Undervoltage protection device and emergency power supply

Abstract

The present invention discloses an undervoltage protection device and an emergency power supply, wherein the undervoltage protection device comprises a DC charging and discharging module, a power storage module, a main control module, and an AC discharge module, wherein the DC charging and discharging module, the power storage module, and the AC discharge module are connected in sequence, and the main control module comprises an undervoltage protection unit and a main control unit, wherein the undervoltage protection unit is connected to the DC charging and discharging module and the main control unit respectively, and the power storage module and the AC discharge module are both connected to the main control unit. The present invention can realize that the power storage module can shut down the main control unit in time under the condition of undervoltage, reduce the discharge loss, and effectively extend the life of the battery pack in the power storage module.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to an undervoltage protection device and an emergency power supply. Background Art

[0002] With the development of society and the improvement of people's living standards, high-performance emergency power supplies have become indispensable emergency power supply equipment in production and life to prevent sudden power outages from affecting people's normal life order and study, as well as causing significant economic losses to particularly important loads in production and life. Traditional emergency power supplies mostly use diesel generator sets, but due to the insurmountable drawbacks of diesel generator sets such as smoke and noise pollution, fire hazards, and large maintenance workload, they have gradually been replaced by new emergency power supplies. Therefore, it is of great significance to study high-performance emergency power supplies.

[0003] At present, the life of most emergency power supplies is generally short and cannot meet users' high requirements for performance and price. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an undervoltage protection device, which can realize that the main control unit of the storage module is shut down in time under the condition of undervoltage, reduce discharge loss, and effectively extend the life of the battery pack in the storage module.

[0005] The invention also provides an emergency power supply.

[0006] In a first aspect, an embodiment of the present invention provides an undervoltage protection device, comprising a DC charging and discharging module, a power storage module, a main control module, and an AC discharge module, wherein the DC charging and discharging module, the power storage module, and the AC discharge module are connected in sequence, and the main control module comprises an undervoltage protection unit and a main control unit, wherein the undervoltage protection unit is connected to the DC charging and discharging module and the main control unit, respectively, and the power storage module and the AC discharge module are both connected to the main control unit.

[0007] The undervoltage protection device of the embodiment of the present invention has at least the following beneficial effects: it can realize that the main control unit of the power storage module is shut down in time when under voltage, thereby reducing discharge loss and effectively extending the life of the battery pack in the power storage module.

[0008] According to an undervoltage protection device of another embodiment of the present invention, the undervoltage protection unit includes a sampling circuit, a switching circuit, and a power supply circuit. The sampling circuit and the power supply circuit are both connected to the main control unit, and the switching circuit is respectively connected to the sampling circuit and the power supply circuit.

[0009] This embodiment has at least the following beneficial effects: the circuit design of the undervoltage protection unit makes the functions easier to distinguish and implement, and also facilitates the conversion of the same functional circuit according to the actual scenario.

[0010] According to some other embodiments of the undervoltage protection device of the present invention, the sampling circuit includes a voltage sampling subcircuit and a temperature sampling subcircuit, and both the voltage sampling subcircuit and the temperature sampling subcircuit are connected to the main control unit.

[0011] This embodiment has at least the following beneficial effects: it can perform voltage sampling and temperature sampling on the undervoltage protection device, wherein voltage sampling can provide data basis for the undervoltage protection of the undervoltage protection device, and temperature sampling can detect the device temperature in real time and disconnect it in case of abnormality, thereby better playing the role of abnormal protection.

[0012] According to some other embodiments of the undervoltage protection device of the present invention, the voltage sampling subcircuit includes a twenty-ninth resistor and a thirty-first resistor, the first end of the twenty-ninth resistor is connected to the power supply circuit, the second end of the twenty-ninth resistor is respectively connected to the main control unit and the first end of the thirty-first resistor, and the second end of the thirty-first resistor is connected to the main control unit.

[0013] This embodiment has at least the following beneficial effects: a specific circuit design is performed on the voltage sampling unit in the above embodiment, and the circuit design in this embodiment can achieve the advantages of simplicity, low cost and easy control.

[0014] According to some other embodiments of the undervoltage protection device of the present invention, the switch circuit includes a first switch sub-circuit and a second switch sub-circuit, the first switch sub-circuit is used to control the main control unit to turn on or off, and the second switch sub-circuit is used to control the power supply circuit to turn on or off.

[0015] This embodiment has at least the following beneficial effects: the main control unit can be shut down in time when the circuit is abnormal, reducing the power consumption of the entire circuit, and the power supply circuit can be controlled by the second switch circuit to wake up the circuit in time when there is external DC input.

[0016] According to some other embodiments of the undervoltage protection device of the present invention, the first switch sub-circuit includes: a third triode, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-third resistor, a first voltage stabilizing diode, and a seventh switch tube, the emitter of the third triode is connected to the first end of the twenty-third resistor, the second end of the twenty-third resistor is respectively connected to the base of the third triode and the first end of the nineteenth resistor, the second end of the nineteenth resistor is connected to the first end of the first voltage stabilizing diode, the second end of the first voltage stabilizing diode is respectively connected to the second end of the seventh switch tube and the first end of the twenty-first resistor, the second end of the twenty-first resistor is respectively connected to the third end of the seventh switch tube and the first end of the twenty-third resistor, the second end of the twenty-third resistor is connected to the collector of the third triode, and the first end of the seventh switch tube is connected to the power supply circuit.

[0017] This embodiment has at least the following beneficial effects: a specific circuit design is performed on the first switch sub-circuit, which can achieve the beneficial effects of a simple and practical circuit and low circuit hardware cost.

[0018] According to some other embodiments of the undervoltage protection device of the present invention, the second switch subcircuit includes: a fourth transistor, a third diode, a fourth diode, a twenty-fourth resistor, a twenty-sixth resistor, and a twenty-eighth resistor, the first end of the twenty-fourth resistor is connected to the first switch subcircuit, the second end of the twenty-fourth resistor is connected to the first end of the third diode, the second end of the third diode is connected to the collector of the fourth transistor, the emitter of the fourth transistor is connected to the first end of the twenty-sixth resistor, the second end of the twenty-sixth resistor is respectively connected to the first end of the twenty-eighth resistor and the base of the fourth transistor, the second end of the twenty-eighth resistor is connected to the first end of the fourth diode, and the second end of the fourth diode is connected to the DC charge and discharge module.

[0019] This embodiment has at least the following beneficial effects: a specific circuit design is performed on the second switch sub-circuit, so as to realize circuit wake-up control and reduce overall power consumption.

[0020] According to some other embodiments of the present invention, the undervoltage protection device further includes a control module, which is connected to the main control unit and is used to detect the working states of the DC charging and discharging module and the AC discharging module.

[0021] This embodiment has at least the following beneficial effects: the working status of the DC charging and discharging module and the AC discharging module can be detected in real time by using the simplest control method.

[0022] According to some other embodiments of the undervoltage protection device of the present invention, the undervoltage protection device further includes a display module, which is connected to the main control unit and is used to display the working status and / or prompt information of the DC charging and discharging module, the power storage module, the AC discharging module, and the main control module.

[0023] This embodiment has at least the following beneficial effects: it can intuitively monitor the working status of the DC charging and discharging module, the power storage module, the AC discharging module and the main control module, and can simultaneously monitor the accompanying warning and other prompt information, providing more convenience for users.

[0024] In a second aspect, an embodiment of the present invention further provides an emergency power supply, which includes the undervoltage protection device in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a module block diagram of a specific embodiment of the undervoltage protection device in the embodiment of the present invention;

[0026] Figure 2 It is a circuit schematic diagram of a specific embodiment of the undervoltage protection device in the embodiment of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0028] In the description of the embodiments of the present invention, if "several" is involved, it means more than one, if "multiple" is involved, it means more than two, if "greater than", "less than" or "exceed" is involved, it should be understood as not including the number itself, if "above", "below" or "within" is involved, it should be understood as including the number itself. If "first" or "second" is involved, it should be understood as being used to distinguish technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0029] In one embodiment of the present invention, referring to Figure 1 , shows a module block diagram of a specific embodiment of the undervoltage protection device in an embodiment of the present invention.

[0030] The invention comprises: a DC charging and discharging module, a power storage module, a main control module and an AC discharging module. The DC charging and discharging module, the power storage module and the AC discharging module are connected in sequence. The main control module comprises an undervoltage protection unit and a main control unit. The undervoltage protection unit is connected to the DC charging and discharging module and the main control unit respectively. The power storage module and the AC discharging module are both connected to the main control unit.

[0031] Among them, the undervoltage protection unit includes a sampling circuit, a switching circuit, and a power supply circuit. The sampling circuit and the power supply circuit are both connected to the main control unit, and the switching circuit is connected to the sampling circuit and the power supply circuit respectively.

[0032] The sampling circuit comprises a voltage sampling subcircuit and a temperature sampling subcircuit, and both the voltage sampling subcircuit and the temperature sampling subcircuit are connected to the main control unit.

[0033] Specifically, refer to Figure 2 , wherein the DC charge and discharge module includes a DC input unit 10, a DC input and output identification unit and a DC conversion unit, wherein the DC input unit 10, the DC input and output identification unit and the DC conversion unit are connected in sequence, wherein the main controller of the DC input and output identification unit is 20 in the figure, and the main controller of the DC conversion unit is 30 in the figure, the DC input and output identification unit is mainly used to identify the type of external signal of the DC input unit 10, and control the opening or closing of the entire circuit according to the signal type, and the DC conversion unit is mainly used to convert the DC voltage signal, wherein the signal type mentioned is provided by the external device connected to the DC input unit 10. It can be understood that the DC input and output identification unit main controller 20 is also externally connected to its own power supply circuit 70, so as to provide power supply guarantee for the DC input and output identification unit.

[0034] In another embodiment of the present invention, referring to Figure 2 , shows a circuit schematic diagram of a specific embodiment of the undervoltage protection device in an embodiment of the present invention. Specifically, the voltage sampling subcircuit includes a twenty-ninth resistor R29 and a thirty-first resistor R31, the first end of the twenty-ninth resistor R29 is connected to the power supply circuit 100, the second end of the twenty-ninth resistor R29 is respectively connected to the main control unit 40 and the first end of the thirty-first resistor R31, and the second end of the thirty-first resistor R31 is connected to the main control unit 40.

[0035] The switch circuit includes a first switch subcircuit and a second switch subcircuit, wherein the first switch subcircuit is used to control the main control unit 40 to be turned on or off, and the second switch subcircuit is used to control the power supply circuit 100 to be turned on or off.

[0036] The first switch sub-circuit includes: a third triode Q3, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-third resistor R23, a first voltage zener diode ZD1, and a seventh switch tube M7. The emitter of the third triode Q3 is connected to the first end of the twentieth resistor R20, the second end of the twentieth resistor R20 is respectively connected to the base of the third triode Q3 and the first end of the nineteenth resistor R19, the second end of the nineteenth resistor R19 is connected to the first end of the first voltage zener diode ZD1, the second end of the first voltage zener diode ZD1 is respectively connected to the second end of the seventh switch tube M7 and the first end of the twenty-first resistor R21, the second end of the twenty-first resistor R21 is respectively connected to the third end of the seventh switch tube M7 and the first end of the twenty-third resistor R23, the second end of the twenty-third resistor R23 is connected to the collector of the third triode Q3, and the first end of the seventh switch tube M7 is connected to the power supply circuit 100.

[0037] Specifically, the operation of the voltage sampling sub-circuit and the power supply circuit 100 is controlled by the on-off of the seventh switch tube M7, and the on-off of the seventh switch tube M7 is controlled by the third triode Q3. It can be understood that when the voltage of the battery pack composed of BT1, BT2, and BT3 is within the normal range, the voltage zener diode ZD1 is in the on state. At this time, the third triode Q3 is turned on. According to the above description, the on-off of the seventh switch tube M7 is controlled by the third triode Q3, so the seventh switch tube M7 is also in the on state at this time. Therefore, the voltage sampling circuit, the power supply circuit 100 and the main control unit 40 are all working normally at this time.

[0038] The battery pack voltage being within the normal range means that the battery pack voltage is within the normal charging and discharging voltage range, and the battery pack within this range will not be damaged due to undervoltage.

[0039] On the premise that the above circuit works normally, the undervoltage protection of the undervoltage protection device in the present invention can be implemented in software form. More specifically, voltage sampling is performed through the VBT_D pin of the main control unit 40. When the sampled voltage is lower than the minimum battery pack voltage threshold set by the main control unit 40, the battery management unit in the power storage module 50 is controlled by the BMS_CTL pin of the main control unit 40 to shut down the battery pack. Specifically, the battery management unit shuts down the battery pack by controlling the eighth switch tube M8 and the ninth switch tube M9.

[0040] The battery pack is not limited to the battery pack composed of BT1, BT2, and BT3. Battery packs with different compositions and voltage values ​​can be set according to actual application scenarios.

[0041] To facilitate understanding of this software form of implementing undervoltage protection, an example is given below. For example, if the battery pack voltage is 12V, the undervoltage critical value is set to 5V. At this time, voltage sampling is performed through the VBT_D pin of the main control unit 40. When the sampled voltage is lower than the lowest battery pack voltage threshold of 5V set by the main control unit 40, the battery management unit in the power storage module is controlled by the BMS_CTL pin of the main control unit 40 to shut down the battery pack. Specifically, the battery management unit shuts down the battery pack by controlling the eighth switch tube M8 and the ninth switch tube M9. The above-mentioned undervoltage critical value can also be called the undervoltage threshold.

[0042] In this embodiment, the undervoltage protection is mainly implemented in hardware form. The undervoltage protection implemented in the above software form only serves as an auxiliary function. The specific process of the undervoltage protection in the above hardware form is that the first voltage zener diode ZD1 is used to limit the hardware undervoltage protection threshold of the battery module. One end of the first voltage zener diode ZD1 is connected to the BT+ end of the battery pack. When the battery pack voltage in the power storage module 50 is lower than the hardware undervoltage protection threshold, the first voltage zener diode ZD1 is turned off and the third triode Q3 is turned off. At the same time, the seventh switch tube M7 is turned off, and the power supply circuit 100 stops working. At this time, the main control unit 40 also stops working. Similarly, the BMS_CTL of the main control unit 40 is turned off. When the power storage module 50 detects that the BMS_CTL of the main control unit 40 has no signal, the power storage module 50 turns off the eighth switch tube M8 and the ninth switch tube M9, thereby turning off the battery pack composed of BT1, BT2, and BT3, and continuously discharges and loses in the undervoltage state to prevent deep discharge of the battery or battery pack from causing irreversible damage to the battery or battery pack.

[0043] Among them, the selection of the first Zener diode ZD1 depends on the battery pack voltage of the storage module 50. When the battery pack of the storage module 50 is discharged to a certain extent, that is, discharged to a voltage lower than the conduction voltage of the first Zener diode ZD1, the Zener diode ZD1 cannot break down. At this time, the third transistor Q3 will be cut off. Because the seventh switch tube M7 is controlled by the third transistor Q3, the seventh switch tube M7 will also be in the off state. At this time, no current enters the power supply circuit 100, and the main control unit 40 automatically sleeps. It can be understood that the type and conduction voltage of the first Zener diode ZD1 are matched with the voltage of the BT1-BT3 battery pack in this embodiment. For example, the battery pack voltage in this embodiment is 12V. In order to better realize the under-voltage protection of the device, if the battery shutdown voltage in this embodiment is selected as 9V, then according to the circuit principle in this embodiment, the Zener diode ZD1 is selected with a conduction voltage of about 8V. The above-mentioned second switch sub-circuit includes: a fourth transistor Q4, a third diode D3, a fourth diode D4, a twenty-fourth resistor R24, a twenty-sixth resistor R26, and a twenty-eighth resistor R28, wherein the first end of the twenty-fourth resistor R24 ​​is connected to the first switch unit, the second end of the twenty-fourth resistor R24 ​​is connected to the first end of the third diode D3, the second end of the third diode D3 is connected to the collector of the fourth transistor Q4, the emitter of the fourth transistor Q4 is connected to the first end of the twenty-sixth resistor R26, the second end of the twenty-sixth resistor R26 is respectively connected to the first end of the twenty-eighth resistor R28 and the base of the fourth transistor Q4, the second end of the twenty-eighth resistor R28 is connected to the first end of the fourth diode D4, and the second end of the fourth diode D4 is connected to the above-mentioned DC charge and discharge module.

[0044] Specifically, when the main control unit 40 is in a sleep state, the second switch unit is used to wake up the power supply circuit 100. Specifically, one end of the fourth diode D4 is connected to DC+. When the DC input unit 10 in the DC charge and discharge module is connected to the charging voltage, the fourth transistor Q4 is turned on through the fourth diode D4, thereby turning on the seventh switch tube M7. At this time, the power supply circuit 100 can be awakened, and then the power supply circuit 100 can be powered by the main control unit 40, thereby waking up the entire circuit.

[0045] In another embodiment of the present invention, based on the above embodiment, a control module is further included to detect the working status of the DC charging and discharging module and the AC discharging module. A display module is also included to display the working status or / and prompt information of the DC charging and discharging module, the power storage module, the AC discharging module, and the main control module, wherein the working status includes but is not limited to the following: normal, abnormal, and the prompt information includes but is not limited to the following: normal value display, abnormal cause, and abnormal location module.

[0046] Specifically, the control module and the display module are respectively connected to the main control module; the control module is composed of a switch S1, a switch S2, and a switch S3; the display module is composed of LED1, LED2, LED3, LED4, LED5, and LED6; the control module and the display module constitute a matrix circuit and are controlled by pins P1, P2, P3, P4, P5, and P6 of the main control unit 40; and the switch control is different according to different detection signals set for the P1-P6 pins of the main control unit 40. For example, the main control unit 40 sets the P2 pin for the voltage detection of the DC input unit 10. After S1 is closed, the voltage detection status of the DC input unit 10 will be displayed through the display module. However, the composition of the display module and the specific signals controlled by the pins of the main control unit 40 can be set according to actual scenarios and are not limited to the above composition.

[0047] Specifically, the present embodiment also includes a temperature sampling unit, which includes a voltage-dividing sampling resistor, a 30th resistor R30, a temperature sensor RT1, a driving resistor, a 25th resistor R25, a 27th resistor R27, and a tenth switch tube M10. The operation of the temperature sampling unit is controlled by the control of the P1 port of the main control unit 40, and the sampling of the temperature sensor RT1 is completed by turning on the M10 switch tube. This control method is used to reduce the static power consumption of the temperature sampling circuit.

[0048] Specifically, the main control chip of the main control unit 40 detects the switching instructions of the switch S1, the switch S2, and the switch S3, controls the above-mentioned DC charge and discharge module through the first communication module 80, controls the working state of the AC discharge module 60 through the second communication module 90, and displays the working state of each circuit module and the corresponding emergency warning or prompt through the display module, so as to provide the user with the real-time state of the emergency power supply when in use, and then monitors and manages the state of the DC charge and discharge module and the AC discharge module in real time according to the state signal fed back by the DC charge and discharge module and the AC discharge module. When the battery pack is under-voltage, the main control unit 40 transmits the signal of shutting down the AC discharge to the AC discharge module 60 through the TX3 and RX3 pins, thereby preventing the battery pack from being over-discharged, reducing circuit loss, increasing the standby time of the emergency power supply, and extending the service life of the emergency power supply.

[0049] Another embodiment of the present invention provides an emergency power supply, which includes the undervoltage protection device in the above embodiment. The above embodiment of the present invention is described in detail in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiment. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. An undervoltage protection device, characterized in that: include: A DC charging and discharging module, a power storage module, a main control module, and an AC discharging module, wherein the DC charging and discharging module, the power storage module, and the AC discharging module are connected in sequence, the main control module comprises an undervoltage protection unit and a main control unit, the undervoltage protection unit is connected to the DC charging and discharging module and the main control unit respectively, and the power storage module and the AC discharging module are both connected to the main control unit; The undervoltage protection unit includes a sampling circuit, a switch circuit, and a power supply circuit. The sampling circuit and the power supply circuit are both connected to the main control unit, and the switch circuit is respectively connected to the sampling circuit and the power supply circuit; The switch circuit includes a first switch subcircuit and a second switch subcircuit, the first switch subcircuit is used to control the main control unit to turn on or off, and the second switch subcircuit is used to control the power supply circuit to turn on or off; The first switch subcircuit includes: a third triode, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-third resistor, a first voltage stabilizing diode, and a seventh switch tube, wherein the emitter of the third triode is connected to the first end of the twenty-third resistor, the second end of the twenty-third resistor is respectively connected to the base of the third triode and the first end of the nineteenth resistor, the second end of the nineteenth resistor is connected to the first end of the first voltage stabilizing diode, the second end of the first voltage stabilizing diode is respectively connected to the second end of the seventh switch tube and the first end of the twenty-first resistor, the second end of the twenty-first resistor is respectively connected to the third end of the seventh switch tube and the first end of the twenty-third resistor, the second end of the twenty-third resistor is connected to the collector of the third triode, and the first end of the seventh switch tube is connected to the power supply circuit; The second switch subcircuit includes: a fourth transistor, a third diode, a fourth diode, a twenty-fourth resistor, a twenty-sixth resistor, and a twenty-eighth resistor. The first end of the twenty-fourth resistor is connected to the first switch subcircuit, the second end of the twenty-fourth resistor is connected to the first end of the third diode, the second end of the third diode is connected to the collector of the fourth transistor, the emitter of the fourth transistor is connected to the first end of the twenty-sixth resistor, the second end of the twenty-sixth resistor is respectively connected to the first end of the twenty-eighth resistor and the base of the fourth transistor, the second end of the twenty-eighth resistor is connected to the first end of the fourth diode, and the second end of the fourth diode is connected to the DC charge and discharge module.

2. An undervoltage protection device according to claim 1, characterized in that: The sampling circuit includes a voltage sampling subcircuit and a temperature sampling subcircuit, and both the voltage sampling subcircuit and the temperature sampling subcircuit are connected to the main control unit.

3. An undervoltage protection device according to claim 2, characterized in that: The voltage sampling subcircuit includes a twenty-ninth resistor and a thirty-first resistor, the first end of the twenty-ninth resistor is connected to the power supply circuit, the second end of the twenty-ninth resistor is respectively connected to the main control unit and the first end of the thirty-first resistor, and the second end of the thirty-first resistor is connected to the main control unit.

4. The undervoltage protection device according to claim 1, characterized in that: It also includes a control module, which is connected to the main control unit and is used to detect the working states of the DC charging and discharging module and the AC discharging module.

5. The undervoltage protection device according to claim 1, characterized in that: It also includes a display module, which is connected to the main control unit and is used to display the working status and / or prompt information of the DC charging and discharging module, the power storage module, the AC discharging module, and the main control module.

6. An emergency power supply, characterized in that: The invention comprises an undervoltage protection device as claimed in any one of claims 1 to 5.

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