Auxiliary power supply module and power distribution system

Abstract

The invention discloses an auxiliary power supply module and a power distribution terminal, and belongs to the field of electric power supplies. The auxiliary power supply module comprises a charging circuit, an energy storage unit, a power failure detection delay circuit, a booster circuit and a power supply output end; the charging circuit is connected with the energy storage unit and is used for charging the energy storage unit through the main power supply voltage under the condition that the main power supply voltage is normal; the power failure detection delay circuit is respectively connected with the charging circuit and the booster circuit, and is used for outputting a working voltage to the booster circuit when the duration that the main power supply voltage is smaller than a first target voltage reaches a target duration; the energy storage unit is connected with the booster circuit and is used for outputting energy storage voltage to the booster circuit; the booster circuit is connected with the power output end and used for supplying power under the working voltage so as to convert the energy storage voltage into power supply voltage and provide the power supply voltage to the power output end, and the power supply voltage is used for supplying power to the power distribution terminal. The service life of the auxiliary power supply module can be prolonged, and the power supply stability is improved.

Description

Technical Field

[0001] This application belongs to the field of power supplies, and particularly relates to an auxiliary power supply module and a power distribution system. Background Art

[0002] When the main power supply voltage drops, the auxiliary power supply module needs to have sufficient electrical energy to supply power to the power distribution terminal, so that the power distribution terminal can report service interruption information, and at the same time collect the positive active power data at the moment of power failure, meeting the functional requirements for timely segmented time-of-use settlement for users. However, the auxiliary power supply modules in related technologies have problems of short service life and poor power supply stability. Summary of the Invention

[0003] This application aims to solve at least one of the technical problems existing in the prior art. For this purpose, this application provides an auxiliary power supply module and a power distribution system, which can improve the service life of the auxiliary power supply module and improve the power supply stability.

[0004] In a first aspect, this application provides an auxiliary power supply module, including a charging circuit, an energy storage unit, a power failure detection delay circuit, a boost circuit, and a power output terminal;

[0005] The charging circuit is connected to the energy storage unit and is used to charge the energy storage unit through the main power supply voltage when the main power supply voltage is normal;

[0006] The power failure detection delay circuit is respectively connected to the charging circuit and the boost circuit, and is used to output a working voltage to the boost circuit when the duration of the main power supply voltage being less than a first target voltage reaches a target duration;

[0007] The energy storage unit is connected to the boost circuit and is used to output an energy storage voltage to the boost circuit;

[0008] The boost circuit is connected to the power output terminal and is used to perform power supply work under the working voltage to convert the energy storage voltage into a power supply voltage and provide it to the power output terminal, and the power supply voltage is used to supply power to the power distribution terminal.

[0009] According to the auxiliary power supply module of this application, when the main power supply voltage is normal, the charging circuit charges the energy storage unit through the main power supply voltage. When the duration of the main power supply voltage being less than the first target voltage reaches the target duration, the power failure detection delay circuit determines that the main power supply voltage has dropped. The boost circuit converts the energy storage voltage of the energy storage unit into a power supply voltage to supply power to the power distribution terminal, avoiding detecting short-term fluctuations of the main power supply voltage as a power failure, thereby preventing the auxiliary power supply module from supplying power to the power distribution terminal during short-term fluctuations of the main power supply voltage, improving the service life of the auxiliary power supply module, and improving the power supply stability.

[0010] According to an embodiment of the present application, the charging circuit includes a voltage input unit, a voltage conversion unit, and a charging management unit;

[0011] The voltage input unit is used to convert the main power supply voltage into a DC voltage;

[0012] The voltage conversion unit is connected to the voltage input unit and is used to convert the DC voltage into a first voltage;

[0013] The charging management unit is connected to the voltage conversion unit and is used to, when the main power supply voltage is normal, charge the energy storage unit with a constant current through the first voltage.

[0014] According to an embodiment of the present application, the power-off detection delay circuit is connected to the voltage input unit and is further used to, when the duration that the DC voltage is less than a second target voltage reaches the target duration, determine that the duration that the main power supply voltage is less than a first target voltage reaches the target duration;

[0015] Alternatively, the power-off detection delay circuit is connected to the voltage conversion unit and is further used to, when the duration that the first voltage is less than a third target voltage reaches the target duration, determine that the duration that the main power supply voltage is less than a first target voltage reaches the target duration.

[0016] According to an embodiment of the present application, the charging management unit is further used to stop charging the energy storage unit when the voltage of the energy storage unit reaches a first voltage threshold; and reduce the charging current of the energy storage unit in the case of a short circuit of the energy storage unit.

[0017] According to an embodiment of the present application, the charging management unit includes a first transistor, a second transistor, and a charging inductor;

[0018] The charging management unit is further used to, in the case of a short circuit of the energy storage unit, periodically control the first transistor and the second transistor to conduct and turn off simultaneously. When the first transistor and the second transistor conduct simultaneously, charge the charging inductor through the first voltage. When the first transistor and the second transistor turn off simultaneously, charge the energy storage unit through the charging inductor.

[0019] According to an embodiment of the present application, the charging management unit further includes a constant current chip, a sampling resistor, an output capacitor, and a first feedback circuit;

[0020] The input terminal and the enable terminal of the constant current chip are respectively connected to the voltage conversion unit. One end of the sampling resistor is connected to the voltage conversion unit, and the other end of the sampling resistor is respectively connected to the sampling terminal of the constant current chip and the second terminal of the second transistor. The control terminal of the second transistor is connected to the first output terminal of the constant current chip. The first terminal of the second transistor is connected to one end of the charging inductor. The other end of the charging inductor is respectively connected to the second terminal of the first transistor and the energy storage unit. The control terminal of the first transistor is connected to the second output terminal of the constant current chip. The first terminal of the first transistor is grounded. One end of the first feedback circuit is connected to the energy storage unit, and the other end of the first feedback circuit is connected to the feedback terminal of the constant current chip. One end of the output capacitor is connected to the energy storage unit, and the other end of the output capacitor is grounded.

[0021] According to an embodiment of the present application, the boost circuit includes a first boost unit and a second boost unit;

[0022] The first boost unit is connected to the energy storage unit and is used for converting the energy storage voltage into a second voltage;

[0023] The power-down detection delay circuit is respectively connected to the first boost unit and the second boost unit, and is further used for outputting the working voltage to the second boost unit through the second voltage when the duration that the main power supply voltage is less than the first target voltage reaches the target duration;

[0024] The second boost unit is respectively connected to the energy storage unit and the power supply output terminal, and is used for performing a power supply operation under the working voltage to convert the energy storage voltage into the power supply voltage and provide it to the power supply output terminal.

[0025] According to an embodiment of the present application, the first boost unit is further used for stopping converting the energy storage voltage into the second voltage when the energy storage voltage is less than the second voltage threshold.

[0026] According to an embodiment of the present application, the first boost unit includes a starting resistor, and the first boost unit is connected to the second boost unit through the starting resistor;

[0027] The second boost unit is further used for pulling down the working voltage to stop the power supply operation in the case of a short circuit of the power supply output terminal;

[0028] The first boost unit is further used for charging the second boost unit through the starting resistor to increase the working voltage and enable the second boost unit to resume the power supply operation.

[0029] According to an embodiment of the present application, the first boost unit further includes a boost inductor, a boost diode, a boost chip, an enable circuit, and a second feedback circuit; the second boost unit includes a transformer, a flyback absorption circuit, a boost control circuit, a third transistor, and a third feedback circuit;

[0030] The energy storage unit is connected to the second secondary coil of the transformer through the series-connected boost inductor, boost diode, and starting resistor; the input terminal and the control terminal of the boost chip are respectively connected to both ends of the boost inductor, the enable terminal of the boost chip is connected to the energy storage unit through the enable circuit, and the feedback terminal of the boost chip is connected to the negative electrode of the boost diode through the second feedback circuit;

[0031] One end of the primary coil of the transformer is respectively connected to the energy storage unit and the flyback absorption circuit, the other end of the primary coil of the transformer is respectively connected to the flyback absorption circuit and the second end of the third transistor, and the boost control circuit is respectively connected to the power-off detection delay circuit, the third feedback circuit, and the control terminal and the first end of the third transistor; the first secondary coil of the transformer and the third feedback circuit are respectively connected to the power output terminal.

[0032] According to an embodiment of the present application, the auxiliary power supply module further includes an anti-AC backflow circuit;

[0033] The anti-AC backflow circuit is connected between the boost circuit and the power output terminal, and is in a conducting state when the boost circuit outputs the supply voltage to provide the supply voltage to the power output terminal; and is in a cut-off state when an AC voltage is input to the power output terminal to disconnect between the boost circuit and the power output terminal.

[0034] According to an embodiment of the present application, the energy storage unit includes a storage battery, and the storage battery includes any one of a lithium battery, a nickel-metal hydride battery, and a lead-acid battery.

[0035] In a second aspect, the present application provides a power distribution system, which is characterized by including:

[0036] The auxiliary power supply module as described in the first aspect above;

[0037] A power distribution terminal, connected to the power output terminal of the auxiliary power supply module, for being powered by the main power supply voltage when the main power supply voltage is normal; and being powered by the supply voltage output by the auxiliary power supply module when the duration that the main power supply voltage is less than the first target voltage reaches the target duration.

[0038] One or more of the above technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0039] When the main power supply voltage is normal, the charging circuit charges the energy storage unit through the main power supply voltage. When the duration that the main power supply voltage is less than the first target voltage reaches the target duration, the power-off detection delay circuit determines that the main power supply voltage is powered off. The boost circuit converts the stored energy voltage of the energy storage unit into a power supply voltage to supply power to the power distribution terminal, avoiding detecting short-term fluctuations of the main power supply voltage as a power-off, thereby preventing the auxiliary power supply module from supplying power to the power distribution terminal during short-term fluctuations of the main power supply voltage, improving the service life of the auxiliary power supply module, and improving the power supply stability;

[0040] Furthermore, when an overvoltage fault occurs in the energy storage unit, undervoltage protection is performed on the energy storage unit. When a short-circuit fault occurs in the energy storage unit, short-circuit protection is performed on the energy storage unit; when the voltage of the energy storage unit is relatively low, power supply to the power distribution terminal is stopped to prevent over-discharge of the energy storage unit; when a short-circuit fault occurs at the power supply output terminal, short-circuit protection is performed on the auxiliary power supply module, and it can self-recover after the short circuit at the power supply output terminal is eliminated; when an AC voltage is connected to the power supply output terminal, reverse power flow of the alternating current is prevented.

[0041] Some of the additional aspects and advantages of this application will be given in the following description, some will become obvious from the following description, or be understood through the practice of this application. Description of the Drawings

[0042] The above and / or additional aspects and advantages of this application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0043] Figure 1 is a schematic structural diagram of the auxiliary power supply module provided by the embodiment of this application;

[0044] Figure 2 is a schematic circuit diagram of the voltage input unit in the auxiliary power supply module provided by the embodiment of this application;

[0045] Figure 3 is a schematic circuit diagram of the voltage conversion unit in the auxiliary power supply module provided by the embodiment of this application;

[0046] Figure 4 is a schematic circuit diagram of the charging management unit in the auxiliary power supply module provided by the embodiment of this application;

[0047] Figure 5 is one of the schematic diagrams of the power-off detection delay circuit in the auxiliary power supply module provided by the embodiment of this application;

[0048] Figure 6 is another schematic diagram of the power-off detection delay circuit in the auxiliary power supply module provided by the embodiment of this application;

[0049] Figure 7It is a schematic circuit diagram of the first boost unit in the auxiliary power supply module provided by an embodiment of the present application;

[0050] Figure 8 It is a schematic circuit diagram of the first part of the second boost unit in the auxiliary power supply module provided by an embodiment of the present application;

[0051] Figure 9 It is a schematic circuit diagram of the second part of the second boost unit in the auxiliary power supply module provided by an embodiment of the present application;

[0052] Figure 10 It is one of the schematic diagrams of the anti - AC back - injection circuit in the auxiliary power supply module provided by an embodiment of the present application;

[0053] Figure 11 It is the second schematic diagram of the anti - AC back - injection circuit in the auxiliary power supply module provided by an embodiment of the present application. Detailed implementation manners

[0054] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application.

[0055] The auxiliary power supply module and the power distribution system provided by the embodiments of the present application will be described below with reference to the drawings.

[0056] Figure 1 It is a schematic structural diagram of the auxiliary power supply module provided by an embodiment of the present application. The auxiliary power supply module is used to supply power to the power distribution terminal when the main power supply voltage drops. The power distribution terminal may include at least one of a dedicated transformer terminal and a meter device (such as a three - phase meter), etc.

[0057] As Figure 1 shown, the auxiliary power supply module provided by the embodiment of the present application includes a charging circuit 1, an energy storage unit 2, a power - down detection delay circuit 3, a boost circuit 4, and a power output terminal 5.

[0058] The charging circuit 1 is connected to the energy storage unit 2 and is used to charge the energy storage unit 2 through the main power supply voltage when the main power supply voltage is normal.

[0059] Among them, the input end of the charging circuit 1 is connected to the main power supply voltage, and the output end of the charging circuit 1 is connected to the energy storage unit 2. When the main power supply voltage is normal (such as the main power supply voltage is within a preset voltage range), the charging circuit 1 converts the main power supply voltage into a voltage for charging the energy storage unit 2, and at the same time, the main power supply voltage supplies power to the power distribution terminal. When the main power supply voltage drops, the charging circuit 1 stops charging the energy storage unit 2, and at the same time, the main power supply voltage does not supply power to the power distribution terminal.

[0060] The power-off detection delay circuit 3 is respectively connected to the charging circuit 1 and the boost circuit 4, and is configured to output a working voltage to the boost circuit 4 when the duration that the main power supply voltage is less than the first target voltage reaches the target duration.

[0061] Among them, the power-off detection delay circuit 3 can detect the situation of the main power supply voltage. When the power-off detection delay circuit 3 detects that the main power supply voltage is normal, it does not output a working voltage to the boost circuit 4; when the duration that the main power supply voltage is less than the first target voltage has not reached the target duration, it does not output a working voltage to the boost circuit 4; when the duration that the main power supply voltage is less than the first target voltage reaches the target duration, it determines that the main power supply voltage has a power-off and outputs a working voltage to the boost circuit 4.

[0062] The energy storage unit 2 is connected to the boost circuit 4 and is configured to output an energy storage voltage to the boost circuit 4. When the main power supply voltage is normal, the energy storage unit 2 stores electrical energy; when the duration that the main power supply voltage is less than the first target voltage reaches the target duration, it outputs an energy storage voltage to the boost circuit 4.

[0063] The boost circuit 4 is connected to the power supply output terminal 5 and is configured to perform a power supply operation under the working voltage to convert the energy storage voltage into a power supply voltage and provide it to the power supply output terminal 5, and the power supply voltage is used to supply power to the distribution terminal.

[0064] Among them, when the main power supply voltage is normal, the boost circuit 4 does not input a working voltage and the boost circuit 4 does not perform a power supply operation; when the duration that the main power supply voltage is less than the first target voltage has not reached the target duration, the boost circuit 4 does not input a working voltage and the boost circuit 4 does not perform a power supply operation; when the duration that the main power supply voltage is less than the first target voltage reaches the target duration, the boost circuit 4 inputs a working voltage and performs a power supply operation according to the working voltage, and converts the energy storage voltage provided by the energy storage unit 3 into a power supply voltage. The power supply voltage can be 110V DC voltage. The power supply output terminal 5 outputs the power supply voltage to the distribution terminal, realizing power supply to the distribution terminal through the auxiliary power supply module when the main power supply voltage has a power-off.

[0065] In this embodiment, by setting the charge and discharge strategy of the auxiliary power supply module, when the duration that the main power supply voltage is less than the first target voltage reaches the target duration, it is determined that the main power supply voltage has a power-off, and the auxiliary power supply module supplies power to the distribution terminal, avoiding detecting a short-term fluctuation of the main power supply voltage as a power-off, thereby preventing the auxiliary power supply module from supplying power to the distribution terminal during a short-term fluctuation of the main power supply voltage, reducing the power supply frequency of the auxiliary power supply module, increasing the service life of the auxiliary power supply module, and improving the power supply stability.

[0066] In some embodiments, the energy storage unit 2 includes a storage battery, which can be any one of a lithium battery, a nickel-metal hydride battery, and a lead-acid battery. Among them, the power of the storage battery can be more than ten watts.

[0067] The lithium battery has the characteristics of high energy density and low cost. The nickel-metal hydride battery can meet the requirements of miniaturization and safety. The lead-acid battery has high safety and low cost. Select the corresponding storage battery as the energy storage unit 2 according to the actual application requirements.

[0068] The related technology uses a super capacitor as the energy storage unit, but the power supply time of the super capacitor is short, which cannot meet the power supply requirements of the distribution terminal after the main power supply voltage drops. In this embodiment, a storage battery is used as the energy storage unit. After the main power supply voltage drops, the storage battery supplies power to the distribution terminal, supporting the function requirement of the distribution terminal to upload the frozen data at two sampling points for more than 30 minutes.

[0069] In some embodiments, as Figure 1 shown, the charging circuit 1 includes a voltage input unit 11, a voltage conversion unit 12, and a charging management unit 13. The voltage input unit 11 is used to convert the main power supply voltage into a DC voltage. The voltage conversion unit 12 is connected to the voltage input unit 11 and is used to convert the DC voltage into a first voltage. The charging management unit 13 is connected to the voltage conversion unit 12 and is used to charge the energy storage unit 2 with a constant current through the first voltage when the main power supply voltage is normal.

[0070] When the main power supply voltage is normal, the voltage input terminal unit 11 accesses the main power supply voltage, which can be a single-phase AC voltage. The voltage input unit 11 performs AC-DC conversion on the main power supply voltage to convert the main power supply voltage into a DC voltage and outputs the DC voltage to the voltage conversion unit 12. The voltage conversion unit 11 inputs the DC voltage, converts the DC voltage into a first voltage, and outputs the first voltage to the charging management unit 13. The charging management unit 13 inputs the first voltage and converts the first voltage into a voltage for charging the energy storage unit 2 to charge the energy storage unit 2 in a constant current charging manner.

[0071] In some embodiments, as Figure 2 shown, the voltage input unit 11 includes a rectifier bridge BD1, a fuse F1, a varistor RV1, a filter inductor L1, a first filter capacitor CX1, a first electrolytic capacitor EC2, a second electrolytic capacitor EC3, a first resistor R9, a second resistor R10, a third resistor R11, and a fourth resistor R13.

[0072] One end of the fuse F1 is connected to the live wire ACL of the main power supply voltage. The other end of the fuse F1 is respectively connected to one end of the varistor RV1 and one end of the filter inductor L1. The other end of the filter inductor L1 is respectively connected to one end of the first filter capacitor CX1 and the first AC terminal AC1 of the rectifier bridge BD1. The other end of the varistor RV1 is respectively connected to the neutral wire CAN of the main power supply voltage, the other end of the first filter capacitor CX1 and the second AC terminal AC2 of the rectifier bridge BD1. The positive output terminal V+ of the rectifier bridge BD1 is respectively connected to the output terminal VBus and the positive electrode of the first electrolytic capacitor EC2. The negative electrode of the first electrolytic capacitor EC2 is connected to the positive electrode of the second electrolytic capacitor EC3. The negative electrode of the second electrolytic capacitor EC3 and the negative output terminal V- of the rectifier bridge BD1 are both grounded. The first resistor R9 and the second resistor R10 are connected in series and then respectively connected to the positive and negative electrodes of the first electrolytic capacitor EC2. The third resistor R11 and the fourth resistor R13 are connected in series and then respectively connected to the positive and negative electrodes of the second electrolytic capacitor EC3.

[0073] Among them, the filter inductor L1 and the first filter capacitor CX1 form an EMI filter circuit to filter the main power supply voltage. The rectifier bridge BD1 rectifies the main power supply voltage from alternating current to pulsating direct current. The pulsating direct current is filtered into a stable direct current voltage by the first electrolytic capacitor EC2 and the second electrolytic capacitor EC3. The first resistor R9, the second resistor R10, the third resistor R11 and the fourth resistor R13 are all voltage-sharing resistors. The output terminal VBus of the voltage input unit 11 outputs a direct current voltage to the voltage conversion unit 12.

[0074] In some embodiments, as Figure 3 shown, the voltage conversion unit 12 includes a first transformer T2, a first flyback absorption circuit 121, a charging control circuit 122, a first feedback circuit 123, a first rectifier filter circuit 124, a fourth transistor Q5 and a nineteenth resistor R52.

[0075] One end of the primary coil of the first transformer T2 is respectively connected to the output terminal VBus of the voltage input unit 11 and the first flyback absorption circuit 121. The other end of the primary coil of the first transformer T2 is respectively connected to the first flyback absorption circuit 121 and the second end of the fourth transistor Q5. The first end of the fourth transistor Q5 is grounded through the nineteenth resistor R52. The charging control circuit 122 is respectively connected to the first feedback circuit 123, the control end and the first end of the fourth transistor Q5. The first feedback circuit 123 is connected to the first rectifier filter circuit 124. One end of the secondary coil of the first transformer T2 is connected to the output terminal V1 through the first rectifier filter circuit 124. The other end of the secondary coil of the first transformer T2 is grounded.

[0076] Among them, the nineteenth resistor R52 is the primary current sampling resistor. The fourth transistor Q5 can be a MOS transistor. The control end of the fourth transistor Q5 can be the gate of the MOS transistor. The first end of the fourth transistor Q5 can be the source of the MOS transistor. The second end of the fourth transistor Q5 can be the drain of the MOS transistor.

[0077] The charging control circuit 122 controls the conduction and cutoff of the fourth transistor Q5. The DC voltage output by the output terminal VBus of the voltage input unit 11 generates a primary high-frequency pulse signal through the fourth transistor Q5. When the fourth transistor Q5 is conducting, the primary coil of the first transformer T2 is excited by the DC voltage. At this time, the secondary of the first transformer T2 is in the reverse-biased cutoff state, and the voltage conversion unit 12 has no voltage output. When the fourth transistor Q5 is cut off, the energy stored in the primary coil of the first transformer T2 is transferred to the secondary and rectified and filtered by the first rectification and filtering circuit 124 into the first voltage. The output terminal V1 of the voltage conversion unit 12 outputs the first voltage to the charging management unit 13.

[0078] In some embodiments, the charging management unit 13 is further configured to stop charging the energy storage unit 2 when the voltage of the energy storage unit 2 reaches the first voltage threshold; and reduce the charging current of the energy storage unit 2 in the case of a short circuit of the energy storage unit 2.

[0079] The charging management unit 13 charges the energy storage unit 2 with a constant charging current. When the voltage of the energy storage unit 2 reaches the preset constant current charging transition voltage, the charging current of the energy storage unit 2 is reduced, so that the energy storage unit 2 enters the maintenance charging state from the constant current charging state; when the voltage of the energy storage unit 2 reaches the charging cut-off voltage, charging of the energy storage unit 2 is stopped.

[0080] When an overvoltage fault occurs in the voltage of the energy storage unit 2, that is, when the voltage of the energy storage unit 2 reaches the first voltage threshold, the charging management unit 13 stops charging the energy storage unit 2 to provide undervoltage protection for the energy storage unit 2. In the case of a short circuit fault of the energy storage unit 2, the charging current of the energy storage unit 2 is reduced to provide short circuit protection for the energy storage unit 2.

[0081] In some embodiments, as Figure 4 shown, the charging management unit 13 includes a first transistor Q7, a second transistor Q6, and a charging inductor L4. The charging management unit 13 is further configured to periodically control the first transistor Q7 and the second transistor Q6 to conduct and cut off simultaneously in the case of a short circuit of the energy storage unit 2. When the first transistor Q7 and the second transistor Q6 conduct simultaneously, the charging inductor L4 is charged through the first voltage. When the first transistor Q7 and the second transistor Q6 cut off simultaneously, the energy storage unit 2 is charged through the charging inductor L4.

[0082] In the case of a short circuit in the energy storage unit 2, by periodically controlling the first transistor Q7 and the second transistor Q6 to conduct and turn off simultaneously, the charging current of the energy storage unit 2 can be effectively reduced, providing short-circuit protection for the energy storage unit 2.

[0083] The circuit topology of the charging management unit 13 can adopt a BOOST boost circuit.

[0084] In some embodiments, the charging management unit 13 further includes a constant current chip U7, a sampling resistor R43, an output capacitor EC7, and a first feedback circuit. The input terminal VIN and the enable terminal CE of the constant current chip U7 are respectively connected to the output terminal V1 of the voltage conversion unit 12. One end of the sampling resistor R43 is connected to the output terminal V1 of the voltage conversion unit 12, and the other end of the sampling resistor R43 is respectively connected to the sampling terminal CSN of the constant current chip U7 and the second end of the second transistor Q6. The control terminal of the second transistor Q6 is connected to the first output terminal HDRV of the constant current chip U7. The first end of the second transistor Q6 is connected to one end of the charging inductor L4. The other end of the charging inductor L4 is respectively connected to the second end of the first transistor Q7 and the voltage terminal VBAT of the energy storage unit 2. The control terminal of the first transistor Q7 is connected to the second output terminal LDRV of the constant current chip U7. The first end of the first transistor Q7 is grounded; one end of the first feedback circuit is connected to the energy storage unit 2, and the other end of the first feedback circuit is connected to the feedback terminal FB of the constant current chip U7; one end of the output capacitor EC7 is connected to the voltage terminal VBAT of the energy storage unit 2, and the other end of the output capacitor EC7 is grounded.

[0085] Among them, the output capacitor EC7 can be an electrolytic capacitor. The first transistor Q7 can be an NMOS transistor. The control terminal of the first transistor Q7 can be the gate of the NMOS transistor. The first end of the first transistor Q7 can be the source of the NMOS transistor. The second end of the first transistor Q7 can be the drain of the NMOS transistor. The second transistor Q6 can be a PMOS transistor. The control terminal of the second transistor Q6 can be the gate of the PMOS transistor. The first end of the second transistor Q6 can be the source of the PMOS transistor. The second end of the second transistor Q6 can be the drain of the PMOS transistor.

[0086] The charging management unit 13 further includes a twentieth resistor R49, an eighth diode D8, and a second diode D15. The twentieth resistor R49 is connected between the control terminal of the first transistor Q7 and the first output terminal LDRV of the constant current chip U7; the positive electrode of the eighth diode D8 is grounded, and the negative electrode of the eighth diode D8 is respectively connected to one end of the charging inductor L4 and the first end of the second transistor Q6; the positive electrode of the second diode D15 is respectively connected to the other end of the charging inductor L4 and the second end of the first transistor Q7, and the negative electrode of the second diode D15 is connected to the voltage terminal VBAT of the energy storage unit 2.

[0087] In some embodiments, the first feedback circuit includes the twenty-first resistor R48 and the twenty-second resistor R55. The feedback terminal FB of the constant current chip U7 is respectively connected to one end of the twenty-first resistor R48 and one end of the twenty-second resistor R55. The other end of the twenty-first resistor R48 is connected to the voltage terminal VBAT of the energy storage unit 2, and the other end of the twenty-second resistor R55 is grounded. Among them, both the twenty-first resistor R48 and the twenty-second resistor R55 are voltage dividing resistors.

[0088] During the constant current charging process of the energy storage unit 2 by the charging management unit 13, the first voltage output by the output terminal V1 of the voltage conversion unit 12 is connected to the charging management unit 13, and the constant current chip U7 enters the constant current charging state. In the constant current charging state, both the first transistor Q7 and the second transistor Q6 are turned on, the current of the charging inductor L4 rises, and the energy in the output capacitor EC7 is transferred to the energy storage unit 2. The sampling resistor R43 detects the external current. When the inductor current rises to the current upper limit set by the sampling resistor R43, the first transistor Q7 is turned off, the inductor current drops, and the energy in the charging inductor L4 is transferred to the output capacitor EC7 and the energy storage unit 2. When the inductor current drops to the current lower limit set by the sampling resistor R43, the first transistor Q7 is turned on again, and so on, to achieve constant current charging.

[0089] The voltage of the energy storage unit 2 is divided by the twenty-first resistor R48 and the twenty-second resistor R55 and fed back to the feedback terminal FB of the constant current chip U7. When the voltage of the feedback terminal FB reaches the constant current charging transition voltage, by adjusting the on and off duration of the first transistor Q7, the charging current is reduced, so that the energy storage unit 2 enters the maintenance charging state from the constant current charging state until the voltage of the energy storage unit reaches the charging cut-off voltage and then ends.

[0090] In some embodiments, the power-down detection delay circuit 3 is connected to the voltage input unit 11 and is further configured to determine that the duration for which the main power supply voltage is less than the first target voltage reaches the target duration when the duration for which the DC voltage is less than the second target voltage reaches the target duration.

[0091] The power-off detection delay circuit 3 is connected to the output terminal VBus of the voltage input unit 11. The power-off condition of the main power supply voltage is judged by detecting the DC voltage at the output terminal VBus of the voltage input unit 11. If the power-off detection delay circuit 3 detects that the DC voltage is normal (e.g., the DC voltage is within the first voltage range), it is determined that the main power supply voltage is normal; if the duration for which the power-off detection delay circuit 3 detects that the DC voltage is less than the second target voltage does not reach the target duration, it is determined that the duration for which the main power supply voltage is less than the first target voltage does not reach the target duration; if the duration for which the power-off detection delay circuit 3 detects that the DC voltage is less than the second target voltage reaches the target duration, it is determined that the duration for which the main power supply voltage is less than the first target voltage reaches the target duration, and the main power supply voltage is powered off. Among them, the first target voltage is different from the second target voltage.

[0092] In some embodiments, the power-off detection delay circuit 3 is connected to the voltage conversion unit 12, and is further configured to determine that the duration for which the main power supply voltage is less than the first target voltage reaches the target duration when the duration for which the first voltage is less than the third target voltage reaches the target duration.

[0093] The power-off detection delay circuit 3 is connected to the output terminal V1 of the voltage conversion unit 12. The power-off condition of the main power supply voltage is judged by detecting the first voltage at the output terminal V1 of the voltage conversion unit 12. If the power-off detection delay circuit 3 detects that the first voltage is normal (e.g., the first voltage is within the second voltage range), it is determined that the main power supply voltage is normal; if the duration for which the power-off detection delay circuit 3 detects that the first voltage is less than the third target voltage does not reach the target duration, it is determined that the duration for which the main power supply voltage is less than the first target voltage does not reach the target duration; if the duration for which the power-off detection delay circuit 3 detects that the first voltage is less than the third target voltage reaches the target duration, it is determined that the duration for which the main power supply voltage is less than the first target voltage reaches the target duration, and the main power supply voltage is powered off. Among them, the first target voltage is different from the third target voltage.

[0094] The power-off detection delay circuit 3 in this embodiment can detect the power-off condition of the main power supply voltage in various ways, improving the diversity of detection.

[0095] In some embodiments, such as Figure 5 and Figure 6 shown, the power-off detection delay circuit 3 includes a circuit input terminal VI, a voltage terminal V2, a circuit output terminal VCC1, a voltage detection unit 31, and a delay output unit 32.

[0096] Among them, the circuit input terminal VI can be connected to the output terminal VBus of the voltage input unit 11, and the voltage of the circuit input terminal VI is the DC voltage output by the output terminal VBus of the voltage input unit 11; the circuit input terminal VI can also be connected to the output terminal V1 of the voltage conversion unit 12, and the voltage of the circuit input terminal VI is the first voltage output by the output terminal V1 of the voltage conversion unit 12.

[0097] The voltage detection unit 31 is respectively connected to the circuit input terminal VI and the delay output unit 32, and is used to provide a control voltage to the delay output unit 32 when the voltage of the circuit input terminal VI is normal; when the voltage of the circuit input terminal VI is less than the first target voltage, stop providing the control voltage to the delay output unit 32.

[0098] Among them, the input terminal of the voltage detection unit 31 is connected to the circuit input terminal VI, and the output terminal of the voltage detection unit 31 is connected to the input terminal of the delay output unit 32. The circuit input terminal VI provides a voltage to the voltage detection unit 31, and the voltage detection unit 31 detects the voltage of the circuit input terminal VI to determine whether the voltage of the circuit input terminal VI is less than the first target voltage. If the voltage of the circuit input terminal VI is greater than or equal to the first target voltage, it is determined that the voltage of the circuit input terminal VI is normal, and the voltage detection unit 31 is in a conducting state, and outputs a control voltage to the delay output unit 32. If the voltage of the circuit input terminal VI is less than the first target voltage, it is determined that the voltage of the circuit input terminal VI has abnormally decreased, but this abnormal decrease may be caused by a short-term voltage fluctuation and is not necessarily a voltage power-off. When it is determined that the voltage of the circuit input terminal VI has abnormally decreased, the voltage detection unit 31 is in an off state and stops providing the control voltage to the delay output unit 32, that is, the voltage detection unit 31 does not output a voltage to the delay output unit 32.

[0099] The delay output unit 32 is respectively connected to the voltage terminal V2 and the circuit output terminal VCC1, and is used to provide a working voltage to the circuit output terminal VCC1 according to the voltage of the voltage terminal V2 when the duration of the voltage of the circuit input terminal VI being less than the first target voltage reaches the target duration; when the voltage of the circuit input terminal VI is normal, stop providing the working voltage to the circuit output terminal VCC1 according to the control voltage; the working voltage is used to control the auxiliary power supply module to supply power to the power distribution terminal.

[0100] Among them, the voltage terminal VCCO supplies voltage to the delay output unit 32. When the duration for which the voltage detection unit 31 stops supplying the control voltage reaches the target duration, that is, when the duration for which the voltage at the circuit input terminal VI is less than the first target voltage reaches the target duration, it is determined that the voltage at the circuit input terminal VI has lost power. The delay output unit 32 is in the conducting state and supplies the operating voltage to the circuit output terminal VCC1 according to the voltage at the voltage terminal V2. The operating voltage output by the circuit output terminal VCC1 is used for the auxiliary power supply module to perform the power supply operation, enabling the auxiliary power supply module to supply power to the power distribution terminal.

[0101] When the duration for which the voltage detection unit 31 stops supplying the control voltage does not reach the target duration, that is, when the duration for which the voltage at the circuit input terminal VI is less than the first target voltage does not reach the target duration, the delay output unit 32 is in the off state and stops supplying the operating voltage to the circuit output terminal VCC1, that is, the circuit output terminal VCC1 does not output voltage. When the voltage detection unit 31 supplies the control voltage, that is, when the voltage at the circuit input terminal VI is normal, the delay output unit 32 is in the off state based on the control of the control voltage and stops supplying the operating voltage to the circuit output terminal VCC1, that is, the circuit output terminal VCC1 does not output voltage. When the circuit output terminal VCC1 does not output voltage, the auxiliary power supply module cannot perform the power supply operation, and the auxiliary power supply module does not supply power to the power distribution terminal.

[0102] The power loss detection delay circuit 3 in this embodiment determines that the voltage at the circuit input terminal VI has lost power when the duration for which the voltage at the circuit input terminal is less than the first target voltage reaches the target duration, avoiding detecting short-term voltage fluctuations as power loss, improving the accuracy of power loss detection, and avoiding the auxiliary power supply module supplying power to the power distribution terminal during short-term voltage fluctuations, reducing the power supply frequency of the auxiliary power supply module, increasing the service life of the auxiliary power supply module, and improving power supply stability.

[0103] In some embodiments, the delay output unit 32 includes a fifth transistor Q2. The control terminal of the fifth transistor Q2 is connected to the voltage detection unit 31, the first terminal of the fifth transistor Q2 is connected to the voltage terminal V2, and the second terminal of the fifth transistor Q2 is connected to the circuit output terminal VCC1. Among them, the fifth transistor Q2 can be a triode, the control terminal of the fifth transistor Q2 can be the base of the triode, the first terminal of the fifth transistor Q2 can be the collector of the triode, and the second terminal of the fifth transistor Q2 can be the emitter of the triode.

[0104] The delay output unit 32 is further configured to turn on the fifth transistor Q2 when the duration that the voltage of the circuit input terminal VI is less than the first target voltage reaches the target duration, connect the voltage terminal V2 to the circuit output terminal VCC1, and supply the operating voltage to the circuit output terminal VCC1 according to the voltage of the voltage terminal V2; when the voltage of the circuit input terminal VI is normal, turn off the fifth transistor Q2 according to the control voltage, disconnect the voltage terminal V2 from the circuit output terminal VCC1, and stop supplying the operating voltage to the circuit output terminal VCC1.

[0105] When the duration that the voltage of the circuit input terminal VI is less than the first target voltage reaches the target duration, it is determined that the voltage of the circuit input terminal VI drops. The voltage detection unit 31 does not output voltage to the delay output unit 32, and the control terminal voltage of the fifth transistor Q2 is increased to its threshold voltage through the voltage of the voltage terminal V2. The fifth transistor Q2 is turned on, the voltage terminal V2 is connected to the circuit output terminal VCC1, and the circuit output terminal VCC1 outputs the operating voltage for the auxiliary power supply module to perform the power supply operation, so that the auxiliary power supply module supplies power to the power distribution terminal.

[0106] When the duration that the voltage of the circuit input terminal VI is less than the first target voltage does not reach the target duration, the voltage detection unit 31 does not output voltage to the delay output unit 32, the control terminal voltage of the fifth transistor Q2 is less than its threshold voltage, the fifth transistor Q2 is in the off state, the voltage terminal V2 is disconnected from the circuit output terminal VCC1, and the circuit output terminal VCC1 does not output voltage.

[0107] When the voltage of the circuit input terminal VI is normal, the voltage detection unit 31 outputs a control voltage to the delay output unit 32. This control voltage pulls down the control terminal voltage of the fifth transistor Q2, the fifth transistor Q2 is in the off state, the voltage terminal V2 is disconnected from the circuit output terminal VCC1, and the circuit output terminal VCC1 does not output voltage.

[0108] In some embodiments, the delay output unit 32 further includes a charging resistor R6 and a charging capacitor C3. One end of the charging capacitor C3 is connected to the control terminal of the fifth transistor Q2, the other end of the charging capacitor C3 is grounded, one end of the charging resistor R6 is connected to the voltage terminal V2, and the other end of the charging resistor R6 is connected to the control terminal of the fifth transistor Q2. Among them, the charging resistor R6 and the charging capacitor C3 form an RC charging circuit. The charging capacitor C3 can be an electrolytic capacitor.

[0109] The delay output unit 32 is further configured to charge the charging capacitor C3 through the charging resistor R6 with the voltage of the voltage terminal V2 when the voltage of the circuit input terminal VI is less than the first target voltage, so as to increase the control terminal voltage of the fifth transistor Q2; when the charging duration of the charging capacitor C3 reaches the target duration, increase the control terminal voltage of the fifth transistor Q2 to its threshold voltage to turn on the fifth transistor Q2.

[0110] When the voltage at the circuit input terminal VI is less than the first target voltage, the voltage detection unit 31 does not output a voltage to the delay output unit 32. The voltage at the control terminal of the fifth transistor Q2 is 0, and the fifth transistor Q2 is in the off state. The voltage at the voltage terminal V2 charges the charging capacitor C3 through the charging resistor R6, and slowly raises the voltage at the control terminal of the fifth transistor Q2. When the charging duration of the charging capacitor C3 reaches the target duration, the voltage at the control terminal of the fifth transistor Q2 rises to its threshold voltage, and the fifth transistor Q2 switches from the off state to the on state, connecting the voltage terminal V2 to the circuit output terminal VCC1, and the circuit output terminal VCC1 outputs the working voltage.

[0111] Among them, the target duration T can be adjusted according to the capacitance value of the charging capacitor C3 and the resistance value of the charging resistor R6, that is, T = R6 * C3. The capacitance value of the charging capacitor C3 can be in the order of microfarads, and the resistance value of the charging resistor R6 can be from dozens of KΩ to hundreds of KΩ.

[0112] In some embodiments, such as Figure 5 and Figure 6 shown, the delay output unit 32 further includes a first voltage regulator diode ZD2, an isolation diode D3, a fourth filter capacitor EC1, and a fifth filter capacitor C4. The control terminal of the fifth transistor Q2 is connected to the voltage detection unit 31. The first end of the first transistor Q2 is connected to the voltage terminal V2. The second end of the first transistor Q2 is connected to the positive electrode of the isolation diode D3. The negative electrode of the isolation diode D3 is connected to the circuit output terminal VCC1; one end of the charging resistor R6 is connected to the voltage terminal V2, and the other end of the charging resistor R6 is respectively connected to the control terminal of the fifth transistor Q2 and one end of the charging capacitor C3. The other end of the charging capacitor C3 is grounded; the voltage regulator diode ZD2 is connected in parallel with the charging capacitor C3; one end of the fourth filter capacitor EC1 is connected to the circuit output terminal VCC1, and the other end of the fourth filter capacitor EC1 is grounded; the fifth filter capacitor C4 is connected in parallel with the fourth filter capacitor EC1.

[0113] Among them, the fourth filter capacitor EC1 can be an electrolytic capacitor. The first voltage regulator diode ZD2 is used to prevent the voltage at the control terminal of the fifth transistor Q2 from being too high.

[0114] In some embodiments, the voltage detection unit 31 is further configured to determine that the voltage at the circuit input terminal VI returns to normal when the voltage at the circuit input terminal VI is greater than the fourth target voltage. When the voltage at the circuit input terminal VI is the DC voltage of the output terminal VBus of the voltage input unit 11, the fourth target voltage is greater than the second target voltage; when the voltage at the circuit input terminal VI is the first voltage of the output terminal V1 of the voltage conversion unit 12, the fourth target voltage is greater than the third target voltage.

[0115] When the voltage at the circuit input terminal VI drops, the voltage at the circuit input terminal VI is 0V. When the voltage at the circuit input terminal VI is greater than the fourth target voltage, it is determined that the voltage at the circuit input terminal VI has returned to normal, and the voltage detection unit 31 immediately switches from the off state to the on state, providing a control voltage to the delay output unit 32. Based on the control of the control voltage, the delay output unit 32 switches from the on state to the off state, stopping the supply of the working voltage to the circuit input terminal VCC1, that is, the circuit input terminal VCC1 does not output the working voltage, the auxiliary power supply module cannot perform the power supply operation, the auxiliary power supply module does not supply power to the power distribution terminal, and the main power supply supplies power to the power distribution terminal.

[0116] It should be noted that the fourth target voltage is greater than the second target voltage / the third target voltage, so that when the voltage at the circuit input terminal VI is stable, that is, when the voltage of the main power supply is stable, the auxiliary power supply module switches to the main power supply to supply power to the power distribution terminal, ensuring the power supply continuity of the power distribution terminal and avoiding the power distribution terminal from stopping or data loss caused by power supply interruption.

[0117] In some embodiments, the voltage detection unit 31 includes a switching element. As Figure 5 shown, the switching element may include an optocoupler U1; as Figure 6 shown, the switching element may also include a sixth transistor Q4.

[0118] The voltage detection unit 31 is further configured to turn on the switching element to provide a control voltage to the delay output unit 32 when the voltage at the circuit input terminal VI is normal; and turn off the switching element to stop providing the control voltage to the delay output unit 1 when the voltage at the circuit input terminal VI is less than the first target voltage.

[0119] When the voltage at the circuit input terminal VI is normal, the voltage at the circuit input terminal VI can turn on the switching element, the voltage detection unit 31 is in the on state, and provides a control voltage to the delay output unit 32. When the voltage at the circuit input terminal VI is less than the first target voltage, the voltage at the circuit input terminal VI is not sufficient to turn on the switching element, the voltage detection unit 31 is in the off state, and stops providing the control voltage to the delay output unit 32, that is, the voltage detection unit 31 does not output voltage to the delay output unit 32.

[0120] In some embodiments, the circuit input terminal VI is connected to the output terminal VBus of the voltage input unit 11, and the voltage at the circuit input terminal VI is the DC voltage of the output terminal VBus of the voltage input unit 11. As Figure 5 shown, the switching element includes an optocoupler U1, and the voltage detection unit 31 further includes a third diode D4, a sixth filter capacitor C2, a fifth resistor R8, a sixth resistor R7, a seventh resistor R12, and an eighth resistor R14.

[0121] The positive input terminal of optocoupler U1 is connected to the circuit input terminal VI through the serially connected fifth resistor R8 and sixth resistor R7. The negative input terminal of optocoupler U1 is grounded through the serially connected seventh resistor R12 and eighth resistor R14. The positive output terminal of optocoupler U1 is connected to the delay output unit 32, and the negative output terminal of optocoupler U1 is grounded. The negative electrode of the third diode D4 is connected to the positive input terminal of optocoupler U1, and the positive electrode of the third diode D4 is connected to the negative input terminal of optocoupler U1. The sixth filter capacitor C2 is connected in parallel with the third diode D4.

[0122] Among them, the positive output terminal of optocoupler U1 is connected to the control terminal of the fifth transistor Q2 in the delay output unit 32. The fifth resistor R8, sixth resistor R7, seventh resistor R12, and eighth resistor R14 are all current-limiting resistors. The sixth filter capacitor C2 functions as signal filtering, and the third diode D4 functions as overvoltage protection.

[0123] When the voltage at the circuit input terminal VI is normal, the light-emitting diode on the primary side of optocoupler U1 has current flowing through it, and the photosensitive triode on the secondary side of optocoupler U1 conducts, and current flows through it according to the current transfer ratio to provide a control voltage to the delay output unit 32. When the voltage at the circuit input terminal VI is less than the first target voltage, no current flows through the light-emitting diode on the primary side of optocoupler U1, the photosensitive triode on the secondary side of optocoupler U1 turns off, and stops providing a control voltage to the delay output unit 32, that is, the voltage detection unit 31 does not output a voltage to the delay output unit 32.

[0124] In some embodiments, the circuit input terminal VI is connected to the output terminal V1 of the voltage conversion unit 12, and the voltage at the circuit input terminal VI is the first voltage of the output terminal V1 of the voltage conversion unit 12. As Figure 6 shown, the switching element includes a sixth transistor Q4, and the voltage detection unit 31 further includes a ninth resistor R25, a tenth resistor R27, and an eleventh resistor R29. The control terminal of the sixth transistor Q4 is respectively connected to the ninth resistor R25 and the tenth resistor R27. The other end of the ninth resistor R25 is connected to the circuit input terminal VI, and the other end of the tenth resistor R27 is grounded. The first end of the second transistor Q4 is connected to the delay output unit 32, and the second end of the second transistor Q4 is grounded through the eleventh resistor R29.

[0125] Among them, the sixth transistor Q4 can be a triode. The control terminal of the sixth transistor Q4 can be the base of the triode, the first end of the sixth transistor Q4 can be the collector of the triode, and the second end of the sixth transistor Q4 can be the emitter of the triode. The ninth resistor R25 and the tenth resistor R27 are both voltage-dividing resistors.

[0126] When the voltage at the circuit input terminal VI is normal, the control terminal voltage of the sixth transistor Q4 reaches its threshold voltage, and the sixth transistor Q4 is in the conducting state, providing a control voltage to the delay output unit 32. When the voltage at the circuit input terminal VI is less than the first target voltage, the control terminal voltage of the sixth transistor Q4 does not reach its threshold voltage, and the sixth transistor Q4 is in the off state, stopping the supply of the control voltage to the delay output unit 32, that is, the voltage detection unit 31 does not output a voltage to the delay output unit 32.

[0127] In some embodiments, the voltage detection unit 31 is further configured to release the charging voltage of the charging capacitor C3 when the voltage at the circuit input terminal VI returns to normal.

[0128] When the voltage at the circuit input terminal VI is less than the second target voltage / the third target voltage, the voltage at the voltage terminal V2 charges the charging capacitor C3 through the charging resistor R6. When the voltage at the circuit input terminal VI returns to normal, it is necessary to release the charging voltage of the charging capacitor C3 to reduce the control terminal voltage of the fifth transistor Q2, turn off the fifth transistor Q2, so that the circuit output terminal VCC1 no longer outputs the working voltage, and the auxiliary power supply module no longer supplies power to the power distribution terminal.

[0129] As Figure 5 shown, when the switching element in the voltage detection unit 31 includes the optocoupler U1, when the voltage at the circuit input terminal VI returns to normal, the optocoupler U1 is in the conducting state, stimulating the charging capacitor C3 to discharge slowly. As Figure 6 shown, when the switching element in the voltage detection unit 31 includes the sixth transistor Q4, when the voltage at the circuit input terminal VI returns to normal, the sixth transistor Q4 is in the conducting state, and the charging voltage of the charging capacitor C3 is released through the eleventh resistor R29.

[0130] In some embodiments, as Figure 1 shown, the boost circuit 4 includes a first boost unit 41 and a second boost unit 42. The first boost unit 41 is connected to the energy storage unit 2 and is configured to convert the energy storage voltage into a second voltage. The power-down detection delay circuit 3 is respectively connected to the first boost unit 41 and the second boost unit 42, and is further configured to output a working voltage to the second boost unit 42 through the second voltage when the duration that the main power supply voltage is less than the first target voltage reaches the target duration. The second boost unit 42 is respectively connected to the energy storage unit 2 and the power output terminal 5, and is configured to perform a power supply operation under the working voltage to convert the energy storage voltage into a power supply voltage and provide it to the power output terminal 5.

[0131] Among them, the first boost unit 41 is connected to the voltage terminal VBAT of the energy storage unit 2 to access the energy storage voltage of the energy storage unit 2 and boost the energy storage voltage to a second voltage. The output terminal of the first boost unit 41 outputs the second voltage. The voltage terminal V2 of the power-down detection delay circuit 3 is connected to the output terminal VCC0 of the first boost unit 41, and the voltage of the voltage terminal V2 of the power-down detection delay circuit 3 is the second voltage of the output terminal VCC0 of the first boost unit 41. The circuit output terminal VCC1 of the power-down detection delay circuit 3 is connected to the second boost unit 42.

[0132] When the power-down detection delay circuit 3 detects that the main power supply voltage is normal, it controls the disconnection between the voltage terminal V2 and the circuit output terminal VCC1 of the power-down detection delay circuit 3 to stop outputting the working voltage to the second boost unit 42; when the power-down detection delay circuit 3 detects that the duration of the main power supply voltage being less than the first target voltage does not reach the first target duration, it controls the disconnection between the voltage terminal V2 and the circuit output terminal VCC1 of the power-down detection delay circuit 3 to stop outputting the working voltage to the second boost unit 42; when the power-down detection delay circuit 3 detects that the duration of the main power supply voltage being less than the first target voltage reaches the first target duration, it controls the connection between the voltage terminal V2 and the circuit output terminal VCC1 of the power-down detection delay circuit 3 and outputs the working voltage to the second boost unit 42 through the second voltage.

[0133] The second boost unit 42 is connected to the voltage terminal VBAT of the energy storage unit 2 to access the energy storage voltage of the energy storage unit 2. When the second boost unit 42 is in the power supply operation, it converts the energy storage voltage provided by the energy storage unit 3 into a power supply voltage. The output terminal VC of the second boost unit 42 is connected to the power supply output terminal 5, so that the power supply output terminal 5 outputs the power supply voltage to the power distribution terminal, realizing power supply to the power distribution terminal by the auxiliary power supply module in the case of power failure of the main power supply voltage.

[0134] In some embodiments, the first boost unit 41 is further configured to stop converting the energy storage voltage into the second voltage when the energy storage voltage is less than the second voltage threshold.

[0135] In the case of power failure of the main power supply voltage, the auxiliary power supply module supplies power to the power distribution terminal, and the energy storage unit 2 is in the discharge state. When the energy storage voltage of the energy storage unit 2 is lower than the second voltage threshold, the first boost unit 41 does not work, the first boost unit 41 does not output the second voltage to the power-down detection delay circuit 3, the power-down detection delay circuit 3 does not output the working voltage to the second boost unit 42, the second boost unit 42 does not perform the power supply operation, and the auxiliary power supply module no longer supplies power to the power distribution terminal, so as to realize the undervoltage protection of the energy storage unit 2.

[0136] In some embodiments, such as Figures 7 to 9As shown, the first boost unit 41 includes a start-up resistor R21, and the first boost unit 41 is connected to the second boost unit 42 through the start-up resistor R21. The second boost unit 42 is further configured to pull down the working voltage to stop the power supply operation when the power output terminal 5 is short-circuited. The first boost unit 41 is further configured to charge the second boost unit 42 through the start-up resistor R21 to increase the working voltage and enable the second boost unit to resume the power supply operation.

[0137] When the power output terminal 5 is short-circuited, the second boost unit 42 pulls down the working voltage to be lower than the start-up minimum voltage for short-circuit protection. At this time, the second boost unit 42 does not perform the power supply operation, that is, it does not output a power supply voltage to the power output terminal 5. After the short circuit of the power output terminal 5 is eliminated, the first boost unit 41 charges the power supply terminal of the second boost unit 42 (this power supply terminal is connected to the working voltage) through the start-up resistor R21, the working voltage rises again, and the second boost unit 42 resumes the power supply operation to provide a power supply voltage to the power output terminal 5, thereby realizing the function of short-circuit self-recovery.

[0138] In some embodiments, as Figures 7 to 9 shown, the first boost unit 41 further includes a boost inductor L2, a boost diode D6, a boost chip U2, an enable circuit, and a second feedback circuit; the second boost unit 42 includes a transformer (i.e., the second transformer T3), a flyback absorption circuit (i.e., the second flyback absorption circuit 421), a boost control circuit 423, a third transistor Q8, and a third feedback circuit 424.

[0139] The voltage terminal VBAT of the energy storage unit 2 is connected to the second secondary coil T3B2 of the second transformer T3 through the series-connected boost inductor L2, boost diode D6, and start-up resistor R21; the input terminal IN and the control terminal SW of the boost chip U2 are respectively connected to both ends of the boost inductor L2, the enable terminal EN of the boost chip U2 is connected to the voltage terminal VBAT of the energy storage unit 2 through the enable circuit, and the feedback terminal FB of the boost chip U2 is connected to the negative electrode of the boost diode D6 through the second feedback circuit.

[0140] One end of the primary coil T3A of the second transformer T3 is respectively connected to the voltage terminal VBAT of the energy storage unit 2 and the second flyback absorption circuit 421, the other end of the primary coil T3A of the second transformer T3 is respectively connected to the second flyback absorption circuit 421 and the second end of the third transistor Q8, the boost control circuit 423 is respectively connected to the circuit output terminal VCC1 of the power-off detection delay circuit 3, the third feedback circuit 424, and the control terminal and the first end of the third transistor Q8; the first secondary coil T3B1 of the second transformer T3 and the third feedback circuit 424 are respectively connected to the power output terminal 5.

[0141] In some embodiments, the second boost unit 42 further includes a second rectifying and filtering circuit 425, a twelfth resistor R44, a third filter capacitor C7, and a fourth diode D7. One end of the first secondary coil T3B1 of the second transformer T3 and the third feedback circuit 424 are respectively connected to the output terminal VC of the second boost unit 42 through the second rectifying and filtering circuit 425. The output terminal VC of the second boost unit 42 is connected to the power output terminal 5, and the other end of the first secondary coil T3B1 of the second transformer T3 is grounded. The first end of the third transistor Q8 is grounded through one end of the twelfth resistor R44.

[0142] One end of the second secondary coil T3B2 of the second transformer T3 is connected to the positive electrode of the fourth diode D7, the negative electrode of the fourth diode D7 is connected to the output terminal VCC0 of the first boost unit 41, and the other end of the second secondary coil T3B2 of the second transformer T3 is grounded; one end of the third filter capacitor C7 is connected to the output terminal VCC0 of the first boost unit 41, and the other end of the third filter capacitor C7 is grounded.

[0143] Among them, the twelfth resistor R44 is a primary current sampling resistor. The third transistor Q8 can be a MOS transistor. The control end of the third transistor Q8 can be the gate of the MOS transistor, the first end of the third transistor Q8 can be the source of the MOS transistor, and the second end of the third transistor Q8 can be the drain of the MOS transistor.

[0144] The main circuit topology of the second boost unit 42 adopts a flyback circuit topology. The energy storage voltage of the energy storage unit 2 is connected to the second boost unit 42 to generate a primary high-frequency pulse signal through the third transistor Q8. The boost control circuit 423 controls the on and off of the third transistor Q8. When the third transistor Q8 is turned on, the primary coil T3A of the second transformer T3 is excited by the energy storage voltage. At this time, the secondary of the second transformer T3 is in the reverse-biased cut-off state and does not output a supply voltage; after the third transistor Q8 is turned off, the energy stored in the primary coil T3A of the second transformer T3 is transferred to the secondary and outputs a supply voltage to the output terminal VC of the second boost unit 42 through the second rectifying and filtering circuit 425.

[0145] In some embodiments, the first boost unit 41 further includes a fifth diode D5 and a first capacitor C5. The fifth diode D5 is connected between the starting resistor R21 and the output terminal VCC0 of the first boost unit 41; one end of the first capacitor C5 is connected to the voltage terminal VBAT of the energy storage unit 2, and the other end of the first capacitor C5 is grounded.

[0146] The enabling circuit includes a thirteenth resistor R16, a fourteenth resistor R18, a fifteenth resistor R20, and a second capacitor C8. The enabling terminal EN of the boost chip U2 is respectively connected to one end of the thirteenth resistor R16 and one end of the fourteenth resistor R18. The other end of the thirteenth resistor R16 is grounded, and the other end of the fourteenth resistor R18 is connected to the voltage terminal VBAT of the energy storage unit 2; the fifteenth resistor R20 and the second capacitor C8 are respectively connected in parallel with the fourteenth resistor R18.

[0147] The second feedback circuit includes a sixteenth resistor R15, a seventeenth resistor R17, an eighteenth resistor R19, and a third capacitor C6. The feedback terminal FB of the boost chip U2 is respectively connected to one end of the sixteenth resistor R15, one end of the seventeenth resistor R17, and one end of the eighteenth resistor R19. The other end of the sixteenth resistor R15 is connected to the negative electrode of the boost diode D6, the other end of the seventeenth resistor R17 is grounded, and the other end of the eighteenth resistor R19 is grounded; one end of the third capacitor C6 is connected to the negative electrode of the boost diode D6, and the other end of the third capacitor C6 is grounded.

[0148] Among them, the first capacitor C5 is an input filter capacitor, the third capacitor C6 is an output filter capacitor, and the fifth diode D5 is an isolation diode. The stored energy voltage of the energy storage unit 2 is boosted to a supply voltage through the boost inductor L2 and the boost diode D6. When the stored energy voltage of the energy storage unit 2 is greater than or equal to the second voltage threshold, the boost chip U2 is enabled, and the output terminal VCC0 of the first boost unit 41 outputs the supply voltage; when the stored energy voltage of the energy storage unit 2 is less than the second voltage threshold, the first boost unit 41 does not work, and the output terminal VCC0 of the first boost unit 41 does not output the supply voltage, thereby achieving the purpose of undervoltage protection of the energy storage unit 2.

[0149] Moreover, after the boost circuit 4 is normally started, the output terminal VCC0 of the first boost unit 41 is connected to the secondary coil of the second transformer T3, and the secondary coil of the second transformer T3 provides power supply for the chip. When the power output terminal 5 is short-circuited, the boost control circuit 423 pulls down the supply voltage to be lower than the minimum startup voltage, and the second boost unit 42 does not supply power, realizing short-circuit protection. After the short circuit at the power output terminal 5 is eliminated, the first boost unit 4 charges the chip power supply terminal through the startup resistor R21 to increase the supply voltage, and the second boost unit 42 resumes power supply work, thereby achieving the function of short-circuit self-recovery.

[0150] In some embodiments, the auxiliary power supply module further includes an anti-ac reverse injection circuit 6. The anti-ac reverse injection circuit 6 is connected between the boost circuit 4 and the power output terminal 5, and is in a conducting state when the boost circuit 4 outputs the supply voltage, and supplies the supply voltage to the power output terminal 5; it is in a cut-off state when an ac voltage is input to the power output terminal 5, and disconnects the boost circuit 4 from the power output terminal 5.

[0151] The auxiliary power supply module in this embodiment also has the function of preventing AC backflow, which can effectively suppress the large inrush current at the moment of reverse connection when the AC voltage is poured back into the current output end 5, so as to ensure that the components in the auxiliary power supply module are not damaged.

[0152] In some embodiments, such as Figure 10 and Figure 11 shown, the AC backflow prevention circuit 6 includes a voltage input end, a voltage output end, a first backflow prevention unit 61 and a second backflow prevention unit 62. The voltage input end includes a positive input end VC+ and a negative input end VC-. The voltage output end includes a positive output end VOUT+ and a negative output end VOUT-.

[0153] Among them, the voltage input end of the AC backflow prevention circuit 6 is connected to the second boost unit 42. When the power supply voltage is output at the output end VC of the second boost unit 42, the voltage input at the voltage input end of the AC backflow prevention circuit 6 is the power supply voltage. The voltage output end of the AC backflow prevention circuit 6 is connected to the power output end 5.

[0154] The first backflow prevention unit 61 is respectively connected to the positive input end VC+ and the positive output end VOUT+, and is used to be in a conducting state when a voltage is input at the voltage input end; in the case where a positive AC voltage is input at the positive output end VOUT+ and a negative AC voltage is input at the negative output end VOUT-, it is in a cut-off state, so that the positive input end VC+ and the positive output end VOUT+ are disconnected.

[0155] The second backflow prevention unit 62 is respectively connected to the negative input end VC- and the negative output end VOUT-. The second backflow prevention unit 62 is also connected to the positive input end VC+ or the positive output end VOUT+, and is used to be in a conducting state when a voltage is input at the voltage input end; in the case where a negative AC voltage is input at the positive output end VOUT+ and a positive AC voltage is input at the negative output end VOUT-, it is in a cut-off state, so that the negative input end VC- and the negative output end VOUT- are disconnected.

[0156] Among them, when a voltage (i.e., the power supply voltage) is input at the voltage input end, a positive DC voltage is input at the positive input end VC+, the negative input end VC- is grounded, and both the first backflow prevention unit 61 and the second backflow prevention unit 62 are in a conducting state, so that the positive input end VC+, the negative input end VC-, the positive output end VOUT+ and the negative output end VOUT- are connected and communicated, the AC backflow prevention circuit 6 is in a conducting state, and the power supply voltage at the voltage input end is provided to the voltage output end, so that the power output end 5 outputs the power supply voltage to supply power to the power distribution terminal.

[0157] When an alternating current is input to the voltage output terminal, if a positive alternating voltage is input to the positive output terminal VOUT+ and a negative alternating voltage is input to the negative output terminal VOUT-, the first anti-backflow unit 61 is in the off state, disconnecting the positive input terminal VC+ from the positive output terminal VOUT+ to prevent the alternating current at the voltage output terminal from being transmitted to the voltage input terminal, that is, to prevent the backflow of alternating current. If a negative alternating voltage is input to the positive output terminal VOUT+ and a positive alternating voltage is input to the negative output terminal VOUT-, the second anti-backflow unit 62 is in the off state, disconnecting the negative input terminal VC- from the negative output terminal VOUT- to prevent the alternating current at the voltage output terminal from being transmitted to the voltage input terminal, that is, to prevent the backflow of alternating current and avoid damaging the auxiliary power supply module. Among them, the alternating current can be 220V or 380V alternating current.

[0158] In some embodiments, such as Figure 10 and Figure 11 shown, the first anti-backflow unit 61 includes an anti-backflow diode D1. The positive electrode of the anti-backflow diode D1 is connected to the positive input terminal VC+, and the negative electrode of the anti-backflow diode D1 is connected to the positive output terminal VC-.

[0159] When a supply voltage is input to the voltage input terminal, a positive direct current voltage is input to the positive input terminal VC+ and the negative input terminal VC- is grounded. The anti-backflow diode D1 conducts, and the first anti-backflow unit 61 is in the on state. When an alternating current is input to the voltage output terminal, if a positive alternating voltage is input to the positive output terminal VOUT+ and a negative alternating voltage is input to the negative output terminal VOUT-, the anti-backflow diode D1 turns off, and the first anti-backflow unit 61 is in the off state, disconnecting the positive input terminal VC+ from the positive output terminal VOUT+ to prevent the backflow of alternating current. If a negative alternating voltage is input to the positive output terminal VOUT+ and a positive alternating voltage is input to the negative output terminal VOUT-, the anti-backflow diode D1 can conduct, and the first anti-backflow unit 61 is in the on state, but the second anti-backflow unit 62 is in the off state to prevent the backflow of alternating current.

[0160] In some embodiments, such as Figure 10 shown, the second anti-backflow unit 62 includes a seventh transistor Q1 and a thermistor PTC1. The control terminal of the seventh transistor Q1 is connected to the positive input terminal VC+, the first terminal of the seventh transistor Q1 is connected to the negative input terminal VC-, the second terminal of the seventh transistor Q1 is connected to one end of the thermistor PTC1, and the other end of the thermistor PTC1 is connected to the negative output terminal VOUT-. Among them, the seventh transistor Q1 can be a MOS transistor with an internal diode. The control terminal of the seventh transistor Q1 can be the gate of the MOS transistor, the first terminal of the seventh transistor Q1 can be the source of the MOS transistor, and the second terminal of the seventh transistor Q1 can be the drain of the MOS transistor.

[0161] The second anti-backflow unit 62 is also configured to turn on the seventh transistor Q1 to make the second anti-backflow unit 62 in a conducting state when a power supply voltage is input at the voltage input terminal; when a negative AC voltage is input at the positive output terminal VOUT+ and a positive AC voltage is input at the negative output terminal VOUT-, increase the resistance value of the thermistor PTC1, turn off the seventh transistor Q1, so as to disconnect between the negative input terminal VC- and the negative output terminal VOUT-.

[0162] When a power supply voltage is input at the voltage input terminal, a positive DC voltage is input at the positive input terminal VC+ and the negative input terminal VC- is grounded, the seventh transistor Q1 is turned on, and the second anti-backflow unit 62 is in a conducting state. When an alternating current is input at the voltage output terminal, if a positive AC voltage is input at the positive output terminal VOUT+ and a negative AC voltage is input at the negative output terminal VOUT-, the anti-backflow diode D1 is turned off, and the current cannot flow into the second anti-backflow unit 62, preventing the alternating current from flowing back; if a negative AC voltage is input at the positive output terminal VOUT+ and a positive AC voltage is input at the negative output terminal VOUT-, a large current instantaneously flows through the seventh transistor Q1, the thermistor PTC1 generates serious heat after the large current flows through it, the resistance value of the thermistor PTC1 rises sharply, and at the same time, since the control terminal voltage of the seventh transistor Q1 does not reach its threshold voltage, the seventh transistor Q1 is turned off, the second anti-backflow unit 62 is in a turned-off state, disconnecting between the negative input terminal VC- and the negative output terminal VOUT-, preventing the alternating current from flowing back.

[0163] In some embodiments, the second anti-backflow unit 62 further includes a twenty-third resistor R4, a twenty-fourth resistor R3, a twenty-fifth resistor R5, a second filter capacitor C1, and a second zener diode ZD1.

[0164] The control terminal of the seventh transistor Q1 is connected to one end of the twenty-third resistor R4, the other end of the twenty-third resistor R4 is respectively connected to one end of the twenty-fourth resistor R3 and one end of the twenty-fifth resistor R5, the other end of the twenty-fourth resistor R3 is connected to the positive input terminal VC+, the other end of the twenty-fifth resistor R5 is respectively connected to the negative input terminal VC- and the first end of the seventh transistor Q1, and the second end of the seventh transistor Q1 is connected to the negative output terminal VOUT- through the thermistor PTC1; the second filter capacitor C1 and the second zener diode ZD1 are respectively connected in parallel with the twenty-fifth resistor R5.

[0165] Among them, the twenty-third resistor R4 is a current-limiting resistor for the control terminal of the seventh transistor Q1, the twenty-fourth resistor R3 and the twenty-fifth resistor R5 are both voltage-dividing resistors, and the second zener diode ZD1 is used to ensure that overvoltage failure does not occur at the control terminal of the seventh transistor Q1.

[0166] In some embodiments, such as Figure 11As shown, the second anti-backflow unit 62 includes a relay K1. Two ends of the contacts of the relay K1 are respectively connected to the negative input terminal VC- and the negative output terminal VOUT-. Two ends of the coil of the relay K1 are respectively connected to the positive output terminal VOUT+ and the negative output terminal VOUT-.

[0167] The second anti-backflow unit 62 is further configured to control the contacts of the relay K1 to close when a power supply voltage is input at the voltage input terminal, so that the second anti-backflow unit 62 is in a conducting state; when a negative AC voltage is input at the positive output terminal VOUT+ and a positive AC voltage is input at the negative output terminal VOUT-, control the contacts of the relay K1 to disconnect, so as to disconnect between the negative input terminal VC- and the negative output terminal VOUT-.

[0168] When a power supply voltage is input at the voltage input terminal, a positive DC voltage is input at the positive input terminal VC+, the negative input terminal VC- is grounded, the positive output terminal VOUT+ outputs a positive voltage, the negative output terminal VOUT- outputs a negative voltage, and the voltage difference between the positive output terminal VOUT+ and the negative output terminal VOUT- is applied to the coil of the relay K1, and the contacts of the relay K1 close, and the second anti-backflow unit 62 is in a conducting state. When an alternating current is input at the voltage output terminal, if a positive AC voltage is input at the positive output terminal VOUT+ and a negative AC voltage is input at the negative output terminal VOUT-, the anti-backflow diode D1 is turned off, and the current cannot flow into the second anti-backflow unit 62 to prevent the alternating current from flowing back; if a negative AC voltage is input at the positive output terminal VOUT+ and a positive AC voltage is input at the negative output terminal VOUT-, no voltage is applied to the coil of the relay K1, the contacts of the relay K1 disconnect, and the second anti-backflow unit 62 is in a turned-off state, disconnecting between the negative input terminal VC- and the negative output terminal VOUT- to prevent the alternating current from flowing back.

[0169] In some embodiments, the second anti-backflow unit 62 further includes a twenty-sixth resistor R34, a freewheeling diode D12, and a sixth diode D14.

[0170] Two ends of the contacts of the relay K1 are respectively connected to the negative input terminal VC- and the negative output terminal VOUT-. Two ends of the coil of the relay K1 are respectively connected to the anode and the cathode of the freewheeling diode D12; the anode of the sixth diode D14 is connected to the anode of the freewheeling diode D12, and the cathode of the sixth diode D14 is connected to the negative output terminal VOUT-; one end of the twenty-sixth resistor R34 is connected to the cathode of the freewheeling diode D12, and the other end of the twenty-sixth resistor R34 is connected to the positive output terminal VOUT+.

[0171] In some embodiments, the anti - AC back - feeding circuit further includes an alarm unit 3. The first anti - back - feeding unit 61 is further configured to be in a conducting state when a negative AC voltage is input to the positive output terminal VOUT + and a positive AC voltage is input to the negative output terminal VOUT -. The alarm unit 2 is respectively connected to the positive input terminal VC +, the negative output terminal VOUT - and the first anti - back - feeding unit 61, and is configured to give an alarm when a negative AC voltage is input to the positive output terminal VOUT + and a positive AC voltage is input to the negative output terminal VOUT -.

[0172] When a voltage is input at the voltage input terminal, a positive DC voltage is input to the positive input terminal VC + and the negative input terminal VC - is grounded, and the alarm unit 3 does not give an alarm. When an alternating current is input at the voltage output terminal, if a positive AC voltage is input to the positive output terminal VOUT + and a negative AC voltage is input to the negative output terminal VOUT -, the first anti - back - feeding unit 61 is in an off state, and current cannot flow into the alarm unit 3, and the alarm unit 3 does not give an alarm; if a negative AC voltage is input to the positive output terminal VOUT + and a positive AC voltage is input to the negative output terminal VOUT -, the alarm unit 3 gives an alarm.

[0173] In some embodiments, the alarm unit 3 includes a light - emitting unit. The alarm unit 3 is further configured to control the light - emitting unit to emit light for alarm when a negative AC voltage is input to the positive output terminal VOUT + and a positive AC voltage is input to the negative output terminal VOUT -.

[0174] When a voltage is input at the voltage input terminal, a positive DC voltage is input to the positive input terminal VC + and the negative input terminal VC - is grounded, the first anti - back - feeding unit 61 is in a conducting state, the light - emitting unit in the alarm unit 3 is short - circuited, the light - emitting unit does not emit light, and the alarm unit 3 does not give an alarm. When an alternating current is input at the voltage output terminal, if a positive AC voltage is input to the positive output terminal VOUT + and a negative AC voltage is input to the negative output terminal VOUT -, the first anti - back - feeding unit 61 is in an off state, current cannot flow into the alarm unit 3, the light - emitting unit does not emit light, and the alarm unit 3 does not give an alarm; if a negative AC voltage is input to the positive output terminal VOUT + and a positive AC voltage is input to the negative output terminal VOUT -, the first anti - back - feeding unit 61 is in a conducting state, the light - emitting unit in the alarm unit 3 is conducting, the light - emitting unit emits light, and the alarm unit 3 gives an alarm.

[0175] In some embodiments, the light - emitting unit includes a light - emitting diode LED1, and the alarm unit 3 further includes a seventh diode D2, a twenty - seventh resistor R2 and a twenty - eighth resistor R1.

[0176] The positive electrode of the light-emitting diode LED1 is connected to the negative output terminal VOUT-, and the negative electrode of the light-emitting diode LED1 is respectively connected to the positive input terminal VC+ and the first anti-backflow unit 61 through the serially connected twenty-seventh resistor R2 and twenty-eighth resistor R1; the positive electrode of the seventh diode D2 is connected to the negative electrode of the light-emitting diode LED1, and the negative electrode of the seventh diode D2 is connected to the positive electrode of the light-emitting diode LED1.

[0177] Wherein, when the first anti-backflow unit 61 includes an anti-backflow diode D1, the negative electrode of the light-emitting diode LED1 is respectively connected to the positive input terminal VC+ and the positive electrode of the anti-backflow diode D1 through the serially connected twenty-seventh resistor R2 and twenty-eighth resistor R1. Both the twenty-seventh resistor R2 and the twenty-eighth resistor R1 are current-limiting resistors to limit the current flowing through the light-emitting diode LED1. The seventh diode D2 is used to short-circuit the light-emitting diode LED1 when a voltage is input to the voltage input terminal.

[0178] According to the auxiliary power supply module provided by the embodiment of the present application, when the main power supply voltage is normal, the charging circuit charges the energy storage unit through the main power supply voltage. When the duration that the main power supply voltage is less than the first target voltage reaches the target duration, the power-off detection delay circuit determines that the main power supply voltage is powered off. The boost circuit converts the stored energy voltage of the energy storage unit into a supply voltage to supply power to the power distribution terminal, avoiding detecting a short-term fluctuation of the main power supply voltage as a power-off, thereby preventing the auxiliary power supply module from supplying power to the power distribution terminal during a short-term fluctuation of the main power supply voltage, improving the service life of the auxiliary power supply module, and improving the power supply stability.

[0179] Moreover, when the energy storage unit 2 has an overvoltage fault, overvoltage protection is performed on the energy storage unit 2. When the energy storage unit 2 has a short-circuit fault, short-circuit protection is performed on the energy storage unit 2. When the voltage of the energy storage unit 2 is relatively low, power supply to the power distribution terminal is stopped to prevent over-discharge of the energy storage unit 2. When a short-circuit fault occurs at the power output terminal 5, short-circuit protection is performed on the auxiliary power supply module, and it can self-recover after the short circuit at the power output terminal 5 is eliminated. When an AC voltage is connected to the power output terminal 5, reverse power feeding of the alternating current is prevented and an alarm is given.

[0180] In addition, the auxiliary power supply module is arranged in the power supply box, which can be installed at the meter tail of the power distribution terminal. By modifying the meter tail cover, the transformation of the existing terminal equipment can be completed. The installation method is simple, and it can be matched without changing the original wiring method of the terminal or modifying the terminal. The size of the power supply box is 147mm×27mm, meeting the requirement of miniaturization. At the same time, the power supply box is designed for waterproof and detachable, facilitating operation and maintenance.

[0181] Correspondingly, the embodiment of the present application also provides a power distribution system.

[0182] The power distribution system provided by the embodiment of the present application includes an auxiliary power supply module and a power distribution terminal. Among them, the auxiliary power supply module is the auxiliary power supply module in the above embodiment. The power distribution terminal is connected to the power output end of the auxiliary power supply module and is used to be powered by the main power supply voltage when the main power supply voltage is normal; when the duration that the main power supply voltage is less than the first target voltage reaches the target duration, it is powered by the power supply voltage output by the auxiliary power supply module. Among them, the power distribution terminal may include at least one of a dedicated transformer terminal and a meter device (such as a three-phase meter).

[0183] The power distribution terminal includes a main power supply end and an auxiliary power supply end. The main power supply end is connected to the main power supply voltage, and the auxiliary power supply end is connected to the power output end of the auxiliary power supply module. When the main power supply voltage is normal, the main power supply voltage supplies power to the power distribution terminal through the main power supply end. When the duration that the main power supply voltage is less than the first target voltage reaches the target duration, the auxiliary power supply module determines that the main power supply voltage has lost power, and the auxiliary power supply module outputs a power supply voltage to the power distribution terminal through the auxiliary power supply end to supply power to the power distribution terminal, so that the power distribution terminal can continue to work, complete power outage event reporting, time-of-use power consumption data uploading, etc.

[0184] The terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually of the same category, and do not limit the number of objects. For example, the first object can be one or more.

[0185] In the description of the present application, "a plurality" means two or more.

[0186] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0187] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. An auxiliary power supply module, characterized in that, It includes a charging circuit, an energy storage unit, a power-off detection delay circuit, a boost circuit, and a power output terminal; The charging circuit is connected to the energy storage unit and is used to charge the energy storage unit with the main power supply voltage when the main power supply voltage is normal; The power-off detection delay circuit is respectively connected to the charging circuit and the boost circuit and is used to output a working voltage to the boost circuit when the duration that the main power supply voltage is less than a first target voltage reaches a target duration; The energy storage unit is connected to the boost circuit and is used to output an energy storage voltage to the boost circuit; The boost circuit is connected to the power output terminal and is used to perform a power supply operation under the working voltage to convert the energy storage voltage into a supply voltage and provide it to the power output terminal, and the supply voltage is used to supply power to a power distribution terminal.

2. The auxiliary power supply module according to claim 1, characterized in that, The charging circuit includes a voltage input unit, a voltage conversion unit, and a charging management unit; The voltage input unit is used to convert the main power supply voltage into a DC voltage; The voltage conversion unit is connected to the voltage input unit and is used to convert the DC voltage into a first voltage; The charging management unit is connected to the voltage conversion unit and is used to charge the energy storage unit with a constant current through the first voltage when the main power supply voltage is normal.

3. The auxiliary power supply module according to claim 2, wherein The power-off detection delay circuit is connected to the voltage input unit and is further used to determine that the duration that the main power supply voltage is less than the first target voltage reaches the target duration when the duration that the DC voltage is less than a second target voltage reaches the target duration; Alternatively, the power-off detection delay circuit is connected to the voltage conversion unit and is further used to determine that the duration that the main power supply voltage is less than the first target voltage reaches the target duration when the duration that the first voltage is less than a third target voltage reaches the target duration.

4. The auxiliary power supply module according to claim 2, wherein The charging management unit is further used to stop charging the energy storage unit when the voltage of the energy storage unit reaches a first voltage threshold; and reduce the charging current of the energy storage unit in the case of a short circuit of the energy storage unit.

5. The auxiliary power supply module according to claim 4, characterized in that, The charging management unit includes a first transistor, a second transistor, and a charging inductor; The charging management unit is further used to periodically control the first transistor and the second transistor to conduct and turn off simultaneously in the case of a short circuit of the energy storage unit. When the first transistor and the second transistor conduct simultaneously, charge the charging inductor with the first voltage. When the first transistor and the second transistor turn off simultaneously, charge the energy storage unit through the charging inductor.

6. The auxiliary power supply module according to claim 5, characterized in that, The charging management unit further includes a constant current chip, a sampling resistor, an output capacitor, and a first feedback circuit; The input terminal and the enable terminal of the constant current chip are respectively connected to the voltage conversion unit. One end of the sampling resistor is connected to the voltage conversion unit, and the other end of the sampling resistor is respectively connected to the sampling terminal of the constant current chip and the second terminal of the second transistor. The control terminal of the second transistor is connected to the first output terminal of the constant current chip. The first terminal of the second transistor is connected to one end of the charging inductor. The other end of the charging inductor is respectively connected to the second terminal of the first transistor and the energy storage unit. The control terminal of the first transistor is connected to the second output terminal of the constant current chip. The first terminal of the first transistor is grounded. One end of the first feedback circuit is connected to the energy storage unit, and the other end of the first feedback circuit is connected to the feedback terminal of the constant current chip; One end of the output capacitor is connected to the energy storage unit, and the other end of the output capacitor is grounded.

7. The auxiliary power supply module according to claim 1, wherein The boost circuit includes a first boost unit and a second boost unit; The first boost unit is connected to the energy storage unit and is used to convert the energy storage voltage into a second voltage; The power-down detection delay circuit is respectively connected to the first boost unit and the second boost unit, and is further used to output the working voltage to the second boost unit through the second voltage when the duration that the main power supply voltage is less than the first target voltage reaches the target duration; The second boost unit is respectively connected to the energy storage unit and the power supply output terminal, and is used to perform a power supply operation under the working voltage to convert the energy storage voltage into the power supply voltage and provide it to the power supply output terminal.

8. The auxiliary power supply module according to claim 7, wherein The first boost unit is further used to stop converting the energy storage voltage into the second voltage when the energy storage voltage is less than the second voltage threshold; 9. The auxiliary power supply module according to claim 7, wherein The first boost unit includes a starting resistor, and the first boost unit is connected to the second boost unit through the starting resistor; The second boost unit is further used to pull down the working voltage to stop the power supply operation in the case of a short circuit at the power supply output terminal; The first boost unit is further used to charge the second boost unit through the starting resistor to increase the working voltage and enable the second boost unit to resume the power supply operation.

10. The auxiliary power supply module according to claim 9, characterized in that, The first boost unit further includes a boost inductor, a boost diode, a boost chip, an enable circuit and a second feedback circuit; the second boost unit includes a transformer, a flyback absorption circuit, a boost control circuit, a third transistor and a third feedback circuit; The energy storage unit is connected to the second secondary coil of the transformer through the series-connected boost inductor, boost diode and starting resistor. The input terminal and the control terminal of the boost chip are respectively connected to both ends of the boost inductor. The enable terminal of the boost chip is connected to the energy storage unit through the enable circuit. The feedback terminal of the boost chip is connected to the negative electrode of the boost diode through the second feedback circuit; One end of the primary coil of the transformer is respectively connected to the energy storage unit and the flyback absorption circuit, and the other end of the primary coil of the transformer is respectively connected to the flyback absorption circuit and the second end of the third transistor. The boost control circuit is respectively connected to the power-down detection delay circuit, the third feedback circuit, the control end and the first end of the third transistor; the first secondary coil of the transformer and the third feedback circuit are respectively connected to the power output terminal.

11. The auxiliary power supply module according to claim 1, characterized in that The auxiliary power supply module further includes an anti-AC backflow circuit; The anti-AC backflow circuit is connected between the boost circuit and the power output terminal, and is in a conducting state when the boost circuit outputs the supply voltage, and supplies the supply voltage to the power output terminal; It is in an off state when an AC voltage is input to the power output terminal, so that the boost circuit is disconnected from the power output terminal.

12. The auxiliary power supply module according to any one of claims 1-11, characterized in that, The energy storage unit includes a storage battery, and the storage battery includes any one of a lithium battery, a nickel-metal hydride battery, and a lead-acid battery.

13. A power distribution system, characterized in that, Including: The auxiliary power supply module according to any one of claims 1-12; A power distribution terminal, connected to the power output terminal of the auxiliary power supply module, for being powered by the main power supply voltage when the main power supply voltage is normal; When the duration that the main power supply voltage is less than the first target voltage reaches the target duration, it is powered by the supply voltage output by the auxiliary power supply module.

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