Three-phase electric meter zero line metering and detecting circuit

Abstract

The application discloses a three-phase electric meter zero line metering and detecting circuit, which comprises a three-phase electric meter and a voltage plate, and further comprises a first relay K1, a second relay K2 and a PLC controller; the input end UA interface of the three-phase electric meter is connected with the output end UA interface of the voltage plate; the input end UB interface of the three-phase electric meter is connected with the output end UB interface of the voltage plate; the input end UC interface of the three-phase electric meter is connected with the output end UC interface of the voltage plate through the first relay K1 and the second relay K2 in sequence; the input end UN interface of the three-phase electric meter is connected with the output end UN interface of the voltage plate through the first relay K1 and the second relay K2 in sequence; and the PLC controller is connected with the first relay K1 and the second relay K2. The three-phase electric meter zero line metering and detecting circuit can switch the original C-phase current to the N-phase through remote control of the current relay, and can realize zero line metering and detection without increasing the output source.

Description

Technical Field

[0001] This invention relates to the field of online neutral wire debugging technology for three-phase meters, and particularly to a neutral wire metering and debugging circuit for three-phase meters. Background Technology

[0002] With the implementation of the IR46 international standard in China, the State Grid Corporation of China released a draft for public comment on the 2020 standard in March 2020, which will replace the currently implemented 2013 standard. Previously, the neutral wire of three-phase electricity meters did not need to be measured; therefore, the testing scheme for three-phase electricity meters was already fixed and mature. According to the requirements of the 2020 draft for public comment, all three-phase direct-connection meters will now include neutral wire measurement functionality. In existing technology, the voltage of the three-phase electricity meter being measured is directly connected to each workstation via a voltage board (e.g., ...). Figure 4 As shown, it is not possible to debug the neutral wire of the three-phase meter, and there is a lack of modification to the debugging scheme and circuit of the three-phase meter calibration device, which cannot adapt to the new changes of the State Grid. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a neutral line metering and adjustment circuit for a three-phase electricity meter, which can switch the original C-phase current to the N-phase by remotely controlling the current relay to perform neutral line adjustment without increasing the output source.

[0004] In a first aspect, embodiments of the present invention provide a neutral line metering and adjustment circuit for a three-phase electricity meter, including a three-phase electricity meter and a voltage board, wherein the circuit further includes a first relay K1, a second relay K2 and a PLC controller.

[0005] The input UA interface of the three-phase meter is connected to the output UA interface of the voltage board.

[0006] The input terminal UB interface of the three-phase meter is connected to the output terminal UB interface of the voltage board.

[0007] The input UC interface of the three-phase meter is connected to the output UC interface of the voltage board via the first relay K1 and the second relay K2 in sequence.

[0008] The input terminal UN interface of the three-phase meter is connected to the output terminal UN interface of the voltage board in sequence through the first relay K1 and the second relay K2.

[0009] The PLC controller is connected to the first relay K1 and the second relay K2.

[0010] In conjunction with the first aspect, the present invention provides a first possible implementation of the first aspect, wherein the thirteenth pin of the first relay K1 and the thirteenth pin of the second relay K2 are connected to the PLC controller via a wire connection.

[0011] In conjunction with the first aspect, this embodiment of the invention provides a second possible implementation of the first aspect, wherein the output terminal UC interface of the voltage board is connected in sequence to the ninth pin of the first relay K1, the first pin of the first relay K1, the first pin of the second relay K2, and the ninth pin of the second relay K2 via wires, and finally connected to the input terminal UC interface of the three-phase meter.

[0012] The PLC controller controls the power supply from the output UC interface of the voltage board to the input UC interface of the three-phase meter.

[0013] In conjunction with the first aspect, the present invention provides a third possible implementation of the first aspect, wherein the output terminal UN interface of the voltage board is connected in sequence to the twelfth pin of the first relay K1, the fourth pin of the first relay K1, the fourth pin of the second relay K2, and the twelfth pin of the second relay K2 via wires, and finally connected to the input terminal UN interface of the three-phase meter.

[0014] The PLC controller controls the output terminal UN interface of the voltage board to supply power to the input terminal UN interface of the three-phase meter.

[0015] In conjunction with the first aspect, the present invention provides a fourth possible implementation of the first aspect, wherein the fourteenth pin of the first relay K1 and the fourteenth pin of the second relay K2 are connected to ground by a wire.

[0016] In conjunction with the first aspect, the present invention provides a fifth possible implementation of the first aspect, wherein a turntable is also included.

[0017] The fifth pin of the first relay K1 is connected to the second red wire terminal and the second blue wire terminal of the rotating coil in sequence via wires, and then connected to the fifth pin of the second relay K2, forming a voltage circuit between the voltage board and the three-phase meter.

[0018] The eighth pin of the first relay K1 is connected to the first red wire terminal and the first blue wire terminal of the rotating coil in sequence through wires, and then connected to the eighth pin of the second relay K2, forming a voltage circuit between the voltage board and the three-phase meter.

[0019] The beneficial effects of the embodiments of the present invention are:

[0020] This invention provides a neutral wire metering and adjustment circuit for a three-phase electricity meter. The electrical design and control program of the voltage and current loops are redesigned, and the single adjustment platform is modified by adding relays and switches. The current relays are switched remotely by PLC control through background software, switching the original C-phase current to the N-phase. This enables neutral wire adjustment and inspection without adding an output source, realizing neutral wire metering and adjustment of the three-phase meter, as well as automated neutral wire adjustment and inspection on the existing adjustment platform. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the connection of the neutral wire metering and adjustment circuit of the three-phase electricity meter of the present invention;

[0023] Figure 2 for Figure 1 Enlarged structural diagram of point A in the middle;

[0024] Figure 3 This is a schematic diagram of the neutral wire metering and adjustment circuit structure of the three-phase electricity meter of the present invention;

[0025] Figure 4 This is a schematic diagram of the connection of a three-phase meter calibration circuit in the prior art;

[0026] Figure 5 This is a schematic diagram of the relay pin structure used in the neutral wire metering and adjustment circuit of the three-phase electricity meter of this invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] The neutral wire metering and adjustment circuit of this invention adopts a relay pin structure, as shown below. Figure 5As shown, pins 13 and 14 of the relay contain a relay coil. Pins 9 and 1 form a normally closed contact, pins 9 and 5 form a normally open contact, pins 12 and 4 form a normally closed contact, and pins 12 and 8 form a normally open contact. By default, the normally open contact is open and the normally closed contact is closed. When a voltage is applied between the two pins via the PLC controller, the relay energizes, the normally open contact closes, and the normally closed contact opens.

[0029] Please refer to Figures 1 to 3 An embodiment of the present invention provides a neutral wire metering and adjustment circuit for a three-phase electricity meter, including a three-phase electricity meter and a voltage board, wherein the circuit also includes a first relay K1, a second relay K2 and a PLC controller.

[0030] The input UA interface of the three-phase meter is connected to the output UA interface of the voltage board.

[0031] The input terminal UB interface of the three-phase meter is connected to the output terminal UB interface of the voltage board.

[0032] The input UC interface of the three-phase meter is connected to the output UC interface of the voltage board via the first relay K1 and the second relay K2 in sequence.

[0033] The input terminal UN interface of the three-phase meter is connected to the output terminal UN interface of the voltage board in sequence through the first relay K1 and the second relay K2.

[0034] The PLC controller is connected to the first relay K1 and the second relay K2.

[0035] The thirteenth pin of the first relay K1 and the thirteenth pin of the second relay K2 are connected to the PLC controller via a wire.

[0036] The output UC interface of the voltage board is connected in sequence to the ninth pin of the first relay K1, the first pin of the first relay K1, the first pin of the second relay K2, and the ninth pin of the second relay K2 via wires, and finally connected to the input UC interface of the three-phase meter.

[0037] The PLC controller controls the power supply from the output UC interface of the voltage board to the input UC interface of the three-phase meter.

[0038] The output terminal UN interface of the voltage board is connected in sequence to the twelfth pin of the first relay K1, the fourth pin of the first relay K1, the fourth pin of the second relay K2, and the twelfth pin of the second relay K2 via wires, and finally connected to the input terminal UN interface of the three-phase meter.

[0039] The PLC controller controls the output terminal UN interface of the voltage board to supply power to the input terminal UN interface of the three-phase meter.

[0040] The fourteenth pin of the first relay K1 and the fourteenth pin of the second relay K2 are connected to ground by a wire.

[0041] This also includes a turntable.

[0042] The fifth pin of the first relay K1 is connected to the second red wire terminal and the second blue wire terminal of the rotating coil in sequence via wires, and then connected to the fifth pin of the second relay K2, forming a voltage circuit between the voltage board and the three-phase meter.

[0043] The eighth pin of the first relay K1 is connected to the first red wire terminal and the first blue wire terminal of the rotating coil in sequence through wires, and then connected to the eighth pin of the second relay K2, forming a voltage circuit between the voltage board and the three-phase meter.

[0044] The embodiments of the present invention aim to protect a neutral wire metering and adjustment circuit for a three-phase electricity meter, and have the following effects:

[0045] To achieve independent measurement of the neutral wire without affecting other existing functions, this invention adds a voltage relay switch and transformer isolation, allowing the relay to function as intended by default. The voltage relay is remotely controlled by a PLC via backend software. By isolating UC and UN and connecting them to each workstation, independent neutral wire adjustment is ensured without affecting existing functions. This allows for three-phase meter neutral wire measurement and adjustment without altering the original adjustment equipment, requiring minimal investment and saving significant new equipment purchase costs.

[0046] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A neutral wire metering and adjustment circuit for a three-phase electricity meter, comprising a three-phase electricity meter and a voltage board, characterized in that, It also includes the first relay K1, the second relay K2, the rotary table, and the PLC controller; The input UA interface of the three-phase meter is connected to the output UA interface of the voltage board; The input terminal UB interface of the three-phase meter is connected to the output terminal UB interface of the voltage board; The input UC interface of the three-phase meter is connected to the output UC interface of the voltage board in sequence through the first relay K1 and the second relay K2; The input terminal UN interface of the three-phase meter is connected to the output terminal UN interface of the voltage board in sequence through the first relay K1 and the second relay K2; The PLC controller is connected to the first relay K1 and the second relay K2; The output UC interface of the voltage board is connected in sequence to the ninth pin of the first relay K1, the first pin of the first relay K1, the first pin of the second relay K2, and the ninth pin of the second relay K2 via wires, and finally connected to the input UC interface of the three-phase meter. The PLC controller controls the power supply from the output UC interface of the voltage board to the input UC interface of the three-phase meter; The output terminal UN interface of the voltage board is connected in sequence to the twelfth pin of the first relay K1, the fourth pin of the first relay K1, the fourth pin of the second relay K2, and the twelfth pin of the second relay K2 via wires, and finally connected to the input terminal UN interface of the three-phase meter. The PLC controller controls the power supply from the output terminal UN interface of the voltage board to the input terminal UN interface of the three-phase meter; The fifth pin of the first relay K1 is connected in sequence to the second red wire terminal and the first blue wire terminal of the rotating coil via wires, and then connected to the eighth pin of the second relay K2, forming a voltage loop between the voltage board and the three-phase meter. The eighth pin of the first relay K1 is connected in sequence to the first red wire terminal and the second blue wire terminal of the rotating coil via wires, and then connected to the fifth pin of the second relay K2, forming a voltage circuit between the voltage board and the three-phase meter.

2. The three-phase meter neutral wire metering and adjustment circuit according to claim 1, characterized in that, The thirteenth pin of the first relay K1 and the thirteenth pin of the second relay K2 are connected to the PLC controller via a wire.

3. The three-phase meter neutral wire metering and adjustment circuit according to claim 1, characterized in that, The fourteenth pin of the first relay K1 and the fourteenth pin of the second relay K2 are connected to ground by a wire.

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