Joint junction box capable of multi-transformation ratio switching and transformation ratio switching and verification method

Abstract

The invention relates to the technical field of combined junction boxes, in particular to a combined junction box capable of switching multiple transformation ratios and a transformation ratio switching and verification method. Comprising a plurality of voltage units and a plurality of current units. In the voltage unit, a voltage connecting piece is connected with a voltage input end and a voltage output end on a first surface; on the second face, the metal wire is connected with the voltage output end and connected with the voltage connecting piece, and the voltage connecting piece is configured to conduct the voltage input end and the voltage output end when tightened. In the current unit, the mutual inductor access end is connected with the current input terminal through a metal wire, each transformation ratio switching terminal is connected with the backflow terminal through a metal wire, each transformation ratio connecting piece is arranged corresponding to each transformation ratio switching terminal, and the transformation ratio connecting pieces are configured to conduct the corresponding transformation ratio switching terminal and the backflow terminal when being tightened. According to the invention, the transformation ratio switching of the mutual inductor is completed under the condition of no power failure through the plurality of transformation ratio connecting pieces.

Description

Technical Field

[0001] This invention relates to the field of junction box technology, and in particular to a junction box capable of switching multiple transformer ratios, as well as a method for switching and verifying transformer ratios. Background Technology

[0002] In recent years, to expand the optimal measurement range of combined current and voltage transformers and to reserve sufficient space for future capacity expansion, multi-ratio current-voltage combined transformers are generally used. Before the current output from the current-voltage combined transformer is input to the user's electricity meter, it needs to pass through a junction box. The junction box is mainly used to calibrate the electricity meter without power interruption to ensure accurate meter readings.

[0003] However, existing junction boxes cannot meet the application scenarios of multi-ratio combined instrument transformers. For example, existing junction boxes can only connect one ratio per phase, while the conductors for other ratios from the combined instrument transformer are left unconnected. When switching ratios in a combined instrument transformer, the dedicated line must first be disconnected and the electrical equipment shut down before wiring corrections can be made at the junction box to achieve the ratio switch. The ratio switching process is complex and slow.

[0004] Therefore, designing a combined junction box that can quickly switch the transformation ratio for current-voltage combined transformers with multiple transformation ratios is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The present invention provides a combined junction box capable of switching multiple transformer ratios and a method for switching and verifying transformer ratios. It can provide multiple input terminals for transformers with multiple transformer ratios and achieve transformer ratio switching without power interruption. At the same time, it can conveniently perform on-site verification of electricity meters.

[0006] This invention provides a multi-ratio switching junction box, comprising: a box body, with multiple voltage units and multiple current units disposed on a first surface of the box body, and multiple metal wires disposed on a second surface of the box body; each voltage unit includes: a voltage input terminal, a voltage output terminal, and a voltage connector, the voltage connector being connected to the voltage input terminal and the voltage output terminal on the first surface; on the second surface, the metal wires being connected to the voltage output terminal and the voltage connector, the voltage connector being configured to conduct electricity between the voltage input terminal and the voltage output terminal when tightened. The current unit includes: a current transformer input terminal, an energy meter input terminal, and a current connecting piece. The current transformer input terminal includes a current input terminal and multiple ratio switching terminals. The energy meter input terminal includes a current output terminal and a return terminal. The current transformer input terminal and the current input terminal are connected through the metal wire. Each ratio switching terminal is connected to the return terminal through the metal wire. The current connecting piece includes multiple ratio connecting pieces, each ratio connecting piece is correspondingly arranged with each ratio switching terminal, and the ratio connecting piece is configured to conduct the corresponding ratio switching terminal and the return terminal when tightened.

[0007] In one technical solution of the present invention, in the current unit, the transformation ratio switching terminal includes a first transformation ratio switching terminal, a second transformation ratio switching terminal, and a third transformation ratio switching terminal, which are disposed on the same side of the first surface; the transformation ratio connecting piece includes a first transformation ratio connecting piece, a second transformation ratio connecting piece, and a third transformation ratio connecting piece; the metal wire includes a first current wire, a second current wire, a third current wire, a fourth current wire, and a fifth current wire; the current input terminal and the current output terminal are connected through the first current wire; the return current terminal is connected to the second current wire; the first transformation ratio connecting piece is configured to conduct the second current wire and the third current wire when tightened; the second transformation ratio connecting piece is configured to conduct the third current wire and the fourth current wire when tightened; and the third transformation ratio connecting piece is configured to conduct the fourth current wire and the fifth current wire when tightened.

[0008] In one technical solution of the present invention, the first current conductor, the second current conductor, the third current conductor, the fourth current conductor, and the fifth current conductor are arranged sequentially along a first direction and disposed along a second direction, the first transformer ratio connecting piece, the second transformer ratio connecting piece, and the third transformer ratio connecting piece are disposed along the first direction, and the second direction is perpendicular to the first direction.

[0009] In one technical solution of the present invention, the length of the second ratio connecting piece exceeds the length of the first ratio connecting piece by 0.8 to 1 cm, and the length of the third ratio connecting piece exceeds the length of the second ratio switching piece by 0.8 to 1 cm.

[0010] In one embodiment of the present invention, the current connector further includes a shorting connector, which connects the first current conductor and the second current conductor. The shorting connector is configured to conduct the first current conductor and the second current conductor when tightened.

[0011] In one technical solution of the present invention, the voltage unit includes a first voltage unit, a second voltage unit, a third voltage unit, and a fourth voltage unit, and the current unit includes a first current unit, a second current unit, and a third current unit; arranged in the order of the first voltage unit, the first current unit, the second voltage unit, the second current unit, the third voltage unit, the third current unit, and the fourth voltage unit along a third direction.

[0012] In one technical solution of the present invention, the current unit further includes a calibrator access terminal, which is disposed on the first surface. The calibrator access terminal includes a calibrator access terminal and a plurality of calibrator ratio terminals. The plurality of calibrator ratio terminals include a first calibrator ratio terminal, a second calibrator ratio terminal, and a third calibrator ratio terminal. The first calibrator ratio terminal, the second calibrator ratio terminal, and the third calibrator ratio terminal are respectively corresponding to the first ratio connecting piece, the second ratio connecting piece, and the third ratio connecting piece. The calibrator access terminal and the return current terminal are connected via a second current conductor. The first calibrator ratio terminal and the first ratio switching terminal are connected via a third current conductor. The second calibrator ratio terminal and the second ratio switching terminal are connected via a fourth current conductor. The third calibrator ratio terminal and the third ratio switching terminal are connected via a fifth current conductor.

[0013] In one technical solution of the present invention, the voltage output terminal includes a meter output terminal and a sampling output terminal, the voltage connector includes a first voltage connector and a second voltage connector, the metal wire includes a first voltage wire and a second voltage wire, the meter output terminal and the first voltage connector are connected through the first voltage wire, and the sampling output terminal and the second voltage connector are connected through the second voltage wire.

[0014] In one technical solution of the present invention, a junction box cover is further included. The junction box cover comprises: a cover body, a data acquisition and processing module, an LED display screen, and a remote communication module. The cover body is disposed on the junction box body and is used to isolate the interior and exterior of the junction box body. The data acquisition and processing module includes a temperature sensor, a humidity sensor, a voltage sampling sensor, and a current sampling sensor. The temperature sensor and the humidity sensor are disposed on the side of the cover body near the interior. The voltage sampling sensor is disposed on the voltage output terminal, and the current sampling sensor is disposed on the current input terminal. The LED display screen is electrically connected to each sensor of the data acquisition and processing module and is used to display the data acquired by each sensor. The remote communication module is electrically connected to each sensor of the data acquisition and processing module and is used to acquire the voltage at the voltage output terminal, the current at the current input terminal, and the temperature and humidity inside the junction box.

[0015] In one technical solution of the present invention, the shape of each of the variable ratio connecting pieces includes: a U-shaped groove is provided at the first end of the variable ratio connecting piece, and the second end of the variable ratio connecting piece is bent at a preset angle to form a raised shape.

[0016] In another technical solution of the present invention, a method for switching the transformer ratio of a combined junction box capable of switching multiple transformer ratios is provided, comprising: reading the transformer ratio corresponding to each transformer ratio switching terminal through an LED display screen; determining the transformer ratio switching terminal to be switched based on the transformer ratio of the current transformer to be switched; removing the junction box cover, determining the corresponding transformer ratio connecting piece and the transformer ratio connecting piece currently in a tightened state according to the transformer ratio switching terminal to be switched; tightening the transformer ratio connecting piece to be switched so that the transformer ratio switching terminal corresponding to the transformer ratio connecting piece to be switched forms a current loop with the energy meter; after the transformer ratio connecting piece to be switched is tightened, opening the transformer ratio connecting piece that was originally in a tightened state so that the transformer ratio connecting piece that was originally in a tightened state forms a current loop with the energy meter. When the transformer ratio connecting piece is tightened, the corresponding transformer ratio switching terminal is disconnected from the current circuit of the energy meter; the junction box cover is installed on the box body; wherein, multiple voltage units and multiple current units are provided on the first surface of the box body, and multiple metal wires are provided on the second surface of the box body; each voltage unit includes: a voltage input terminal, a voltage output terminal, and a voltage connecting piece, the voltage connecting piece being connected to the voltage input terminal and the voltage output terminal on the first surface; on the second surface, the metal wires are connected to the voltage output terminal and the voltage connecting piece, the voltage connecting piece being configured to conduct the voltage input terminal and the voltage output terminal when tightened; each current unit includes: a current transformer connection terminal. The system includes an electricity meter access terminal and a current connector. The current transformer access terminal includes a current input terminal and multiple ratio switching terminals. The electricity meter access terminal includes a current output terminal and a return terminal. The current transformer access terminal and the current input terminal are connected via a metal wire. Each ratio switching terminal is connected to the return terminal via a metal wire. The current connector includes multiple ratio connectors, each corresponding to a ratio switching terminal. The ratio connector is configured to conduct electricity to the corresponding ratio switching terminal and return terminal when tightened. The system also includes a junction box cover, which includes a cover body, a data acquisition and processing module, an LED display screen, and a remote communication module. The cover body is located at the... The main body of the box is used to isolate the interior and exterior of the box body; the data acquisition and processing module includes a temperature sensor, a humidity sensor, a voltage sampling sensor, and a current sampling sensor. The temperature sensor and the humidity sensor are located on the side of the main body of the box body near the interior, the voltage sampling sensor is located at the voltage output terminal, and the current sampling sensor is located at the current input terminal; the LED display screen is electrically connected to each sensor of the data acquisition and processing module and is used to display the data collected by each sensor; the remote communication module is electrically connected to each sensor of the data acquisition and processing module and is used to acquire the voltage at the voltage output terminal, the current at the current input terminal, and the temperature and humidity inside the box.

[0017] In another technical solution of the present invention, a verification method for a combined junction box capable of multiple transformer ratio switching is provided, comprising: reading the current value measured by the energy meter in the current loop to be verified through an LED display screen; removing the junction box cover to determine the transformer ratio connecting piece currently in a tightened state; determining the corresponding transformer ratio switching terminal based on the transformer ratio connecting piece currently in a tightened state, and determining the transformer ratio terminal of the calibrator based on the transformer ratio switching terminal; connecting the polarity terminal of the calibrator to the calibrator input terminal, and connecting the non-polarity terminal of the calibrator to the transformer ratio terminal of the calibrator, so that the calibrator is connected to the current transformer; opening the transformer ratio connecting piece currently in a tightened state, so that the calibrator is connected in series to the current loop of the current transformer; reading the current value of the current loop according to the calibrator and comparing it with the current value measured by the energy meter; if the current value read by the calibrator and the current value measured by the energy meter are within the error range, then the energy meter is normal; if the current value read by the calibrator and the current value measured by the energy meter are within the error range, then the energy meter is normal. If the current value measured by the energy meter exceeds the error range, the energy meter is abnormal. The junction box cover is installed on the box body to complete the calibration operation. The calibrator access terminal is located on the first side and includes a calibrator access terminal and multiple calibrator ratio terminals. The multiple calibrator ratio terminals include a first calibrator ratio terminal, a second calibrator ratio terminal, and a third calibrator ratio terminal. The first, second, and third calibrator ratio terminals are respectively associated with the first, second, and third ratio connecting pieces. The calibrator access terminal and the return current terminal are connected via the second current conductor. The first calibrator ratio terminal and the first ratio switching terminal are connected via the third current conductor. The second calibrator ratio terminal and the second ratio switching terminal are connected via the fourth current conductor. The third calibrator ratio terminal and the third ratio switching terminal are connected via the fifth current conductor.

[0018] This invention achieves transformer ratio switching without power interruption by setting multiple ratio switching terminals, which are connected to multiple ratio taps on the current transformer, and by setting multiple ratio connecting pieces. On the one hand, it avoids the problem of uncontrolled switching of the transformer ratio conductors on the current transformer side, which may cause grounding current shunting and affect the accuracy of metering. On the other hand, it achieves the technical effect of rapid ratio switching according to the power load on the user side. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1This is a schematic diagram of a combined junction box capable of switching multiple ratios, provided by an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the second side of a combined junction box capable of switching multiple ratios, provided by an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the voltage unit in the combined junction box provided by an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the current unit in the combined junction box provided by an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the wiring connection between the combined junction box and the current transformer, energy meter and calibrator provided in an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the junction box cover of the combined junction box provided in an embodiment of the present invention.

[0026] The above figures include the following reference numerals:

[0027] 1. Box body; 2. Voltage unit; 201. First voltage unit; 202. Second voltage unit; 203. Third voltage unit; 204. Fourth voltage unit; 3. Current unit; 301. First current unit; 302. Second current unit; 303. Third current unit; 4. Metal wire; 5. Junction box cover; 21. Voltage input terminal; 22. Voltage output terminal; 23. Voltage connector; 31. Current transformer connection terminal; 32. Energy meter connection terminal; 33. Current connector; 34. Calibrator connection terminal; 41. First current wire ; 42. Second current conductor; 43. Third current conductor; 44. Fourth current conductor; 45. Fifth current conductor; 51. Cover body; 52. LED display screen; 61. Calibrator input terminal; 62. Calibrator ratio terminal; 221. Meter output terminal; 222. Sampling output terminal; 231. First voltage connector; 232. Second voltage connector; 311. Current input terminal; 312. Ratio switching terminal; 321. Current output terminal; 322. Return current terminal; 331. Ratio connector; 332. Shorting connector. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0030] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0031] Current junction boxes are no longer suitable for the application scenarios of multi-ratio combined instrument transformers. When the current lines of multi-ratio combined instrument transformers are led from the transformer itself to a traditional junction box, only two conductors for each phase and one ratio can be connected, preventing the connection of all conductors for the remaining ratios. The conductors on the transformer side are left unconnected, which can easily cause grounding current shunting, affecting metering accuracy. Furthermore, during ratio replacement work, to prevent the risk to the motor from an open circuit on the transformer side, power must be cut off on that side. The power outage process requires reporting a power outage plan and implementing safety controls, resulting in long working hours and significant safety pressure.

[0032] like Figure 1 As shown, an embodiment of the present invention provides a combined junction box capable of switching multiple transformation ratios, including a box body 1, multiple voltage units 2, and multiple current units 3. Inside the box body 1 is a first surface for mounting the multiple voltage units 2 and multiple current units 3, and a second surface is the surface opposite to the first surface. Figure 2 As shown, multiple metal wires 4 are provided on the second surface, and the main body 1 of the box is made of insulating material.

[0033] Among them, such as Figure 3As shown, in voltage unit 2, voltage input terminal 21 and voltage output terminal 22 are disposed on the first surface, and voltage input terminal 21 and voltage output terminal 22 are connected to metal wire 4 on the second surface. However, a voltage connector 23 is disposed between voltage input terminal 21 and voltage output terminal 22. One end of voltage connector 23 is connected to metal wire 4, and the other end is provided with a tightening screw. When the screw is tightened, voltage input terminal 21 and voltage output terminal 22 are connected.

[0034] The voltage input terminal 21 is connected to an external transformer, and the voltage output terminal 22 is connected to an external energy meter. In normal operation of the junction box, the voltage connector 23 is tightened with screws, allowing the energy meter and the transformer to conduct through the voltage connector 23 and the metal wire 4, thus achieving parallel connection between the energy meter and the transformer.

[0035] In this embodiment, the voltage output terminal 22 specifically includes a meter output terminal 221 and a sampling output terminal 222, wherein the meter output terminal 221 is externally connected to an energy meter, and the sampling output terminal 222 is externally connected to a voltage calibrator. The voltage connector 23 includes a first voltage connector 231 and a second voltage connector 232, and the metal wire 4 includes a first voltage wire and a second voltage wire.

[0036] In this circuit, one end of both the first voltage connector 231 and the second voltage connector 232 is connected to the voltage input terminal 21, i.e., connected to the current transformer. The other end of the first voltage connector 231 is connected to one end of the first voltage conductor, and the other end of the first voltage conductor is connected to the energy meter. Under normal operating conditions, the first voltage connector 231 is normally closed, enabling parallel connection between the energy meter and the current transformer. The other end of the second voltage connector 232 is connected to one end of the second voltage conductor, and the other end of the second voltage conductor is connected to the voltage calibrator, enabling parallel connection between the voltage calibrator and the current transformer when the second voltage connector 232 is tightened with screws. When testing the energy meter, the second voltage connector 232 is tightened with screws. Under normal operating conditions, the second voltage connector 232 is opened, creating an open circuit between the voltage calibrator and the current transformer.

[0037] In this embodiment, as Figure 4 As shown, the current unit 3 includes: a current transformer connection terminal 31, an energy meter connection terminal 32, and a current connecting piece 33. The current transformer connection terminal 31 includes a current input terminal 311 and multiple ratio switching terminals 312. The current input terminal 311 is used to connect to the current input terminal of the current transformer, and each ratio switching terminal 312 is connected to one ratio of the current transformer.

[0038] The electricity meter connection terminal 32 includes a current output terminal 321 and a return terminal 322, which are respectively connected to the input terminal and the output segment of the current module of the electricity meter. Through the terminals in the current unit 3, a current path is formed whereby the current input from the current transformer through the current input terminal 311 passes through the current output terminal 321 and the return terminal 322 of the electricity meter, and finally flows back to the current transformer through a ratio switching terminal 312.

[0039] A current connecting piece 33 is provided between the current transformer input terminal 31 and the energy meter input terminal 32. The current connecting piece 33 includes multiple ratio connecting pieces 331 and shorting connecting pieces 332. Each ratio connecting piece 331 corresponds to the ratio of a current transformer and is connected to a ratio switching terminal 312, so that each ratio connecting piece 331 and each ratio switching terminal 312 are configured accordingly.

[0040] In this embodiment, the transformer ratio connecting piece 331 is configured to conduct the corresponding transformer ratio switching terminal 312 and return terminal 322 when tightened.

[0041] Specifically, the transformer ratio switching terminal 312 includes a first transformer ratio switching terminal, a second transformer ratio switching terminal, and a third transformer ratio switching terminal, and the first transformer ratio switching terminal, the second transformer ratio switching terminal, and the third transformer ratio switching terminal are located on the same side of the first surface. The transformer ratio connecting piece 331 corresponding to each transformer ratio switching terminal 312 includes a first transformer ratio connecting piece, a second transformer ratio connecting piece, and a third transformer ratio connecting piece.

[0042] like Figure 5 As shown, the current unit 3 includes a first current conductor 41, a second current conductor 42, a third current conductor 43, a fourth current conductor 44, and a fifth current conductor 45. The first current conductor 41 is connected to the current input terminal 311 and the current output terminal 321. The second current conductor 42 is connected to the return current terminal 322. The third, fourth, and fifth current conductors 43, 44, and 45 are respectively connected to the first, second, and third turns ratio switching terminals. The first end of the first turns ratio connecting piece is fixedly connected to the second current conductor 42, and the second end is configured to be connected to the third current conductor 43 by tightening a screw. The first end of the second turns ratio connecting piece is fixedly connected to the second current conductor 42, and the second end is configured to be connected to the fourth current conductor 44 by tightening a screw. The first end of the third turns ratio connecting piece is fixedly connected to the second current conductor 42, and the second end is configured to be connected to the fifth current conductor 45 by tightening a screw.

[0043] With the above setup, the current transformer is connected to the current input terminal 311, and the energy meter is connected to the current output terminal 321. If the required transformer ratio is the first ratio switching terminal, the first ratio connecting piece is tightened with screws, keeping the second and third ratio connecting pieces disconnected. Then, the second current conductor 42 and the third current conductor 43 are connected through the first ratio connecting piece. Because the first ratio connecting piece and the return terminal 322 are connected through the second current conductor 42, the first ratio switching terminal connected to the third current conductor 43 is connected to the return terminal 322. This forms a current input from the transformer that flows sequentially from the current input terminal 311 to the current output terminal 321, the energy meter, the return terminal 322, the first ratio connecting piece, and the first ratio switching terminal. Finally, it returns to the transformer through the first ratio switching terminal.

[0044] Similarly, if the transformer ratio to be connected is the second or third ratio switching terminal, tighten the corresponding ratio connecting piece 331 while keeping the other ratio connecting pieces 331 open. It is important to note that during the switch from one ratio to another, the ratio connecting piece 331 corresponding to the original ratio must be kept tightened first. After tightening the connecting piece 331 of the ratio to be switched, then further loosen the connecting piece 331 corresponding to the original ratio. This is because if the transformer is in an open-circuit state at any moment, it will cause a sharp rise in the transformer's output voltage, resulting in a significant safety risk.

[0045] In this embodiment, as Figure 5 As shown, the first current conductor 41, the second current conductor 42, the third current conductor 43, the fourth current conductor 44, and the fifth current conductor 45 are arranged sequentially along the first direction and set along the second direction. The first transformer ratio connector, the second transformer ratio connector, and the third transformer ratio connector are set along the first direction, and the second direction is perpendicular to the first direction. The first current conductor 41, the second current conductor 42, the third current conductor 43, the fourth current conductor 44, and the fifth current conductor 45 are all straight lines. Correspondingly, the first transformer ratio switching terminal, the second transformer ratio switching terminal, and the third transformer ratio switching terminal are also arranged sequentially along the second direction. During setup, they can be arranged according to the transformer ratio values ​​of each transformer ratio switching terminal 312. For example, the transformer ratio corresponding to the first transformer ratio switching terminal is 50 / 5A, the transformer ratio corresponding to the second transformer ratio switching terminal is 100 / 5A, and the transformer ratio corresponding to the third transformer ratio switching terminal is 150 / 5A. This makes it easier to remember and identify the transformer ratio corresponding to each transformer ratio switching terminal 312 during transformer ratio operation.

[0046] In another embodiment of the invention, such as Figure 3As shown, the length of the second ratio connecting piece exceeds the length of the first ratio connecting piece by 0.8 to 1 cm, and the length of the third ratio connecting piece exceeds the length of the second ratio switching piece by 0.8 to 1 cm. 0.8 cm is approximately the diameter of a screw. Even though the first, second, and third ratio switching terminals are arranged adjacent to each other, the lengths of the connecting pieces gradually increase from the first to the second and then to the third ratio connecting piece. This allows for a more compact internal structure within the junction box.

[0047] In this embodiment, the junction box is 286 mm long and 85 mm wide.

[0048] The shorting connector 332 has its first end attached to the first current conductor 41 and its second end attached to the second current conductor 42. The shorting connector 332 is configured to establish continuity between the first current conductor 41 and the second current conductor 42 when the second end is tightened with a screw. The shorting connector 332 is primarily used when an electricity meter malfunctions and requires repair or replacement. The continuity between the first current conductor 41 and the second current conductor 42 short-circuits the electricity meter, facilitating further repair or replacement work.

[0049] In this embodiment, the first end of each transformer ratio connecting piece 331 is a fixed end, which is provided with a U-shaped groove so that the transformer ratio connecting piece 331 is in close contact with the first surface. The second end is the end that is tightened by screws. Tightening the screws makes the transformer ratio connecting piece 331 contact the metal wire 4, or loosening the screws makes the transformer ratio connecting piece 331 separate from the metal wire 4.

[0050] The second end of each transformer ratio connecting piece 331 is bent at a 90-degree angle to form a raised shape, which makes it easy to separate the transformer ratio connecting piece 331 from the metal wire 4 after loosening the screw.

[0051] In this embodiment, as Figure 3 As shown, the current unit 3 also includes a calibrator access terminal 34, which is disposed on the first side. The calibrator access terminal 34 includes a calibrator access terminal 61 and multiple calibrator ratio terminals 62. The calibrator access terminal 61 is connected to the second current conductor 42. The multiple calibrator ratio terminals 62 include a first calibrator ratio terminal, a second calibrator ratio terminal, and a third calibrator ratio terminal, which are respectively disposed corresponding to the first ratio connecting piece, the second ratio connecting piece, and the third ratio connecting piece, and are connected to the third current conductor 43, the fourth current conductor 44, and the fifth current conductor 45.

[0052] like Figure 1 and Figure 5As shown, the specific locations include a first side and a second side on the first surface. On the first side, a current input terminal 311, a calibrator connection terminal 61, a first transformation ratio terminal, a second transformation ratio terminal, and a third transformation ratio terminal are sequentially arranged. Each terminal is connected to one end of a first current conductor 41, a second current conductor 42, a third current conductor 43, a fourth current conductor 44, and a fifth current conductor 45, respectively, along the same direction. The metal conductors on the first surface are arranged in the same direction, from the first side to the second side. On the second side, a current output terminal 321, a return terminal 322, a calibrator first transformation ratio terminal, a calibrator second transformation ratio terminal, and a calibrator third transformation ratio terminal are sequentially arranged. Each terminal on the second side is connected to the other end of a first current conductor 41, a second current conductor 42, a third current conductor 43, a fourth current conductor 44, and a fifth current conductor 45, respectively.

[0053] When on-site verification is required, connect the polarity terminal of the calibrator to the calibrator access terminal 61, and connect the non-polarity terminal of the calibrator to the calibrator ratio terminal 62 of the current transformer ratio. By checking the voltage, current, phase, power, and power error of the calibrator, it can be determined whether the energy meter is normal.

[0054] In this embodiment, as Figure 6 As shown, a junction box cover 5 is provided. The junction box cover 5 includes: a cover body 51, a data acquisition and processing module, an LED display screen 52, and a remote communication module. The cover body 51 is disposed on the box body 1. The cover body 51 is used to isolate the interior and exterior of the box body 1.

[0055] The data acquisition and processing module includes a temperature sensor, a humidity sensor, a voltage sampling sensor, and a current sampling sensor. The temperature and humidity sensors are located on the inner side of the cover body 51 to collect the temperature and humidity inside the junction box. The temperature threshold is set to 55 degrees Celsius, and the humidity threshold is set to 80%.

[0056] A voltage sampling sensor is installed at the voltage output terminal 22 of voltage unit 2 to collect the voltage of each phase live wire. A current sampling sensor is installed at the current input terminal 311 to collect the current of each phase live wire.

[0057] A circuit board is integrated on the inner side of the cover body 51, which processes the information collected by the sensors in the data acquisition and processing module into data and displays it on the LED display screen 52. The LED display screen 52 is electrically connected to each sensor of the data acquisition and processing module and is located on the side of the cover body 51 exposed to the outside of the box body 1, so that the voltage, phase angle, current, power factor, etc. of each phase wire can be obtained without opening the junction box cover 5. The LED display screen can also display information such as the rated voltage of the current transformer and the transformation ratio corresponding to each transformation ratio connecting piece 331.

[0058] In this embodiment, multiple voltage units 2 and multiple current units 3 are provided because current distribution network standards typically include three live wires and one neutral wire. Correspondingly, each live wire needs to be connected to a voltage unit 2 to connect to an electricity meter, thereby enabling voltage measurement on the corresponding live wire. Similarly, a current unit 3 is used to measure the current on the live wire. The neutral wire has near-zero current when the load is balanced, therefore only one voltage unit 2 needs to be connected. This embodiment provides a three-phase four-wire multi-ratio switching junction box, specifically including four voltage units 2 and three current units 3.

[0059] The voltage unit 2 includes a first voltage unit 201, a second voltage unit 202, a third voltage unit 203, and a fourth voltage unit 204. The current unit 3 includes a first current unit 301, a second current unit 302, and a third current unit 303. The first voltage unit 201 and the first current unit 301 are used to connect the voltage and current on the U-phase live wire to the energy meter, thereby measuring the voltage and current on the U-phase live wire. Similarly, the second voltage unit 202 and the second current unit 302 are used to measure the voltage and current on the V-phase live wire, and similarly, the second voltage unit 202 and the second current unit 302 are used to measure the voltage and current on the W-phase live wire. The fourth voltage unit 204 is used to measure the voltage on the neutral wire N.

[0060] In this embodiment, the order of setting each voltage unit 2 and current unit 3 is as follows: along the third direction, the order is: first voltage unit 201, first current unit 301, second voltage unit 202, second current unit 302, third voltage unit 203, third current unit 303, and fourth voltage unit 204.

[0061] In practical work scenarios, this setup is an intuitive and safe layout based on safety, ease of construction, and maintenance considerations. Adjacent placement of the same phase's live wires allows for unambiguous identification of which phase the current loop belongs to when switching transformer ratios, ensuring the accuracy of subsequent operations. Simultaneously, sequentially setting the other two phases' live wires makes it easy to identify the remaining two phases after determining any one phase's live wire, using external labels as a guide.

[0062] In this embodiment, the voltage calibrator and the current calibrator can be packaged into the same combined calibration device.

[0063] When the electrical load on the user side increases, the transformation ratio of the current transformer needs to be replaced. This is because current transformers can only guarantee accurate metering and acceptable error when the primary current is within the range of 30% to 120% of its rated value. If the load changes and deviates from this range, serious metering errors will occur, and even equipment damage may result.

[0064] This embodiment also provides a method for switching the transformation ratio of a combined junction box capable of switching multiple transformation ratios, including:

[0065] The first step is to read the transformation ratio corresponding to each transformation ratio switching terminal 312 through the LED display screen 52;

[0066] The second step is to determine the required switching ratio switching terminal 312 based on the ratio of the current transformer to be switched.

[0067] The third step is to remove the junction box cover 5, and determine the corresponding transformer ratio connecting piece 331 according to the required transformer ratio switching terminal 312, as well as the transformer ratio connecting piece 331 that is currently being tightened.

[0068] The fourth step is to tighten the transformer ratio connecting piece 331 to be switched, so that the transformer ratio switching terminal 312 corresponding to the transformer ratio connecting piece 331 to be switched forms a current loop with the energy meter.

[0069] Fifth step: After tightening the transformer ratio connecting piece 331 to be switched, loosen the transformer ratio connecting piece 331 that was originally tightened, so that the transformer ratio switching terminal 312 corresponding to the transformer ratio connecting piece 331 that was originally tightened is disconnected from the current circuit of the energy meter.

[0070] Step 6: Install the junction box cover 5 onto the box body 1 to complete the switching of the transformer ratio.

[0071] In another optional embodiment of the present invention, a verification method for a combined junction box capable of switching multiple transformation ratios is provided, comprising:

[0072] The first step is to read the current value measured by the energy meter in the current loop to be verified through the LED display screen 52;

[0073] The second step is to remove the junction box cover and determine the transformer connecting piece that is currently in a tightened state.

[0074] The third step is to determine the corresponding ratio switching terminal 312 based on the ratio connecting piece 331 that is in the tightening state, and then determine the ratio terminal of the calibrator based on the ratio switching terminal 312.

[0075] The third step is to connect the polarity terminal of the calibrator to the calibrator input terminal 61 and the non-polarity terminal of the calibrator to the calibrator transformation ratio terminal, so that the calibrator and the current transformer are connected.

[0076] The fourth step is to loosen the transformer ratio connecting piece 331, which is currently in a tightened state, so that the calibrator is connected in series with the current circuit of the transformer.

[0077] The fifth step involves reading the current value of the current loop using the calibrator and comparing it with the current value measured by the energy meter. If the current value read by the calibrator and the current value measured by the energy meter are within the error range, the energy meter is normal. If the current value read by the calibrator and the current value measured by the energy meter exceed the error range, the energy meter is abnormal. The abnormal energy meter can then be further repaired or replaced.

[0078] Step 6: Install the junction box cover 5 onto the box body 1 to complete the verification process.

[0079] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0080] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0081] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A combined junction box capable of switching multiple ratios, characterized in that, include: The box body (1) has multiple voltage units (2) and multiple current units (3) on its first surface, and multiple metal wires (4) on its second surface. The voltage unit (2) includes a voltage input terminal (21), a voltage output terminal (22), and a voltage connector (23). The voltage connector (23) is connected to the voltage input terminal (21) and the voltage output terminal (22) on the first side. On the second side, the metal wire (4) is connected to the voltage output terminal (22) and the voltage connector (23). The voltage connector (23) is configured to conduct electricity between the voltage input terminal (21) and the voltage output terminal (22) when tightened. The current unit (3) includes: a current transformer access terminal (31), an energy meter access terminal (32), and a current connecting piece (33). The current transformer access terminal (31) includes a current input terminal (311) and multiple transformation ratio switching terminals (312). The energy meter access terminal (32) includes a current output terminal (321) and a return terminal (322). The current transformer access terminal (31) and the current input terminal (311) are connected through the metal wire (4). Each transformation ratio switching terminal (312) is connected to the return terminal (322) through the metal wire (4). The current connector (33) includes multiple ratio connectors (331), each ratio connector (331) is correspondingly arranged with each ratio switching terminal (312), and the ratio connector (331) is configured to conduct the corresponding ratio switching terminal (312) and the return terminal (322) when tightened.

2. The multi-ratio switching junction box according to claim 1, characterized in that, In the current unit (3), the transformation ratio switching terminal (312) includes a first transformation ratio switching terminal, a second transformation ratio switching terminal, and a third transformation ratio switching terminal, wherein the first transformation ratio switching terminal, the second transformation ratio switching terminal, and the third transformation ratio switching terminal are disposed on the same side of the first surface; The transformer ratio connecting piece (331) includes a first transformer ratio connecting piece, a second transformer ratio connecting piece, and a third transformer ratio connecting piece. The metal wire (4) includes a first current wire, a second current wire, a third current wire, a fourth current wire, and a fifth current wire. The current input terminal (311) and the current output terminal (321) are connected through the first current wire. The return terminal (322) is connected to the second current wire. The first transformer ratio connecting piece is configured to conduct the second current wire and the third current wire when tightened. The second transformer ratio connecting piece is configured to conduct the third current conductor and the fourth current conductor when tightened, and the third transformer ratio connecting piece is configured to conduct the fourth current conductor and the fifth current conductor when tightened.

3. The multi-ratio switching combined junction box according to claim 2, characterized in that, The first current conductor, the second current conductor, the third current conductor, the fourth current conductor, and the fifth current conductor are arranged sequentially along a first direction and along a second direction. The first transformer ratio connecting piece, the second transformer ratio connecting piece, and the third transformer ratio connecting piece are arranged along the first direction, and the second direction is perpendicular to the first direction.

4. The multi-ratio switching combined junction box according to claim 3, characterized in that, The length of the second ratio connecting piece exceeds the length of the first ratio connecting piece by 0.8 to 1 cm, and the length of the third ratio connecting piece exceeds the length of the second ratio switching piece by 0.8 to 1 cm.

5. The multi-ratio switching combined junction box according to claim 2, characterized in that, The current connector (33) further includes a shorting connector (332) that connects the first current conductor and the second current conductor, and the shorting connector (332) is configured to conduct the first current conductor and the second current conductor when tightened.

6. The combined junction box capable of switching multiple ratios according to claim 1, characterized in that, The voltage unit (2) includes a first voltage unit, a second voltage unit, a third voltage unit, and a fourth voltage unit, and the current unit (3) includes a first current unit, a second current unit, and a third current unit; Along a third direction, the first voltage unit, the first current unit, the second voltage unit, the second current unit, the third voltage unit, the third current unit, and the fourth voltage unit are arranged in that order.

7. The combined junction box capable of switching multiple ratios according to claim 2, characterized in that, The current unit (3) further includes a calibrator access terminal (34), which is disposed on the first surface. The calibrator access terminal (34) includes a calibrator access terminal and multiple calibrator ratio terminals. The multiple calibrator ratio terminals include a first calibrator ratio terminal, a second calibrator ratio terminal, and a third calibrator ratio terminal. The first calibrator ratio terminal, the second calibrator ratio terminal, and the third calibrator ratio terminal are respectively configured to correspond to the first ratio connecting piece, the second ratio connecting piece, and the third ratio connecting piece. The calibrator access terminal and the return current terminal (322) are connected through the second current wire, the calibrator first ratio terminal and the first ratio switching terminal are connected through the third current wire, the calibrator second ratio terminal and the second ratio switching terminal are connected through the fourth current wire, and the calibrator third ratio terminal and the third ratio switching terminal are connected through the fifth current wire.

8. The combined junction box capable of switching multiple ratios according to claim 1, characterized in that, The voltage output terminal (22) includes a meter output terminal (221) and a sampling output terminal (222). The voltage connector (23) includes a first voltage connector (231) and a second voltage connector (232). The metal wire (4) includes a first voltage wire and a second voltage wire. The meter output terminal (221) and the first voltage connector (231) are connected through the first voltage wire. The sampling output terminal (222) and the second voltage connector (232) are connected through the second voltage wire.

9. The combined junction box capable of switching multiple ratios according to claim 1, characterized in that, It also includes a junction box cover (5), which includes: a cover body (51), a data acquisition and processing module, an LED display screen (52), and a remote communication module. The cover body (51) is disposed on the box body (1) and is used to isolate the inside and outside of the box body (1). The data acquisition and processing module includes a temperature sensor, a humidity sensor, a voltage sampling sensor, and a current sampling sensor. The temperature sensor and the humidity sensor are located on the side of the cover body (51) near the interior. The voltage sampling sensor is located at the voltage output terminal (22), and the current sampling sensor is located at the current input terminal (311). The LED display screen (52) is electrically connected to each sensor of the data acquisition and processing module and is used to display the data acquired by each sensor; The remote communication module is electrically connected to each sensor of the data acquisition and calculation module to obtain the voltage of the voltage output terminal (22), the current of the current input terminal (311), and the internal temperature and humidity.

10. The multi-ratio switching junction box according to claim 1, characterized in that, The shape of each of the variable ratio connecting pieces (331) includes: a U-shaped groove is provided at the first end of the variable ratio connecting piece (331), and the second end of the variable ratio connecting piece (331) is bent at a preset angle to form a raised shape.

11. A method for switching the transformation ratio of a combined junction box capable of switching multiple transformation ratios, characterized in that, include: The turns ratios corresponding to each turns ratio switching terminal (312) are read through the LED display screen (52); Based on the transformer ratio to be switched, determine the transformer ratio switching terminal (312) to be switched. Remove the junction box cover (5), and determine the corresponding transformer ratio connecting piece (331) and the transformer ratio connecting piece (331) that is currently in the tightening state according to the required switching ratio terminal (312). Tighten the transformer ratio connecting piece (331) to be switched so that the transformer ratio switching terminal (312) corresponding to the transformer ratio connecting piece (331) to be switched forms a current loop with the energy meter; After the required transformer ratio connecting piece (331) is tightened, the transformer ratio connecting piece (331) that was originally in the tightened state is opened, so that the transformer ratio switching terminal (312) corresponding to the transformer ratio connecting piece (331) that was originally in the tightened state is disconnected from the current circuit of the energy meter. Install the junction box cover (5) onto the box body (1); The box body (1) has multiple voltage units (2) and multiple current units (3) on its first surface, and multiple metal wires (4) on its second surface. Each voltage unit (2) includes a voltage input terminal (21), a voltage output terminal (22), and a voltage connector (23). The voltage connector (23) is connected to the voltage input terminal (21) and the voltage output terminal (22) on the first surface. On the second surface, the metal wires (4) are connected to the voltage output terminal (22) and the voltage connector (23). 23) Connection, the voltage connector (23) is configured to conduct the voltage input terminal (21) and voltage output terminal (22) when tightened; the current unit (3) includes: a transformer input terminal (31), an energy meter input terminal (32) and a current connector (33), the transformer input terminal (31) includes a current input terminal (311) and multiple ratio switching terminals (312), the energy meter input terminal (32) includes a current output terminal (321) and a return terminal (322), the transformer input terminal (31) and the current input terminal (311) are connected. The transformer ratio switching terminal (312) is connected to the return current terminal (322) via the metal wire (4); the current connecting piece (33) includes multiple transformer ratio connecting pieces (331), each transformer ratio connecting piece (331) is correspondingly arranged with each transformer ratio switching terminal (312), and the transformer ratio connecting piece (331) is configured to conduct the corresponding transformer ratio switching terminal (312) and the return current terminal (322) when tightened, and also includes a junction box cover (5), the junction box cover (5) including: a cover body (51), data The data acquisition and processing module includes an LED display screen (52) and a remote communication module. The cover body (51) is disposed on the box body (1) to isolate the inside and outside of the box body (1). The data acquisition and processing module includes a temperature sensor, a humidity sensor, a voltage sampling sensor, and a current sampling sensor. The temperature sensor and the humidity sensor are disposed on the side of the cover body (51) near the inside. The voltage sampling sensor is disposed on the voltage output terminal (22), and the current sampling sensor is disposed on the current input terminal (311). The LED display screen (52) is electrically connected to each sensor of the data acquisition and calculation module and is used to display the data collected by each sensor; the remote communication module is electrically connected to each sensor of the data acquisition and calculation module and is used to obtain the voltage of the voltage output terminal (22), the current of the current input terminal (311), and the internal temperature and humidity.

12. A verification method for a combined junction box capable of switching multiple ratios, characterized in that, include: The current value measured by the energy meter in the current loop to be verified is read through the LED display screen (52); Remove the junction box cover (5) and determine the transformer connecting piece (331) that is currently in a tightened state. The transformer ratio switching terminal (312) is determined according to the transformer ratio connecting piece (331) which is in the tightening state, and the transformer ratio terminal of the calibrator is determined according to the transformer ratio switching terminal (312); Connect the polarity terminal of the calibrator to the calibrator input terminal, and connect the non-polarity terminal of the calibrator to the transformation ratio terminal of the calibrator, so that the calibrator is connected to the current transformer. Open the transformer ratio connecting piece (331) that is currently in a tightened state, so that the calibrator is connected in series to the current circuit of the transformer; The current value of the current loop is read by the calibrator and compared with the current value measured by the energy meter. If the current value read by the calibrator and the current value measured by the energy meter are within the error range, the energy meter is normal. If the current value read by the calibrator and the current value measured by the energy meter exceed the error range, the energy meter is abnormal. Install the junction box cover (5) onto the box body (1) to complete the verification operation; The calibrator access terminal (34) is located on the first side. The calibrator access terminal (34) includes the calibrator access terminal and multiple calibrator ratio terminals. The multiple calibrator ratio terminals include a first calibrator ratio terminal, a second calibrator ratio terminal, and a third calibrator ratio terminal. The first calibrator ratio terminal, the second calibrator ratio terminal, and the third calibrator ratio terminal are respectively configured to correspond to the first ratio connecting piece, the second ratio connecting piece, and the third ratio connecting piece. The calibrator access terminal and the return current terminal (322) are connected through a second current wire. The first calibrator ratio terminal and the first ratio switching terminal are connected through a third current wire. The second calibrator ratio terminal and the second ratio switching terminal are connected through a fourth current wire. The third calibrator ratio terminal and the third ratio switching terminal are connected through a fifth current wire.

Images