CN217901884U - Ring main unit electric energy metering device - Google Patents

Abstract

This application relates to the technical field of electric energy metering of ring network cabinets, in particular to an electric energy metering device of ring network cabinets, including three front-inserted, low-voltage meters and The voltage sampling collection unit also includes A-phase, B-phase, and C-phase plug-type voltage transformers fixedly installed in the rear insertion holes through screw connections, and current transformers fixedly installed on the phase lines of A-phase and C-phase. By using electronic voltage transformers and current transformers with plug-type structures as voltage and current sampling units, the "high voltage, high current" signal is converted into a "low voltage, small current" signal, and then connected to the remote communication module The low-voltage meter does not need to remove the original front plug with cable branch during installation, only the plug needs to be replaced, the installation time of the whole device is short, and the insulation performance of the original cable room will not be damaged, which is very practical.

Description

A ring network cabinet electric energy metering device

technical field

The present application relates to the technical field of electric energy metering of a ring network cabinet, in particular to an electric energy metering device of a ring network cabinet.

Background technique

The statements in this section merely provide background technical information relevant to this application and do not necessarily constitute prior art.

Existing 10kV overhead or cable lines have a large number of contact points, boundaries or sections where there is a lack of electric energy metering devices, and when mutual loads often occur, the input or output power of other lines is artificially packaged and combined to calculate the line loss of 10kV branch lines, which may There is a positive line loss and a negative line loss, resulting in distortion of the line loss rate of the 10kV sub-line. At present, the 10kV ring main unit connected to the underground cable and realizes the power supply of the ring network has become the main application type of the urban distribution network. The ring main unit has been equipped with a station terminal DTU. The low-voltage current transformer CT obtains voltage and current signals to measure voltage, current, power and electric energy respectively, but the accuracy of electric energy is 1.0 level or even lower, which only meets the measurement requirements and cannot reach the 0.5S level required by electric energy measurement, and cannot be used as a synchronous line 10kV sub-line loss in the same period of power loss; for the ring main unit not equipped with station terminal DTU, if an additional 10kV high-voltage metering cabinet is added to realize electric energy metering, the floor space must be increased, and a complete set of metering devices needs to be installed in case of power failure. The operation time is long, the transformation cost is high, and the reliability of power supply is greatly reduced.

The Chinese utility model patent with the application number CN201620322733.1 and titled "Ring Main Unit Electric Energy Metering Component, Metering Device, and Component Connection Structure" discloses a ring main unit electric energy metering component, metering device, and component connection structure. The rear plug-in type of the metering device of the ring network cabinet based on the electronic voltage sensor and the closed current transformer is adopted, and the rear plug-in type voltage sensor of the self-feeding and electronic PT is connected to the rear end of the original cable branch, combined with the closed current Transformer, which gathers voltage and current signals to low-voltage meters to realize voltage, current, power measurement and electric energy metering, has the characteristics of small size, light weight, high precision, convenient installation and low renovation cost, but the original cable needs to be replaced The front plug of the branch and the reinstallation of the cable branch on the matching front plug take a long time to install and change the insulation performance of the original cable room. The safety of the equipment may bring hidden dangers of reinstallation. Figure 5 is a schematic diagram of the rear plug-in installation or replacement steps of the electric energy metering device of the ring main unit in the prior art.

Therefore, in view of the problems that the voltage and current transformers currently configured in the ring network cabinet do not meet the measurement accuracy requirements, the cost of adding a complete set of metering cabinets is high, the existing metering devices using new electronic sensors change the original insulation performance and the installation time is long, it is necessary to design An electric energy metering device for a ring network cabinet solves the above problems.

Contents of the invention

Based on this, aiming at the above technical problems, the present application provides an electric energy metering device for a ring main unit.

The technical solution adopted by this application to solve the problems existing in the prior art is:

This application proposes an electric energy metering device for a ring network cabinet, including three front-plug, low-voltage meters fixedly installed on the ring network cabinet corresponding to phase lines A, B, and C, and a plug-type voltage transformer A voltage sampling collection unit for step-down isolation of the collected voltage, the front plug includes a body, a front insertion hole is opened on one side of the upper end of the body, a rear insertion hole is opened on the other side of the upper end of the body, and a rear connector is opened at the lower end of the body The front insertion hole, the rear insertion hole and the rear connector hole are connected in a T-shape; the rear connector holes are respectively fixedly connected with phase wires of phase A, phase B and phase C;

It also includes A-phase, B-phase, C-phase plug-type voltage transformers fixedly installed in the rear insertion hole through threaded connection,

The A-phase, B-phase, and C-phase plug-type voltage transformers are respectively electrically connected to the A-phase, B-phase, and C-phase phase lines inside the front plug, and the A-phase, B-phase, and C-phase plug-type voltage transformers are The outside of the front plug is electrically connected to the voltage sampling and converging unit through the primary side voltage signal line,

The voltage sampling and gathering unit is electrically connected to the low-voltage meter through the secondary side voltage signal line;

It also includes a current transformer fixedly installed on the A-phase and C-phase phase lines, the current transformer is electrically connected to the low-voltage meter through the secondary side current signal line,

The low-voltage meter is electrically connected to an external power source through a power line.

Preferably, the low-voltage meter includes an electric energy metering unit for collecting and counting signals collected by the current transformer and plug-type voltage transformer, and a processing unit, and the processing unit includes a remote communication module.

Preferably, a stress cone for increasing the insulation shielding diameter of the high-voltage cable is fixedly sheathed on the phase line cable which is inserted forward and located below the rear joint hole.

Preferably, the voltage sampling and gathering unit is connected with a ground wire.

Preferably, the voltage sampling and gathering unit outputs three phase voltages and one zero-sequence voltage signal after stepping down and isolating the voltage collected by the plug-type voltage transformer.

Preferably, the current transformer is an open-type current transformer.

Preferably, the transformation ratio of the open-type current transformer is 2000/1.

Preferably, the front plug is sequentially composed of an inner conductive layer, an intermediate insulating layer and an outer conductive layer from inside to outside, and the inner conductive layer, the intermediate insulating layer and the outer conductive layer are integrally formed.

Preferably, a ground socket is fixed on the outer conductive layer of the front plug.

Preferably, the working power of the low-voltage meter is 48V DC or 220V AC on the secondary side of the 10kV high-voltage voltage transformer of the ring main unit.

Compared with the prior art, the beneficial effects of the present application are:

1. The utility model has invented a plug-type metering device for the ring network cabinet. The newly developed electronic voltage transformer based on the plug-type structure and the high-precision open-type current transformer are used as voltage and current sampling units respectively, and " High-voltage, high-current" signals are transformed into "low-voltage, small-current" signals, and then connected to low-voltage meters with remote communication modules. It is not necessary to remove the original front plug with cable branches during installation, only the plug is replaced, and the whole set The installation time of the device is about 30 minutes, and the insulation performance of the original cable room will not be damaged.

2. Compared with the rear plug-in metering device of the ring network cabinet, this application does not need to remove the connection relationship between the original cable accessories and cable branches, and will not damage the insulation performance of the original cable accessories and cable branches, and has higher safety performance.

3. Compared with the rear plug-in metering device of the ring network cabinet, the present invention has low equipment cost, short installation time, reduces labor intensity of installers, does not occupy additional land area, low transformation cost, and convenient and fast construction and installation.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application, and do not constitute improper limitations to the present application.

Fig. 1 is a system composition diagram of a ring main unit electric energy metering device of the present application,

Fig. 2 is the structural outline drawing of a low-voltage meter of a ring main unit electric energy metering device of the present application,

Fig. 3 is a working principle diagram of a low-voltage meter of a ring main unit electric energy metering device of the present application,

Fig. 4 is a cross-sectional view of a ring main unit electric energy metering device inserted in front of the present application,

Fig. 5 is a schematic diagram of the rear plug-in installation or replacement steps of the electric energy metering device of the ring main unit in the prior art,

Fig. 6 is a schematic diagram of plug-type installation or replacement steps of a ring main unit electric energy metering device of the present application.

In the picture:

1. Cable, 2. Current transformer, 3. Stress cone, 4. Primary side voltage signal line, 5. Plug-type voltage transformer, 6. Front insertion, 7. Voltage sampling collection unit, 8. Low-voltage meter, 9. Power line, 10. Secondary side voltage signal line, 11. Ground wire, 12. Secondary side current signal line, 13. Watch case, 14. Battery, 15. Button, 16. Alarm light, 17. Infrared communication Lamp, 18. Pulse indicator light, 19. LCD screen, 20. Remote communication module, 21. Power supply aviation socket, 22. Secondary side voltage aviation socket, 23. Secondary side current aviation socket, 24. Front insertion hole, 25 , rear insertion hole, 26, front insertion body, 27, rear connector hole, 28, grounding seat, 29, inner conductive layer, 30, intermediate insulating layer, 31, outer conductive layer.

Detailed ways:

The application will be further described below in conjunction with the accompanying drawings and embodiments.

It should be noted that the terminology used herein is only for describing specific embodiments, and is not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

In this disclosure, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom" etc. refer to The orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only a relative term determined for the convenience of describing the structural relationship between the components or elements of the present disclosure. Public restrictions.

Figure 1 and Figure 2 are preferred embodiments of a ring network cabinet electric energy metering device of the present application. As shown in the figure, a ring network cabinet electric energy metering device of the present application includes fixed installation on the ring network cabinet corresponding to phase A, phase B Three front plugs 6 of phase and C phase phase lines, a low-voltage meter 8, and a voltage sampling collection unit 7 for step-down isolation of the voltage collected by the plug-type voltage transformer 5, and Fig. 4 shows the front Schematic diagram of the structure of the plug 6, the front plug 6 includes a body 26, a front insertion hole 24 is opened on one side of the upper end of the body 26, a rear insertion hole 25 is opened on the other side of the upper end of the body 26, and a rear connector is opened on the lower end of the body 26 The hole 27, the front insertion hole 24, the rear insertion hole 25 and the rear joint hole 27 are connected in a T shape; the rear joint hole 27 is fixedly connected with phase lines A, B and C;

A kind of electric energy metering device of the ring network cabinet of the present application also includes A phase, B phase, and C phase plug-type voltage transformer 5 fixedly installed in the rear insertion hole 25 through screw connection, and the A phase, B phase, C phase The phase plug-type voltage transformer 5 is electrically connected to the A-phase, B-phase, and C-phase phase wires inside the front plug-in 6, and the A-phase, B-phase, and C-phase plug-type voltage transformers 5 are respectively passed through the front plug-in 6. The primary side voltage signal line 4 is electrically connected to the voltage sampling collection unit 7, and the voltage sampling collection unit 7 is electrically connected to the low voltage meter 8 through the secondary side voltage signal line 10; the front plug 6 is located under the rear connector hole 27 The phase line cable 1 is fixedly sleeved with a stress cone 3 for increasing the diameter of the high-voltage cable insulation shield; The inner conductive layer 11 , the intermediate insulating layer 12 and the outer conductive layer 13 are integrally formed, and the outer conductive layer 31 of the front plug 6 is fixed with a grounding seat 28 .

The electric energy metering device of a ring main unit of the present application also includes a current transformer 2 fixedly installed on the A-phase and C-phase phase lines, and the current transformer 2 is electrically connected to the low-voltage meter 8 through the secondary side current signal line 12 connected, the low-voltage meter 8 is electrically connected to an external power supply through a power line 9, and the voltage sampling collection unit 7 outputs three phase voltages and a zero-sequence voltage signal, the current transformer 2 is an open-type current transformer, and the transformation ratio of the open-type current transformer is 2000/1; the voltage sampling collection unit 7 is connected to a ground wire 11 .

As shown in Figure 3, the low-voltage meter 8 includes an electric energy metering unit for collecting and counting the signals collected by the current transformer 2 and the plug-type voltage transformer 5, and a processing unit, and the processing unit includes a remote Communication module 20, power supply module, local RS485 interface, key interface, infrared communication module, pulse interface, battery module, encryption module, storage module and display module. A housing 13 is provided outside the low-voltage meter 8, and a battery 14 is arranged in the housing 13. A liquid crystal screen 19 for display is provided on the front of the housing 13, and a button 15, an alarm lamp 16, and an infrared communication lamp 17 are arranged below the liquid crystal screen 19. And pulse indicator light 18, low-voltage gauge 8 below are provided with power supply aviation socket 21, secondary side voltage aviation socket 22, secondary side current aviation socket 23.

In this embodiment, the working power of the low-voltage meter 8 is 48V DC or 220V AC on the secondary side of the 10kV high-voltage voltage transformer of the ring main unit.

The reference application number is CN202021165348.3, and the name is a Chinese utility model patent for a plug-type voltage sensor for a ring network cabinet. It introduces a plug-type voltage sensor for a ring network cabinet, which includes a body and is installed inside the body. Capacitor, circuit board, metal shielding net and error adjustment circuit, the upper end of the device body adopts a conical joint, and the inside of the conical joint is provided with a primary copper nut, the capacitor is welded on the circuit board, and the primary copper nut is connected to the circuit board , the body is made of epoxy resin, the lower end of the body forms a cavity, the error adjustment circuit is arranged in the cavity, the error adjustment circuit is connected to the circuit board, the lower end of the body is provided with a metal base plate, the metal base plate There are signal output cables and grounding terminals on it. It has the advantages of low power consumption, high accuracy, strong anti-interference ability, three-in-one measurement, measurement and protection, and can directly replace the insulating plug of the cable joint for installation.

其中电容为金属化薄膜电容；2个开口式电流互感器2分别卡在环网柜电缆室库的A、C两相电缆分支上，通过电流感应输出线性的二次侧电流信号，原副线圈匝比1：2000。从10kV环网柜的三相电缆分支经过堵头式电压互感器5、电流互感器2变换，分别获得了三相低压电压信号、两相小电流信号，接入低压表计8，经过内部电能计量单元和处理器的测量与运算，通过二元法计量原理实现三相电压、电流、功率的测量，以及分相与合相电能的计算。In this application, plug-type voltage transformers 5 with the same structure are used, and three plug-type voltage transformers 5 are made by adopting the principle of internal high-voltage capacitor step-down and impedance voltage division. The three-phase voltage signals on the primary side are connected to the voltage sampling and After the converging unit 7, after step-down and isolation, the secondary side outputs stable three-phase voltages and a zero-sequence voltage signal, and the transformation ratios are respectively

Among them, the capacitor is a metallized film capacitor; two open-type current transformers 2 are respectively stuck on the A and C two-phase cable branches of the cable room of the ring network cabinet, and the linear secondary side current signal is output through current induction. The primary and secondary coils Turn ratio 1:2000. From the three-phase cable branch of the 10kV ring network cabinet, through the plug-type voltage transformer 5 and the current transformer 2, the three-phase low-voltage voltage signal and the two-phase small current signal are respectively obtained, connected to the low-voltage meter 8, and passed through the internal electric energy The measurement and calculation of the metering unit and the processor realize the measurement of three-phase voltage, current and power, as well as the calculation of split-phase and combined-phase electric energy through the measurement principle of binary method.

Figure 6 is a schematic diagram of plug-type installation or replacement steps of a ring main unit electric energy metering device of the present application. Compared with the schematic diagram of plug-in installation or replacement steps of the ring main unit electric energy metering device in the prior art in Figure 5, this application does not need to be dismantled The connection relationship between the original cable accessories and the cable branches will not destroy the insulation performance of the original cable accessories and the cable branches, and the safety performance is higher; it avoids the need to replace the front plug of the original cable branch when installing or replacing in the prior art shown in Figure 5 , Plug and reinstall the cable branch in the matching front, the installation time of the whole device is long, and it will not change the insulation performance of the original cable room, reducing the safety hazard of reinstallation.

The above are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Although the specific implementation of the application has been described above in conjunction with the accompanying drawings, it does not limit the scope of protection of the application. Those skilled in the art should understand that on the basis of the technical solution of the application, those skilled in the art do not need to pay creative work Various modifications or deformations that can be made are still within the protection scope of the present application.

Claims (10)

1. The utility model provides a looped netowrk cabinet electric energy metering device which characterized in that:

comprises three front plugs (6) which are fixedly arranged on a ring main unit and correspond to phase lines A, B and C, a low-voltage meter (8) and a voltage sampling and collecting unit (7) for reducing and isolating the voltage collected by a plug type voltage transformer (5),

the front plug (6) comprises a body (26), a front insertion hole (24) is formed in one side of the upper end of the body (26), a rear insertion hole (25) is formed in the other side of the upper end of the body (26), a rear joint hole (27) is formed in the lower end of the body (26), and the front insertion hole (24), the rear insertion hole (25) and the rear joint hole (27) are communicated in a T shape; phase lines A, B and C are fixedly connected in the rear joint hole (27) respectively;

also comprises an A-phase plug type voltage transformer, a B-phase plug type voltage transformer and a C-phase plug type voltage transformer (5) which are fixedly arranged in the rear insertion hole (25) through threaded connection,

the A-phase, B-phase and C-phase plug type voltage transformers (5) are respectively and electrically connected with the A-phase, B-phase and C-phase wires inside the front plug (6), the A-phase, B-phase and C-phase plug type voltage transformers (5) are respectively and electrically connected with the voltage sampling and collecting unit (7) through the primary side voltage signal wire (4) outside the front plug (6),

the voltage sampling and collecting unit (7) is electrically connected with the low-voltage meter (8) through a secondary side voltage signal wire (10);

the low-voltage meter also comprises a current transformer (2) fixedly arranged on the phase line of the A phase and the phase line of the C phase, the current transformer (2) is electrically connected with the low-voltage meter (8) through a secondary side current signal line (12),

the low-voltage meter (8) is electrically connected with an external power supply through a power line (9).

2. The ring main unit electric energy metering device of claim 1, characterized in that:

the low-voltage meter (8) comprises an electric energy metering unit and a processing unit, wherein the electric energy metering unit is used for collecting and counting signals collected by the current transformer (2) and the plug type voltage transformer (5), and the processing unit comprises a remote communication module (20).

3. The ring main unit electric energy metering device of claim 1, characterized in that:

and the front plug (6) is positioned on the phase line cable (1) below the rear joint hole (27), and the stress cone (3) used for increasing the insulation shielding diameter of the high-voltage cable is fixedly sleeved on the phase line cable (1).

4. The ring main unit electric energy metering device of claim 1, characterized in that:

the voltage sampling and collecting unit (7) is connected with a ground wire (11).

5. The ring main unit electric energy metering device of claim 1 or 4, wherein:

the voltage sampling and collecting unit (7) performs voltage reduction and isolation on the voltage collected by the plug type voltage transformer (5) and then outputs three phase voltages and a zero sequence voltage signal.

6. The ring main unit electric energy metering device of claim 1, characterized in that:

the current transformer (2) is an open-type current transformer.

7. The ring main unit electric energy metering device of claim 6, characterized in that:

the transformation ratio of the open type current transformer is 2000/1.

8. The ring main unit electric energy metering device of claim 1, characterized in that:

the front plug (6) is composed of an inner conducting layer (29), a middle insulating layer (30) and an outer conducting layer (31) from inside to outside in sequence, and the inner conducting layer (29), the middle insulating layer (30) and the outer conducting layer (31) are integrally formed.

9. The ring main unit electric energy metering device of claim 8, wherein:

and a grounding seat (28) is fixedly arranged on the outer conducting layer (31) of the front plug (6).

10. The ring main unit electric energy metering device of claim 1, characterized in that:

the working power supply of the low-voltage meter (8) is direct current 48V or alternating current 220V on the secondary side of a 10kV high-voltage potential transformer of the ring main unit.

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