Switching power supply circuit, control method and system for intelligent electric energy meter

Abstract

The invention relates to the technical field of switching power supplies, and provides a switching power supply circuit, a control method and a system for an intelligent electric energy meter, and the circuit comprises a main power module which is connected between a power grid voltage and the intelligent electric energy meter and is used for providing a power supply for the intelligent electric energy meter; the fault detection module is connected to the main power supply module and the auxiliary power supply module and is used for carrying out fault detection on the main power supply module and determining whether the main power supply module has a fault; and the auxiliary power supply module is connected in parallel with the main power supply module between the power grid voltage and the intelligent electric energy meter, is connected to the fault detection module, and is used for providing a power supply for the intelligent electric energy meter when the main power supply module fails. Through the scheme, reliability of the switching power supply is guaranteed, and power consumption and electromagnetic interference of the switching power supply are reduced.

Description

[Technical field]

[0001] The present invention relates to the technical field of switching power supplies, and in particular to a switching power supply circuit, a control method and a system for a smart electric energy meter. [Background technology]

[0002] The power chip is the core component of the entire switching power supply, which determines the reliability, working efficiency, electromagnetic compatibility and other performance of the switching power supply. However, with the widespread access of new energy sources to the grid, the complexity of the power grid continues to increase. For example, the input of uncertain voltage, high three-phase four-wire input voltage, harmonic interference and other situations continue to increase, resulting in a significant increase in the failure rate of the switching power supply of smart energy meters, and the reliability of the power supply is greatly affected. [Summary of the invention]

[0003] The embodiments of the present invention provide a switching power supply circuit, a control method and a system for a smart electric energy meter, aiming to solve the technical problems existing in the related art.

[0004] In a first aspect, an embodiment of the present invention provides a switching power supply circuit for a smart electric energy meter, comprising:

[0005] A main power supply module, a fault detection module and a secondary power supply module;

[0006] The main power supply module is connected between the grid voltage and the smart energy meter, and is used to provide power for the smart energy meter;

[0007] The fault detection module is connected between the main power module and the auxiliary power module, and is used to perform fault detection on the main power module to determine whether the main power module fails;

[0008] The secondary power supply module is connected in parallel with the main power supply module, and is connected between the grid voltage and the smart power meter, and is connected to the fault detection module, and is used to provide power to the smart power meter when the main power supply module fails.

[0009] In one embodiment, optionally, the main power module includes a silicon carbide MOSFET power chip, and the auxiliary power module includes a common silicon MOSFET power chip.

[0010] In one embodiment, optionally, it further includes:

[0011] The preprocessing module is connected between the grid voltage and the main power module and the auxiliary power module, and is used for preprocessing the voltage output by the grid voltage.

[0012] In one embodiment, optionally, the preprocessing module includes:

[0013] EMC processing unit and full-wave rectification unit;

[0014] The EMC processing unit is connected to the grid voltage and is used to perform electromagnetic compatibility processing on the output of the grid voltage;

[0015] The full-wave rectification unit is connected to the EMC processing unit and is used for converting the input alternating current into direct current.

[0016] In one embodiment, optionally, the main power supply module includes:

[0017] A first protection unit, a first transformer, a silicon carbide MOSFET power chip, a PWM controller, a first output rectification unit, a first voltage output unit and a first feedback unit;

[0018] The first protection unit is connected to the full-wave rectification unit and is used to protect the input voltage and current;

[0019] The first transformer is connected to the first protection unit and is used to transform the input voltage to obtain a first target voltage;

[0020] The silicon carbide MOSFET power chip is connected to the first transformer and is used to provide a first power supply;

[0021] The PWM controller is connected to the silicon carbide MOSFET power chip and is used to control the silicon carbide MOSFET power chip;

[0022] The first output rectifying unit is connected to the first transformer and is used to rectify the first target voltage output by the first transformer to obtain a first output voltage;

[0023] The first voltage output unit is connected between the first output rectifier unit and the smart ammeter, and is used to output a first output voltage to the smart ammeter;

[0024] The first feedback unit is connected between the first voltage output unit and the PWM controller, and is used to feed back the first output voltage to the PWM controller, so that the PWM controller is controlled according to the feedback voltage.

[0025] In one embodiment, optionally, the secondary power supply module includes:

[0026] A step-down unit, a second protection unit, a second transformer, a common silicon MOSFET power chip, a second output rectifier unit, a second voltage output unit, and a second feedback unit;

[0027] The step-down unit is connected to the full-wave rectifier unit and is used to step down the input voltage to obtain a stepped-down voltage;

[0028] The second protection unit is connected to the voltage reduction unit and is used to protect the input voltage and current;

[0029] The second transformer is connected to the second protection unit and is used to transform the input voltage to obtain a second target voltage;

[0030] The common silicon MOSFET power chip is connected to the second transformer and is used to provide a second power supply;

[0031] The second output rectifying unit is connected to the second transformer and is used to rectify the second target voltage output by the second transformer to obtain a second output voltage;

[0032] The second voltage output unit is connected between the second output rectifying unit and the intelligent ammeter, and is used to output a second output voltage to the intelligent ammeter;

[0033] The second feedback unit is connected between the second voltage output unit and the common silicon MOSFET power chip, and is used for feeding back the second output voltage to the common silicon MOSFET power chip.

[0034] In one embodiment, optionally, it further includes:

[0035] The power enabling module is connected between the fault detection module and the secondary power module, and is used to start the secondary power module to work when the fault detection module detects that the main power module has a fault.

[0036] In one embodiment, optionally, it further includes:

[0037] The microprocessor is connected to the fault detection module and is used to output fault information to a preset terminal when the fault detection module detects that the main power module fails.

[0038] According to a second aspect of the present invention, there is provided a control method for a switching power supply circuit of a smart electric energy meter, comprising:

[0039] When the main power module works normally, the main power module provides power to the smart energy meter;

[0040] Fault detection is performed on the main power module. When a fault is detected in the main power module, power is provided to the smart electric energy meter through the secondary power module.

[0041] In one embodiment, optionally, it further includes:

[0042] When a fault is detected in the main power module, fault information is output to a preset terminal.

[0043] According to a third aspect of the present invention, there is provided a smart electric energy meter system, comprising a switching power supply circuit as described in any one of the embodiments of the first aspect; and a smart electric energy meter.

[0044] In the above schemes implemented by the switching power supply circuit, control method and system for smart electric energy meter, the switching power supply circuit for smart electric energy meter includes: a main power supply module, a fault detection module and a secondary power supply module; the main power supply module is connected between the grid voltage and the smart electric energy meter to provide power for the smart electric energy meter; the fault detection module is connected to the main power supply module and the secondary power supply module to perform fault detection on the main power supply module to determine whether the main power supply module fails; the secondary power supply module is connected in parallel with the main power supply module between the grid voltage and the smart electric energy meter and connected to the fault detection module to provide power for the smart electric energy meter when the main power supply module fails. In the present invention, two power supply modules, namely the main power supply module and the secondary power supply module, are provided. When one power supply module fails, the other power supply module is used to provide power for the smart electric energy meter. In this way, the reliability of the switching power supply is guaranteed by the main power supply module and the secondary power supply module. At the same time, by controlling only one of the power supplies to work, the power consumption and electromagnetic interference of the switching power supply are reduced.

Brief Description of the Drawings

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 A schematic block diagram of a switching power supply circuit for a smart electric energy meter according to an embodiment of the present invention is shown.

[0047] Figure 2 A schematic block diagram of a switching power supply circuit for a smart electric energy meter according to another embodiment of the present invention is shown.

[0048] Figure 3 A specific structural schematic diagram of a switching power supply circuit for a smart electric energy meter according to an embodiment of the present invention is shown.

[0049] Figure 4 A flow chart of a method for controlling a switching power supply circuit of a smart electric energy meter according to an embodiment of the present invention is shown.

[0050] Figure 5 A schematic block diagram of a smart electric energy meter system according to an embodiment of the present invention is shown. [Specific implementation method]

[0051] In order to better understand the technical solution of the present invention, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0052] It should be clear that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0054] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0055] See also Figure 1 , Figure 1 A schematic block diagram of a switching power supply circuit for a smart electric energy meter according to an embodiment of the present invention is shown.

[0056] like Figure 1 As shown, a switching power supply circuit for a smart electric energy meter according to an embodiment of the present invention includes:

[0057] A main power supply module 11, a fault detection module 12 and a secondary power supply module 13;

[0058] The main power supply module 11 is connected between the grid voltage and the smart energy meter, and is used to provide power for the smart energy meter;

[0059] The fault detection module 12 is connected between the main power module 11 and the auxiliary power module 13, and is used to perform fault detection on the main power module 11 to determine whether the main power module 11 is faulty;

[0060] The secondary power supply module 13 is connected in parallel with the main power supply module, and is connected between the grid voltage and the smart power meter, and is connected to the fault detection module 12, and is used to provide power to the smart power meter when the main power supply module 11 fails.

[0061] In the above embodiment, two power modules are provided, namely a main power module and a secondary power module. When one power module fails, the other power module is used to provide power to the smart energy meter. In this way, the reliability of the switching power supply is ensured by the main power module and the secondary power module. At the same time, by controlling only one of the power supplies to work, the power consumption and electromagnetic interference of the switching power supply are reduced.

[0062] In one embodiment, optionally, the main power module 11 includes a silicon carbide MOSFET power chip, and the auxiliary power module includes a common silicon MOSFET power chip.

[0063] In the above embodiment, the main power module includes a silicon carbide MOSFET power chip, and the auxiliary power module includes a common silicon MOSFET power chip. Since silicon carbide MOSFET has high withstand voltage and high working frequency, it is very suitable for power supply with high voltage input, so the main power supply has the advantages of high efficiency and simple circuit. Since the auxiliary power supply adopts traditional silicon MOSFET power chip, the withstand voltage is low, so it is necessary to add a step-down circuit, which leads to low working efficiency, but high circuit reliability.

[0064] like Figure 2 As shown, in one embodiment, optionally, it also includes:

[0065] The power enabling module 21 is connected between the fault detection module 12 and the secondary power module 13, and is used to start the secondary power module to work when the fault detection module detects that the main power module has a fault.

[0066] In this embodiment, the fault detection of the main switch circuit is connected to the power enable module, and if it fails, the auxiliary switch power supply is started. In this way, only one switch circuit works, reducing power consumption and electromagnetic interference generated by the switch power supply itself.

[0067] In one embodiment, optionally, it further includes:

[0068] The microprocessor 22 is connected to the fault detection module 12 and is used to output fault information to a preset terminal when the fault detection module 12 detects that the main power module 11 has a fault.

[0069] In this embodiment, the output voltage of the main switch circuit is connected to the fault detection module. If a fault is detected, a warning is reported through the microprocessor, thereby facilitating timely processing of the fault and further improving the reliability of the smart energy meter.

[0070] In one embodiment, optionally, it further includes:

[0071] The preprocessing module is connected between the grid voltage and the main power module and the auxiliary power module, and is used for preprocessing the voltage output by the grid voltage.

[0072] like Figure 3 As shown, in one embodiment, optionally, the preprocessing module includes:

[0073] EMC processing unit 31 and full-wave rectification unit 32;

[0074] The EMC processing unit 31 is connected to the grid voltage and is used to perform electromagnetic compatibility processing on the output of the grid voltage;

[0075] The full-wave rectifier unit 32 is connected to the EMC processing unit and is used to convert the input alternating current into direct current.

[0076] In the above embodiment, electromagnetic interference can be reduced by performing electromagnetic compatibility processing on the output of the grid voltage, thereby improving the anti-interference capability of the switching power supply circuit.

[0077] In one embodiment, optionally, the main power supply module 11 includes:

[0078] A first protection unit 33, a first transformer 34, a silicon carbide MOSFET power chip 35, a PWM controller 36, a first output rectifier unit 37, a first voltage output unit 38 and a first feedback unit 39;

[0079] The first protection unit 33 is connected to the full-wave rectification unit and is used to protect the input voltage and current; wherein the first protection unit can perform overvoltage and overcurrent protection.

[0080] The first transformer 34 is connected to the first protection unit 33 and is used to transform the input voltage to obtain a first target voltage;

[0081] The silicon carbide MOSFET power chip 35 is connected to the first transformer and is used to provide a first power supply;

[0082] The PWM controller 36 is connected to the silicon carbide MOSFET power chip and is used to control the silicon carbide MOSFET power chip;

[0083] The first output rectifying unit 37 is connected to the first transformer and is used to rectify the first target voltage output by the first transformer to obtain a first output voltage;

[0084] The first voltage output unit 38 is connected between the first output rectifier unit and the smart ammeter, and is used to output a first output voltage to the smart ammeter;

[0085] The first feedback unit 39 is connected between the first voltage output unit and the PWM controller, and is used to feed back the first output voltage to the PWM controller, so that the PWM controller performs control according to the fed-back voltage.

[0086] like Figure 3 As shown, in one embodiment, optionally, the secondary power supply module 13 includes:

[0087] A step-down unit 41, a second protection unit 42, a second transformer 43, a common silicon MOSFET power chip 44, a second output rectifier unit 45, a second voltage output unit 46 and a second feedback unit 47;

[0088] The step-down unit 41 is connected to the full-wave rectifier unit and is used to step down the input voltage to obtain a stepped-down voltage;

[0089] Since the auxiliary power supply uses traditional silicon MOSFET power chip with low voltage resistance, it is necessary to add a step-down circuit, which leads to low working efficiency but high circuit reliability.

[0090] The second protection unit 42 is connected to the voltage reduction unit and is used to protect the input voltage and current;

[0091] The second transformer 43 is connected to the second protection unit and is used to transform the input voltage to obtain a second target voltage;

[0092] The common silicon MOSFET power chip 44 is connected to the second transformer and is used to provide a second power supply;

[0093] The second output rectifying unit 45 is connected to the second transformer and is used to rectify the second target voltage output by the second transformer to obtain a second output voltage;

[0094] The second voltage output unit 46 is connected between the second output rectifier unit and the smart ammeter, and is used to output a second output voltage to the smart ammeter;

[0095] The second feedback unit 47 is connected between the second voltage output unit and the common silicon MOSFET power chip, and is used to feed back the second output voltage to the common silicon MOSFET power chip.

[0096] In the above scheme, the dual-switching power supply scheme is adopted, which not only takes advantage of the high voltage resistance, surge resistance and harmonics of silicon carbide MOSFET, but also uses the traditional silicon MOSFET power chip as the auxiliary power supply to ensure the reliability of the energy meter. By controlling only one switching power supply to be in working state, power consumption and electromagnetic interference can be reduced on the basis of ensuring reliability. At the same time, the main switching power supply circuit is monitored for power failure, and the MCU and communication module are used for reporting and warning, which further improves reliability.

[0097] Figure 4 A flow chart of a method for controlling a switching power supply circuit of a smart electric energy meter according to an embodiment of the present invention is shown.

[0098] like Figure 4 As shown, a control method for a switching power supply circuit of a smart electric energy meter includes:

[0099] Step S401, when the main power module works normally, the main power module provides power to the smart electric energy meter;

[0100] Step S402: Perform fault detection on the main power module. When it is detected that the main power module fails, the secondary power module provides power to the smart electric energy meter.

[0101] In the present invention, two power modules are provided, namely a main power module and a secondary power module. When one power module fails, the other power module is used to provide power for the smart electric energy meter. In this way, the reliability of the switching power supply is guaranteed by the main power module and the secondary power module. At the same time, by controlling only one of the power supplies to work, the power consumption and the electromagnetic interference of the switching power supply are reduced.

[0102] In one embodiment, optionally, the main power module includes a silicon carbide MOSFET power chip, and the auxiliary power module includes a common silicon MOSFET power chip.

[0103] In the above embodiment, the main power module includes a silicon carbide MOSFET power chip, and the auxiliary power module includes a common silicon MOSFET power chip. Since silicon carbide MOSFET has high withstand voltage and high working frequency, it is very suitable for power supply with high voltage input, so the main power supply has the advantages of high efficiency and simple circuit. Since the auxiliary power supply adopts traditional silicon MOSFET power chip, the withstand voltage is low, so it is necessary to add a step-down circuit, which leads to low working efficiency, but high circuit reliability.

[0104] In one embodiment, optionally, it further includes:

[0105] When a fault is detected in the main power module, fault information is output to a preset terminal.

[0106] In this embodiment, if a main power module fault is detected, the fault information is output to the preset for reporting and warning, thereby facilitating timely handling of the fault and further improving the reliability of the smart energy meter.

[0107] Figure 5 A schematic block diagram of a smart electric energy meter system according to an embodiment of the present invention is shown.

[0108] like Figure 5 As shown, the present invention further provides a smart electric energy meter system 50, comprising a switching power supply circuit 10 as described in any one of the embodiments of the first aspect; and a smart electric energy meter 20.

[0109] It should be noted that those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the smart energy meter system described above can refer to the corresponding process in the aforementioned switching power supply circuit embodiment, and will not be repeated here.

[0110] It should be noted that the function of the switching power supply circuit for the smart energy meter provided in this embodiment is mainly realized by the circuit connection relationship between the various circuit modules, and does not rely on the program module in a certain circuit module. In addition, the various circuit modules in the switching power supply circuit for the smart energy meter can be realized by analog circuits or digital circuits, and for the circuit modules that can be implanted with program modules, the realization of their module functions can be realized by program modules provided by the prior art.

[0111] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0112] It should be understood that, although the terms first, second, etc. may be used to describe the setting units in the embodiments of the present invention, these setting units should not be limited to these terms. These terms are only used to distinguish the setting units from each other. For example, without departing from the scope of the embodiments of the present invention, the first setting unit may also be referred to as the second setting unit, and similarly, the second setting unit may also be referred to as the first setting unit.

[0113] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0114] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, systems and methods can be implemented in other ways. For example, the system embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of systems or units, which can be electrical, mechanical or other forms.

[0115] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0116] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A switching power supply circuit for a smart electric energy meter, characterized in that: include: A main power supply module, a fault detection module and a secondary power supply module; The main power supply module is connected between the grid voltage and the smart energy meter, and is used to provide power for the smart energy meter; The fault detection module is connected between the main power module and the auxiliary power module, and is used to perform fault detection on the main power module to determine whether the main power module fails; The secondary power supply module is connected in parallel with the main power supply module, and is connected between the grid voltage and the smart power meter, and is connected to the fault detection module, and is used to provide power to the smart power meter when the main power supply module fails.

2. The switching power supply circuit for a smart electric energy meter according to claim 1, characterized in that: The main power module includes a silicon carbide MOSFET power chip, and the auxiliary power module includes a common silicon MOSFET power chip.

3. The switching power supply circuit for a smart electric energy meter according to claim 1, characterized in that: Also includes: The preprocessing module is connected between the grid voltage and the main power module and the auxiliary power module, and is used for preprocessing the voltage output by the grid voltage.

4. The switching power supply circuit for a smart electric energy meter according to claim 3, characterized in that: The preprocessing module comprises: EMC processing unit and full-wave rectifier unit; The EMC processing unit is connected to the grid voltage and is used to perform electromagnetic compatibility processing on the output of the grid voltage; The full-wave rectification unit is connected to the EMC processing unit and is used for converting the input alternating current into direct current.

5. The switching power supply circuit for a smart electric energy meter according to claim 4, characterized in that: The main power supply module comprises: A first protection unit, a first transformer, a silicon carbide MOSFET power chip, a PWM controller, a first output rectification unit, a first voltage output unit and a first feedback unit; The first protection unit is connected to the full-wave rectification unit and is used to protect the input voltage and current; The first transformer is connected to the first protection unit and is used to transform the input voltage to obtain a first target voltage; The silicon carbide MOSFET power chip is connected to the first transformer and is used to provide a first power supply; The PWM controller is connected to the silicon carbide MOSFET power chip and is used to control the silicon carbide MOSFET power chip; The first output rectifying unit is connected to the first transformer and is used to rectify the first target voltage output by the first transformer to obtain a first output voltage; The first voltage output unit is connected between the first output rectifier unit and the smart ammeter, and is used to output a first output voltage to the smart ammeter; The first feedback unit is connected between the first voltage output unit and the PWM controller, and is used to feed back the first output voltage to the PWM controller, so that the PWM controller is controlled according to the feedback voltage.

6. The switching power supply circuit for a smart electric energy meter according to claim 4, characterized in that: The secondary power supply module comprises: A step-down unit, a second protection unit, a second transformer, a common silicon MOSFET power chip, a second output rectifier unit, a second voltage output unit, and a second feedback unit; The step-down unit is connected to the full-wave rectifier unit and is used to step down the input voltage to obtain a stepped-down voltage; The second protection unit is connected to the voltage reduction unit and is used to protect the input voltage and current; The second transformer is connected to the second protection unit and is used to transform the input voltage to obtain a second target voltage; The common silicon MOSFET power chip is connected to the second transformer and is used to provide a second power supply; The second output rectifying unit is connected to the second transformer and is used to rectify the second target voltage output by the second transformer to obtain a second output voltage; The second voltage output unit is connected between the second output rectifying unit and the intelligent ammeter, and is used to output a second output voltage to the intelligent ammeter; The second feedback unit is connected between the second voltage output unit and the common silicon MOSFET power chip, and is used for feeding back the second output voltage to the common silicon MOSFET power chip.

7. The switching power supply circuit for a smart electric energy meter according to claim 1, characterized in that: Also includes: The power enabling module is connected between the fault detection module and the secondary power module, and is used to start the secondary power module to work when the fault detection module detects that the main power module has a fault.

8. The switching power supply circuit for a smart electric energy meter according to claim 1, characterized in that: Also includes: The microprocessor is connected to the fault detection module and is used to output fault information to a preset terminal when the fault detection module detects that the main power module fails.

9. A control method for a switching power supply circuit of a smart electric energy meter, characterized in that: Applied to the switching power supply circuit according to any one of claims 1 to 8, the method comprising: When the main power module works normally, the main power module provides power to the smart energy meter; Fault detection is performed on the main power module. When a fault is detected in the main power module, power is provided to the smart electric energy meter through the secondary power module.

10. The control method for the switch power supply circuit of the smart electric energy meter according to claim 9, characterized in that: Also includes: When a fault is detected in the main power module, fault information is output to a preset terminal.

11. A smart electric energy meter system, characterized in that: include: The switching power supply circuit according to any one of claims 1 to 8; and A smart electric energy meter is connected to the switching power supply circuit.

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