073] In this embodiment, the switch tube Q3 is an NPN transistor. The base of the NPN transistor is the control terminal of the switch tube Q3, the emitter of the NPN transistor is the second terminal of the switch tube Q3, and the collector of the NPN transistor is the third terminal of the switch tube Q3.

[0074] In addition, the switch tube Q3 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate-commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon-controlled rectifier (SCR) device, a junction-gate field-effect transistor (JFET) device, a MOS-controlled thyristor (MCT) device, etc.

[0075] In some embodiments, the indicating unit 143 includes a light emitting diode LED1 and a resistor R5 .

[0076] The anode of the light emitting diode LED1 is connected to the selection module 12 , the cathode of the light emitting diode LED1 is connected to the first end of the resistor R5 , and the second end of the resistor R5 is connected to the cathode of the battery 200 through the third switch unit 142 .

[0077] The light emitting diode LED1 can be a red light emitting diode or a light emitting diode of other colors. The resistor R5 is a current limiting resistor.

[0078] In some embodiments, the light emitting diode LED1 and the light emitting diode LED2 are light emitting diodes of different colors.

[0079] In some embodiments, the undervoltage blocking module 15 includes a voltage regulator diode DZ2 .

[0080] The cathode of the voltage-stabilizing tube DZ2 is connected to the selection module, and the anode of the voltage-stabilizing tube DZ2 is connected to the second indication module.

[0081] Specifically, the minimum voltage that causes the voltage regulator diode DZ2 to be turned on is the third threshold.

[0082] The following combination Figure 3 The working principle of the undervoltage protection circuit 100 is described.

[0083] When the battery voltage exceeds a first threshold (e.g., 10.5V), resistors R10, R2, and R7 divide the battery voltage, causing Zener diode DZ1 to break down. Switch Q2 then turns on, pulling down the voltage at pin 1 of relay RLY1. This energizes the coil of relay RLY1, closing its normally open contact with the common contact. Current flows sequentially through BAT+ / D1 / RLY1 / LED2 / R9 / BAT-. LED2 illuminates, and the battery discharges into the load (resistor RL6).

[0084] When the battery voltage is less than or equal to a first threshold (e.g., 10.5V), resistors R10, R2, and R7 divide the battery voltage, preventing Zener diode DZ1 from breaking down. At this point, switch Q2 turns off, the coil of relay RLY1 is deenergized, and the normally closed contact of relay RLY1 closes to the common contact. Consequently, switch Q1 turns on, and the voltage across resistor R12 reaches a high level, turning on switch Q3. Current flows sequentially through BAT+ / D1 / RLY1 / DZ2 / LED1 / R5 / Q3 / BAT-. At this point, the battery is not discharging to the load (resistor RL6), LED2 (e.g., the green LED) turns off, and LED1 (e.g., the red LED) turns on.

[0085] In addition, when the battery voltage is lower than the third threshold (e.g., 9.5V), the voltage regulator DZ2 is reversely cut off, and the battery cannot discharge the light-emitting diode LED1, and the light-emitting diode LED1 is turned off, thereby preventing the battery from being discharged. At this time, both the light-emitting diode LED1 and the light-emitting diode LED2 are turned off.

[0086] It should be noted that the first threshold, the second threshold, and the third threshold can be set according to the actual situation of the battery. It is only necessary to adjust the relevant parameters in the circuit accordingly, which will not be described in detail in this case.

[0087] Different from the related technical solutions, the embodiment of the present application provides an undervoltage protection circuit and an energy storage power supply, which is configured to cut off the switch module when the battery voltage is less than or equal to the first threshold value, and then the selection module promptly cuts off the connection between the battery and the load. This can prevent the load from operating in a battery undervoltage state, because undervoltage operation may cause the load to not work properly and may even cause permanent damage to the load device. Only when the battery voltage is greater than the first threshold value will the switch module be turned on, thereby ensuring that the load obtains a stable power supply within the normal voltage range, which is conducive to the load device maintaining good performance and stable operating state. By energizing the second indication module to send a second indication signal when the battery is undervoltage (the switch module is cut off), the user can intuitively know that the battery is in an undervoltage state and promptly understand the battery power status so as to take corresponding measures such as charging. When the battery voltage is normal (the switch module is turned on), the first indication module is energized to send a first indication signal, which allows the user to clearly understand that the current battery can supply power to the load normally, without having to worry about the load malfunctioning due to power problems. In summary, the embodiments of the present application prevent the battery from continuing to discharge in an undervoltage state by promptly cutting off the connection between the load and the battery, thereby protecting the internal structure of the battery, extending the battery life, reducing battery failures and safety hazards caused by excessive discharge, and improving the safety and stability of the battery during discharge.

[0088] An embodiment of the present application further provides an energy storage power supply, which includes the undervoltage protection circuit as described above.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Under the idea of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the present invention as described above. For the sake of simplicity, they are not provided in detail. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An undervoltage protection circuit, characterized in that: The undervoltage protection circuit includes a switch module, a selection module, a first indication module, and a second indication module; The switch module is connected to the selection module and the positive electrode of the battery respectively. The selection module is also connected to the positive electrode of the battery, the first indication module, and the second indication module respectively. The first indication module and the second indication module are also connected to the negative electrode of the battery respectively. The first indication module is connected in parallel with the load. The switch module is configured to be turned on when the battery voltage is greater than a first threshold, and turned off when the battery voltage is less than or equal to the first threshold; The selection module is configured to establish a connection between the positive electrode of the battery and the first indication module, and disconnect the connection between the positive electrode of the battery and the second indication module when the switch module is turned on; and to establish a connection between the positive electrode of the battery and the second indication module, and disconnect the connection between the positive electrode of the battery and the first indication module when the switch module is turned off; The first indication module is configured to be powered when connected to the positive electrode of the battery and to issue a first indication signal; The second indication module is configured to be powered when connected to the positive electrode of the battery and to send a second indication signal.

2. The undervoltage protection circuit according to claim 1, characterized in that: The switch module includes a voltage dividing unit and a first switch unit; The first end of the voltage dividing unit is connected to the positive electrode of the battery, the second end of the voltage dividing unit is connected to the control end of the first switch unit, the third end of the first switch unit is connected to the selection module, and the third end of the voltage dividing unit and the second end of the first switch unit are both connected to the negative electrode of the battery; The voltage dividing unit is configured to, when the battery voltage is greater than the first threshold, have a voltage greater than a second threshold; and when the battery voltage is less than or equal to the first threshold, have a voltage less than or equal to the second threshold; wherein the second threshold is less than the first threshold; The first switch unit is configured to be turned on when the voltage of the voltage dividing unit is greater than the second threshold, and to be turned off when the voltage of the voltage dividing unit is less than or equal to the second threshold.

3. The undervoltage protection circuit according to claim 2, characterized in that: The voltage dividing unit includes a resistor R2, a resistor R7, and a resistor R10; The first end of the resistor R2 is connected to the positive electrode of the battery, the second end of the resistor R2 is connected to the first end of the resistor R7, the second end of the resistor R7 is connected to the first end of the resistor R10 and the control end of the first switch unit, and the second end of the resistor R10 is connected to the negative electrode of the battery.

4. The undervoltage protection circuit according to claim 2, characterized in that: The first switch unit includes a voltage regulator tube DZ1, a resistor R6, and a switch tube Q2; The negative electrode of the voltage-stabilizing tube DZ1 is connected to the second end of the voltage-dividing unit, the positive electrode of the voltage-stabilizing tube DZ1 is connected to the first end of the resistor R6 and the control end of the switch tube Q2, the third end of the switch tube Q2 is connected to the selection module, and the second end of the resistor R6 and the second end of the switch tube Q2 are both connected to the negative electrode of the battery.

5. The undervoltage protection circuit according to claim 1, characterized in that: The selection module includes a relay RLY1, a resistor R1, and a voltage regulator tube TVS1; the relay RLY1 includes a coil, a common contact, a normally closed contact, and a normally open contact; The second end of the coil is connected to the positive electrode of the battery through the resistor R1, the second end of the coil is also connected to the first end of the voltage regulator tube TVS1, the first end of the coil is connected to the second end of the voltage regulator tube TVS1 and the switch module, the common contact is connected to the positive electrode of the battery, the normally open contact is connected to the first indication module, and the normally closed contact is connected to the second indication module.

6. The undervoltage protection circuit according to claim 1, characterized in that: The first indication module includes a light emitting diode LED2 and a resistor R9; The positive electrode of the light-emitting diode LED2 is connected to the selection module and the first end of the load, the negative electrode of the light-emitting diode LED2 is connected to the first end of the resistor R9, and the second end of the resistor R9 is connected to the negative electrode of the battery and the second end of the load.

7. The undervoltage protection circuit according to claim 1, wherein: The second indication module includes a second switch unit, a third switch unit, and an indication unit; The control end and the first end of the second switch unit are both connected to the selection module, the second end of the second switch unit is connected to the negative electrode of the battery, the output end of the second switch unit is connected to the control end of the third switch unit, the third end of the third switch unit is connected to the selection module via the indication unit, and the second end of the third switch unit is connected to the negative electrode of the battery; The second switch unit is configured to be turned on when connected to the positive electrode of the battery; The third switch unit is configured to be turned on when the second switch unit is turned on; The indication unit is configured to be powered when the third switch unit is turned on and to send the second indication signal.

8. The undervoltage protection circuit according to claim 7, characterized in that: The second switch unit includes a resistor R3, a resistor R4, a resistor R11, a capacitor C11, and a switch tube Q1; A first end of the resistor R3 is connected to the selection module, a second end of the resistor R3 is connected to the first end of the capacitor C11 and the control end of the switch tube Q1, a third end of the switch tube Q1 is connected to the selection module through the resistor R4, a second end of the switch tube Q1 is connected to the first end of the resistor R11 and the control end of the third switch unit, and the second end of the capacitor C11 and the second end of the resistor R11 are both connected to the negative electrode of the battery.

9. The undervoltage protection circuit according to claim 7, characterized in that: The third switch unit includes a resistor R8, a resistor R12, and a switch tube Q3; A first end of the resistor R8 is connected to the output end of the second switch unit, a second end of the resistor R8 is connected to the control end of the switch tube Q3 and the first end of the resistor R12, a third end of the switch tube Q3 is connected to the selection module through the indication unit, and a second end of the switch tube Q3 and a second end of the resistor R12 are both connected to the negative electrode of the battery.

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

Images