A method for diagnosing a connection state of a joint junction box and a joint junction box

Abstract

The present application belongs to the technical field of joint terminal box, and discloses a diagnosis method for the wiring state of a joint terminal box and the joint terminal box, and the specific steps comprise: collecting phase voltage and current signals in situ inside the joint terminal box; performing digital signal processing on the collected signals to extract characteristic quantities, and comparing the extracted characteristic quantities with a preset wiring standard database in real time; determining the wiring state according to the comparison result, and outputting the determination result; cutting off the power supply when the determination result is an open circuit or a short circuit fault; and reading the data of an electric energy meter and checking the data with the collected data in the box. The present application embeds a judgment unit inside the joint terminal box, realizes in-situ collection and processing of voltage and current signals in the joint terminal box, and avoids installation complexity and reliability problems caused by a split structure; the present application extracts multiple characteristic quantities in the joint terminal box, and compares them with a preset wiring standard database, so that more accurate fault positioning is realized.

Description

Technical Field

[0001] This invention belongs to the field of junction box technology, specifically relating to a diagnostic method for the wiring status of a junction box and a junction box. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In meter installation and power connection services, the junction box is the core connecting component of the electricity metering circuit, and its wiring accuracy directly affects metering accuracy and electricity safety. Traditionally, the internal wiring status of junction boxes is determined by meter installers using external calibration instruments to measure point by point. If an anomaly is found, the junction box's lead seal or locking mechanism must be reopened, the internal wiring adjusted, and re-calibrated. This process is cumbersome, leads to repeated damage to the lead seal, and results in unclear fault location. Furthermore, traditional offline testing can only provide vague abnormal signals and cannot accurately locate fault types such as phase loss, short circuit, or incorrect phase sequence, ultimately requiring secondary diagnosis by skilled personnel.

[0004] To address the aforementioned shortcomings, existing technology discloses a split-type low-voltage junction box operation condition visualization intelligent transformation device, including a master unit at the junction box inlet and a slave unit at the outlet. The slave unit uses voltage and current signals from the inlet and outlet ends respectively, and performs cross-sectional comparison at the same time to determine abnormalities such as fuse blowouts and incorrect connection of the junction box. At the same time, LED indicator lights and LCD modules are configured to realize operation condition visualization, improving the efficiency of wiring detection and fault identification.

[0005] However, the above solution has the following drawbacks: The above solution adopts a split structure with a host at the incoming end and a slave at the outgoing end, relying on the host-slave connection cable to transmit data. During installation, the original incoming and outgoing cables need to be reconnected to the modification device and then connected to the junction box through pins. The installation is complicated and time-consuming, and the split connection structure is prone to poor contact and signal transmission interruption problems. In addition, the above solution can only indirectly judge fuse and circuit malfunctions by the difference between the incoming and outgoing signals. The detection dimension is single and the fault location accuracy is insufficient, which makes it difficult to meet the operational needs of rapid verification and accurate diagnosis at the meter installation and power connection site. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a diagnostic method for the wiring status of a combined junction box and a combined junction box, which can solve the technical problems of complex installation and insufficient fault location accuracy in the prior art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: Firstly, a diagnostic method for the wiring status of a junction box is provided, the specific steps of which include: Collect the voltage and current signals of each phase inside the junction box; The characteristic quantities of each phase voltage and current signal are extracted and compared with the preset wiring standard database in real time. The wiring status is determined based on the comparison results, and the determination result is output; when the determination result is an open circuit or short circuit fault, the power supply is cut off. Read the electricity meter data and compare it with the data collected in the box.

[0008] Furthermore, the characteristic quantities include the effective value of voltage, the effective value of current, phase sequence, power factor angle, three-phase balance, and circuit on / off status; the wiring standard database includes the voltage amplitude range, current amplitude range, positive phase sequence rules, power factor angle range, three-phase balance threshold, and on / off determination threshold.

[0009] Furthermore, the logic for determining the wiring status is as follows: The extracted feature quantities conform to the parameter range of the wiring standard database, and the wiring is judged to be normal; If any of the following conditions are met, it is determined to be an open circuit: the effective value of a phase voltage is close to 0, but other phases are normal; or the effective value of a phase current is 0, but the power is positive; or there is no circuit signal in the circuit continuity detection, it is determined to be an open circuit. If the effective value of a phase voltage is close to 0 and the phase current is large, it is determined to be a short circuit. If the extracted zero-crossing order is reversed or out of order, it is determined to be a phase sequence error; If the phase difference between the extracted phase voltage and current is close to 180°, and the load characteristic judgment is not valid, then it is determined to be a reverse polarity connection.

[0010] Furthermore, the judgment result is visualized by an indicator light group, which includes a first indicator light for indicating whether the wiring is normal or faulty, and a second indicator light for indicating the type of fault.

[0011] Furthermore, the first indicator light has two states: constantly lit and flashing. A constantly lit light indicates that the wiring is normal, while a flashing light indicates a wiring fault. The second indicator light has two states: off and lit. The lit light also has multiple color states. An off light indicates that there is no fault, while a lit light indicates that there is a fault. Different colors represent different faults.

[0012] Secondly, a combined junction box is provided, which applies the above-mentioned diagnostic method for the wiring status of a combined junction box, including a combined junction box, an evaluation unit, and an indicator light group; the evaluation unit is built into the combined junction box, and the indicator light group is embedded in the outer wall of the combined junction box; The evaluation unit includes a microcontroller, a voltage sampling module, a current sampling module, and a communication module; The voltage sampling module is configured to collect the voltage signals of each phase inside the junction box, and the current sampling module is configured to collect the current signals of each phase inside the junction box. The microcontroller has a pre-set wiring standard database. The microcontroller is configured to receive the acquisition signals from the voltage sampling module and the current sampling module, process the acquisition signals to extract feature quantities, compare the extracted feature quantities with the pre-set wiring standard database in real time, determine the wiring status based on the comparison results, and output the determination results. The indicator light group is configured to illuminate the corresponding indicator light based on the determination result of the microcontroller; The communication module is configured to read data from the electricity meter and compare it with the data collected inside the box.

[0013] Furthermore, the indicator light group includes a first indicator light for indicating whether the wiring is normal or faulty, and a second indicator light for indicating the type of fault.

[0014] Furthermore, the first indicator light has two states: constantly lit and flashing. A constantly lit light indicates that the wiring is normal, while a flashing light indicates a wiring fault. The second indicator light has two states: off and lit. The lit light also has multiple color states. An off light indicates that there is no fault, while a lit light indicates that there is a fault. Different colors represent different faults.

[0015] Furthermore, it also includes a DIP switch group, which connects to the voltage sampling module and the current sampling module.

[0016] Furthermore, an interface is provided on the side wall of the junction box, through which the wires of the communication module extend out of the junction box and connect to the electricity meter.

[0017] Compared with the prior art, the advantages and positive effects of this invention are: This invention integrates the evaluation unit within the junction box, enabling in-situ acquisition and processing of voltage and current signals within the junction box. This avoids the installation complexity and reliability issues associated with a separate structure. Furthermore, by extracting multiple characteristic quantities within the junction box and comparing them with a pre-defined wiring standard database, this invention provides multi-dimensional detection capabilities, achieving more accurate fault location. Additionally, this invention interacts with an external electricity meter, providing external verification of internal diagnostic results through the comparison of electricity meter data, further enhancing the reliability of the diagnosis. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] Figure 1 This is a flowchart of the diagnostic method of Embodiment 1 or Embodiment 2 of the present invention; Figure 2 This is a connection diagram of the evaluation unit and the indicator light group in Embodiment 1 or Embodiment 2 of the present invention; Figure 3 This is a schematic diagram showing the position of the indicator light group in Embodiment 1 or Embodiment 2 of the present invention; Figure 4 This is a schematic diagram of the position of the DIP switch group in Embodiment 2 of the present invention; In the picture: 1. Junction box; 2. First indicator light; 3. Second indicator light; 4. Evaluation unit; 41. Microcontroller; 42. Voltage sampling module; 43. Current sampling module; 44. Communication module; 5. DIP switch group. Detailed Implementation

[0020] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] Definitions: A junction box is a device used to connect and distribute electrical energy lines in an electrical energy metering circuit. A junction box contains multiple terminals to connect different phase lines and neutral lines. The accuracy of its internal wiring directly affects the accuracy of electrical energy metering and electrical safety.

[0022] The present invention will now be described in detail with reference to the accompanying drawings.

[0023] Example 1 This embodiment discloses a method for diagnosing the wiring status of a combined junction box, such as... Figure 1 As shown, the specific steps include: First, the evaluation unit 4 is used to collect the voltage and current signals of each phase inside the junction box 1. In-situ acquisition means that the voltage and current signals of each phase are directly obtained inside the junction box 1. This acquisition method avoids disassembling the junction box 1, ensuring the directness and real-time nature of the data source, so as to reflect the real electrical state inside the junction box.

[0024] Subsequently, the evaluation unit 4 performs digital signal processing on the collected phase voltage and current signals, extracts feature quantities, and compares them in real time with the preset wiring standard database within the evaluation unit 4 to generate comparison results. It can be understood that through digital signal processing, the collected analog voltage and current signals are converted from analog to digital, and digital algorithms are used to analyze and calculate the digital signals, extracting time-domain or frequency-domain feature quantities from the original signal data. This facilitates comparison with the range thresholds of the wiring standard database, aiding in subsequent diagnosis and judgment.

[0025] It should be noted that the wiring standard database is a collection of electrical characteristic parameter ranges stored under normal wiring conditions. The wiring standard database is used as a comparison benchmark to determine whether the currently collected characteristic quantities meet the normal operating conditions, thereby identifying potential wiring abnormalities.

[0026] Next, the evaluation unit 4 determines the wiring status based on the comparison results and outputs the results. When the result indicates an open circuit or short circuit fault, the power supply is cut off. It can be understood that the wiring status refers to the connection status of each phase line within the junction box 1, such as normal, open circuit, short circuit, incorrect phase sequence, or reversed polarity. The evaluation unit 4 determines the current wiring status within the junction box 1 based on the comparison results. It can also be understood that an open circuit fault means a break in the circuit, preventing current flow; a short circuit fault means an abnormal connection between two points in the circuit, causing an abnormal increase in current. For these two types of faults, cutting off the power supply prevents equipment damage and ensures personal safety.

[0027] Finally, the evaluation unit 4 reads the electricity meter data and compares it with the data collected inside the junction box. It should be noted that the electricity meter data refers to electrical parameters such as voltage, current, and power recorded by the external electricity metering device. By interacting with the external electricity meter and comparing it with the data collected inside the junction box, the evaluation unit 4 can achieve cross-validation of the diagnostic results and improve the reliability of the diagnosis.

[0028] Specifically, the evaluation unit 4 interacts with an external electricity meter through a communication interface, reads the A-phase voltage and current data recorded by the electricity meter, and compares the A-phase data provided by the electricity meter with the A-phase data collected and processed internally by the evaluation unit 4. If both data show that the A-phase voltage and current are zero, the reliability of the internal diagnostic results is verified.

[0029] Understandably, existing split-type solutions rely on the connection cable between the master and slave units to transmit data, which is complex and time-consuming to install, and prone to problems such as poor contact and signal transmission interruption. This embodiment integrates the evaluation unit inside the combined junction box, realizing in-situ signal acquisition and processing, avoiding the installation complexity and reliability issues caused by the split structure. Furthermore, existing split-type solutions mainly rely on the signal difference between the incoming and outgoing lines to indirectly determine fuse or connection abnormalities, resulting in a relatively single detection dimension. This embodiment extracts multiple feature quantities within the combined junction box and compares them with a preset wiring standard database, providing multi-dimensional detection capabilities and achieving more accurate fault location.

[0030] In addition, this embodiment also interacts with external electricity meters to verify the internal diagnostic results by checking the electricity meter data, thereby further enhancing the reliability and credibility of the diagnosis.

[0031] In this embodiment, as Figure 2 As shown, the steps for digital signal processing of the acquired signal include: The analog voltage and current signals acquired in situ inside the junction box are converted into digital signals through analog-to-digital conversion, so that they can be recognized and processed by the evaluation unit 4. The evaluation unit 4 performs DSP data processing on the digital signals, including FFT fast Fourier transform, phase calculation, harmonic analysis and feature extraction.

[0032] In this embodiment, the characteristic quantities include the effective voltage value, the effective current value, the phase sequence, the power factor angle, the three-phase balance, and the circuit continuity status. The effective voltage and effective current values ​​reflect the actual magnitudes of the voltage and current; the phase sequence is the order in which the three-phase voltage or current appears, used to determine if the wiring is correct; the power factor angle is the phase difference between the voltage and current; the three-phase balance is an indicator that measures the symmetry of the amplitude and phase of the three-phase voltage or current, used to determine the stability of the system operation; and the circuit continuity status is used to determine whether the circuit is conducting or disconnected.

[0033] By performing digital signal processing on the acquired signals, a solid data foundation is provided for subsequent real-time comparison with the preset wiring standard database.

[0034] In this embodiment, the wiring standard database includes voltage amplitude range, current amplitude range, positive phase sequence rules, power factor angle range, three-phase balance threshold, and on / off determination threshold.

[0035] The voltage amplitude range refers to the upper and lower limits allowed for each phase voltage signal under normal operating conditions, such as ±10% of the rated voltage. The current amplitude range refers to the upper and lower limits allowed for each phase current signal under normal load conditions. The positive phase sequence rule is used to define the correct time sequence of each phase voltage or current in a three-phase power system, which in this embodiment is ABC, BCA, or CAB. The power factor angle range is the normal phase difference between the in-phase voltage and current, normally 0°-60°, depending on the load characteristics; resistive loads are close to 0°, and inductive loads lag. The three-phase balance threshold is the allowable range of relative deviation between the three-phase voltage and current amplitudes, expressed as a percentage, such as voltage imbalance less than 2% or current imbalance less than 5%. The continuity judgment threshold is a critical value used to determine whether a circuit is in a conducting or disconnected state. For example, when the voltage or current is lower than a set value, the circuit can be determined to be disconnected; when the voltage or current is higher than a set value, the circuit can be determined to be conducting.

[0036] Understandably, the evaluation unit 4 compares the extracted effective voltage value with the voltage amplitude range in the database to determine whether the voltage is within the normal operating range; it compares the extracted phase sequence with the positive phase sequence rule to identify phase sequence errors; it compares the extracted power factor angle with the power factor angle range to determine the load characteristics and whether there is a possibility of reverse polarity; it compares the extracted three-phase balance with the three-phase balance threshold to evaluate the system balance; and it compares the extracted circuit on / off status with the on / off judgment threshold to determine the open or short circuit status of the circuit.

[0037] It should be noted that this embodiment designs a comparison mechanism of multiple parameters, enabling the evaluation unit 4 to cross-validate and comprehensively judge the collected data from multiple dimensions, thereby improving the accuracy and reliability of the wiring status determination and avoiding misjudgment and omission.

[0038] In this embodiment, the extracted features are compared with a preset database to generate a comparison result. The comparison result and the wiring status are designed with clear judgment logic to distinguish between normal and abnormal wiring conditions. This judgment logic includes: The extracted feature quantities conform to the parameter range of the wiring standard database, and the wiring is judged to be normal; If the effective value of a phase voltage is close to 0, but other phases are normal, or the effective value of a phase current is 0, but the power is positive; or there is no circuit signal in the circuit continuity detection, then it is determined to be an open circuit. If the effective value of a phase voltage is close to 0 and the phase current is very large, it is determined to be a short circuit. If the extracted zero-crossing order is reversed (e.g., ACB) or out of order (e.g., BAC), it is determined to be a phase sequence error; If the phase difference between the extracted phase voltage and current is close to 180° (normally they should be in phase or lagging), and the load characteristics are not determined (e.g., a phase difference of close to 180° occurs with a resistive load), then it is determined to be a reverse polarity connection.

[0039] It is understood that the logic of this embodiment can clearly distinguish between normal wiring and various common wiring fault types, including open circuit, short circuit, phase sequence error, and reverse polarity. This accurate fault identification capability avoids vague diagnosis or misjudgment, enabling maintenance personnel to quickly locate problems and take targeted corrective measures, such as automatically cutting off power for open circuit and short circuit faults, thereby effectively ensuring the safe and stable operation of the power system and reducing the risk of equipment damage or accidents caused by wiring errors.

[0040] In practical applications, outputting the judgment result through the evaluation unit 4 cannot intuitively convey complex diagnostic information to the user. Therefore, in this embodiment, the judgment result is visually output by an indicator light group, such as... Figure 1 , Figure 2 As shown, the indicator light group includes a first indicator light 2 for indicating normal or faulty wiring, and a second indicator light 3 for indicating the type of fault. The first indicator light has two states: constantly lit and flashing. A constantly lit indicator light indicates normal wiring, while a flashing indicator light indicates a wiring fault. The second indicator light has two states: off and lit. The lit indicator light has multiple color states: off indicates no fault, and lit indicates a fault. Different colors represent different faults. The first indicator light 2 and the second indicator light 3 are respectively installed on both sides of the junction box 1.

[0041] This embodiment decomposes and maps the complex wiring status determination results onto a combination of different states, colors, and flashing patterns of two indicator lights, thereby achieving intuitive visual output. Users do not need to view detailed text information; they can quickly understand the current wiring status simply by looking at it, making it convenient for users to judge the wiring status of the junction box.

[0042] In this embodiment, the evaluation unit 4 is connected to the driving circuit of the first indicator light and the second indicator light. The judgment result of the evaluation unit 4 is transmitted to the driving circuit of the first indicator light and the second indicator light to control the on / off state, color and flashing frequency of the first indicator light and the second indicator light.

[0043] In this embodiment, when the first indicator light is constantly on and the second indicator light is off, it indicates that the wiring is normal; when the first indicator light is flashing and the second indicator light is yellow, it indicates that the wiring is open; when the first indicator light is flashing and the second indicator light is green, it indicates that the wiring is short-circuited; when the first indicator light is flashing and the second indicator light is red, it indicates that the wiring is incorrect.

[0044] Example 2 This embodiment discloses a combined junction box device, which applies a diagnostic method for the wiring status of a combined junction box disclosed in Embodiment 1, such as... Figure 1 As shown, the system includes a junction box 1, an indicator light group, and an evaluation unit 4; wherein, the evaluation unit 4 is built into the junction box 1, and the indicator light group is embedded on the outer wall of the junction box 1. The evaluation unit 4 includes a microcontroller 41, a voltage sampling module 42, a current sampling module 43, and a communication module 44.

[0045] The voltage sampling module 42 is configured to collect phase voltage signals inside the junction box 1, and the current sampling module 43 is configured to collect phase current signals inside the junction box 1. The microcontroller 41 has a preset wiring standard database. The microcontroller 41 is configured to receive the collected signals from the voltage sampling module 42 and the current sampling module 43, process the collected signals, extract multiple feature quantities, compare the extracted feature quantities with the preset wiring standard database in real time, determine the wiring status based on the comparison results, and output the determination results.

[0046] In addition, the indicator light group is electrically connected to the microcontroller 41, and the indicator light group is configured to light up the corresponding indicator light according to the judgment result of the microcontroller 41; the communication module 44 is electrically connected to the microcontroller 41 and is configured to read the energy meter data and verify it with the data collected in the box.

[0047] It is understood that in this embodiment, the evaluation unit 4 is built into the junction box 1 to perform in-situ signal acquisition and processing, and combined with a multi-dimensional comparison mechanism of multiple feature quantities, thereby avoiding the need for master-slave connection lines and cable reconnection required by the split structure, while improving the accurate identification capability of fault types, and achieving the effect of simplifying the installation process and improving the fault location accuracy.

[0048] Specifically, existing technologies employ a separate host and slave structure, requiring the original incoming and outgoing cables to be reconnected to the modification device during installation, resulting in complex operations and a high risk of poor contact. In contrast, this solution fully integrates the evaluation unit 4 into the combined junction box 1, allowing the voltage sampling module 42 and current sampling module 43 to directly collect signals in their original positions within the box, eliminating the need for external cable reconnection and fundamentally eliminating the installation complexity and signal transmission interruption risks associated with the separate connection structure.

[0049] The microcontroller 41 extracts multiple characteristic quantities such as the effective value of voltage, the effective value of current, phase sequence, and harmonic content, and compares them in real time with a preset wiring standard database. This enables it to accurately distinguish specific fault types such as open circuits, short circuits, and phase sequence errors, overcoming the problem of limited detection dimensions caused by existing technologies that rely solely on the difference between incoming and outgoing line signals. Simultaneously, the judgment result is visually output by an indicator light group using a combination of color and flashing, facilitating user judgment of the wiring status of the junction box. Furthermore, it uses the communication module 44 to read data from the electricity meter for dual verification.

[0050] In this embodiment, the indicator light group includes a first indicator light 2 and a second indicator light 3. The first indicator light has two states: constantly on and flashing; the second indicator light has two states: off and on, and the on state includes multiple color states. The first indicator light is used to indicate whether the wiring is normal or faulty, and the second indicator light is used to indicate the type of fault. That is, when the first indicator light indicates an abnormality, the second indicator light can further clarify the specific fault type. Specifically, the first indicator light has two states: constantly on and flashing. A constantly on indicator light indicates normal wiring, and a flashing indicator light indicates a wiring fault. The second indicator light has two states: off and on, and the on state includes multiple color states. An off indicator light indicates no fault, and an on indicator light indicates a fault. Different colors represent different faults. This design effectively overcomes the limitations of a single indicator light in expressing complex states, significantly improving the efficiency of users' understanding of equipment status and the convenience of fault diagnosis.

[0051] This embodiment decomposes and maps the complex wiring status determination results onto a combination of different states, colors, and flashing patterns of two indicator lights, thereby achieving intuitive visual output. Users do not need to view detailed text information; they can quickly understand the current wiring status simply by looking at it, making it convenient for users to judge the wiring status of the junction box.

[0052] In this embodiment, the indicator light group can be composed of light-emitting diodes (LEDs), small indicator bulbs, or other electroluminescent devices, and is typically connected to the output port of a microcontroller via a circuit. The microcontroller controls its on / off state, flashing frequency, and color. The first indicator light uses a monochrome LED, such as a white LED, and achieves constant illumination or flashing by controlling the on / off state of its power supply current or pulse width modulation (PWM). When the microcontroller 41 determines that the wiring is normal, the first indicator light remains illuminated; when it determines that the wiring is abnormal, the first indicator light flashes at a preset frequency (e.g., 1Hz). The second indicator light uses an RGB tri-color LED, integrating red, green, and blue light-emitting chips. By controlling the current magnitude and combination of different color chips, various colors can be emitted.

[0053] In this embodiment, the combined junction box device further includes a DIP switch group 5, which includes a voltage DIP switch group and a current DIP switch group. The voltage DIP switch group is connected to the voltage sampling module, and the current DIP switch group is connected to the current sampling module. It is understood that the voltage DIP switch group is used to configure or adjust the parameters of the voltage sampling module, and the current DIP switch group is used to configure or adjust the parameters of the current sampling module, enhancing the configuration flexibility and adaptability of the voltage and current sampling modules, enabling them to accurately match the measurement requirements in different application scenarios. The value range of both the voltage and current DIP switch groups is 0000~1111. For example, a DIP switch in the voltage DIP switch group set to 0010 represents a 10000 / 100 voltage transformer; a DIP switch set to 0101 represents a 35000 / 100 voltage transformer. A DIP switch in the current DIP switch group set to 0001 represents a 100 / 5 current transformer; a DIP switch set to 0100 represents a 200 / 5 current transformer. This design avoids measurement errors caused by mismatched sampling parameters, improving the accuracy and reliability of wiring status diagnosis.

[0054] In this embodiment, the voltage sampling module uses a voltage transformer, and the current sampling module uses a current transformer. The voltage transformer reduces the high-voltage signal inside the junction box to a low-voltage range that the microcontroller 41 can handle, while the current transformer reduces the large-current signal inside the junction box to a small-current range that the microcontroller can handle, thus improving safety.

[0055] In this embodiment, voltage transformers are connected in parallel between the phase voltage terminals and the neutral terminal within the junction box 1; the current transformers adopt a through-type or wound-type structure, with their primary side directly sleeved on the conductor of the current loop, and their secondary side outputting a small mA-level current signal, which is converted into a voltage signal by a sampling resistor and then sent to the microcontroller 41. The voltage and current transformers protect the microcontroller from high-voltage surges while also providing it with low-voltage signals for processing.

[0056] In this embodiment, the communication module is an RS485 interface. The junction box 1 acquires the voltage and current signals of the energy meter through the RS485 interface and compares them with the voltage and current data inside the junction box. Specifically, the microcontroller 41 periodically sends data read commands to the energy meter through the RS485 interface to obtain the real-time measured voltage and current data of each phase of the energy meter. The microcontroller 41 compares the data acquired from the energy meter with the internally acquired data, setting an error threshold, for example, 5%. If the relative error between the internally acquired data and the energy meter measurement data is within 5%, the internally acquired data is considered reliable and the diagnostic result is valid; otherwise, it indicates an internal sampling fault, an energy meter fault, or an actual wiring abnormality. This dual verification mechanism ensures the robustness of the wiring status determination.

[0057] In this embodiment, an interface is provided on the side wall of the junction box, and the wires of the communication module extend out of the junction box through the interface to connect with the electricity meter.

[0058] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for diagnosing the wiring status of a junction box, characterized in that, The specific steps include: Collect the voltage and current signals of each phase inside the junction box; The characteristic quantities of each phase voltage and current signal are extracted and compared with the preset wiring standard database in real time. The wiring status is determined based on the comparison results, and the determination result is output; when the determination result is an open circuit or short circuit fault, the power supply is cut off. Read the electricity meter data and compare it with the data collected in the box.

2. The diagnostic method for the wiring status of a combined junction box as described in claim 1, characterized in that, The characteristic quantities include the effective value of voltage, the effective value of current, phase sequence, power factor angle, three-phase balance, and circuit on / off status; the wiring standard database includes the voltage amplitude range, current amplitude range, positive phase sequence rules, power factor angle range, three-phase balance threshold, and on / off determination threshold.

3. The diagnostic method for the wiring status of a combined junction box as described in claim 1, characterized in that, The wiring status determination logic is as follows: The extracted feature quantities conform to the parameter range of the wiring standard database, and the wiring is judged to be normal; If any of the following conditions are met, it is determined to be an open circuit: the effective value of a phase voltage is close to 0, but other phases are normal; or the effective value of a phase current is 0, but the power is positive; or there is no circuit signal in the circuit continuity detection, it is determined to be an open circuit. If the effective value of a phase voltage is close to 0 and the phase current is large, it is determined to be a short circuit. If the extracted zero-crossing order is reversed or out of order, it is determined to be a phase sequence error; If the phase difference between the extracted phase voltage and current is close to 180°, and the load characteristic judgment is not valid, then it is determined to be a reverse polarity connection.

4. The diagnostic method for the wiring status of a combined junction box as described in claim 1, characterized in that, The determination result is visualized by an indicator light group, which includes a first indicator light for indicating whether the wiring is normal or faulty, and a second indicator light for indicating the type of fault.

5. The diagnostic method for the wiring status of a combined junction box as described in claim 4, characterized in that, The first indicator light has two states: constantly lit and flashing. A constantly lit light indicates that the wiring is normal, while a flashing light indicates that the wiring is faulty. The second indicator light has two states: off and lit. The lit light has multiple color states. Off indicates that there is no fault, while lit light indicates that there is a fault. Different colors represent different faults.

6. A combined junction box device, characterized in that, It includes a junction box, a judging unit, and an indicator light group; the judging unit is built into the junction box, and the indicator light group is embedded in the outer wall of the junction box; The evaluation unit includes a microcontroller, a voltage sampling module, a current sampling module, and a communication module; The voltage sampling module is configured to collect the voltage signals of each phase inside the junction box, and the current sampling module is configured to collect the current signals of each phase inside the junction box. The microcontroller has a preset wiring standard database. The microcontroller is configured to receive the acquisition signals from the voltage sampling module and the current sampling module, extract feature quantities from the acquisition signals, compare the extracted feature quantities with the preset wiring standard database in real time, determine the wiring status based on the comparison results, and output the determination results. The indicator light group is configured to illuminate the corresponding indicator light based on the determination result of the microcontroller; The communication module is configured to read data from the electricity meter and compare it with the data collected inside the box.

7. A combined junction box device as described in claim 6, characterized in that, The indicator light group includes a first indicator light for indicating whether the wiring is normal or faulty, and a second indicator light for indicating the type of fault.

8. The diagnostic method for the wiring status of a combined junction box as described in claim 7, characterized in that, The first indicator light has two states: constantly lit and flashing. A constantly lit light indicates that the wiring is normal, while a flashing light indicates that the wiring is faulty. The second indicator light has two states: off and lit. The lit light has multiple color states. Off indicates that there is no fault, while lit light indicates that there is a fault. Different colors represent different faults.

9. A combined junction box device as described in claim 7, characterized in that, It also includes a DIP switch group, which connects to the voltage sampling module and the current sampling module.

10. A combined junction box device as described in claim 7, characterized in that, An interface is provided on the side wall of the junction box, through which the wires of the communication module extend out of the junction box and connect to the electricity meter.

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