PE detection circuit, method and system with single-phase electric energy meter double live wires and LN

Abstract

The invention discloses a PE detection circuit, method and system with single-phase electric energy meter double live wires and LN. The circuit comprises a photoelectric coupler, a relay and an N-MOS transistor, and a pin 1 of the photoelectric coupler is connected with a line L1 and a line L2 through a preset resistor; a pin 2 of the photoelectric coupler is connected with a PE wire through the relay; a phototriode is connected between a pin 3 and a pin 4 of the photoelectric coupler, one end, far away from the phototriode, of the pin 3 is grounded, and one end, far away from the phototriode, of the pin 4 is connected with a preset IO port through the N-MOS tube. According to the invention, a double-live-wire wiring mode can be supported, in a single-phase LN wiring mode, the LN wiring mode can be automatically identified to carry out PE detection, a rapid pulse detection mode is adopted to avoid leakage exceeding, specifically, PE detection can be carried out by calculating the number of pulses, and meanwhile, PE state detection of single-phase systems at home and abroad is met.

Description

Technical Field

[0001] The present invention relates to the technical field of electric energy meters, and more specifically, to a PE detection circuit, method and system with double live wires and LN of a single-phase electric energy meter. Background Art

[0002] The existing PE detection cannot support the dual-live-wire mode, especially the 240V voltage system in the United States. In addition, in the single-phase LN system, it cannot support the reverse connection of LN for PE status detection.

[0003] In the prior art, PE detection may cause mA-level leakage, and multiple accumulations may cause the system leakage to exceed the standard. In addition, the prior art uses a level method to make judgments, which is easily affected by temperature and causes misjudgment. Summary of the invention

[0004] The object of the present invention is to provide a PE detection circuit, method and system with double live wires and LN of a single-phase electric energy meter, which can solve the problems of excessive leakage and misjudgment in PE detection in the prior art.

[0005] A first aspect of the present invention provides a PE detection circuit having a single-phase electric energy meter with two live wires and LN, comprising the following steps:

[0006] Optocouplers, relays and N-MOS tubes, among which,

[0007] Pin 1 of the photocoupler is connected to the L1 line and the L2 line via a preset resistor;

[0008] Pin 2 of the photoelectric coupler is connected to a PE line through the relay;

[0009] A phototransistor is connected between pin 3 and pin 4 of the photocoupler, one end of pin 3 away from the phototransistor is grounded, and one end of pin 4 away from the phototransistor is connected to a preset IO port through the N-MOS tube.

[0010] In this solution, the L1 line is connected to the pin 1 of the photocoupler via a first diode and a preset resistor in sequence.

[0011] In this solution, the L2 line is connected to the pin 2 of the photoelectric coupler via a second diode and a preset resistor in sequence, wherein the connection sequence of the L1 line and the L2 line is not restricted.

[0012] In this solution, the preset resistor includes a first resistor, a second resistor, a third resistor and a fourth resistor connected in series.

[0013] The second aspect of the present invention further provides a PE detection method with a single-phase electric energy meter having two live wires and LN, which is applied to any of the PE detection circuits with a single-phase electric energy meter having two live wires and LN, wherein the method comprises:

[0014] Whether to perform PE detection based on relay control, wherein the relay is closed to perform PE status detection, and the relay is disconnected after the detection is completed;

[0015] When the relay is closed, the pulse count is calculated, where:

[0016] If the preset IO port is always at a low level within three consecutive measurement cycles, it means that PE is not connected;

[0017] If the preset IO port has a corresponding number of high and low pulses within three consecutive measurement cycles, it indicates that the PE access is normal. At this time, the time period of the low-level pulse is used to judge the current voltage access mode, which includes the dual-live wire L1-L2 mode and the LN single-phase mode.

[0018] In this scheme, when the voltage UL1 is greater than UL2, the positive half-wave portion of the voltage is limited by the first resistor, the second resistor, the third resistor and the fourth resistor to drive the phototransistor between pins 3 and 4 of the optocoupler to turn on, and at the same time drive the N-MOS tube to generate a high-level pulse, where UL1 is the L1 line voltage and UL2 is the L2 line voltage.

[0019] In this solution, when the voltages UL1 and UL2 are switched through zero, the phototransistor in the photocoupler is not turned on, the N-MOS tube is turned on and a low-level pulse appears, wherein the PE test terminal is connected to the input and output ports of the single-chip microcomputer.

[0020] The third aspect of the present invention further provides a PE detection system with a single-phase electric energy meter having two live wires and LN, comprising a memory and a processor, wherein the memory comprises a PE detection method program with a single-phase electric energy meter having two live wires and LN, and when the PE detection method program with a single-phase electric energy meter having two live wires and LN is executed by the processor, the following steps are implemented:

[0021] Whether to perform PE detection based on relay control, wherein the relay is closed to perform PE status detection, and the relay is disconnected after the detection is completed;

[0022] When the relay is closed, the pulse count is calculated, where:

[0023] If the preset IO port has been a low-level pulse for three consecutive measurement cycles, it means that PE is not connected;

[0024] If the preset IO port has a corresponding number of high and low pulses within three consecutive measurement cycles, it indicates that the PE access is normal. At this time, the time period of the low-level pulse is used to judge the current voltage access mode, which includes the dual-live wire L1-L2 mode and the LN single-phase mode.

[0025] In this scheme, when the voltage UL1 is greater than UL2, the positive half-wave portion of the voltage is limited by the first resistor, the second resistor, the third resistor and the fourth resistor to drive the phototransistor between pins 3 and 4 of the optocoupler to turn on, and at the same time drive the N-MOS tube to generate a high-level pulse, where UL1 is the L1 line voltage and UL2 is the L2 line voltage.

[0026] In this solution, when the voltages UL1 and UL2 are switched through zero, the phototransistor in the photocoupler is not turned on, the N-MOS tube is turned on and a low-level pulse appears, wherein the PE test terminal is connected to the input and output ports of the single-chip microcomputer.

[0027] The present invention discloses a PE detection circuit, method and system with a single-phase electric energy meter having dual live wires and LN, which can support a dual live wire wiring mode, and in a single-phase LN wiring mode, can automatically identify the LN wiring mode for PE detection, and avoid excessive leakage by adopting a fast pulse detection mode. Specifically, PE detection can be performed by calculating the number of pulses, and at the same time meet the PE status detection of single-phase systems at home and abroad. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention shows a schematic structural diagram of a PE detection circuit with double live wires and LN of a single-phase electric energy meter;

[0029] Figure 2 A flow chart of a PE detection method of a single-phase electric energy meter with double live wires and LN is shown in the present invention;

[0030] Figure 3 The block diagram of the PE detection system of the present invention with double live wires and LN of a single-phase electric energy meter is shown. DETAILED DESCRIPTION

[0031] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0033] Figure 1 A structural schematic diagram of a PE detection circuit with double live wires and LN of a single-phase electric energy meter of the present application is shown.

[0034] like Figure 1 As shown, the present application discloses a PE detection circuit with double live wires and LN of a single-phase electric energy meter, the circuit comprising:

[0035] Photocoupler O1, relay K1 and N-MOS tube Q2, among which,

[0036] Pin 1 of the photocoupler O1 is connected to the L1 line and the L2 line via a preset resistor;

[0037] Pin 2 of the photoelectric coupler O1 is connected to a PE line via the relay K1;

[0038] A phototransistor is connected between pin 3 and pin 4 of the photocoupler O1, the end of pin 3 away from the phototransistor is grounded, and the end of pin 4 away from the phototransistor, a PE test terminal (PE_STA), is connected to a preset IO port through the N-MOS tube.

[0039] It should be noted that, in this embodiment, Figure 1 As shown, the L1 line is connected to the pin 1 of the photocoupler O1 through the first diode D1 and the preset resistor in sequence, and the L2 line is connected to the pin 2 of the photocoupler O1 through the second diode D2 and the preset resistor in sequence, wherein the wiring sequence of the L1 line and the L2 line is not restricted, and the L1 line and the L2 line are specifically double live wires: 240V, 60Hz, wherein the preset resistor includes a first resistor R1, a second resistor R2, a third resistor R3 and a fourth resistor R4 connected in series.

[0040] Specifically, the relay K1 has a corresponding control circuit, wherein the control circuit includes a fifth resistor, a sixth resistor and a PNP transistor Q1; and a path is also included between the PE test terminal and the phototransistor, and the path is connected in series with a seventh resistor and an eighth resistor, specifically, as Figure 1 As shown, the N-MOS tube and the PE test end are also connected in parallel with a first capacitor.

[0041] Figure 2 A flow chart of a PE detection method of a single-phase electric energy meter with double live wires and LN is shown in the present application.

[0042] like Figure 2 As shown, the present application discloses a PE detection method with a single-phase electric energy meter with two live wires and LN, comprising the following steps:

[0043] S202, whether to perform PE detection based on the relay control, wherein the relay is closed to perform PE status detection, and the relay is disconnected after the detection is completed;

[0044] S204, when the relay is closed, the pulse number is calculated;

[0045] S206, if the preset IO port has been a low level pulse for three consecutive measurement cycles, it indicates that the PE is not connected;

[0046] S208, if the preset IO port has a corresponding number of high and low pulses within three consecutive measurement cycles, it indicates that the PE access is normal. At this time, the time period of the low level pulse is used to determine the current voltage access mode.

[0047] It should be noted that, in this embodiment, how to perform PE detection of dual live wires and LN single phase with a single-phase electric energy meter is specifically described, wherein first, whether to perform PE detection is based on the relay control, wherein the relay is closed to perform PE status detection, and the relay is disconnected after the detection is completed to prevent leakage from exceeding the standard and causing malfunction. Specifically, when the relay is closed, the number of pulses is calculated, wherein when the voltage UL1 is greater than UL2, the positive half-wave part of the voltage is limited by the first resistor, the second resistor, the third resistor and the fourth resistor to drive the phototransistor between pins 3 and 4 of the optocoupler to turn on, and at the same time drive the N-MOS tube to generate a high-level pulse, wherein UL1 is the L1 line voltage, UL2 is the L2 line voltage, and when the voltages UL1 and UL2 are switched through zero, the phototransistor in the optocoupler is not turned on, the N-MOS tube is turned on and a low-level pulse appears, wherein the PE test terminal is connected to the input and output ports of the single-chip microcomputer.

[0048] Therefore, when calculating the pulse, if the preset IO port has been a low-level pulse for three consecutive measurement cycles, it indicates that PE is not connected; if the preset IO port has a corresponding number of high and low pulses within three consecutive measurement cycles, it indicates that PE is connected normally. At this time, the time period of the low-level pulse is used to judge the current voltage access mode. Accordingly, the access mode includes the dual-live wire L1-L2 mode and the LN single-phase mode.

[0049] Figure 3 The block diagram of the PE detection system of the present invention with double live wires and LN of a single-phase electric energy meter is shown.

[0050] like Figure 3As shown, the present invention discloses a PE detection system with a single-phase electric energy meter with two live wires and LN, including a memory and a processor, wherein the memory includes a PE detection method program with a single-phase electric energy meter with two live wires and LN, and when the PE detection method program with a single-phase electric energy meter with two live wires and LN is executed by the processor, the following steps are implemented:

[0051] Whether to perform PE detection based on relay control, wherein the relay is closed to perform PE status detection, and the relay is disconnected after the detection is completed;

[0052] When the relay is closed, the pulse count is calculated, where:

[0053] If the preset IO port is always at a low level within three consecutive measurement cycles, it means that PE is not connected;

[0054] If the preset IO port has a corresponding number of high and low pulses within three consecutive measurement cycles, it indicates that the PE access is normal. At this time, the time period of the low-level pulse is used to judge the current voltage access mode, which includes the dual-live wire L1-L2 mode and the LN single-phase mode.

[0055] It should be noted that, in this embodiment, how to perform PE detection of dual live wires and LN single phase with a single-phase electric energy meter is specifically described, wherein first, whether to perform PE detection is based on the relay control, wherein the relay is closed to perform PE status detection, and the relay is disconnected after the detection is completed to prevent leakage from exceeding the standard and causing malfunction. Specifically, when the relay is closed, the number of pulses is calculated, wherein when the voltage UL1 is greater than UL2, the positive half-wave part of the voltage is limited by the first resistor, the second resistor, the third resistor and the fourth resistor to drive the phototransistor between pins 3 and 4 of the optocoupler to turn on, and at the same time drive the N-MOS tube to generate a high-level pulse, wherein UL1 is the L1 line voltage, UL2 is the L2 line voltage, and when the voltages UL1 and UL2 are switched through zero, the phototransistor in the optocoupler is not turned on, the N-MOS tube is turned on and a low-level pulse appears, wherein the PE test terminal is connected to the input and output ports of the single-chip microcomputer.

[0056] Therefore, when calculating the pulse, if the preset IO port has been a low-level pulse for three consecutive measurement cycles, it indicates that PE is not connected; if the preset IO port has a corresponding number of high and low pulses within three consecutive measurement cycles, it indicates that PE is connected normally. At this time, the time period of the low-level pulse is used to judge the current voltage access mode. Accordingly, the access mode includes the dual-live wire L1-L2 mode and the LN single-phase mode.

[0057] The present invention discloses a PE detection circuit, method and system with a single-phase electric energy meter having dual live wires and LN, which can support a dual live wire wiring mode, and in a single-phase LN wiring mode, can automatically identify the LN wiring mode for PE detection, and avoid excessive leakage by adopting a fast pulse detection mode. Specifically, PE detection can be performed by calculating the number of pulses, and at the same time meet the PE status detection of single-phase systems at home and abroad.

[0058] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device 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, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0059] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0060] In addition, all functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0061] A person of ordinary skill in the art can understand that: all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks or optical disks, and other media that can store program codes.

[0062] Alternatively, if the above-mentioned integrated unit of the present invention is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present invention can be essentially or partly reflected in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, RAM, magnetic disks or optical disks.

Claims

1. A PE detection circuit with double live wires and LN of a single-phase electric energy meter, characterized in that: The circuit comprises: Optocouplers, relays and N-MOS tubes, among which, Pin 1 of the photocoupler is connected to the L1 line and the L2 line via a preset resistor; Pin 2 of the photoelectric coupler is connected to a PE line through the relay; A phototransistor is connected between pin 3 and pin 4 of the photocoupler, one end of pin 3 away from the phototransistor is grounded, and one end of pin 4 away from the phototransistor is connected to a preset IO port through the N-MOS tube.

2. A PE detection circuit with double live wires and LN of a single-phase electric energy meter according to claim 1, characterized in that: The L1 line is connected to the pin 1 of the photocoupler via a first diode and a preset resistor in sequence.

3. A PE detection method with double live wires and LN of a single-phase electric energy meter according to claim 1, characterized in that: The L2 line is connected to the pin 2 of the photocoupler via a second diode and a preset resistor in sequence, wherein the connection sequence of the L1 line and the L2 line is not restricted.

4. A PE detection method with double live wires and LN of a single-phase electric energy meter according to claim 1, characterized in that: The preset resistor includes a first resistor, a second resistor, a third resistor and a fourth resistor connected in series.

5. A PE detection method with double live wires and LN of a single-phase electric energy meter, characterized in that: The PE detection circuit with double live wires and LN of a single-phase electric energy meter as described in any one of claims 1 to 4, wherein the method comprises: Whether to perform PE detection based on relay control, wherein the relay is closed to perform PE status detection, and the relay is disconnected after the detection is completed; When the relay is closed, the pulse count is calculated, where: If the preset IO port has been a low-level pulse for three consecutive measurement cycles, it means that PE is not connected; If the preset IO port has a corresponding number of high and low pulses within three consecutive measurement cycles, it indicates that the PE access is normal. At this time, the time period of the low-level pulse is used to judge the current voltage access mode, which includes the dual-live wire L1-L2 mode and the LN single-phase mode.

6. A PE detection method with double live wires and LN of a single-phase electric energy meter according to claim 5, characterized in that: When the voltage UL1 is greater than UL2, the positive half-wave portion of the voltage is limited by the first resistor, the second resistor, the third resistor and the fourth resistor to drive the phototransistor between pins 3 and 4 of the optocoupler to turn on, and at the same time drive the N-MOS tube to generate a high-level pulse, where UL1 is the L1 line voltage and UL2 is the L2 line voltage.

7. A PE detection method with double live wires and LN of a single-phase electric energy meter according to claim 6, characterized in that: When the voltages UL1 and UL2 are switched through zero, the phototransistor in the photocoupler is not turned on, the N-MOS tube is turned on and a low level pulse appears, wherein the PE test terminal is connected to the input and output ports of the single chip microcomputer.

8. A PE detection system with double live wires and LN of a single-phase electric energy meter, characterized in that: The invention comprises a memory and a processor, wherein the memory comprises a PE detection method program of a single-phase electric energy meter with two live wires and LN, and the PE detection method program of a single-phase electric energy meter with two live wires and LN is implemented as follows when executed by the processor: Whether to perform PE detection based on relay control, wherein the relay is closed to perform PE status detection, and the relay is disconnected after the detection is completed; When the relay is closed, the pulse count is calculated, where: If the preset IO port has been a low-level pulse for three consecutive measurement cycles, it means that PE is not connected; If the preset IO port has a corresponding number of high and low pulses within three consecutive measurement cycles, it indicates that the PE access is normal. At this time, the time period of the low-level pulse is used to judge the current voltage access mode, which includes the dual-live wire L1-L2 mode and the LN single-phase mode.

9. A PE detection system with double live wires and LN of a single-phase electric energy meter according to claim 8, characterized in that: When the voltage UL1 is greater than UL2, the positive half-wave portion of the voltage is limited by the first resistor, the second resistor, the third resistor and the fourth resistor to drive the phototransistor between pins 3 and 4 of the optocoupler to turn on, and at the same time drive the N-MOS tube to generate a high-level pulse, where UL1 is the L1 line voltage and UL2 is the L2 line voltage.

10. A PE detection system with double live wires and LN of a single-phase electric energy meter according to claim 9, characterized in that: When the voltages UL1 and UL2 are switched through zero, the phototransistor in the photocoupler is not turned on, the N-MOS tube is turned on and a low level pulse appears, wherein the PE test terminal is connected to the input and output ports of the single chip microcomputer.

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