Layered wiring type intelligent metering box

Abstract

The application discloses a layered wiring type intelligent metering box body and relates to the field of electric power metering. Through the through heat dissipation holes formed in the inner part of the online clamp and the cooperation of the air inlet and outlet pipes and the air supply assembly, a closed quantifiable cooling circulation loop for the high-risk bending stress area of the cable is constructed. The first and second temperature sensors are used to collect the temperature difference between the air inlet and outlet in real time, and the real-time current obtained by the current transformer and the reference resistivity are combined to calculate the theoretical heating power and the predicted heat dissipation temperature. The application constructs a precise closed flow guide air duct in the inner part of the online clamp, and cooperates with the double temperature sensors of the air inlet and outlet, realizes the online monitoring of the cable resistance change, can strip the temperature rise interference caused by normal load fluctuation, realizes the quantitative prediction of the aging degree before the damage of the insulating layer, solves the problems of quantitative monitoring and early discovery of the cable aging hidden fault, breaks through the lagging limitation of the traditional alarm which only depends on the environmental temperature, and is more suitable for severe working conditions.

Description

Technical Field

[0001] This invention relates to the field of metering box technology, and specifically to a layered wiring type intelligent metering box. Background Technology

[0002] As a key terminal device in the power system that integrates energy metering, load monitoring, and data communication, the stability and security of the metering box directly affect the power supply quality and electricity safety at the end of the distribution network. Inside the metering box, a large number of energy meters, circuit breakers, and a complex hierarchical wiring system are integrated.

[0003] With the continuous growth of electrical load, layered cabling generates significant heat accumulation due to the Joule effect during high-current operation. However, existing technologies for cable condition monitoring and aging prediction still have significant shortcomings, mainly relying on periodic manual inspections or simple ambient temperature alarm threshold settings. This approach has a significant lag, failing to detect insulation degradation caused by thermal cycling in real time, and making it difficult to achieve accurate quantitative prediction and graded early warning before electrical faults occur.

[0004] Due to their functional characteristics, metering boxes require the internal storage of meters, controllers, and other components. The space is compact and susceptible to external dust interference. During implementation, to connect the power cables to the electricity meter terminals, the wiring needs to be bent below the terminals, reducing its mechanical strength and increasing its brittleness. Simultaneously, the electronic heat generated by the electricity meters, switching power supplies, communication modules, and other electronic components integrated within the metering chamber, combined with the Joule heat of the cables themselves, results in a significantly higher ambient temperature in this area compared to other parts of the box.

[0005] Currently, existing technologies for assessing cable health primarily rely on periodic manual inspections or simple environmental temperature alarm threshold settings. Manual inspections are limited by detection frequency and struggle to capture instantaneous abnormal fluctuations; while temperature threshold alarms typically only trigger when the temperature reaches its limit. Therefore, current technologies cannot accurately quantify and predict the degree of cable aging online, making it difficult to identify insulation performance degradation trends in the early stages of aging. Due to the lack of quantitative prediction methods, maintenance personnel often lack early warnings before faults occur. This allows cables to experience insulation breakdown, flashover discharge, or short-circuit tripping due to severe carbonization at local bends, even before reaching environmental alarm thresholds. This increases the risk of unplanned equipment outages, potentially leading to large-scale power outages or electrical fires, seriously threatening the reliability of power supply at the distribution end and related personal and property safety.

[0006] Therefore, it is necessary to study a layered wiring type intelligent metering box. Summary of the Invention

[0007] Therefore, the purpose of this invention is to provide a layered wiring type intelligent metering box, which effectively solves the existing problems.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a layered wiring type intelligent metering box, comprising... The cable clamp is fixed inside the box to hold the cable and has through-holes for heat dissipation. The air inlet duct is fixed to one side of the clamp, and its internal air inlet channel is connected to one end of the heat dissipation hole; the inlet of the air inlet duct is connected to the air supply component. The air outlet duct is fixed on the other side of the clamp. Its internal air outlet channel is connected to the other end of the heat dissipation hole. The outlet of the air inlet duct is connected to the heat dissipation chamber, and heat dissipation fins are installed in the heat dissipation chamber. The first temperature sensor and the second temperature sensor are respectively installed on the air inlet side of the air inlet pipe and the air outlet side of the air outlet pipe, and are used to obtain the air inlet temperature and air outlet temperature of the cable; calculate the difference between the air inlet temperature and the air outlet temperature to obtain the real-time heat dissipation temperature of the cable. Current transformers are used to obtain the real-time current of cables, predict the heat dissipation of cables based on the real-time current, obtain the predicted heat dissipation temperature based on the predicted heat dissipation, and compare the predicted heat dissipation temperature with the real-time heat dissipation temperature to determine the degree of aging of cables.

[0009] Furthermore, the housing is provided with an air inlet chamber and a heat dissipation chamber. The air inlet chamber is equipped with an air supply component, and the heat dissipation chamber is connected to the air outlet pipe and is provided with heat dissipation fins. The heat dissipation chamber is connected to the air inlet chamber through a return pipe.

[0010] Furthermore, the air supply component is equipped with a power adjustment module, which is communicatively connected to the monitoring results of the aging degree. When the aging degree is detected to exceed a preset threshold, the air supply volume of the air supply component is increased.

[0011] Furthermore, the air supply assembly is connected to a first channel and a second channel, the first channel being connected to the air inlet pipe and the second channel being connected to the inlet chamber.

[0012] Furthermore, both the air inlet chamber and the cable inlet chamber are equipped with heat dissipation windows on their sides. The heat dissipation windows have a semi-enclosed structure with an opening at the bottom and a dustproof net inside.

[0013] Furthermore, when the aging level reaches a threshold, a local audible and visual alarm is triggered, and a graded early warning signal is sent to an external monitoring center via a wireless communication module. The early warning level is proportional to the aging level.

[0014] Furthermore, the wire clamp includes a first card holder, a second card holder, and a third card holder; the opposite surfaces of the first card holder and the second card holder are respectively provided with a first slot and a second slot, and the opposite surfaces of the second card holder and the third card holder are provided with a third slot and a fourth slot. The first slot and the second slot are joined together to form a first wire groove group, and heat dissipation holes are provided on the outer periphery of the first slot and the second slot. The third slot and the fourth slot are joined together to form a second wire groove group. The first wire groove group and the second wire groove group are provided with wire outlet holes, and a wire conduit penetrating the air inlet pipe is provided on one side of the first wire groove group.

[0015] Furthermore, it also includes a protective plate, which is fastened to the outside of the wire clamp.

[0016] Furthermore, the current transformer includes a first transformer and a second transformer, which respectively collect the live wire current and the neutral wire current; and obtain the real-time current of the cable based on the neutral wire current and the live wire current.

[0017] Furthermore, the reference resistivity of the cable within the clamp under the current environment and the standard specific heat capacity of the air in the heat dissipation hole are obtained; the theoretical heat generation power of the cable is calculated based on the real-time current and the reference resistivity; the predicted heat dissipation temperature is calculated by combining the real-time airflow of the air supply component and the standard specific heat capacity; the aging characteristic coefficient is obtained by calculating the ratio of the measured heat dissipation temperature difference to the predicted heat dissipation temperature and then processing it through a moving average; and the state of the cable is determined based on the aging characteristic coefficient.

[0018] The beneficial effects of the above technical solution are: This invention identifies the bending stress zone below the metering chamber terminals as a high-risk failure point. A through-hole for heat dissipation is created inside the cable clamp, connected to the air supply assembly and heat dissipation chamber via inlet and outlet ducts, forming a closed, quantifiable, and controllable cooling loop. The temperature difference obtained by the temperature sensors on the inlet and outlet sides directly reflects the heat carried away by the air from the cable, i.e., the measured heat dissipation. Simultaneously, a current transformer is used to obtain real-time current, which, combined with a reference resistivity, calculates the theoretical heat generation power. This, along with the real-time airflow and the standard specific heat capacity of air, predicts the outlet temperature rise under ideal heat dissipation conditions. When the measured temperature is significantly higher than the predicted value, it indicates an increase in cable resistance, thus quantifying the cable's material aging and insulation degradation. This enables online monitoring of cable resistance changes, effectively eliminating temperature rise interference caused by normal load fluctuations. It allows for quantitative prediction of aging levels before visible physical damage to the insulation layer occurs, solving the problem of quantitative monitoring of latent cable aging faults. It overcomes the limitations of traditional alarms relying solely on ambient temperature, making it more suitable for harsh operating conditions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of another embodiment of the present invention; Figure 4 This is a schematic diagram of the implementation structure of the wire clamp of the present invention; Figure 5 This is a schematic diagram of the internal structure of the wire clamp; Figure 6 This is a top view of the wire clamp structure. Figure 7 This is a cross-sectional view of the wire clamp. Figure 8 This is a block diagram illustrating the implementation principle of the present invention.

[0020] Reference numerals: 1. Control room; 2. Air inlet chamber; 3. Cable inlet chamber; 4. Metering chamber; 5. Heat dissipation chamber; 6. Heat dissipation fins; 7. Air inlet pipe; 71. Air inlet duct; 8. Column; 9. Cable clamp; 91. First card holder; 92. Second card holder; 93. Third card holder; 94. First cable tray group; 95. Second cable tray group; 96. Heat dissipation hole; 97. Cable outlet hole; 98. Cable conduit; 99. Protective plate; 10. Air supply assembly; 11. Air outlet pipe; 12. Current transformer; 13. First temperature sensor; 14. Second temperature sensor; 15. Heat dissipation window; 16. Guide plate. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Example 1: This example aims to provide a layered wiring type intelligent metering box, which is mainly used in the power system at the end of the distribution network to solve the safety hazards caused by the compact layered wiring, poor heat dissipation, and lack of cable aging monitoring methods in the existing metering box.

[0022] Specifically, such as Figures 1 to 3 As shown, the metering box includes a control room 1 and a metering room 4. The control room 1 is equipped with a main incoming busbar, a circuit breaker, wiring terminals, and outgoing cables. Current is supplied into the metering box through the incoming busbar and the circuit breaker. By controlling the on / off state of the circuit breaker, the power supply can be switched on and off, and then the circuit can be inspected or automatically tripped for protection. The outgoing cables are connected to the metering room 4 to supply power to multiple energy meters.

[0023] Metering chamber 4 has multiple layered spaces, each containing an electricity meter and a cable clamp 9. The cable clamp 9 contains a bent section of cable, one end of which connects to the electricity meter, and the other end connects to the outgoing cable, thus supplying power to the electricity meter. This layered structure of the metering box ensures a more standardized arrangement of multiple electricity meters and bent cable sections.

[0024] In practical applications, historical experience and practice have shown that the bent section of cable below the meter in metering chamber 4 is the part of the entire circuit that ages fastest and has the highest probability of failure. This section of cable integrates the highest heat load, the greatest mechanical stress, and the worst heat dissipation environment. Its aging degree can serve as a leading indicator for assessing the overall cable health status and can represent the degree of cable aging. Based on this, this embodiment specifically provides a cable analysis scheme for this area to estimate the degree of cable aging and realize intelligent monitoring and control of the metering box.

[0025] Specifically, this includes a cable clamp 9 fixed inside the enclosure, which is used to hold the cable. The cable clamp 9 has through-holes 96 inside, allowing the cable to be secured while also providing a heat dissipation channel for gas movement around its periphery. By providing airflow, a quantifiable thermal balance system is constructed. This involves comparing the deviation of measured current and temperature values ​​from the energy conservation equation, thereby transforming the cable aging process into a variable that can be calculated online, thus enabling intelligent monitoring and control of the metering enclosure.

[0026] Specifically, in this embodiment, on the one hand, axial heat dissipation holes 96 are opened inside the cable clamp 9, and the air supply component 10 drives the air to flow through the cable surface, concentrating the heat energy that was originally dissipated in the box into the airflow, forming a controllable heat transfer path; on the other hand, the theoretical heat generation power and expected temperature rise are calculated by the current transformer 12 and the initial resistance parameters, and the actual temperature rise is measured by the inlet and outlet air temperature sensors to establish a temperature rise benchmark under healthy conditions; on the third hand, the ratio of the actual temperature rise to the expected temperature rise is used as the aging characteristic coefficient, and the fan speed adjustment, early warning push, audible and visual alarm and even trip protection are automatically executed according to the range of the coefficient.

[0027] In the specific implementation structure, such as Figures 1 to 3 As shown, multiple wire clamps 9 are arranged horizontally on the uprights 8 inside the metering box, forming multiple metering zones. The basic function of the wire clamps 9 is to hold and secure the cables. Unlike ordinary wire clamps 9, in this embodiment, the wire clamps 9 have axially penetrating heat dissipation holes 96 inside. The shape of the heat dissipation holes 96 can be circular, rectangular, or other cross-sections that facilitate airflow, and their number can be adjusted according to the heat generation power of the cable and the required heat dissipation area. In this embodiment, six metering zones are used as an example for illustration.

[0028] In this embodiment, the cable clamp 9 is not only used to securely fasten the cable, but also has a through-type heat dissipation hole 96 inside, which ensures that while the cable is physically supported, its circumferential convection space can be formed to collect the heat dissipation energy of the cable and to quantify the degree of cable aging. At the same time, it accelerates the heat dissipation of the cable in this area and has a certain protective effect.

[0029] The air inlet duct 7 is fixed to one side of the cable clamp 9, and its internal air inlet channel 71 is connected to one end of the heat dissipation hole 96. The inlet of the air inlet duct 7 is connected to the air supply component 10. The air supply component 10 can be an axial flow fan, which pressurizes the air from one side of the air inlet duct 7 and drives the air to flow through the heat dissipation hole 96 to achieve directional collection and quantifiable measurement of heat. This allows the temperature rise at the outlet side of the heat dissipation hole 96 to establish a quantitative correspondence with the actual heat generation power of the cable, creating conditions for subsequent aging assessment.

[0030] Meanwhile, the air supply component 10 is equipped with a power adjustment module, which is connected in communication with the analysis module that judges the monitoring results of the cable aging degree. When the aging degree is detected to exceed the preset threshold, the air supply volume of the air supply component 10 is increased.

[0031] The enclosure contains an air inlet chamber 2 and a heat dissipation chamber 5. The air inlet chamber 2 houses an air supply assembly 10. The heat dissipation chamber 5 is connected to an air outlet duct 11 and contains heat dissipation fins 6. The heat dissipation chamber 5 is connected to the air inlet chamber 2 via a return pipe. Specifically, the air outlet duct 11 is fixed to the other side of the clamp 9, and its internal air outlet is connected to the other end of the heat dissipation hole 96. The outlet of the air inlet duct 7 is connected to the heat dissipation chamber 5, and heat dissipation fins 6 are installed within the heat dissipation chamber 5. The internal structural layout of the enclosure includes an air inlet chamber 2 and a heat dissipation chamber 5. The heat dissipation chamber 5 is connected to the air outlet duct 11 and also to the air inlet chamber 2 via a return pipe, forming a hot air flow path.

[0032] In practical implementation, the air inlet chamber 2 is located in the lower left area of ​​the enclosure, corresponding to the inlet wiring area, and the air supply assembly 10 is installed inside. The heat dissipation chamber 5 is located at the top of the enclosure, spanning the control area and the metering area. It is an enclosed space with heat dissipation fins 6 installed inside. Heat exchange is carried out through heat exchange. The external area can be equipped with fans as needed to accelerate the heat dissipation of the heat dissipation fins 6, or heat dissipation can be carried out through natural diffusion.

[0033] An air inlet duct 7 is fixed to one side of the clamp 9, with its internal air inlet channel 71 connected to one end of the heat dissipation hole 96 on the clamp 9. The inlet of the air inlet duct 7 is directly connected to the air supply assembly 10. An air outlet duct 11 is fixed to the other side of the clamp 9, with its internal air outlet channel connected to the other end of the heat dissipation hole 96. The outlet of the air outlet duct 11 is connected to the heat dissipation chamber 5, and heat dissipation fins 6 are installed in the heat dissipation chamber 5 to improve heat dissipation efficiency by increasing the heat exchange area. During operation, the air supply assembly 10 forces air into the air inlet duct 7. The air flows through the heat dissipation hole 96 of the clamp 9, carrying away heat, and then enters the air outlet duct 11, flowing into the heat dissipation chamber 5. Heat is transferred to the outside of the chamber through the fins, and the cooled air returns to the air inlet chamber 2 through the return pipe. This not only prevents external dust from entering the metering area but also ensures that the airflow parameters in the loop are known and stable, meeting the requirements of quantitative thermal balance analysis.

[0034] A first temperature sensor 13 and a second temperature sensor 14 are provided. The first temperature sensor 13 is located on the air inlet side of the air inlet pipe 7, and the second temperature sensor 14 is located on the air outlet side of the air outlet pipe 11, to obtain the air inlet temperature and the air outlet temperature; the difference between the air inlet temperature and the air outlet temperature is calculated to obtain the real-time heat dissipation temperature of the cable.

[0035] Specifically, both the first temperature sensor 13 and the second temperature sensor 14 are Pt100 platinum resistance thermometers, extending into the center of the pipe to directly contact the airflow. The signals measured by both sensors are isolated and amplified before being sent to the analog input port of the controller. The sampling frequency is set to 5 times per second, and a sliding median filter is used to remove instantaneous disturbances. The controller calculates the difference between the inlet and outlet air temperatures to obtain the measured temperature rise, i.e., the heat dissipation temperature. The specific calculation method is as follows:

[0036] In the formula, The outlet air temperature, For the inlet temperature, The measured difference between the inlet and outlet values ​​represents the temperature rise corresponding to the heat carried away by the air from the cable surface, and serves as the real-time heat dissipation temperature.

[0037] Current transformer 12 is used to acquire the real-time current of the cable at the outgoing end and predict the heat dissipation of the cable based on the real-time current. In this embodiment, current transformer 12 includes two independent coils; such as Figure 2 As shown, the live and neutral wires of the outgoing cables are respectively installed in control room 1. The first current transformer collects the live wire current, and the second current transformer collects the neutral wire current. Both signals are sent to the controller simultaneously. The controller first calculates the current difference. If the current difference exceeds the preset leakage threshold, it determines that there is a ground leakage, pauses the aging assessment, and prioritizes issuing a leakage alarm. The system then outputs a leakage alarm and clearly displays the leakage status on the human-machine interface, pausing the aging assessment. After the leakage fault is cleared, the system automatically resumes aging monitoring.

[0038] If the current difference is within the normal range, then the effective value of the load current should be taken. The specific calculation formula is as follows:

[0039] In the formula, For live wire current, Neutral current, This is the effective value of the load current, i.e., the real-time current of the cable.

[0040] The predicted heat dissipation temperature is obtained based on the predicted heat dissipation of the cable; the reference resistivity of the cable in the current environment and the standard specific heat capacity of the air in the heat dissipation hole 96 are obtained; the theoretical heat dissipation power of the cable is calculated based on the real-time current and the reference resistivity; and the predicted heat dissipation temperature is calculated by combining the real-time air supply volume and the standard specific heat capacity of the air supply component 10.

[0041] Assuming no leakage current and normal imbalance in the circuit, the theoretical heating power is calculated using the effective heating current. Considering that the resistivity change of the bent section of the cable during long-term service includes two parts: a normal component that changes with temperature and a permanent increase due to aging, to use only the resistance under healthy conditions as a reference when predicting temperature rise, the initial resistance stored in the parameter table (obtained through short-time low-current testing during equipment commissioning, or set according to national standard values ​​when cable specifications are known), rather than a real-time calculated resistance, is used. The predicted temperature rise is based on the heat exchange equation, and the specific calculation formula is as follows:

[0042] In the formula, Theoretical heating power, The reference resistor is for the length of the cable inside clamp 9. As weight, Real-time temperature at the air inlet This is the reference temperature.

[0043] Assuming a quasi-steady-state heat exchange process occurs within clamp 9, the heat carried away by the airflow should equal the heat generated:

[0044] In the formula To predict heat dissipation temperature, The heat exchange efficiency factor. air density, For air supply volume, This refers to the specific heat capacity of air at constant pressure.

[0045] By comparing the predicted and real-time heat dissipation temperatures, and calculating the ratio of the measured temperature difference to the predicted temperature, the aging degree of the cable is quantified. To eliminate interference caused by instantaneous load fluctuations or power grid surges, an aging characteristic coefficient is obtained after moving average processing. The specific quantification formula is as follows:

[0046] In the formula, For window length, it is recommended to set it to 5-10 minutes. For real-time heat dissipation temperature, To predict heat dissipation temperature.

[0047] When the aging level reaches the threshold, a local audible and visual alarm is triggered, and a graded early warning signal is sent to the external monitoring center via the wireless communication module. The early warning level is proportional to the aging level.

[0048] This embodiment is based on the aging characteristic coefficient. Determine the cable status; in specific implementation, according to... The size of the value determines the corresponding status level of the cable, which can be set as follows: when If the area is determined to be in the normal fluctuation range, it will run silently and record the baseline; when If the area is identified as an early warning observation zone, the system will automatically increase the fan power; when If the area is identified as an accelerated aging zone, a maintenance recommendation signal is sent to the monitoring center; when If the value is greater than 1.6, it is determined to be a critical danger zone, triggering a local audible and visual alarm, and initiating forced cooling or remote tripping protection.

[0049] The cable bend below the four terminals in the metering chamber bears the highest heat load, the greatest residual mechanical stress, and the worst heat dissipation conditions. It is the weakest link in the entire circuit. However, traditional inspections cannot reach this hidden location, and the ambient temperature sensor cannot distinguish between normal load temperature rise and abnormal heating caused by aging.

[0050] like Figure 8 As shown, in this embodiment, during operation, the live and neutral wire currents are first obtained through dual current transformers. After confirming no leakage current, the equivalent heating current is calculated, and the pre-stored initial resistance is called. The resistance is corrected by combining the measured inlet and outlet air temperatures to obtain the theoretical heating power. Then, the expected temperature rise that can fluctuate with the load is calculated. The actual temperature rise is directly given by the inlet and outlet air temperature sensors, thus achieving effective quantification that is only sensitive to the increase in resistance. This embodiment uses a sliding window to average the temperature rise ratio to eliminate instantaneous disturbances and divides it into four levels according to the ratio range: silent operation and recording the baseline when healthy; automatic increase of fan power to delay aging when entering the early warning observation zone; push of maintenance signal to the monitoring center when entering the aging acceleration zone; and triggering local audible and visual alarms, forced cooling, or remote trip protection when entering the critical danger zone, forming a graded response mechanism. At the same time, the closed loop greatly reduces dust intrusion, meets the usage requirements of the metering box, and prevents external dust from entering, providing a practical and feasible technical path for preventive maintenance of the power distribution network.

[0051] Example 2

[0052] This embodiment further describes the structure of the air supply assembly 10 and the heat dissipation window 15 based on embodiment 1. In embodiment 1, the incoming line chamber 3, the control room 1, and the metering room 4 can be equipped with separate heat dissipation windows 15 for natural heat dissipation.

[0053] Based on this, such as Figure 3 As shown, in this embodiment, the air outlet of the air supply assembly 10 is divided into a first channel and a second channel. The first channel is connected to the air inlet pipe 7 of the wire clamp 9 and is used to supply cooling air to the heat dissipation hole 96 to meet the airflow circuit required for quantitative assessment of cable aging. The second channel is connected to the inside of the cable inlet chamber 3 and is used to blow away the surface of devices such as terminals to reduce the ambient temperature of the cable inlet chamber. The flow distribution between the two channels can be adjusted according to actual needs. When the degree of aging is high, the cooling capacity of the first channel can be prioritized.

[0054] In a further embodiment, a heat exchange chamber may be provided on the rear side of the component, the air inlet pipe 7 may branch off and pass through the heat exchange chamber before entering the second outlet pipe, and finally the air is cooled and refluxed in the heat dissipation chamber 5.

[0055] In addition, both the air inlet chamber 2 and the cable inlet chamber 3 are equipped with semi-enclosed heat dissipation windows 15 on their sides. During implementation, to avoid interference, a baffle plate 16 is installed inside the air inlet chamber 2 to prevent backflowing gas from affecting the air intake of the heat dissipation window 15. This heat dissipation window 15 has only a horizontal opening at the bottom, with a dust filter installed inside the opening. When the fan is running, outside air is drawn in through the lower opening; large dust particles are difficult to enter due to gravity, while fine dust particles are intercepted by the dust filter. When the fan stops, airflow exchange essentially ceases. This design effectively reduces dust accumulation inside the enclosure while ensuring ventilation and heat dissipation, providing a clean and stable working environment for the temperature sensor and electrical components.

[0056] Example 3

[0057] like Figures 4 to 7 As shown, the wire clamp 9 includes a first card holder 91, a second card holder 92, and a third card holder 93. A first slot and a second slot are respectively formed on the opposite surfaces of the first card holder 91 and the second card holder 92. When they are joined together, they form a first wire groove group 94. A heat-conducting layer is provided on the inner wall of the first wire groove group 94 to facilitate heat dissipation to the heat dissipation hole 96. A third slot and a fourth slot are respectively formed on the opposite surfaces of the second card holder 92 and the third card holder 93. When they are joined together, they form a second wire groove group 95.

[0058] like Figure 5 As shown, both the first cable tray group 94 and the second cable tray group 95 are provided with cable outlet holes 97 for cable lead-out. Each cable tray has a separate cable outlet hole 97. The lower cable outlet hole 97 passes through the upper cable tray to allow the cable to be led out and connected to the meter.

[0059] like Figure 4As shown, through-holes 96 are provided on the outer periphery of the first and second slots. These through-holes 96 are arranged on both sides of the cable outlet 97, avoiding the position of the cable outlet 97, to ensure that the airflow channel does not interfere with the cable outlet 97. A conduit 98 is provided on one side of the first cable tray group 94, which passes through the air inlet pipe 7. This conduit 98 is used to guide the cooling air introduced by the air inlet pipe 7 directly to the through-holes 96, while preventing the airflow from entering the interior of the first cable tray group 94 and directly contacting the cable, thereby preventing dust or moisture from adhering to the cable surface.

[0060] like Figure 7 As shown, a protective plate 99 is also fastened to the outside of the wire clamp 9. The protective plate 99 is injection molded from insulating material, and its inner contour matches the shape of the wire clamp 9. It is fixedly connected to the wire clamp 9 by clips or screws. The protective plate 99 tightens the first card holder 91, the second card holder 92, and the third card holder 93 from the outside, forming an integrated constraint. This effectively suppresses the relative displacement between the card holders caused by long-term vibration or thermal expansion and contraction, thereby ensuring that the heat dissipation holes 96 are always precisely aligned, preventing loose air leakage at the air duct interface, and significantly improving the overall rigidity and long-term reliability of the wire clamp 9.

[0061] In this embodiment, the first cable tray group 94 between the first card holder 91 and the second card holder 92 is used to hold the live wire and the neutral wire. These two types of cables carry the load current and generate significant heat during operation due to the Joule effect. Therefore, it is necessary to set through heat dissipation holes 96 on the outer periphery of the tray and connect them to the air inlet pipe 7 and the air outlet pipe 11 to remove the heat through forced convection, while providing the necessary airflow loop for quantitative aging assessment. The second cable tray group 95 between the second card holder 92 and the third card holder 93 is used to hold the ground wire and the communication line. The ground wire has almost no current flowing through it during normal operation, and the communication line transmits weak electrical signals. Both generate very little heat, and the heat dissipation requirements can be met by natural convection and heat conduction. Therefore, no heat dissipation holes 96 are set on the outer periphery of this cable tray group, and it is not necessary to connect it to the air duct.

[0062] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A layered wiring type intelligent metering box, characterized in that: include The cable clamp is fixed inside the box to hold the cable and has through-holes for heat dissipation. The air inlet duct is fixed to one side of the clamp, and its internal air inlet channel is connected to one end of the heat dissipation hole; the inlet of the air inlet duct is connected to the air supply component. The air outlet duct is fixed on the other side of the clamp. Its internal air outlet channel is connected to the other end of the heat dissipation hole. The outlet of the air inlet duct is connected to the heat dissipation chamber, and heat dissipation fins are installed in the heat dissipation chamber. The first temperature sensor and the second temperature sensor are respectively installed on the air inlet side of the air inlet pipe and the air outlet side of the air outlet pipe, and are used to obtain the air inlet temperature and air outlet temperature of the cable. Calculate the difference between the inlet and outlet air temperatures to obtain the real-time heat dissipation temperature of the cable; Current transformers are used to obtain the real-time current of cables, predict the heat dissipation of cables based on the real-time current, obtain the predicted heat dissipation temperature based on the predicted heat dissipation, and compare the predicted heat dissipation temperature with the real-time heat dissipation temperature to determine the degree of aging of cables.

2. The layered wiring intelligent metering box according to claim 1, characterized in that: The housing is provided with an air inlet chamber and a heat dissipation chamber. The air inlet chamber is equipped with an air supply component, and the heat dissipation chamber is connected to the air outlet pipe and is provided with heat dissipation fins. The heat dissipation chamber is connected to the air inlet chamber through a return pipe.

3. The layered wiring intelligent metering box according to claim 2, characterized in that: The air supply component is equipped with a power adjustment module, which is connected in communication with the monitoring results of the aging degree. When the aging degree is detected to exceed a preset threshold, the air supply volume of the air supply component is increased.

4. The layered wiring intelligent metering box according to claim 2, characterized in that: The air supply assembly is connected to a first channel and a second channel. The first channel is connected to the air inlet pipe, and the second channel is connected to the inlet chamber.

5. The layered wiring intelligent metering box according to claim 4, characterized in that: Both the air inlet chamber and the cable inlet chamber are equipped with heat dissipation windows on their sides. The heat dissipation windows have a semi-enclosed structure with an opening at the bottom and a dustproof net inside.

6. The layered wiring type intelligent metering box according to claim 1, characterized in that: When the aging level reaches a threshold, a local audible and visual alarm is triggered, and a graded early warning signal is sent to an external monitoring center via a wireless communication module. The early warning level is proportional to the aging level.

7. The layered wiring type intelligent metering box according to claim 1, characterized in that: The wire clamp includes a first card holder, a second card holder, and a third card holder; the opposite surfaces of the first card holder and the second card holder are respectively provided with a first slot and a second slot, and the opposite surfaces of the second card holder and the third card holder are provided with a third slot and a fourth slot. The first slot and the second slot are joined together to form a first wire groove group, and heat dissipation holes are provided on the outer periphery of the first slot and the second slot. The third slot and the fourth slot are joined together to form a second wire groove group. The first wire groove group and the second wire groove group are provided with wire outlet holes, and a wire conduit through an air inlet pipe is provided on one side of the first wire groove group.

8. The layered wiring type intelligent metering box according to claim 7, characterized in that: It also includes a protective plate, which is fastened to the outside of the clamp.

9. The layered wiring intelligent metering box according to claim 1, characterized in that: The current transformer includes a first transformer and a second transformer, which respectively collect the live wire current and the neutral wire current; and obtain the real-time current of the cable based on the neutral wire current and the live wire current.

10. The layered wiring type intelligent metering box according to claim 1, characterized in that: Obtain the reference resistivity of the cable in the clamp under the current environment and the standard specific heat capacity of the air in the heat dissipation hole; calculate the theoretical heat generation power of the cable based on the real-time current and reference resistivity; calculate the predicted heat dissipation temperature by combining the real-time air volume of the air supply component and the standard specific heat capacity; obtain the aging characteristic coefficient by calculating the ratio of the measured heat dissipation temperature difference to the predicted heat dissipation temperature and processing it by moving average; and determine the condition of the cable based on the aging characteristic coefficient.

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