Digital junction box intelligent application device based on circuit board

Abstract

The invention discloses a digital junction box intelligent application device based on a circuit board, and the device comprises a pull-out housing and an intelligent control board disposed in the pull-out housing, and the intelligent control board is provided with a single-chip microcomputer, a control power supply, a single-phase electric control circuit, a zero line control circuit, a working state circuit, and a function selection circuit. The three groups of single-phase electric control circuits respectively correspond to A, B and C three-phase live wires of the three-phase four-wire electric energy meter, the null line control circuit corresponds to a null line of the three-phase four-wire electric energy meter, the control power supply supplies power to the intelligent control panel, and the single-phase electric control circuits, the null line control circuit, the working state circuit and the function selection circuit are all connected with the single-chip microcomputer. According to the design, intelligent control and automation functions are integrated, the operation process is simplified, human intervention and errors are reduced, the intelligent level of an electric power system is improved, a safer and more convenient working environment is provided for operators, and finally efficient and reliable electric energy management is achieved.

Description

Technical Field

[0001] The invention relates to an electric energy meter junction box, in particular to a digital junction box intelligent application device based on a circuit board. Background Art

[0002] Digital junction box: The digital junction box is used to connect the energy meter to the power system to ensure accurate measurement and effective transmission of electric energy. The energy meter is responsible for measuring power consumption, and the digital junction box reliably connects the energy meter to the power system. These components work together to ensure efficient, safe and accurate energy measurement, while facilitating the installation, maintenance and management of the system.

[0003] With the expansion of high-voltage and small-power users and the increase in electricity usage changes, quality problems with junction box installation also arise. According to statistics on abnormal data from the procurement system, 11.15% of metering failures are caused by junction box problems, which not only leads to electricity omissions, but may also cause service public opinion problems. Common unqualified installations include exposed copper on the voltage and current wires of the junction box, loose connecting pieces, unsealed junction boxes, and wrong wiring of junction boxes. When calibrating three-phase meters on site, facing conventional junction boxes, operators need to disassemble the junction box casing, loosen the screws, and open the voltage and current connecting pieces in turn to open the voltage and short the current. However, in this process, operators often accidentally touch live connecting pieces and screws or forget to restore the connecting pieces after calibration.

[0004] Traditional energy meter junction boxes are used to connect energy meters to the power system to ensure accurate measurement of electrical energy. They are usually made of durable metal or high-strength plastic and contain multiple terminals and connection points for fixing and connecting current and voltage lines. The installation and wiring process requires professional technicians to ensure that all connections are tight and well insulated. The junction box is equipped with a protective cover to prevent the entry of foreign substances and is equipped with safety devices such as fuses to prevent overload or short circuit. Although the structure is simple, the operation is complicated and lacks intelligent functions. The maintenance cost is high and the safety risk is also greater. With the advancement of science and technology, the application of more advanced digital junction boxes has been promoted.

[0005] The patent number is 201820430013.6, and the name is a direct-access electricity meter junction box. It records that through the setting of the anti-open circuit component, it is possible to detect in time whether the voltage connection is good. When in use, the design of the electricity meter junction box lacks intelligence and automation features, which means that operators need to manually wire and configure, which is not only time-consuming and labor-intensive, but also easy to waste time. At the same time, the scalability and upgrade capabilities of traditional junction boxes are limited, and they cannot adapt to the growing needs and changes of modern power systems, resulting in potential problems that cannot be discovered and solved in time. Its disadvantages are: First, hardware failures are difficult to repair. Traditional junction boxes rely on hardware. These components may age or fail over time, and the electricity metering failure phenomenon cannot be avoided; second, the protection is insufficient. The existing junction boxes may not be adequate in terms of dustproof, waterproof, fireproof, etc., especially in harsh environments, which can easily cause damage to internal components and affect the normal operation of the junction box. Summary of the invention

[0006] In view of the problems existing in the above-mentioned prior art, the present invention provides a digital junction box intelligent application device based on a circuit board, including hardware technology, software technology and cutting-edge developments in electrical engineering. The hardware design of the digital junction box usually adopts a highly integrated circuit, so that the device can perform complex data processing and realize diversified functions; from the perspective of electrical engineering, the digital junction box is a revolutionary upgrade to the traditional junction box. The traditional junction box relies on manual wiring and physical connection, while the digital junction box reduces human intervention and potential errors through electronic means. In terms of safety, the digital junction box integrates a protection mechanism to ensure that the equipment and system can still operate safely under extreme conditions.

[0007] The design simplifies the operation process and reduces human intervention and errors by integrating intelligent control and automation functions. Through this innovative design, the digital junction box not only improves the intelligence level of the power system, but also provides a safer and more convenient working environment for operators, ultimately achieving efficient and reliable power management.

[0008] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a digital junction box intelligent application device based on a circuit board, which is a junction box of a three-phase four-wire electric energy meter, comprising: a pull-out shell and an intelligent control board arranged in the pull-out shell, the intelligent control board is provided with a single-chip microcomputer, a control power supply, a single-phase electric control circuit, a neutral line control circuit, a working state circuit, and a function selection circuit, three groups of single-phase electric control circuits are arranged, and they correspond to the A, B, and C three-phase live wires of the three-phase four-wire electric energy meter respectively, the neutral line control circuit corresponds to the neutral line of the three-phase four-wire electric energy meter, and the four wires in the three-phase four-wire electric energy meter are respectively connected to the three groups of single-phase electric control circuits and the neutral line control circuit, the control power supply supplies power to the intelligent control board, the single-phase electric control circuit, the neutral line control circuit, the working state circuit, and the function selection circuit are all connected to the single-chip microcomputer, the single-phase electric control circuit, the neutral line control circuit, and the working state circuit are controlled by the single-chip microcomputer to work, and the function selection circuit controls the single-chip microcomputer to adjust the function.

[0009] Furthermore, the pull-out housing includes: a junction box, a cover plate slidably mounted on the junction box, the junction box and the cover plate are fixed by a bolt, the junction box is provided with a cavity for installing the intelligent control board, the cavity opening is provided with a card slot, the cover plate is slidably mounted on the junction box through the slot, the junction shell is provided with a threading hole for wiring the single-phase power control circuit and the neutral line control circuit, and the junction box is provided with a fixing hole for fixing the junction box on the background plate or the metering cabinet body.

[0010] Furthermore, the cover plate is marked with wiring prompt characters.

[0011] Furthermore, the pull-out housing has a handle and a sealing device, wherein the handle is a protruding square with holes, which is mounted on the cover plate by bolts to facilitate dragging the cover plate, and the sealing device is used to fix the seal connection to ensure that the cover plate and the junction box are not illegally disassembled.

[0012] Furthermore, the control power supply is an AC / DC conversion module, which draws power from the neutral wire and the live wire of the three-phase four-wire electric energy meter.

[0013] Furthermore, the single-phase electrical control circuit includes: a phase voltage DC contactor, a phase current incoming DC contactor, a phase current outgoing DC contactor, a fuse, a phase voltage contactor selection circuit, a phase current incoming contactor selection circuit, a phase current outgoing contactor selection circuit and two four-wire terminal blocks, wherein the four terminals of the two four-wire terminal blocks are respectively a phase voltage terminal, a phase current incoming terminal, a phase current outgoing terminal and a connecting terminal.

[0014] Furthermore, one end of the coil of the phase voltage DC contactor, the phase current incoming line DC contactor, and the phase current outgoing line DC contactor is connected to the control power supply, and the other end is connected to the pin on the single-chip microcomputer through the phase voltage contactor selection circuit, the phase current incoming line contactor selection circuit, and the phase current outgoing line contactor selection circuit, respectively. The phase voltage terminals in the two four-wire wiring banks are connected to the fuse, the normally open contact and the common contact of the phase voltage DC contactor in sequence through wires. The phase voltage terminals are also connected to the single-phase live wire of the three-phase four-wire electric energy meter through wires. The two phase current terminals in the two four-wire wiring banks are connected to the single-phase live wire of the three-phase four-wire electric energy meter through wires. The incoming terminals, the two phase current outgoing terminals, and the two connecting terminals are connected by wires, the common contact of the phase current incoming DC contactor and the normally open contact of the phase current outgoing DC contactor are both connected to the wires between the two phase current outgoing terminals, the normally open contact of the phase current incoming DC contactor is connected to the wires between the two phase current incoming terminals, the normally closed contact of the phase current incoming DC contactor is connected to the control power supply, the normally closed contact of the phase current outgoing DC contactor is connected to the control power supply, and the common contact of the phase current outgoing DC contactor is connected to the wires between the two connecting terminals.

[0015] Furthermore, the neutral line control circuit includes: two two-wire terminal blocks, a fuse, a neutral line DC contactor, and a neutral line contactor selection circuit. Both of the two-wire terminal blocks are provided with a neutral line terminal. One end of the coil of the neutral line DC contactor is connected to the control power supply, and the other end is connected to the pin on the single-chip computer through a wire and the neutral line contactor selection circuit. The neutral line terminals of the two two-wire terminal blocks are connected to the fuse, the normally open contact and the common contact of the neutral line DC contactor in sequence through wires, and the normally closed contact of the neutral line DC contactor is connected to the control power supply.

[0016] Furthermore, the phase voltage contactor selection circuit, the phase current incoming line contactor selection circuit, the phase current outgoing line contactor selection circuit, and the neutral line contactor selection circuit all adopt contactor selection circuits with the same structure, and the contactor selection circuit includes: two resistors and a transistor, the emitter of the transistor is connected to the control power supply, the base of the transistor is respectively connected to the emitter of the transistor and the pin on the single-chip computer through two resistors, and the collector of the transistor is connected to the other end of the coil in the DC contactor.

[0017] Furthermore, the function selection circuit includes: a normal working button, a powered working button, a verification working button and three resistors. One ends of the normal working button, the powered working button and the verification working button are connected together and connected to the control power supply. The other ends of the normal working button, the powered working button and the verification working button are respectively connected to three pins on the microcontroller through wires. One ends of the three resistors are connected together, and the other ends are respectively connected to the other ends of the normal working button, the powered working button and the verification working button.

[0018] Furthermore, the working status circuit includes: a normal working indicator light, a powered working indicator light, a verification working indicator light and three resistors, one end of the normal working indicator light, the powered working indicator light and the verification working indicator light are respectively connected to the three pins of the single-chip computer, and the other ends of the normal working indicator light, the powered working indicator light and the verification working indicator light are respectively connected to the control power supply through resistors.

[0019] Furthermore, the control method is as follows: The digital junction box intelligent application device defaults to a normal working state. In the normal working state, the phase voltage DC contactors, phase current incoming DC contactors and neutral DC contactors in the three groups of single-phase power control circuits are closed, and the phase current outgoing DC contactors in the three groups of single-phase power control circuits are disconnected; Adjust from normal working state to live working state: the state of phase current incoming DC contactor in three groups of single-phase power control circuits remains unchanged, and the phase current outgoing DC contactor turns to closed state. After 5s, the phase voltage DC contactor and the neutral line DC contactor are disconnected; Adjust from normal working state to verification operation: the states of phase voltage DC contactors, phase current outgoing DC contactors and neutral line DC contactors in the three groups of single-phase power control circuits remain unchanged, and the phase current incoming DC contactors are turned to the disconnected state.

[0020] The beneficial effects of the present invention are as follows: the digital junction box demonstrates its significant advantages in many aspects. Through pre-setting and automatic configuration, it not only improves efficiency and accuracy, but also significantly reduces the risk of human error, ensuring the consistency and reliability of operation. In addition, the digital junction box can achieve simple management, allowing on-site operators to easily understand the status of the equipment and make real-time adjustments and maintenance. This equipment adopts a modular design, making it more flexible in adapting to different application requirements and can be expanded or modified according to specific needs.

[0021] The digital junction box integrates multiple functions, including normal state, disconnect state and verification state. The combination of these functions greatly improves the safety of equipment and personnel and prevents the occurrence of misoperation. Its flexible configuration, high integration and good compatibility enable the digital junction box to provide excellent performance in various environments.

[0022] Through intelligent diagnosis and predictive maintenance, the digital junction box can perform preventive repairs before problems occur, ensuring the reliability and stability of the system. This intelligent feature makes maintenance work more efficient, reducing downtime and maintenance costs. Its efficient management and intelligent control not only optimize energy use, but also only require one seal during use, simplifying the operation process and further achieving energy-saving and environmental protection effects.

[0023] Although the initial investment in digital junction boxes is high, in the long run, they are highly cost-effective because they significantly improve work efficiency and greatly reduce maintenance costs. After applying digital junction boxes, not only can higher productivity be achieved, but also a better management and maintenance experience can be enjoyed, providing strong protection for future power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the internal structure of the patent of this invention; Figure 2 This is a schematic diagram of the top view structure described in the patent of this invention; Figure 3 It is the relay state under normal working condition of the present invention; Figure 4 It is the relay state under the live working state of the present invention; Figure 5 Verify the relay status in the working state of the patent of this invention; In the figure: 1. A-phase voltage DC contactor; 2. A-phase current incoming DC contactor; 3. A-phase current outgoing DC contactor; 4. B-phase voltage DC contactor; 5. B-phase current incoming DC contactor; 6. B-phase current outgoing DC contactor; 7. C-phase voltage DC contactor; 8. C-phase current incoming DC contactor; 9. C-phase current outgoing DC contactor; 10. Neutral DC contactor; 11. Terminal block; 12. Fuse; 13. Control power supply; 14. Single-chip microcomputer; 15. Normal working button; 16. Live working button; 17. Verification working button; 18. Fixing hole; 19. Sealing device; 20. Inlet hole; 21. Pull-out housing; 22. Card slot; 23. Electric energy meter. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below through the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0027] like Figure 1-5As shown, a digital junction box intelligent application device based on a circuit board is a junction box of a three-phase four-wire electric energy meter 23, comprising: a pull-out housing 21 and an intelligent control board arranged in the pull-out housing 21, the intelligent control board is provided with a single-chip microcomputer 14, a control power supply 13, a single-phase electric control circuit, a neutral line control circuit, a working state circuit, and a function selection circuit, three groups of single-phase electric control circuits are arranged, and they correspond to the A, B, and C three-phase live wires of the three-phase four-wire electric energy meter 23 respectively, the neutral line control circuit corresponds to the neutral line of the three-phase four-wire electric energy meter 23, the control power supply 13 supplies power to the intelligent control board, the single-phase electric control circuit, the neutral line control circuit, the working state circuit, and the function selection circuit are all connected to the single-chip microcomputer 14, the single-phase electric control circuit, the neutral line control circuit, and the working state circuit are controlled by the single-chip microcomputer 14 to work, and the function selection circuit controls the single-chip microcomputer 14 to adjust the function.

[0028] like Figure 2 As shown, the pull-out housing 21 includes: a junction box, a cover plate slidably mounted on the junction box, the junction box and the cover plate are fixed by a bolt, the junction box is provided with a cavity for installing the intelligent control board, and a card slot 22 is provided at the opening of the cavity. The cover plate is slidably mounted on the junction box through the slot, and the cover plate is connected by the card slot 22 to reduce the gap to prevent dust and moisture from entering. The junction shell is provided with a threading hole for wiring the single-phase power control circuit and the neutral line control circuit, and the junction box is provided with a fixing hole 18 for fixing the junction box on the background board or the metering cabinet body, thereby increasing the flexibility and stability of the installation.

[0029] The cover is marked with wiring prompt characters, namely A phase voltage line UA, A phase current input line A1, A phase current output line A2, B phase voltage line UB, B phase current input line B1, B phase current output line B2, C phase voltage line UC, C phase current input line C1, C phase current output line C2, and grounding wire (neutral wire) UN.

[0030] The pull-out housing 21 has a handle and a sealing device 19. The handle is a protruding square with holes, which is installed on the cover plate by bolts to facilitate dragging the cover plate. The sealing device 19 is used to fix the sealing connection to ensure that the cover plate and the junction box are not illegally disassembled.

[0031] The use of a pull-out shell 21 allows assembly, disassembly and inspection to be carried out without completely removing the shell, greatly reducing the workload of the operators. The cover is fixed by the card slot 22 to make it more secure, which does not affect the sealing and reduces the time and material waste of installing screws. Only one seal needs to be sealed.

[0032] The control power supply 13 is an AC / DC conversion module, which draws power from the neutral line and the live line of the three-phase four-wire electric energy meter 23. The control power supply 13 ensures the accuracy of electric energy measurement.

[0033] like Figure 1 , 3 As shown in Figures 4 and 5, the three groups of single-phase power control circuits are respectively A-phase power control circuit, B-phase power control circuit and C-phase power control circuit.

[0034] The A-phase electrical control circuit includes: an A-phase voltage DC contactor 1, an A-phase current input DC contactor 2, an A-phase current output DC contactor 3, a fuse 12, an A-phase voltage contactor selection circuit, an A-phase current input contactor selection circuit, an A-phase current output contactor selection circuit and two four-wire terminal blocks, wherein the four terminals of the two four-wire terminal blocks are respectively an A-phase voltage terminal, an A-phase current input terminal, an A-phase current output terminal and a connection terminal.

[0035] One end of the coil of the A-phase voltage DC contactor 1, the A-phase current input DC contactor 2, and the A-phase current output DC contactor 3 is connected to the control power supply 13, and the other end is connected to the pin on the single-chip computer 14 through the A-phase voltage contactor selection circuit, the A-phase current input contactor selection circuit, and the A-phase current output contactor selection circuit respectively. The A-phase voltage terminal in the two four-wire terminal blocks is connected to the fuse 12, the normally open contact and the common contact of the A-phase voltage DC contactor 1 in sequence through wires. The A-phase voltage terminal is also connected to the A-phase live wire of the three-phase four-wire electric energy meter 23 through a wire. The two A-phase current input terminals in the two four-wire terminal blocks are connected to the A-phase live wire of the three-phase four-wire electric energy meter 23 through a wire. The terminals, the two A-phase current outlet terminals, and the two A-phase connecting terminals are connected by wires; the common contact of the A-phase current input DC contactor 2 and the normally open contact of the A-phase current output DC contactor 3 are both connected to the wires between the two A-phase current output terminals; the normally open contact of the A-phase current input DC contactor 2 is connected to the wires between the two A-phase current input terminals; the normally closed contact of the A-phase current input DC contactor 2 is connected to the control power supply 13; the normally closed contact of the A-phase current output DC contactor 3 is connected to the control power supply 13; and the common contact of the A-phase current output DC contactor 3 is connected to the wires between the two connecting terminals.

[0036] The B-phase electrical control circuit includes: a B-phase voltage DC contactor 4, a B-phase current input DC contactor 5, a B-phase current output DC contactor 6, a fuse 12, a B-phase voltage contactor selection circuit, a B-phase current input contactor selection circuit, a B-phase current output contactor selection circuit and two four-wire terminal blocks, wherein the four terminals of the two four-wire terminal blocks are respectively a B-phase voltage terminal, a B-phase current input terminal, a B-phase current output terminal and a connection terminal.

[0037] One end of the coil of the B-phase voltage DC contactor 4, the B-phase current input DC contactor 5, and the B-phase current output DC contactor 6 is connected to the control power supply 13, and the other end is connected to the pin on the single-chip computer 14 through the B-phase voltage contactor selection circuit, the B-phase current input contactor selection circuit, and the B-phase current output contactor selection circuit respectively. The B-phase voltage terminal in the two four-wire wiring banks is connected to the fuse 12, the normally open contact and the common contact of the B-phase voltage DC contactor 4 in sequence through wires. The B-phase voltage terminal is also connected to the B-phase live wire of the three-phase four-wire electric energy meter 23 through a wire. The two B-phase current input terminals in the two four-wire wiring banks are connected to the B-phase live wire of the three-phase four-wire electric energy meter 23 through a wire. The terminals, the two B-phase current outlet terminals, and the two B-phase connecting terminals are connected by wires; the common contact of the B-phase current input DC contactor 5 and the normally open contact of the B-phase current output DC contactor 6 are both connected to the wires between the two B-phase current output terminals; the normally open contact of the B-phase current input DC contactor 5 is connected to the wires between the two B-phase current input terminals; the normally closed contact of the B-phase current input DC contactor 5 is connected to the control power supply 13; the normally closed contact of the B-phase current output DC contactor 6 is connected to the control power supply 13; and the common contact of the B-phase current output DC contactor 6 is connected to the wires between the two connecting terminals.

[0038] The C-phase electrical control circuit includes: a C-phase voltage DC contactor 7, a C-phase current input DC contactor 8, a C-phase current output DC contactor 9, a fuse 12, a C-phase voltage contactor selection circuit, a C-phase current input contactor selection circuit, a C-phase current output contactor selection circuit and two four-wire terminal blocks, wherein the four terminals of the two four-wire terminal blocks are respectively a C-phase voltage terminal, a C-phase current input terminal, a C-phase current output terminal and a connection terminal.

[0039] One end of the coil of the C-phase voltage DC contactor 7, the C-phase current input DC contactor 8, and the C-phase current output DC contactor 9 is connected to the control power supply 13, and the other end is connected to the pin on the single-chip computer 14 through the C-phase voltage contactor selection circuit, the C-phase current input contactor selection circuit, and the C-phase current output contactor selection circuit respectively. The C-phase voltage terminal in the two four-wire wiring banks is connected to the fuse 12, the normally open contact and the common contact of the C-phase voltage DC contactor 7 in sequence through wires. The C-phase voltage terminal is also connected to the C-phase live wire of the three-phase four-wire electric energy meter 23 through a wire. The two C-phase current input terminals in the two four-wire wiring banks are connected to the C-phase live wire of the three-phase four-wire electric energy meter 23 through a wire. The two C-phase current outlet terminals and the two C-phase connecting terminals are connected by wires; the common contact of the C-phase current input DC contactor 8 and the normally open contact of the C-phase current output DC contactor 9 are both connected to the wires between the two C-phase current output terminals; the normally open contact of the C-phase current input DC contactor 8 is connected to the wires between the two C-phase current input terminals; the normally closed contact of the C-phase current input DC contactor 8 is connected to the control power supply 13; the normally closed contact of the C-phase current output DC contactor 9 is connected to the control power supply 13; and the common contact of the C-phase current output DC contactor 9 is connected to the wires between the two connecting terminals.

[0040] The neutral line control circuit includes: two two-wire terminal blocks, a fuse 12, a neutral line DC contactor 10, and a neutral line contactor selection circuit. The two two-wire terminal blocks are each provided with a neutral line terminal. One end of the coil of the neutral line DC contactor 10 is connected to the control power supply 13, and the other end is connected to the pin on the single-chip computer 14 through a wire and the neutral line contactor selection circuit. The neutral line terminals of the two two-wire terminal blocks are connected to the fuse 12, the normally open contact and the common contact of the neutral line DC contactor 10 in sequence through a wire, and the normally closed contact of the neutral line DC contactor 10 is connected to the control power supply 13.

[0041] A phase voltage contactor selection circuit, A phase current incoming contactor selection circuit, A phase current outgoing contactor selection circuit, B phase voltage contactor selection circuit, B phase current incoming contactor selection circuit, B phase current outgoing contactor selection circuit, C phase voltage contactor selection circuit, C phase current incoming contactor selection circuit, C phase current outgoing contactor selection circuit, and neutral line contactor selection circuit all use contactor selection circuits with the same structure, and the contactor selection circuit includes: two resistors and a transistor, the emitter of the transistor is connected to the control power supply 13, the base of the transistor is respectively connected to the emitter of the transistor and the pin on the single chip computer 14 through two resistors, and the collector of the transistor is connected to the other end of the coil in the DC contactor.

[0042] Both the four-wire terminal block and the two-wire terminal block are terminal blocks 11, which are used to connect wires and calibrate instruments and equipment to ensure ease and reliability of operation. These design elements not only improve the functionality of the junction box, but also significantly improve the operating efficiency and long-term stability of the equipment.

[0043] The function selection circuit includes: a normal working button 15, a live working button 16, a verification working button 17 and three resistors. One ends of the normal working button 15, the live working button 16 and the verification working button 17 are connected together and connected to the control power supply 13. The other ends of the normal working button 15, the live working button 16 and the verification working button 17 are respectively connected to the three pins on the single-chip computer 14 through wires. One ends of the three resistors are connected together, and the other ends are respectively connected to the other ends of the normal working button 15, the live working button 16 and the verification working button 17.

[0044] The working status circuit includes: a normal working indicator light, a powered working indicator light, a verification working indicator light and three resistors, one end of the normal working indicator light, the powered working indicator light and the verification working indicator light are respectively connected to the three pins of the single-chip computer 14, and the other ends of the normal working indicator light, the powered working indicator light and the verification working indicator light are respectively connected to the control power supply 13 through resistors.

[0045] The pin on the single chip computer 14 is connected to the control power supply 13 .

[0046] The control method is as follows: like Figure 3 As shown, the digital junction box intelligent application device defaults to a normal working state. In the normal working state, the A-phase voltage DC contactor 1, the A-phase current incoming DC contactor 2, the B-phase voltage DC contactor 4, the B-phase current incoming DC contactor 5, the C-phase voltage DC contactor 7, the C-phase current incoming DC contactor 8, and the neutral DC contactor 10 in the neutral control circuit are closed, and the A-phase current outgoing DC contactor 3, the B-phase current outgoing DC contactor 6, and the C-phase current outgoing DC contactor 9 are disconnected; like Figure 4 As shown, the normal working state is adjusted to the live working state: the states of the A-phase current incoming line DC contactor 2, the B-phase current incoming line DC contactor 5, and the C-phase current incoming line DC contactor 8 remain unchanged, and the A-phase current outgoing line DC contactor 3, the B-phase current outgoing line DC contactor 6, and the C-phase current outgoing line DC contactor 9 are turned into the closed state. After 5s, the A-phase voltage DC contactor 1, the B-phase voltage DC contactor 4, the C-phase voltage DC contactor 7 and the neutral line DC contactor 10 are disconnected; like Figure 5As shown, the normal working state is adjusted to the verification operation: the states of A phase voltage DC contactor 1, A phase current outlet DC contactor 3, B phase voltage DC contactor 4, B phase current outlet DC contactor 6, C phase voltage DC contactor 7, C phase current outlet DC contactor 9 and neutral line DC contactor 10 remain unchanged, and A phase current incoming DC contactor 2, B phase current incoming DC contactor 5, and C phase current incoming DC contactor 8 are turned to the disconnected state.

[0047] This digital junction box is designed with a number of innovative features to improve operational convenience and equipment safety. First, Figure 3-5 As shown, the A-phase voltage connector in the junction box of a direct-access electric energy meter 23 with patent number 201820430013.6 is improved to an A-phase voltage DC contactor 1, the A-phase current connector is improved to an A-phase current incoming DC contactor 2 and an A-phase current outgoing DC contactor 3, the B-phase voltage connector is improved to a B-phase voltage DC contactor 4, the B-phase current connector is improved to a B-phase current incoming DC contactor 5 and a B-phase current outgoing DC contactor 6, the C-phase voltage connector is improved to a C-phase voltage DC contactor 7, the C-phase current connector is improved to a C-phase current incoming DC contactor 8 and a C-phase current outgoing DC contactor 9, and the grounding phase voltage connector is improved to a neutral DC contactor 10. A single-chip microcomputer 14 is added so that it can be intelligently controlled and automatically calibrated, which greatly reduces the calibration time and labor costs.

[0048] The digital junction box is different from the traditional junction box. The original metal connecting piece is easy to fall off and the connecting plastic dial head cannot withstand multiple uses. The plastic part is easily damaged. Now a miniature toggle switch is used to reduce the time of manual screwing and the risk of contacting live objects. The three-phase current part is disconnected uniformly by the linkage mechanism. The chip is used to set simple operation statements. When disconnected, the phase is set first and then zero. After recovery, the linkage control is carried out according to the principle of zero and then phase. The two main switches on the right side of the junction box control the current verification respectively. The current is normal. The two main switches on the lower side of the junction box control the voltage verification. The voltage is normal. According to the requirements, high-voltage users are required to conduct periodic and temporary inspections every year, which greatly reduces the verification time and labor costs; The top cover of the digital junction box shell adopts a pull-out type, which can be installed, disassembled and checked by quickly removing the shell without affecting the sealing. It reduces the time for operators to install and remove screws and only needs to seal one seal, reducing material waste; Wiring marks are set on the outside of the shell to standardize on-site wiring for operators; by providing clear wiring instructions, operators can quickly find the corresponding wiring points during installation, adjustment or maintenance to avoid misoperation.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A digital junction box intelligent application device based on a circuit board, which is a junction box for a three-phase four-wire electric energy meter, characterized in that: include: A pull-out shell and an intelligent control board arranged in the pull-out shell, the intelligent control board is provided with a single-chip microcomputer, a control power supply, a single-phase electric control circuit, a neutral line control circuit, a working status circuit, and a function selection circuit. Three groups of single-phase electric control circuits are arranged, and they correspond to the A, B, and C three-phase live wires of the three-phase four-wire electric energy meter respectively. The neutral line control circuit corresponds to the neutral line of the three-phase four-wire electric energy meter. The four wires in the three-phase four-wire electric energy meter are respectively connected to the three groups of single-phase electric control circuits and the neutral line control circuit. The control power supply supplies power to the intelligent control board. The single-phase electric control circuit, the neutral line control circuit, the working status circuit, and the function selection circuit are all connected to the single-chip microcomputer. The single-phase electric control circuit, the neutral line control circuit, and the working status circuit are controlled by the single-chip microcomputer, and the function selection circuit controls the single-chip microcomputer to adjust the function.

2. According to the circuit board-based digital junction box intelligent application device of claim 1, it is characterized in that: The pull-out housing includes: a junction box, a cover plate slidably mounted on the junction box, the junction box and the cover plate are fixed by a bolt, the junction box is provided with a cavity for installing an intelligent control board, a card slot is provided at the opening of the cavity, the cover plate is slidably mounted on the junction box through the slot, the junction shell is provided with a threading hole for wiring a single-phase power control circuit and a neutral line control circuit, and the junction box is provided with a fixing hole for fixing the junction box on a background plate or a metering cabinet body.

3. The circuit board-based digital junction box intelligent application device according to claim 2, characterized in that: The cover plate is marked with wiring prompt characters.

4. The circuit board-based digital junction box intelligent application device according to claim 2, characterized in that: The pull-out housing has a handle and a sealing device. The handle is a protruding square with holes, which is installed on the cover plate by bolts to facilitate dragging the cover plate. The sealing device is used to fix the sealing connection to ensure that the cover plate and the junction box are not illegally disassembled.

5. The circuit board-based digital junction box intelligent application device according to claim 1, characterized in that: The control power supply is an AC / DC conversion module, which draws power from the neutral wire and the live wire of the three-phase four-wire electric energy meter.

6. The circuit board-based digital junction box intelligent application device according to claim 1, characterized in that: The single-phase power control circuit includes: a phase voltage DC contactor, a phase current incoming DC contactor, a phase current outgoing DC contactor, a fuse, a phase voltage contactor selection circuit, a phase current incoming contactor selection circuit, a phase current outgoing contactor selection circuit and two four-wire terminal blocks, wherein the four terminals of the two four-wire terminal blocks are respectively a phase voltage terminal, a phase current incoming terminal, a phase current outgoing terminal and a connecting terminal.

7. The circuit board-based digital junction box intelligent application device according to claim 6, characterized in that: One end of the coil of the phase voltage DC contactor, the phase current incoming line DC contactor, and the phase current outgoing line DC contactor is connected to the control power supply, and the other end is connected to the pins on the single-chip microcomputer through the phase voltage contactor selection circuit, the phase current incoming line contactor selection circuit, and the phase current outgoing line contactor selection circuit, respectively. The phase voltage terminals in the two four-wire wiring banks are connected to the fuse, the normally open contact and the common contact of the phase voltage DC contactor in sequence through wires. The phase voltage terminals are also connected to the single-phase live wire of the three-phase four-wire electric energy meter through wires. The two phase current incoming line terminals in the two four-wire wiring banks are connected to the single-phase live wire of the three-phase four-wire electric energy meter through wires. The terminals, the two phase current outgoing line terminals and the two connecting terminals are connected by wires; the common contact of the phase current incoming line DC contactor and the normally open contact of the phase current outgoing line DC contactor are both connected to the wires between the two phase current outgoing line terminals; the normally open contact of the phase current incoming line DC contactor is connected to the wires between the two phase current incoming line terminals; the normally closed contact of the phase current incoming line DC contactor is connected to the control power supply; the normally closed contact of the phase current outgoing line DC contactor is connected to the control power supply; and the common contact of the phase current outgoing line DC contactor is connected to the wires between the two connecting terminals.

8. The circuit board-based digital junction box intelligent application device according to claim 7, characterized in that: The neutral line control circuit comprises: two two-wire terminal blocks, a fuse, a neutral line DC contactor, and a neutral line contactor selection circuit. Both of the two-wire terminal blocks are provided with a neutral line terminal. One end of the coil of the neutral line DC contactor is connected to the control power supply, and the other end is connected to the pin on the single-chip computer through a wire and the neutral line contactor selection circuit. The neutral line terminals of the two two-wire terminal blocks are connected to the fuse, the normally open contact and the common contact of the neutral line DC contactor in sequence through wires, and the normally closed contact of the neutral line DC contactor is connected to the control power supply.

9. The circuit board-based digital junction box intelligent application device according to claim 8, characterized in that: The phase voltage contactor selection circuit, the phase current incoming contactor selection circuit, the phase current outgoing contactor selection circuit, and the neutral line contactor selection circuit all adopt contactor selection circuits with the same structure. The contactor selection circuit comprises: two resistors and a transistor, the emitter of the transistor is connected to the control power supply, the base of the transistor is respectively connected to the emitter of the transistor and the pin on the single chip computer through two resistors, and the collector of the transistor is connected to the other end of the coil in the DC contactor.

10. The circuit board-based digital junction box intelligent application device according to claim 1, characterized in that: The function selection circuit includes: a normal working button, a live working button, a verification working button and three resistors. One ends of the normal working button, the live working button and the verification working button are connected together and connected to the control power supply. The other ends of the normal working button, the live working button and the verification working button are respectively connected to the three pins on the microcontroller through wires. One ends of the three resistors are connected together, and the other ends are respectively connected to the other ends of the normal working button, the live working button and the verification working button.

11. The circuit board-based digital junction box intelligent application device according to claim 1, characterized in that: The working status circuit includes: a normal working indicator light, a powered working indicator light, a verification working indicator light and three resistors. One end of the normal working indicator light, the powered working indicator light and the verification working indicator light are respectively connected to the three pins of the single-chip microcomputer, and the other ends of the normal working indicator light, the powered working indicator light and the verification working indicator light are respectively connected to the control power supply through resistors.

12. The circuit board-based digital junction box intelligent application device according to claim 8, characterized in that: The control method is as follows: The digital junction box intelligent application device defaults to a normal working state. In the normal working state, the phase voltage DC contactors, phase current incoming DC contactors and neutral DC contactors in the three groups of single-phase power control circuits are closed, and the phase current outgoing DC contactors in the three groups of single-phase power control circuits are disconnected; Adjust from normal working state to live working state: the state of phase current incoming DC contactor in three groups of single-phase power control circuits remains unchanged, and the phase current outgoing DC contactor turns to closed state. After 5s, the phase voltage DC contactor and the neutral line DC contactor are disconnected; Adjust from normal working state to verification operation: the states of phase voltage DC contactors, phase current outgoing DC contactors and neutral line DC contactors in the three groups of single-phase power control circuits remain unchanged, and the phase current incoming DC contactors are turned to the disconnected state.

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