Detection device and method for an electric energy metering secondary circuit

Abstract

The application discloses a kind of detection device and method of electric energy metering secondary circuit.The detection device of electric energy metering secondary circuit includes measurement module and control module;Measurement module is used to select A phase voltage output end, B phase voltage output end, C phase voltage output end, A phase current output end, C phase current output end, A phase voltage input end, B phase voltage input end, C phase voltage input end, A phase current input end, C phase current input end and ground terminal at least two are connected, to measure the resistance between any two phase voltage loops of voltage transformer secondary circuit, the resistance between any two phase voltage loops of electric energy meter, B phase ground resistance, A phase current loop resistance of current transformer secondary circuit, C phase current loop resistance and the resistance between voltage loop and current loop of electric energy meter;Control module is used to detect whether the wiring of electric energy metering secondary circuit is correct based on the resistance measured by measurement module.

Description

Technical Field

[0001] This invention relates to the field of electrical energy metering technology, and in particular to a detection device and method for a secondary circuit of electrical energy metering. Background Technology

[0002] Electricity metering is the foundation of electricity trade settlement, and the accuracy of electricity metering is crucial. There are three main existing electricity metering methods: high-voltage supply with high-voltage metering, high-voltage supply with low-voltage metering, and low-voltage supply with low-voltage metering. High-voltage supply with high-voltage metering generally uses a three-phase three-wire connection. A three-phase three-wire electricity metering device typically consists of a voltage transformer, a current transformer, a junction box, an electricity meter, and secondary voltage and current wiring. Before connecting electricity to a user, a secondary circuit check is required to verify the wiring is correct and meets requirements, ensuring metering accuracy. One important step in checking the secondary circuit wiring is to disconnect the voltage and current connection pieces in the junction box and use a multimeter in resistance mode to measure the resistance of the electricity meter side circuit and the transformer side circuit. The resistance values ​​are used to troubleshoot the secondary circuit wiring. Abnormal resistance values ​​indicate incorrect wiring. If the wiring is correct, it can also help determine if there are any internal abnormalities in the electricity meter and transformer.

[0003] However, using a multimeter to measure resistance to determine wiring has the following problems: 1) It requires measuring the resistance values ​​of multiple circuits, such as the phase-to-phase resistance of the voltage circuit on the energy meter side, the phase-to-phase resistance of the voltage circuit on the transformer side, the phase-to-ground resistance of phase B, the resistance of the current circuit, and the resistance between the voltage and current circuits, making the measurement process time-consuming and inefficient; 2) The measurement data needs to be manually recorded for future troubleshooting, but there are problems such as recording errors; 3) The inspection results need to be judged manually, which may lead to incorrect judgments due to insufficient skills of maintenance personnel, resulting in metering errors or safety accidents; 4) The resistance on the transformer side is very small, generally between 0.1 and 0.2 ohms, and the multimeter's insufficient resolution and sensitivity may cause it to fail to display minute differences in resistance values, increasing the difficulty of judgment. Summary of the Invention

[0004] This invention provides a detection device and method for the secondary circuit of power metering, which helps to quickly and accurately determine the wiring status of the secondary circuit of power metering.

[0005] In a first aspect, the present invention provides a detection device for a secondary circuit of an energy metering system, the secondary circuit of which includes: a voltage transformer secondary circuit, a current transformer secondary circuit, and an energy meter; the voltage transformer secondary circuit includes an A-phase voltage output terminal, a B-phase voltage output terminal, and a C-phase voltage output terminal; the current transformer secondary circuit includes an A-phase current output terminal and a C-phase current output terminal; the energy meter includes an A-phase voltage input terminal, a B-phase voltage input terminal, a C-phase voltage input terminal, an A-phase current input terminal, and a C-phase current input terminal; the detection device for the secondary circuit of the energy metering system includes:

[0006] The measurement module is used to select and connect at least two of the following: the A-phase voltage output terminal, the B-phase voltage output terminal, the C-phase voltage output terminal, the A-phase current output terminal, the C-phase current output terminal, the A-phase voltage input terminal, the B-phase voltage input terminal, the C-phase voltage input terminal, the A-phase current input terminal, the C-phase current input terminal, and the ground terminal, in order to measure the resistance between any two phase voltage loops of the voltage transformer secondary circuit, the resistance between any two phase voltage loops of the energy meter, the B-phase ground resistance, the A-phase current loop resistance and the C-phase current loop resistance of the current transformer secondary circuit, and the resistance between the voltage loop and the current loop of the energy meter.

[0007] A control module, connected to the measurement module, is used to control the measurement module and, based on the resistance measured by the measurement module, to detect whether the wiring of the secondary circuit for the power metering is correct.

[0008] Optionally, the measurement module includes a measurement unit and a switching unit;

[0009] The switching unit is used to select at least two of the following terminals to be connected to the measuring unit to form a measuring circuit: the A-phase voltage output terminal, the B-phase voltage output terminal, the C-phase voltage output terminal, the A-phase current output terminal, the C-phase current output terminal, the A-phase voltage input terminal, the B-phase voltage input terminal, the C-phase voltage input terminal, the A-phase current input terminal, the C-phase current input terminal, and the ground terminal.

[0010] The measuring unit is used to sample the current and voltage in the measuring circuit;

[0011] The control module connects the measuring unit and the switching unit, and is used to control the measuring unit and the switching unit, and calculate the resistance based on the current and voltage sampled by the measuring unit, so as to detect whether the wiring of the secondary circuit of the power metering is correct.

[0012] Optionally, the measuring unit includes a first measuring unit, a second measuring unit, and a third measuring unit, and the switching unit includes a first relay, a second relay, a third relay, a fourth relay, and a fifth relay;

[0013] The first relay, the second relay, the third relay, the fourth relay, and the fifth relay all include a coil, a first contact group, and a second contact group. The first contact group and the second contact group all include a first contact, a second contact, and a third contact.

[0014] The first contact in the first contact group of the first relay is connected to the C-phase voltage input terminal and the second detection terminal of the second measuring unit; the second contact in the first contact group of the first relay is connected to the third contact in the second contact group of the fifth relay and the third contact in the first contact group of the fourth relay; and the third contact in the first contact group of the first relay is connected to the second contact in the second contact group of the second relay.

[0015] The first contact in the second contact group of the first relay is connected to the A-phase voltage input terminal, the second contact in the second contact group of the first relay is connected to the first contact in the first contact group of the fourth relay, and the third contact in the second contact group of the first relay is connected to the A-phase voltage output terminal.

[0016] The first contact in the first contact group of the second relay is connected to the B-phase voltage output terminal, and the second contact in the first contact group of the second relay is connected to the B-phase voltage input terminal.

[0017] The first contact in the second contact group of the second relay is connected to the C-phase voltage output terminal, and the third contact in the second contact group of the second relay is grounded;

[0018] The first contact in the first contact group of the third relay is connected to the C-phase current input terminal and the third contact in the first contact group of the fifth relay. The second contact in the first contact group of the third relay is connected to the first contact in the second contact group of the fourth relay. The third contact in the first contact group of the third relay is connected to the A-phase current input terminal.

[0019] The first contact in the second contact group of the third relay is connected to the C-phase current output terminal, the second contact in the second contact group of the third relay is connected to the second detection terminal of the third measuring unit, and the third contact in the second contact group of the third relay is connected to the A-phase current output terminal.

[0020] The second contact in the first contact group of the fourth relay is connected to the first detection terminal of the first measuring unit;

[0021] The second contact in the second contact group of the fourth relay is connected to the first detection terminal of the third measuring unit, and the third contact in the second contact group of the fourth relay is grounded;

[0022] The first contact in the first contact group of the fifth relay is connected to the A-phase current input terminal, and the second contact in the first contact group of the fifth relay is connected to the first detection terminal of the second measuring unit.

[0023] The first contact in the second contact group of the fifth relay is connected to the B-phase voltage input terminal, and the second contact in the second contact group of the fifth relay is connected to the second detection terminal of the first measuring unit.

[0024] Optionally, the first measurement unit, the second measurement unit, and the third measurement unit each include: a power supply, a sampling resistor, a current-limiting resistor, and an analog-to-digital converter;

[0025] The sampling resistor and the current-limiting resistor are connected in series between the first terminal and the first detection terminal of the power supply. The second terminal of the power supply is connected to the second detection terminal. The analog-to-digital converter is connected to the control module, the first and second terminals of the power supply, and both ends of the sampling resistor. The analog-to-digital converter is used to convert the current signal of the sampling resistor and the voltage signal between the first and second terminals of the power supply into digital signals.

[0026] Optionally, the resistance values ​​of the sampling resistor and the current limiting resistor are selected based on a first numerical relationship and a second numerical relationship, the resistance between the first detection terminal and the second detection terminal is used as a disturbance, and the change in the digital quantity of the analog-to-digital converter caused by the disturbance is selected based on the first numerical relationship;

[0027] Wherein, the first numerical relationship is the numerical relationship between the resistance value of the sampling resistor, the resistance value of the current limiting resistor, the disturbance amount and the resulting change in the digital quantity of the analog-to-digital converter, the resolution of the analog-to-digital converter, and the voltage between the first and second terminals of the power supply.

[0028] The second numerical relationship is the numerical relationship between the resistance value of the sampling resistor, the resistance value of the current limiting resistor, the voltage range of the analog-to-digital converter, and the voltage between the first and second terminals of the power supply.

[0029] Optionally, the first numerical relationship is expressed as:

[0030]

[0031] The second numerical relationship is expressed as follows:

[0032]

[0033] Among them, R 采 R is the resistance value of the sampling resistor. 限 The resistance value of the current-limiting resistor is given, ΔD is the change in the digital quantity of the analog-to-digital converter caused by the disturbance, ΔR is the disturbance amount, and U is the digital quantity of the analog-to-digital converter. ADC / 2 n U is the resolution of the analog-to-digital converter, n is the number of bits in the analog-to-digital converter, and U is the bit depth of the converter. ADCU represents the voltage range of the analog-to-digital converter. 电源 The voltage is the voltage between the first and second terminals of the power supply.

[0034] Optionally, the detection device for the secondary circuit of the power metering system further includes:

[0035] A storage module, connected to the control module, is used to store the current and voltage sampled by the measurement unit, as well as the resistance calculated based on the current and voltage sampled by the measurement unit;

[0036] The display module, connected to the control module, is used to display the current and voltage sampled by the measurement unit, as well as the judgment result on whether the wiring of the secondary circuit of the power metering is correct.

[0037] Optionally, the secondary circuit for electricity metering further includes a junction box, which has multiple terminals, and the multiple terminals are connected one-to-one with the A-phase voltage output terminal, the B-phase voltage output terminal, the C-phase voltage output terminal, the A-phase current output terminal, the C-phase current output terminal, the A-phase voltage input terminal, the B-phase voltage input terminal, the C-phase voltage input terminal, the A-phase current input terminal, and the C-phase current input terminal;

[0038] The detection device for the secondary circuit of the power metering also includes: an upper housing, a lower housing, a circuit board, and multiple contacts; the measurement module and the control module are formed on the circuit board, the upper housing is located on one side of the circuit board, the lower housing is located on the other side of the circuit board, the upper housing and the lower housing enclose the circuit board, the contacts are disposed on the lower housing, and the measurement module is connected to the terminal in the junction box through the contacts.

[0039] Secondly, the present invention provides a method for detecting a secondary circuit of an energy metering system, executed by a detection device for the secondary circuit of the energy metering system; the secondary circuit of the energy metering system includes: a voltage transformer secondary circuit, a current transformer secondary circuit, and an energy meter; the voltage transformer secondary circuit includes an A-phase voltage output terminal, a B-phase voltage output terminal, and a C-phase voltage output terminal; the current transformer secondary circuit includes an A-phase current output terminal and a C-phase current output terminal; the energy meter includes an A-phase voltage input terminal, a B-phase voltage input terminal, a C-phase voltage input terminal, an A-phase current input terminal, and a C-phase current input terminal; the detection device for the secondary circuit of the energy metering system includes: a measurement module and a control module, wherein the control module is connected to the measurement module;

[0040] The detection method for the secondary circuit of the power metering system includes:

[0041] The control module controls the measurement module to select at least two of the following connections: the A-phase voltage output terminal, the B-phase voltage output terminal, the C-phase voltage output terminal, the A-phase current output terminal, the C-phase current output terminal, the A-phase voltage input terminal, the B-phase voltage input terminal, the C-phase voltage input terminal, the A-phase current input terminal, the C-phase current input terminal, and the ground terminal, in order to measure the resistance between any two phase voltage loops of the voltage transformer secondary circuit, the resistance between any two phase voltage loops of the energy meter, the B-phase ground resistance, the A-phase current loop resistance and the C-phase current loop resistance of the current transformer secondary circuit, and the resistance between the voltage loop and the current loop of the energy meter.

[0042] The control module uses the resistance measured by the measurement module to detect whether the wiring of the secondary circuit for electricity metering is correct.

[0043] Thirdly, the present invention provides an energy metering system, characterized in that it includes an energy metering device, the energy metering device having an energy metering secondary circuit, and the energy metering system further includes a detection device for the energy metering secondary circuit as described in any embodiment of the present invention.

[0044] The detection device and method for the secondary circuit of electricity metering provided by this invention, through a control module, controls a measurement module to select at least two of the following connections: phase A voltage output terminal, phase B voltage output terminal, phase C voltage output terminal, phase A current output terminal, phase C current output terminal, phase A voltage input terminal, phase B voltage input terminal, phase C voltage input terminal, phase A current input terminal, phase C current input terminal, and ground terminal. This allows for the measurement of the resistance between any two phase voltage loops of the voltage transformer secondary circuit, the resistance between any two phase voltage loops of the electricity meter, the phase B resistance to ground, the resistance of the phase A current loop and phase C current loop of the current transformer secondary circuit, and the resistance between the voltage and current loops of the electricity meter. Based on the resistance measured by the measurement module, the control module detects whether the wiring of the secondary circuit of electricity metering is correct, which helps to quickly and accurately determine the wiring status of the secondary circuit of electricity metering.

[0045] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in this invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the structure of a secondary circuit for electricity metering and its detection device provided by the present invention;

[0048] Figure 2 This is a schematic diagram of another secondary circuit for electricity metering and its detection device provided by the present invention;

[0049] Figure 3 This is a schematic diagram of the circuit structure of a measurement module provided by the present invention;

[0050] Figure 4 This is a schematic diagram of the structure of a relay provided by the present invention;

[0051] Figure 5 This is a schematic diagram of the circuit structure of a measurement unit provided by the present invention;

[0052] Figure 6 This is a control timing diagram of a relay provided by the present invention;

[0053] Figures 7 to 12 This is a schematic diagram of the circuit structure of the measurement module in different working stages;

[0054] Figure 13 This is a schematic diagram of the structure of a secondary circuit for electricity metering provided by the present invention;

[0055] Figure 14 This is a front view of a detection device for a secondary circuit of electricity metering provided by the present invention;

[0056] Figure 15 yes Figure 14 A schematic diagram of the explosion effect of the detection device in the secondary circuit of the power metering system;

[0057] Figure 16 This is a flowchart illustrating a detection method for a secondary circuit of electricity metering provided by the present invention. Detailed Implementation

[0058] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0059] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0060] This embodiment provides a detection device for the secondary circuit of power metering. Figure 1 This is a schematic diagram of the structure of a secondary circuit for electricity metering and its detection device provided by the present invention. See also... Figure 1 The secondary circuit for electricity metering includes: the secondary circuit of a voltage transformer, the secondary circuit of a current transformer, and an electricity meter 110; the secondary circuit of the voltage transformer includes the A-phase voltage output terminal U. A Phase B voltage output terminal U B and C-phase voltage output terminal U C The secondary circuit of the current transformer includes the A-phase current output terminal I. A and C-phase current output terminal I C The electricity meter 110 includes the A-phase voltage input terminal U. a Phase B voltage input terminal U b C-phase voltage input terminal U c Phase A current input terminal I a and C-phase current input terminal I c The detection device for the secondary circuit of the electricity metering system includes: a measurement module 210 and a control module 220.

[0061] Measurement module 210 is used to select the A-phase voltage output terminal U A Phase B voltage output terminal U B C-phase voltage output terminal U C Phase A current output terminal I A C-phase current output terminal I C Phase A voltage input terminal U a Phase B voltage input terminal U b C-phase voltage input terminal U c Phase A current input terminal I a and C-phase current input terminal I cConnect to at least two of the grounding terminals to measure the resistance between any two phase voltage loops of the voltage transformer secondary circuit, the resistance between any two phase voltage loops of the energy meter 110, the resistance of phase B to ground, the resistance of phase A current loop of the current transformer secondary circuit, the resistance of phase C current loop, and the resistance between the voltage loop and the current loop of the energy meter 110.

[0062] The control module 220 is connected to the measurement module 210. The control module 220 is used to control the measurement module 210 and, based on the resistance measured by the measurement module 210, to detect whether the wiring of the secondary circuit of the power metering is correct.

[0063] Specifically, this embodiment is applicable to a three-phase three-wire energy metering device with high-voltage supply and high-voltage metering. This energy metering device includes a first voltage transformer, a second voltage transformer, a first current transformer, a second current transformer, and an energy meter 110. The energy metering secondary circuit in this embodiment is the secondary circuit of the aforementioned energy metering device. The voltage transformer secondary circuit further includes the secondary winding PT1 of the first voltage transformer and the secondary winding PT2 of the second voltage transformer. The first end of the secondary winding PT1 of the first voltage transformer is connected to the A-phase voltage output terminal U. A The second terminal of the secondary winding PT1 of the first voltage transformer is connected to the B-phase voltage output terminal U. B The first terminal of the secondary winding PT2 of the second voltage transformer is grounded, and the second terminal of the secondary winding PT2 is connected to the C-phase voltage output terminal U. C The secondary circuit of the current transformer also includes the secondary winding CT1 of the first current transformer and the secondary winding CT2 of the second current transformer. The first terminal of the secondary winding CT1 of the first current transformer is connected to the energy meter 110, and the second terminal of the secondary winding CT1 of the first current transformer is connected to the A-phase current output terminal I. A And grounded, the first end of the secondary winding CT2 of the second current transformer is connected to the energy meter 110, and the second end of the secondary winding CT2 of the second current transformer is connected to the C-phase current output terminal I. C And grounded. The A-phase voltage input terminal U of the energy meter 110. a Used to connect to the A-phase voltage output terminal U A Phase B voltage input terminal U b Used to connect to the B-phase voltage output terminal U B C-phase voltage input terminal U c Used to connect to the C-phase voltage output terminal U C Phase A current input terminal I a Used to connect to the A-phase current output terminal I A C-phase current input terminal I c Used to connect to the C-phase current output terminal I CWhen checking whether the wiring of the secondary circuit of the electricity meter is correct, it is necessary to disconnect the A-phase voltage input terminal U of the electricity meter 110. a Phase B voltage input terminal U b C-phase voltage input terminal U c Phase A current input terminal I a and C-phase current input terminal I c Connections to the secondary circuits of voltage transformers and current transformers.

[0064] The control module 220 can control the measurement module 210 to be in different operating modes. For example, the measurement module 210 may include the following operating modes:

[0065] (1) Control module 220 controls measurement module 210 and A-phase voltage output terminal U A and the voltage output terminal U of phase B B Connect to make the A-phase voltage output terminal U A Measurement module 210 and phase B voltage output terminal U B A measurement circuit is formed, and the resistance between the A-phase and B-phase voltage circuits of the secondary circuit of the voltage transformer is measured through the measurement module 210.

[0066] (2) Control module 220 controls measurement module 210 and B-phase voltage output terminal U B and C-phase voltage output terminal U C Connect to make the B-phase voltage output terminal U B Measurement module 210 and C-phase voltage output terminal U C A measurement circuit is formed, and the resistance between the B-phase and C-phase voltage circuits of the secondary circuit of the voltage transformer is measured through the measurement module 210.

[0067] (3) Control module 220 controls measurement module 210 and A-phase voltage output terminal U A and C-phase voltage output terminal U C Connect to make the A-phase voltage output terminal U A Measurement module 210 and C-phase voltage output terminal U C A measurement circuit is formed, and the resistance between the A-phase and C-phase voltage circuits of the secondary circuit of the voltage transformer is measured through the measurement module 210.

[0068] (4) The control module 220 controls the A-phase voltage input terminal U of the measurement module 210 and the energy meter 110. a and B-phase voltage input terminal U b Connect to make the A-phase voltage input terminal U a Measurement module 210 and phase B voltage input terminal U b A measurement circuit is formed, and the resistance between the A-phase and B-phase voltage circuits of the energy meter 110 is measured through the measurement module 210;

[0069] (5) The control module 220 controls the measurement module 210 and the B-phase voltage input terminal U of the energy meter 110. b and C-phase voltage input terminal U c Connect to make the B-phase voltage input terminal U b Measurement module 210 and C-phase voltage input terminal U c A measurement circuit is formed, and the resistance between the B-phase and C-phase voltage circuits of the energy meter 110 is measured through the measurement module 210;

[0070] (6) The control module 220 controls the A-phase voltage input terminal U of the measurement module 210 and the energy meter 110. a and C-phase voltage input terminal U c Connect to make the A-phase voltage input terminal U a Measurement module 210 and C-phase voltage input terminal U c A measurement circuit is formed, and the resistance between the A-phase and C-phase voltage circuits of the energy meter 110 is measured through the measurement module 210;

[0071] (7) The control module 220 controls the B-phase voltage input terminal U of the measurement module 210 and the energy meter 110. b Connect to the grounding terminal so that the B-phase voltage input terminal U of the energy meter 110 is connected. b The measurement module 210 and the grounding terminal form a measurement circuit, and the B-phase ground resistance of the secondary circuit of the power metering is measured through the measurement module 210.

[0072] (8) Control module 220 controls measurement module 210 and A-phase current output terminal I A and Phase A current input terminal I a Connect to make the A-phase current output terminal I A Measurement module 210 and phase A current input terminal I a A measurement loop is formed, and the resistance of the A-phase current loop in the secondary circuit of the current transformer is measured through the measurement module 210.

[0073] (9) Control module 220 controls measurement module 210 and C-phase current output terminal I C and C-phase current input terminal I c Connect to make the C-phase current output terminal I C Measurement module 210 and C-phase current input terminal I c A measurement loop is formed, and the resistance of the C-phase current loop of the secondary circuit of the current transformer is measured through the measurement module 210.

[0074] (10) Control module 220 controls measurement module 210 and A-phase current output terminal I A Connect to the ground terminal to make the A-phase current output terminal I AThe measurement module 210 and the grounding terminal form a measurement circuit, and the measurement module 210 measures the resistance to ground of the A-phase current loop of the secondary circuit of the current transformer.

[0075] (11) Control module 220 controls measurement module 210 and C-phase current output terminal I C Connect to the ground terminal to make the C-phase current output terminal I C The measurement module 210 and the grounding terminal form a measurement circuit, and the C-phase current loop resistance to ground of the secondary circuit of the current transformer is measured through the measurement module 210.

[0076] (12) The control module 220 controls the measurement module 210 and the C-phase voltage input terminal U of the energy meter 110. c and Phase A current input terminal I a Connect to make the C-phase voltage input terminal U c Measurement module 210 and phase A current input terminal I a A measurement circuit is formed, and the resistance between the voltage circuit and the current circuit of the energy meter 110 is measured through the measurement module 210.

[0077] The control module 220 can determine whether the resistance value measured by the measurement module 210 is abnormal. If the resistance value measured by the measurement module 210 is abnormal, it indicates that the corresponding circuit wiring is incorrect. If the resistance value measured by the measurement module 210 is not abnormal, it indicates that the corresponding circuit wiring is correct.

[0078] The technical solution of this invention involves a control module that controls a measurement module to connect at least two of the following: phase A voltage output terminal, phase B voltage output terminal, phase C voltage output terminal, phase A current output terminal, phase C current output terminal, phase A voltage input terminal, phase B voltage input terminal, phase C voltage input terminal, phase A current input terminal, phase C current input terminal, and ground terminal. This allows for the measurement of the resistance between any two phase voltage loops in the secondary circuit of the voltage transformer, the resistance between any two phase voltage loops in the energy meter, the phase B resistance to ground, the resistance of the phase A current loop in the secondary circuit of the current transformer, the resistance of the phase C current loop, and the resistance between the voltage and current loops of the energy meter. Based on the resistance measured by the measurement module, the control module detects whether the wiring of the energy metering secondary circuit is correct, facilitating a quick and accurate assessment of the wiring status of the energy metering secondary circuit.

[0079] Figure 2 This is a schematic diagram of another power metering secondary circuit and its detection device provided by the present invention. (Combined with...) Figure 1 and Figure 2 Optionally, the measurement module 210 includes a measurement unit 211 and a switching unit 212. The switching unit 212 is used to select the A-phase voltage output terminal U. A Phase B voltage output terminal U BC-phase voltage output terminal U C Phase A current output terminal I A C-phase current output terminal I C Phase A voltage input terminal U a Phase B voltage input terminal U b C-phase voltage input terminal U c Phase A current input terminal I a and C-phase current input terminal I c At least two of the terminals, including the ground terminal, are connected to the measuring unit 211 to form a measuring loop. The measuring unit 211 is used to sample the current and voltage on the measuring loop. The control module 220 connects the measuring unit 211 and the switching unit 212, and is used to control the measuring unit 211 and the switching unit 212, and calculate the resistance based on the current and voltage sampled by the measuring unit 211, so as to detect whether the wiring of the secondary circuit 100 for energy metering is correct.

[0080] Specifically, the control module 220 may include a microcontroller. The control module 220 can control the switching unit 212 to perform switching actions to select the A-phase voltage output terminal U. A Phase B voltage output terminal U B C-phase voltage output terminal U C Phase A current output terminal I A C-phase current output terminal I C Phase A voltage input terminal U a Phase B voltage input terminal U b C-phase voltage input terminal U c Phase A current input terminal I a and C-phase current input terminal I c At least two of the terminals, including the ground terminal, are connected to the measurement unit 211 to form different measurement loops. The measurement unit 211 can sample the current and voltage on the measurement loop and transmit the sampled current and voltage data to the control module 220 to calculate the resistance based on the current and voltage sampled by the measurement unit 211, thereby detecting whether the corresponding wiring in the secondary circuit 100 of the power metering is correct.

[0081] Combination Figure 1 and Figure 2 Furthermore, the detection device for the secondary circuit of the electricity metering system also includes a storage module 230 and a display module 240. The storage module 230 is connected to the control module 220 and is used to store the current and voltage sampled by the measurement unit 211, as well as the resistance calculated based on the current and voltage sampled by the measurement unit 211. The display module 240 is connected to the control module 220 and is used to display the current and voltage sampled by the measurement unit 211, as well as the result of determining whether the wiring of the secondary circuit 100 of the electricity metering system is correct. Specifically, the display module 240 may include a display screen.

[0082] Figure 3 This is a schematic diagram of the circuit structure of a measurement module provided by the present invention. Figure 4 This is a schematic diagram of the structure of a relay provided by the present invention. (Combined with...) Figure 3 and Figure 4 Based on the above embodiments, optionally, the measurement unit in the measurement module specifically includes a first measurement unit 211a, a second measurement unit 211b, and a third measurement unit 211c, and the switching unit in the measurement module specifically includes a first relay, a second relay, a third relay, a fourth relay, and a fifth relay. Each of the first, second, third, fourth, and fifth relays includes a coil L, a first contact group, and a second contact group. Both the first and second contact groups include a first contact a, a second contact b, and a third contact c.

[0083] The first contact a in the first contact group Relay1-1 of the first relay is connected to the C-phase voltage input terminal U. c The second detection terminal of the second measurement unit 211b is connected to the second contact b in the first contact group Relay1-1 of the first relay, which is connected to the third contact c in the second contact group Relay5-2 of the fifth relay and the third contact c in the first contact group Relay4-1 of the fourth relay. The third contact c in the first contact group Relay1-1 of the first relay is connected to the second contact b in the second contact group Relay2-2 of the second relay.

[0084] The first contact a in the second contact group Relay1-2 of the first relay is connected to the A-phase voltage input terminal U. a The second contact b in the second contact group Relay1-2 of the first relay is connected to the first contact a in the first contact group Relay4-1 of the fourth relay, and the third contact c in the second contact group Relay1-2 of the first relay is connected to the A-phase voltage output terminal U. A .

[0085] The first contact a in the first contact group Relay2-1 of the second relay is connected to the B-phase voltage output terminal U. B The second contact b in the first contact group Relay2-1 of the second relay is connected to the B-phase voltage input terminal U. b .

[0086] The first contact a in the second contact group Relay2-2 of the second relay is connected to the C-phase voltage output terminal U. C The third contact c in the second contact group Relay2-2 of the second relay is grounded.

[0087] The first contact a in the first contact group Relay3-1 of the third relay is connected to the C-phase current input terminal I. c The third contact c in the first contact group Relay5-1 of the fifth relay, the second contact b in the first contact group Relay3-1 of the third relay are connected to the first contact a in the second contact group Relay4-2 of the fourth relay, and the third contact c in the first contact group Relay3-1 of the third relay are connected to the A-phase current input terminal I. a .

[0088] The first contact a in the second contact group Relay3-2 of the third relay is connected to the C-phase current output terminal I. C The second contact b in the second contact group Relay3-2 of the third relay is connected to the second detection terminal of the third measuring unit 211c, and the third contact c in the second contact group Relay3-2 of the third relay is connected to the A-phase current output terminal I. A .

[0089] The second contact b in the first contact group Relay4-1 of the fourth relay is connected to the first detection terminal of the first measuring unit 211a.

[0090] The second contact b in the second contact group Relay4-2 of the fourth relay is connected to the first detection terminal of the third measuring unit 211c, and the third contact c in the second contact group Relay4-2 of the fourth relay is grounded.

[0091] The first contact a in the first contact group Relay5-1 of the fifth relay is connected to the A-phase current input terminal I. a The second contact b in the first contact group Relay5-1 of the fifth relay is connected to the first detection terminal of the second measuring unit 211b.

[0092] The first contact a in the second contact group Relay5-2 of the fifth relay is connected to the B-phase voltage input terminal U. b The second contact b in the second contact group Relay5-2 of the fifth relay is connected to the second detection terminal of the first measuring unit 211a.

[0093] For example, the structures of the first relay, second relay, third relay, fourth relay, and fifth relay can be the same as those of... Figure 4The relays shown have the same structure, including contacts 1 to 8. A coil L connects contacts 1 and 8. Contacts 2 to 4 form a first contact group, where contact 2 corresponds to the first contact a, contact 3 corresponds to the second contact b, and contact 4 corresponds to the third contact c. Contacts 5 to 7 form a second contact group, where contact 5 corresponds to the first contact a, contact 6 corresponds to the second contact b, and contact 7 corresponds to the third contact c. The control module can energize or de-energize the coil L to control the first and second contact groups. When the coil L is energized, the contacts in the first and second contact groups actuate.

[0094] Figure 5 This is a circuit structure diagram of a measurement unit provided by the present invention, which shows the specific circuit structure and simplified structure of the first measurement unit 211a, the second measurement unit 211b, and the third measurement unit 211c. For convenience, Figure 3 China and Israel Figure 5 The simplified structure shown replaces the first measurement unit 211a, the second measurement unit 211b, and the third measurement unit 211c. Combined with... Figure 3 and Figure 5 Optionally, the first measurement unit 211a, the second measurement unit 211b, and the third measurement unit 211c each include: a power supply 2111, a sampling resistor R. 采 Current limiting resistor R 限 And analog-to-digital converter 2112. Sampling resistor R 采 and current limiting resistor R 限 The power supply 2111 is connected in series between its first terminal and the first detection terminal, and its second terminal is connected to the second detection terminal. The analog-to-digital converter 2112 is connected to the control module 220, the first and second terminals of the power supply 2111, and the sampling resistor R. 采 At both ends, the analog-to-digital converter 2112 is used to convert the sampling resistor R 采 The current signal and the voltage signal between the first and second poles of the power supply 2111 are converted into digital signals.

[0095] Specifically, the power supply 2111 includes a battery. The first terminal of the power supply 2111 can be the positive terminal of the battery, and the second terminal of the power supply 2111 can be the negative terminal of the battery. The voltage signal between the first and second terminals of the power supply 2111 is the voltage signal of the battery. 测 This represents the resistance between the first and second detection terminals. I represents the current flowing through the sampling resistor R. 采The current. To improve the accuracy and sensitivity of the detection device in the secondary circuit of the power metering system, it is necessary to focus on designing the first measurement unit 211a, the second measurement unit 211b, and the third measurement unit 211c to improve the measurement resolution and ensure the accuracy of the measurement and the correctness of the wiring judgment. The measurement conditions of the first measurement unit 211a, the second measurement unit 211b, and the third measurement unit 211c include the following two types:

[0096] (1) Measure the resistance between any two phase voltage circuits of the power meter 110.

[0097] Because the phase-to-phase resistance on the electricity meter side is relatively large, i.e., R 测 The resistance is relatively large, so it is easy to measure the corresponding resistance value through the first measuring unit 211a, the second measuring unit 211b and the third measuring unit 211c, and to determine whether the wiring is correct.

[0098] (2) Measure the resistance between any two phase voltage loops of the voltage transformer secondary circuit, the resistance of phase B to ground, the resistance of phase A current loop and phase C current loop of the current transformer secondary circuit, and the resistance between the voltage loop and current loop of the energy meter 110.

[0099] Because the phase-to-phase resistance, phase-to-ground resistance (B-phase), and resistance of each current loop on the voltage transformer and current transformer sides are relatively small, generally around 0.1 ohms, i.e., R... 测 Relatively small, R 测 The current change caused by connecting the first and second detection terminals is small, therefore the sampling resistor R can be used. 采 The current change between the first and second detection terminals is amplified, and the current change value is converted into a larger digital value through the analog-to-digital converter 2112.

[0100] Optionally, the sampling resistor R 采 and current limiting resistor R 限 The resistance value is selected based on the first and second numerical relationships, and the resistance R between the first and second detection terminals is... 测 As a disturbance, the change in the digital quantity of the analog-to-digital converter 2112 caused by the disturbance is selected based on a first numerical relationship. The first numerical relationship is the sampling resistor R. 采 The resistance value and current limiting resistor R 限 The numerical relationship between the resistance value, the disturbance amount and the resulting change in the digital value of the analog-to-digital converter 2112, the resolution of the analog-to-digital converter 2112, and the voltage between the first and second terminals of the power supply 2111. The second numerical relationship is the sampling resistor R. 采 The resistance value and current limiting resistor R 限The numerical relationship between the resistance value, the voltage range of the analog-to-digital converter 2112, and the voltage between the first and second terminals of the power supply 2111.

[0101] Specifically, let U ADC Given the voltage range of analog-to-digital converter 2112 and its bit depth n, the resolution of analog-to-digital converter 2112 is U. ADC / 2 n Sampling resistor R 采 and current limiting resistor R 限 It can be used as a normal working point, because R 测 Since it is relatively small, it can be taken as a disturbance quantity ΔR. Then, the current change ΔI caused by the disturbance quantity ΔR can be expressed as:

[0102]

[0103] Among them, R 采 It also indicates the resistance value of the sampling resistor, R. 限 It also indicates the resistance value of the current-limiting resistor, U. 电源 This is the voltage between the first and second terminals of power supply 2111.

[0104] The change in digital quantity ΔD of the analog-to-digital converter 2112 caused by the disturbance ΔR can be expressed as:

[0105]

[0106] At the same time, the normal operating point should satisfy the sampling resistor R 采 The voltage is less than the voltage range of the analog-to-digital converter 2112, that is:

[0107]

[0108] From equations (2) and (3), we can obtain:

[0109]

[0110]

[0111] Equation (4) represents the first numerical relationship, and Equation (5) represents the second numerical relationship.

[0112] The sampling resistor R can be determined according to equations (4) and (5). 采 and current limiting resistor R 限 The resistance value must be determined, and the digital change value ΔD of the analog-to-digital converter 2112 caused by the disturbance ΔR must be selected to satisfy equation (4).

[0113] Figure 6This is a control timing diagram of a relay provided by the present invention, wherein a low level indicates that the coil in the relay is de-energized, and a high level indicates that the coil in the relay is energized. Figures 7 to 12 This is a circuit structure diagram of the measurement module in different working stages. The control module in the detection device of the secondary circuit for electricity metering can adopt... Figure 6 The control timing shown controls Figure 3 , Figures 7 to 12 The energization / de-energization of the internal coils of each relay controls the operation of the relay contacts. The following section combines... Figure 3 , Figures 6 to 12 The working principle of the detection device for the secondary circuit of electricity metering is illustrated.

[0114] In phase t1, see Figure 3 and Figure 6 The coils of the first, third, fourth, and fifth relays are all de-energized, while the coil of the second relay is energized. The first contact a and the second contact b in the first contact group Relay1-1 and the second contact group Relay1-2 of the first relay are connected. The second contact b and the third contact c in the first contact group Relay2-1 and the second contact group Relay2-2 of the second relay are connected. The first contact a and the second contact b in the first contact group Relay3-1 and the second contact group Relay3-2 of the third relay are connected. The first contact a and the second contact b in the first contact group Relay4-1 and the second contact group Relay4-2 of the fourth relay are connected. The first contact a and the second contact b in the first contact group Relay5-1 and the second contact group Relay5-2 of the fifth relay are connected. Phase A voltage input terminal U a The first measuring unit 211a and the B-phase voltage input terminal U b A measurement circuit is formed, and the resistance between the A-phase and B-phase voltage circuits of the energy meter 110 is measured through the first measurement unit 211a. The C-phase voltage input terminal U... c The second measuring unit 211b and the A-phase current input terminal I a A measurement circuit is formed, and the resistance between the voltage and current circuits of the energy meter 110 is measured by the second measurement unit 211b. The C-phase current output terminal I... C The third measuring unit 211c and the C-phase current input terminal I c A measurement circuit is formed, and the resistance of the C-phase current loop of the secondary circuit of the current transformer is measured through the third measurement unit 211c.

[0115] In phase t2, see Figure 6 and Figure 7The coils of the first and third relays are energized, while the coil of the second relay is de-energized. The second contact b and the third contact c in the first contact group Relay1-1 of the first relay are connected, and the second contact b and the third contact c in the second contact group Relay1-2 of the first relay are connected. The first contact a and the second contact b in the first contact group Relay2-1 and the second contact group Relay2-2 of the second relay are connected. The second contact b and the third contact c in the first contact group Relay3-1 of the third relay are connected, and the second contact b and the third contact c in the second contact group Relay3-2 of the third relay are connected. Phase A voltage output terminal U... A The first measuring unit 211a and the B-phase voltage output terminal U B A measurement circuit is formed, and the resistance between the A-phase and B-phase voltage circuits of the voltage transformer's secondary circuit is measured through the first measurement unit 211a. The A-phase current output terminal I... A The third measuring unit 211c and the A-phase current input terminal I a A measurement circuit is formed, and the resistance of the A-phase current loop of the secondary circuit of the current transformer is measured through the third measurement unit 211c.

[0116] In phase t3, see Figure 6 and Figure 8 The coil of the fourth relay is energized. The second contact b and the third contact c in the first contact group Relay4-1 of the fourth relay are connected, and the second contact b and the third contact c in the second contact group Relay4-2 of the fourth relay are also connected. Phase B voltage output terminal U... B The first measuring unit 211a and the C-phase voltage output terminal U C A measurement circuit is formed, and the resistance between the B-phase and C-phase voltage circuits of the voltage transformer's secondary circuit is measured through the first measurement unit 211a. The A-phase current output terminal I... A The third measuring unit 211c and the grounding terminal form a measuring circuit, and the A-phase current loop resistance to ground of the secondary circuit of the current transformer is measured through the third measuring unit 211c.

[0117] In phase t4, see Figure 6 and Figure 9 The coil of the second relay is energized, and the coil of the third relay is de-energized. The second contact b and the third contact c in the first contact group Relay2-1 of the second relay are connected, and the second contact b and the third contact c in the second contact group Relay2-2 of the second relay are also connected. The first contact a and the second contact b in the first contact group Relay3-1 of the third relay are connected, and the first contact a and the second contact b in the second contact group Relay3-2 of the third relay are also connected. Phase B voltage input terminal U... bThe first measuring unit 211a and the grounding terminal form a measuring circuit, and the phase-to-ground resistance of the energy meter 110 (b-phase) is measured through the first measuring unit 211a. The C-phase current output terminal I... C The third measuring unit 211c and the grounding terminal form a measuring circuit, and the C-phase current loop resistance to ground of the secondary circuit of the current transformer is measured through the third measuring unit 211c.

[0118] In the t5 stage, see Figure 6 and Figure 10 The coil of the first relay is de-energized. The first contact a and the second contact b in the first contact group Relay1-1 of the first relay are connected, and the first contact a and the second contact b in the second contact group Relay1-2 of the first relay are connected. Phase B voltage input terminal U... b The first measuring unit 211a and the C-phase voltage input terminal U c A measurement circuit is formed, and the resistance between the B-phase and C-phase voltage circuits of the energy meter 110 is measured through the first measurement unit 211a.

[0119] In stage t6, see Figure 6 and Figure 11 The coil of the fourth relay is de-energized, and the coil of the fifth relay is energized. The first contact a and the second contact b in the first contact group Relay4-1 of the fourth relay are connected, and the first contact a and the second contact b in the second contact group Relay4-2 of the fourth relay are connected. The second contact b and the third contact c in the first contact group Relay5-1 of the fifth relay are connected, and the second contact b and the third contact c in the second contact group Relay5-2 of the fifth relay are connected. Phase A voltage input terminal U... a The first measuring unit 211a and the C-phase voltage input terminal U c A measurement circuit is formed, and the resistance between the A-phase and C-phase voltage circuits of the energy meter 110 is measured through the first measurement unit 211a. The C-phase current output terminal I... C The third measuring unit 211c and the C-phase current input terminal I c A measurement circuit is formed, and the resistance of the C-phase current loop of the secondary circuit of the current transformer is measured through the third measurement unit 211c.

[0120] In stage t7, see Figure 6 and Figure 12The coil of the first relay is energized, and the coil of the second relay is de-energized. The second contact b and the third contact c in the first contact group Relay1-1 of the first relay are connected, and the second contact b and the third contact c in the second contact group Relay1-2 of the first relay are connected. The first contact a and the second contact b in the first contact group Relay2-1 of the second relay are connected, and the first contact a and the second contact b in the second contact group Relay2-2 of the second relay are connected. Phase A voltage output terminal U... A The first measuring unit 211a and the C-phase voltage output terminal U C A measurement circuit is formed, and the resistance between the A-phase and C-phase voltage circuits of the secondary circuit of the voltage transformer is measured through the first measurement unit 211a.

[0121] In the t8 phase, see Figure 6 The coils of the first, second, third, fourth, and fifth relays are all de-energized, and the measurement is complete.

[0122] The technical solution of this embodiment controls the energization and de-energization of the coils in the first, second, third, fourth, and fifth relays through a control module, thereby controlling the contacts in each relay to operate. This causes the first measuring unit 211a, the second measuring unit 211b, and the third measuring unit 211c to measure the resistance of their respective measuring circuits. The control module then determines whether the wiring of the corresponding circuit is correct based on whether the resistance measured by the first measuring unit 211a, the second measuring unit 211b, and the third measuring unit 211c is abnormal. This helps to quickly and accurately determine the wiring status of the secondary circuit for power metering.

[0123] Figure 13 This is a schematic diagram of the structure of a secondary circuit for electricity metering provided by the present invention. Figure 14 This is a front view of a detection device for a secondary circuit of electricity metering provided by the present invention. Figure 15 yes Figure 14 A schematic diagram illustrating the explosion effect of the detection device in the secondary circuit of the electricity metering system. (Combined with...) Figure 2 , Figures 13 to 15 Based on the above embodiments, optionally, the secondary circuit 100 for electricity metering also includes a junction box 120, which has multiple terminals connected to the A-phase voltage output terminal U. A Phase B voltage output terminal U B C-phase voltage output terminal U C Phase A current output terminal I A C-phase current output terminal I C Phase A voltage input terminal U a Phase B voltage input terminal U b C-phase voltage input terminal Uc Phase A current input terminal I a and C-phase current input terminal I c One-to-one correspondence connection.

[0124] The detection device for the secondary circuit of electricity metering also includes: an upper housing 201, a lower housing 202, a circuit board 203, multiple contacts 204, and multiple springs 205; a measurement module 210, a control module 220, a storage module 230, and a display module 240 are formed on the circuit board 203. The upper housing 201 is located on one side of the circuit board 203, and the lower housing 202 is located on the other side of the circuit board 203. The upper housing 201 and the lower housing 202 enclose the circuit board 203. The contacts 204 are disposed on the lower housing 202. The contacts 204 can be connected to the measurement module 210 through wires, so that the measurement module 210 can be connected to the terminals in the junction box 120 through the contacts 204. The springs 205 are used to connect the circuit board 203 and the lower housing 202. The upper housing 201 has a through hole that penetrates the upper housing 201. The position of the display module 240 on the circuit board 203 corresponds to the position of the through hole in the upper housing 201, so that the staff can observe the display module 240 and display the test results through the display module 240.

[0125] For example, the junction box 120 of the secondary circuit 100 for electricity metering is provided with multiple connecting pieces 121 for connecting the terminals. When the detection device of the secondary circuit for electricity metering is used for testing, the connecting pieces 121 on the junction box 120 are first untied. The position of the contact 204 is aligned with the screw on the junction box 120. The detection device of the secondary circuit for electricity metering is pressed on the top of the junction box 120. At this time, each contact 204 is in close contact with the screw on the junction box 120. The measurement module 210 starts to quickly measure the current of the secondary circuit 100 for electricity metering and calculates the resistance. The wiring is judged based on the current magnitude and resistance value. The resistance value and judgment result are displayed on the display module 240. At the same time, the measurement data is saved for easy retrieval later.

[0126] The present invention also provides a method for detecting a secondary circuit of electricity metering, which is executed by the detection device for the secondary circuit of electricity metering in any of the above embodiments. Figure 16 This is a schematic flowchart of a detection method for a secondary circuit in electricity metering provided by the present invention. See also... Figure 16 The method specifically includes the following steps:

[0127] S110. The control module controls the measurement module to select at least two of the following connections: phase A voltage output terminal, phase B voltage output terminal, phase C voltage output terminal, phase A current output terminal, phase C current output terminal, phase A voltage input terminal, phase B voltage input terminal, phase C voltage input terminal, phase A current input terminal, phase C current input terminal, and ground terminal, in order to measure the resistance between any two phase voltage loops of the voltage transformer secondary circuit, the resistance between any two phase voltage loops of the energy meter, the phase B resistance to ground, the phase A current loop resistance of the current transformer secondary circuit, the phase C current loop resistance, and the resistance between the voltage loop and the current loop of the energy meter.

[0128] S120. The control module detects whether the wiring of the secondary circuit for electricity metering is correct based on the resistance measured by the measurement module.

[0129] The technical solution of this invention involves a control module that controls a measurement module to connect at least two of the following: phase A voltage output terminal, phase B voltage output terminal, phase C voltage output terminal, phase A current output terminal, phase C current output terminal, phase A voltage input terminal, phase B voltage input terminal, phase C voltage input terminal, phase A current input terminal, phase C current input terminal, and ground terminal. This allows for the measurement of the resistance between any two phase voltage loops in the secondary circuit of the voltage transformer, the resistance between any two phase voltage loops in the energy meter, the phase B resistance to ground, the resistance of the phase A current loop in the secondary circuit of the current transformer, the resistance of the phase C current loop, and the resistance between the voltage and current loops of the energy meter. Based on the resistance measured by the measurement module, the control module detects whether the wiring of the energy metering secondary circuit is correct, facilitating a quick and accurate assessment of the wiring status of the energy metering secondary circuit.

[0130] Based on the above embodiments, step S110 may optionally include:

[0131] The control module controls the switching unit to select at least two of the following terminals to be connected to the measurement unit: Phase A voltage output terminal, Phase B voltage output terminal, Phase C voltage output terminal, Phase A current output terminal, Phase C current output terminal, Phase A voltage input terminal, Phase B voltage input terminal, Phase C voltage input terminal, Phase A current input terminal, Phase C current input terminal, and ground terminal, in order to form a measurement circuit.

[0132] The control module controls the measurement unit to sample the current and voltage in the measurement circuit.

[0133] Accordingly, step S120 specifically includes:

[0134] The control module calculates the resistance based on the current and voltage sampled by the measurement unit to detect whether the wiring of the secondary circuit for electricity metering is correct.

[0135] Optionally, the control module controls the switching unit to select at least two of the following: phase A voltage output terminal, phase B voltage output terminal, phase C voltage output terminal, phase A current output terminal, phase C current output terminal, phase A voltage input terminal, phase B voltage input terminal, phase C voltage input terminal, phase A current input terminal, phase C current input terminal, and ground terminal to connect to the measurement unit to form a measurement circuit, including:

[0136] The control module controls the energization / de-energization of the internal coils of the first, second, third, fourth, and fifth relays to control the operation of their contacts. This causes the first, second, and third measuring units to form a measuring circuit with the corresponding ports of the A-phase voltage output terminal, B-phase voltage output terminal, C-phase voltage output terminal, A-phase current output terminal, C-phase current output terminal, A-phase voltage input terminal, B-phase voltage input terminal, C-phase voltage input terminal, A-phase current input terminal, C-phase current input terminal, and ground terminal, respectively. The first, second, and third measuring units then sample the current and voltage in the measuring circuit.

[0137] The present invention also provides an energy metering system, including an energy metering device having an energy metering secondary circuit. The energy metering system further includes a detection device for the energy metering secondary circuit in any of the above embodiments. Therefore, the system has the corresponding functional modules and beneficial effects of the detection device for the energy metering secondary circuit, which will not be elaborated here.

[0138] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0139] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A detection device for a secondary circuit of an electricity metering system, characterized in that, The secondary circuit for electricity metering includes: a voltage transformer secondary circuit, a current transformer secondary circuit, and an electricity meter; the voltage transformer secondary circuit includes an A-phase voltage output terminal, a B-phase voltage output terminal, and a C-phase voltage output terminal; the current transformer secondary circuit includes an A-phase current output terminal and a C-phase current output terminal; the electricity meter includes an A-phase voltage input terminal, a B-phase voltage input terminal, a C-phase voltage input terminal, an A-phase current input terminal, and a C-phase current input terminal; the detection device for the secondary circuit for electricity metering includes: The measurement module is used to select and connect at least two of the following: the A-phase voltage output terminal, the B-phase voltage output terminal, the C-phase voltage output terminal, the A-phase current output terminal, the C-phase current output terminal, the A-phase voltage input terminal, the B-phase voltage input terminal, the C-phase voltage input terminal, the A-phase current input terminal, the C-phase current input terminal, and the ground terminal, in order to measure the resistance between any two phase voltage loops of the voltage transformer secondary circuit, the resistance between any two phase voltage loops of the energy meter, the B-phase ground resistance, the A-phase current loop resistance and the C-phase current loop resistance of the current transformer secondary circuit, and the resistance between the voltage loop and the current loop of the energy meter. The measurement module includes a measurement unit and a switching unit, and the measurement unit includes a first measurement unit, a second measurement unit, and a third measurement unit; A control module, connected to the measurement module, is used to control the measurement module and, based on the resistance measured by the measurement module, to detect whether the wiring of the secondary circuit for the power metering is correct.

2. The detection device for the secondary circuit of power metering according to claim 1, characterized in that, The switching unit is used to select at least two of the following terminals to be connected to the measuring unit to form a measuring circuit: the A-phase voltage output terminal, the B-phase voltage output terminal, the C-phase voltage output terminal, the A-phase current output terminal, the C-phase current output terminal, the A-phase voltage input terminal, the B-phase voltage input terminal, the C-phase voltage input terminal, the A-phase current input terminal, the C-phase current input terminal, and the ground terminal. The measuring unit is used to sample the current and voltage in the measuring circuit; The control module connects the measuring unit and the switching unit, and is used to control the measuring unit and the switching unit, and calculate the resistance based on the current and voltage sampled by the measuring unit, so as to detect whether the wiring of the secondary circuit of the power metering is correct.

3. The detection device for the secondary circuit of power metering according to claim 2, characterized in that, The switching unit includes a first relay, a second relay, a third relay, a fourth relay, and a fifth relay; The first relay, the second relay, the third relay, the fourth relay, and the fifth relay all include a coil, a first contact group, and a second contact group. The first contact group and the second contact group all include a first contact, a second contact, and a third contact. The first contact in the first contact group of the first relay is connected to the C-phase voltage input terminal and the second detection terminal of the second measuring unit; the second contact in the first contact group of the first relay is connected to the third contact in the second contact group of the fifth relay and the third contact in the first contact group of the fourth relay; and the third contact in the first contact group of the first relay is connected to the second contact in the second contact group of the second relay. The first contact in the second contact group of the first relay is connected to the A-phase voltage input terminal, the second contact in the second contact group of the first relay is connected to the first contact in the first contact group of the fourth relay, and the third contact in the second contact group of the first relay is connected to the A-phase voltage output terminal. The first contact in the first contact group of the second relay is connected to the B-phase voltage output terminal, and the second contact in the first contact group of the second relay is connected to the B-phase voltage input terminal. The first contact in the second contact group of the second relay is connected to the C-phase voltage output terminal, and the third contact in the second contact group of the second relay is grounded; The first contact in the first contact group of the third relay is connected to the C-phase current input terminal and the third contact in the first contact group of the fifth relay. The second contact in the first contact group of the third relay is connected to the first contact in the second contact group of the fourth relay. The third contact in the first contact group of the third relay is connected to the A-phase current input terminal. The first contact in the second contact group of the third relay is connected to the C-phase current output terminal, the second contact in the second contact group of the third relay is connected to the second detection terminal of the third measuring unit, and the third contact in the second contact group of the third relay is connected to the A-phase current output terminal. The second contact in the first contact group of the fourth relay is connected to the first detection terminal of the first measuring unit; The second contact in the second contact group of the fourth relay is connected to the first detection terminal of the third measuring unit, and the third contact in the second contact group of the fourth relay is grounded; The first contact in the first contact group of the fifth relay is connected to the A-phase current input terminal, and the second contact in the first contact group of the fifth relay is connected to the first detection terminal of the second measuring unit. The first contact in the second contact group of the fifth relay is connected to the B-phase voltage input terminal, and the second contact in the second contact group of the fifth relay is connected to the second detection terminal of the first measuring unit.

4. The detection device for the secondary circuit of power metering according to claim 3, characterized in that, The first measurement unit, the second measurement unit, and the third measurement unit each include: a power supply, a sampling resistor, a current-limiting resistor, and an analog-to-digital converter; The sampling resistor and the current-limiting resistor are connected in series between the first terminal and the first detection terminal of the power supply. The second terminal of the power supply is connected to the second detection terminal. The analog-to-digital converter is connected to the control module, the first and second terminals of the power supply, and both ends of the sampling resistor. The analog-to-digital converter is used to convert the current signal of the sampling resistor and the voltage signal between the first and second terminals of the power supply into digital signals.

5. The detection device for the secondary circuit of power metering according to claim 4, characterized in that, The resistance values ​​of the sampling resistor and the current limiting resistor are selected based on a first numerical relationship and a second numerical relationship. The resistance between the first detection terminal and the second detection terminal is used as a disturbance. The change in the digital quantity of the analog-to-digital converter caused by the disturbance is selected based on the first numerical relationship. Wherein, the first numerical relationship is the numerical relationship between the resistance value of the sampling resistor, the resistance value of the current limiting resistor, the disturbance amount and the resulting change in the digital quantity of the analog-to-digital converter, the resolution of the analog-to-digital converter, and the voltage between the first and second terminals of the power supply. The second numerical relationship is the numerical relationship between the resistance value of the sampling resistor, the resistance value of the current limiting resistor, the voltage range of the analog-to-digital converter, and the voltage between the first and second terminals of the power supply.

6. The detection device for the secondary circuit of power metering according to claim 5, characterized in that, The first numerical relationship is expressed as: ； The second numerical relationship is expressed as follows: ； in, R 采 The resistance value of the sampling resistor is given. R 限 The resistance value of the current-limiting resistor is... D The change in digital quantity of the analog-to-digital converter caused by the disturbance is the value of the change in digital quantity. R Let be the disturbance amount. U ADC / 2 n Let n be the resolution of the analog-to-digital converter, and n be the number of bits in the analog-to-digital converter. U ADC The voltage range of the analog-to-digital converter. U 电源 The voltage is the voltage between the first and second terminals of the power supply.

7. The detection device for the secondary circuit of power metering according to claim 1, characterized in that, The detection device for the secondary circuit of the power metering system also includes: A storage module, connected to the control module, is used to store the current and voltage sampled by the measurement unit, as well as the resistance calculated based on the current and voltage sampled by the measurement unit; The display module, connected to the control module, is used to display the current and voltage sampled by the measurement unit, as well as the judgment result on whether the wiring of the secondary circuit of the power metering is correct.

8. The detection device for the secondary circuit of power metering according to any one of claims 1-7, characterized in that, The secondary circuit for electricity metering also includes a junction box, which has multiple terminals, and each of the multiple terminals is connected to the A-phase voltage output terminal, the B-phase voltage output terminal, the C-phase voltage output terminal, the A-phase current output terminal, the C-phase current output terminal, the A-phase voltage input terminal, the B-phase voltage input terminal, the C-phase voltage input terminal, the A-phase current input terminal, and the C-phase current input terminal in a corresponding manner. The detection device for the secondary circuit of the power metering also includes: an upper housing, a lower housing, a circuit board, and multiple contacts; The measuring module and the control module are formed on the circuit board. The upper housing is located on one side of the circuit board, and the lower housing is located on the other side of the circuit board. The upper housing and the lower housing enclose the circuit board. The contact is disposed on the lower housing. The measuring module is connected to the terminal in the junction box through the contact.

9. A method for detecting a secondary circuit in an electricity metering system, characterized in that, The detection is performed by a detection device in the secondary circuit of the electricity metering system; the secondary circuit of the electricity metering system includes: a voltage transformer secondary circuit, a current transformer secondary circuit, and an electricity meter; the voltage transformer secondary circuit includes an A-phase voltage output terminal, a B-phase voltage output terminal, and a C-phase voltage output terminal; the current transformer secondary circuit includes an A-phase current output terminal and a C-phase current output terminal; the electricity meter includes an A-phase voltage input terminal, a B-phase voltage input terminal, a C-phase voltage input terminal, an A-phase current input terminal, and a C-phase current input terminal; the detection device of the secondary circuit of the electricity metering system includes: a measurement module and a control module, the control module being connected to the measurement module; The detection method for the secondary circuit of the power metering system includes: The control module controls the measurement module to select at least two of the following connections: the A-phase voltage output terminal, the B-phase voltage output terminal, the C-phase voltage output terminal, the A-phase current output terminal, the C-phase current output terminal, the A-phase voltage input terminal, the B-phase voltage input terminal, the C-phase voltage input terminal, the A-phase current input terminal, the C-phase current input terminal, and the ground terminal, in order to measure the resistance between any two phase voltage loops of the voltage transformer secondary circuit, the resistance between any two phase voltage loops of the energy meter, the B-phase ground resistance, the A-phase current loop resistance and the C-phase current loop resistance of the current transformer secondary circuit, and the resistance between the voltage loop and the current loop of the energy meter. The control module uses the resistance measured by the measurement module to detect whether the wiring of the secondary circuit for electricity metering is correct.

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