Anti-condensation device for grounding box in tunnel and grounding box

Abstract

The present application relates to the technical field of earthing boxes, and discloses an anti-condensation device for an earthing box in a tunnel and an earthing box, including: a heater for evaporating the condensed water in the earthing box; a power taking unit configured to obtain the induced voltage of the cable line in the tunnel and supply power to the heater when the induced voltage is sufficient; a storage battery configured to supply power to the heater when the induced voltage is insufficient; a control unit configured to control at least one of the power taking unit and the storage battery to operate when the temperature inside the earthing box is lower than a preset temperature, and control the power taking unit to charge the storage battery; the control unit is configured to determine the standard heating power of the heater, adjust the standard heating power to obtain a target heating power, and make the heater work at the target heating power. The present application takes power through the induced voltage of the cable line to supply power to the heater, thereby reducing the heating power consumption and achieving long-term endurance of the heater.

Description

Technical Field

[0001] The present application relates to the technical field of grounding boxes, and in particular, to a condensate prevention device and a grounding box for a grounding box in a tunnel. Background Art

[0002] With the increasing requirements for the reliability of power transmission and supply, the proportion of high-voltage cables in urban power supply lines is continuously increasing, and the advantages of cable power transmission in tunnels are becoming more and more obvious. Cable tunnels are generally located dozens of meters deep underground, with a large temperature difference from the outside world. In high-temperature seasons or rainy weather, condensate water and water droplets are likely to appear in the grounding boxes in the tunnel, which may easily cause risks such as corrosion of bolt connection parts and insulation aging due to condensate water, greatly affecting the safe and stable operation of cable line tests and posing great potential safety hazards.

[0003] In related technologies, the commonly used cabinet dehumidification methods mainly include forced ventilation method, desiccant method, and electric heating method, etc. The forced ventilation method reduces the humidity in the cabinet by forming convection with dry air outside, but it is not suitable for the situation where the environmental humidity in the cable tunnel is also high. The desiccant method achieves dehumidification by hanging desiccants in the cabinet and using the desiccants to absorb moisture, but the desiccants need to be replaced manually regularly, and the maintenance cost is relatively high. In addition, the grounding boxes in the tunnel are deep underground, so the difficulty of ventilation and the difficulty of replacing desiccants are both very large. The electric heating method installs heaters in the cabinet, and the local temperature in the cabinet rises by heating, thereby reducing the relative humidity in the cabinet. However, since the heaters are installed in the grounding boxes in the tunnel, not only is it difficult to replace the heater batteries, but also the power consumption of the heaters is relatively large, resulting in the problem that the heaters are difficult to last for a long time. Summary of the Invention

[0004] The present application provides a condensate prevention device and a grounding box for a grounding box in a tunnel, which solve the technical problems that the current heaters used for condensate prevention have high power consumption and are inconvenient to replace batteries in the tunnel, resulting in difficulty in lasting for a long time and being difficult to be applicable to the grounding boxes in the tunnel. The present application obtains power for supplying the heaters by taking power from the induced voltage of the cable line, and adaptively adjusts the heating power of the heaters, thereby reducing the heating power consumption and realizing the long-term operation of the heaters.

[0005] To achieve the above object, the main technical solutions adopted in the present application include:

[0006] In the first aspect, an embodiment of the present application provides a condensate prevention device for a grounding box in a tunnel, and the condensate prevention device includes:

[0007] A heater, which is arranged inside the side plate of the box body of the grounding box, and the heater is used to heat the surrounding space of the grounding copper bar in the grounding box to evaporate the condensed water in the grounding box;

[0008] A power taking unit, which is arranged outside the side plate of the box body, and the power taking unit is configured to obtain the induced voltage of the cable line in the tunnel and supply power to the heater when the induced voltage is sufficient;

[0009] A storage battery, which is configured to supply power to the heater when the induced voltage is insufficient;

[0010] A control unit, which is configured to control at least one of the power taking unit and the storage battery to work when the temperature inside the grounding box is lower than a preset temperature, and control the power taking unit to charge the storage battery when the temperature inside the grounding box is not lower than the preset temperature;

[0011] The control unit is configured to determine the standard heating power of the heater according to the temperature inside the box and the historical load current of the cable line, and adjust the standard heating power according to the real-time load current of the cable line to obtain the target heating power, so that the heater works at the target heating power.

[0012] The anti-condensation water device proposed in the embodiment of the present application, by setting a heater, a power taking unit, a storage battery and a control unit in the grounding box in the tunnel, uses the power taking unit to take the induced voltage of the cable line as the main power supply of the heater, takes the storage battery as the backup power supply of the heater, and adjusts the heating power of the heater adaptively according to the temperature inside the box and the load current of the cable line through the control unit, so as to dynamically control the heater to maintain the temperature inside the box at the desired temperature at the heating power suitable for the temperature inside the box. Therefore, the embodiment of the present application can use the collaborative work of the power taking unit and the storage battery to ensure that the heater meets the demand for evaporating condensed water, and also adaptively adjusts the heating power of the heater to avoid waste of power supply energy caused by excessive heating of the temperature inside the box by the heater, greatly reducing unnecessary heating energy consumption, so as to ensure that the heater can last for a long time with the energy provided by the induced voltage of the cable line, and further effectively avoid grounding box failures caused by condensed water.

[0013] Optionally, in some embodiments of the present application, the control unit is further configured to:

[0014] Determine that the induced voltage is sufficient when the real-time load current of the cable line is greater than or equal to a first threshold;

[0015] When the real-time load current of the cable line is less than the first threshold, it is determined that the induced voltage is insufficient.

[0016] The embodiment of the present application realizes the real-time monitoring of the induced voltage according to the magnitude of the real-time load current of the cable line, so as to determine whether the induced voltage is sufficient, and further enables the control unit to timely obtain the power supply capacity of the cable line, so as to achieve precise dynamic control of the coordinated operation of the power-taking unit and the storage battery.

[0017] Optionally, in some embodiments of the present application, the control unit is further configured to:

[0018] When the historical load current of the cable line is greater than or equal to the first threshold, determine the surface temperature of the grounding copper bar according to the historical load current of the cable line, and perform a thermal field simulation according to the current temperature inside the grounding box, the surface temperature of the grounding copper bar, and different heating powers, so as to determine the standard heating power according to the simulation results;

[0019] When the historical load current of the cable line is less than the first threshold, perform a thermal field simulation according to the current temperature inside the grounding box and different heating powers, so as to determine the standard heating power according to the simulation results;

[0020] Wherein, the standard heating power is used to increase the temperature inside the box and maintain it at the desired temperature.

[0021] The embodiment of the present application comprehensively analyzes the temperature inside the box, the surface temperature of the grounding copper bar, and the load current of the cable line, so as to determine the standard heating power by using the thermal field simulation results under different heating powers. By introducing the factor of the surface temperature of the grounding copper bar into the thermal field simulation, the embodiment of the present application makes full use of the thermal effect generated by the grounding copper bar itself due to its own current flow to assist in evaporating and condensing water, so that the thermal field simulation effect is more accurate, and it is ensured that the standard heating power determined according to the simulation results can achieve a more precise and economical power supply strategy, reduce unnecessary consumption and waste of the induced electric energy and the electric energy of the storage battery by the heater, and provide an accurate data basis for subsequent adaptive adjustment to obtain the target heating power, which is beneficial to improving the accuracy of the adaptive adjustment.

[0022] Optionally, in some embodiments of the present application, when the historical load current of the cable line is greater than or equal to the first threshold, the control unit is further configured to:

[0023] Determine the change trend of the real-time load current according to the real-time load current and the historical load current, and obtain the load current fluctuation amount;

[0024] When the load current fluctuation amount is greater than or equal to the second threshold, if the real-time load current shows an upward trend, a first adjustment coefficient is determined according to the difference between the load current fluctuation amount and the second threshold, and the standard heating power is reduced according to the first adjustment coefficient to obtain the target heating power; if the real-time load current shows a downward trend, a second adjustment coefficient is determined according to the difference between the load current fluctuation amount and the second threshold, and the standard heating power is increased according to the second adjustment coefficient to obtain the target heating power;

[0025] And when the load current fluctuation amount is less than the second threshold, the standard heating power is used as the target heating power.

[0026] By adaptively adjusting the first threshold and the second threshold on the basis of the standard heating power in the embodiments of the present application, the heating power of the heater can be accurately controlled according to the different heat effects generated by the grounding copper bar under different load current conditions, so that the target heating power obtained through adaptive adjustment can not only more accurately meet the heat demand for condensate evaporation under different load current conditions, but also save power consumption, keep the grounding box stable and dry while maximizing power saving and reducing unnecessary energy waste, so as to avoid the risk of excessive energy consumption of the power taking unit and the battery, and thus is beneficial to improving the long-term endurance ability of the heater.

[0027] Optionally, in some embodiments of the present application, the power taking unit includes:

[0028] A power taking coil configured to generate the induced voltage according to the operating magnetic field of the cable line, wherein the plane of the power taking coil is perpendicular to the cable line, and the cable line passes through the center point of the plane of the coil;

[0029] A rectification and voltage stabilization module, the input end of the rectification and voltage stabilization module is connected to the power taking coil, and the rectification and voltage stabilization module is configured to perform voltage stabilization processing on the induced voltage and output a first voltage signal;

[0030] A DC / DC conversion module configured to perform voltage conversion on the first voltage signal and output a second voltage signal to supply power to the heater according to the second voltage signal.

[0031] In the embodiments of the present application, an induction voltage of a cable line is obtained through a power-taking coil, and the induction voltage is regulated and voltage-converted through a rectification and voltage regulation module and a DC / DC conversion module, so as to effectively convert the induction voltage generated by the magnetic field during the operation of the cable into a power source that can directly drive a heater, thereby providing a continuous and relatively independent power supply for the heater. Compared with the traditional method of using a battery to supply power to the heater, the power supply using the power-taking unit can directly obtain electric energy from the operating magnetic field of the tunnel cable, without the need to frequently enter the tunnel to open the grounding box for battery replacement, which is beneficial to improving the endurance of the heater, reducing the manpower maintenance cost, improving the power utilization rate, and having a simple circuit structure and low cost, thus greatly reducing the construction difficulty.

[0032] Optionally, in some embodiments of the present application, the control unit includes:

[0033] A first controllable switch, which is connected between the DC / DC conversion module and the heater;

[0034] A control chip, a first output end of the control chip is connected to a control end of the first controllable switch, and the control chip is configured to control the first controllable switch to close when the temperature inside the grounding box is lower than a preset temperature.

[0035] Optionally, in some embodiments of the present application, the control unit further includes:

[0036] A second controllable switch, which is connected between the storage battery and the heater;

[0037] A first input end of the control chip is connected to an output end of the DC / DC conversion module, a second output end of the control chip is connected to a control end of the second controllable switch, and the control chip is further configured to control the second controllable switch to close when a second voltage signal output by the DC / DC conversion module is lower than a first preset voltage and the temperature inside the grounding box is lower than the preset temperature, so as to supply power to the heater through the storage battery.

[0038] In the embodiments of the present application, by setting a storage battery, it is ensured that the heater can still be effectively powered when the induction voltage of the cable line is insufficient, guaranteeing the continuous operation of the heater under special working conditions. Thus, through the dynamic switching between the power-taking unit and the storage battery, while improving the reliability of the anti-condensation device, the reasonable distribution and flexible utilization of electric energy are realized, and the stability of the anti-condensation performance is ensured to the greatest extent.

[0039] Optionally, in some embodiments of the present application, the control unit further includes:

[0040] The second input terminal of the control chip is connected to the output terminal of the rectification and voltage regulation module, and the third output terminal of the control chip is connected to the control terminal of the rectification and voltage regulation module. The control chip is further configured to compare the first voltage signal output by the rectification and voltage regulation module with a second preset voltage, and generate a control signal according to the comparison result and send it to the control terminal of the rectification and voltage regulation module.

[0041] In the embodiment of the present application, the control chip compares the first voltage signal corresponding to the induced voltage with the second preset voltage, and controls the rectification and voltage regulation module to adjust according to the comparison result, so as to realize the voltage stabilization process of the first voltage signal, thereby improving the power supply quality of the power extraction unit.

[0042] In a second aspect, an embodiment of the present application provides a grounding box, which includes:

[0043] A grounding copper bar;

[0044] A box body;

[0045] And the anti-condensation device according to the above embodiment, wherein the anti-condensation device is arranged inside the grounding box.

[0046] The grounding box proposed in the embodiment of the present application maintains the temperature inside the box at the desired temperature through the anti-condensation device arranged inside the grounding box and has a long battery life. Therefore, while ensuring to meet the demand for evaporating condensed water, it also adaptively adjusts the heating power of the anti-condensation device to avoid excessive heating of the temperature inside the box by the anti-condensation device, resulting in waste of power supply energy, greatly reducing unnecessary heating energy consumption, ensuring that the anti-condensation device can have a long battery life, and effectively avoiding grounding box failures caused by condensed water.

[0047] Optionally, the box body includes a box cover and a box bottom, and the box cover and the box bottom are connected by hinges and bolts. The grounding copper bar is fixed on the box bottom through a metal fixing member;

[0048] Wherein, a one-way breathing valve is arranged on the box cover, and the one-way breathing valve is used to discharge the water vapor converted from the condensed water.

[0049] In the embodiment of the present application, through the connection structure between the box cover and the box bottom, sufficient operating space can be provided for the operation inside the grounding box, which is beneficial to the maintenance work and improves the work efficiency. In addition, in the embodiment of the present application, by setting the one-way breathing valve on the box cover, the function of restricting air convection while maintaining the air pressure balance inside and outside the grounding box is realized, thereby effectively improving the anti-condensation effect. Description of the Drawings

[0050] To more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0051] Figure 1 Schematic structural diagram of a condensate prevention device for a grounding box in a tunnel proposed in an embodiment of the present application;

[0052] Figure 2 Schematic diagram of thermal field simulation proposed in an embodiment of the present application;

[0053] Figure 3 Schematic diagram of the power supply principle of the power taking unit and the battery unit proposed in an embodiment of the present application;

[0054] Figure 4 Schematic sectional view of a grounding box proposed in an embodiment of the present application;

[0055] Figure 5 Schematic diagram of the box body structure of a grounding box proposed in an embodiment of the present application;

[0056] Figure 6 Schematic structural diagram of a condensate prevention device for a grounding box in a tunnel proposed in another embodiment of the present application. Specific embodiments

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0058] With the increasing requirements for the reliability of power transmission and supply, the proportion of high-voltage cables in urban power supply lines is constantly increasing, and the advantages of cable power transmission in tunnels are becoming more and more obvious. The grounding box in the tunnel is an important device used in the cable power transmission system in the tunnel, which can effectively guide the current of the cable to the ground, thereby providing grounding protection for the cable, preventing accidents such as electrical fires and electric shocks caused by current leakage, and ensuring the safe operation of the power system. The cable tunnel is generally located dozens of meters deep underground, with a large temperature difference from the outside world. In the high-temperature season or rainy weather, condensation water, water droplets, etc. are likely to appear in the grounding box in the tunnel, which is likely to cause risks such as corrosion of bolt connection parts and insulation aging due to condensation water, which greatly affects the safe and stable operation of cable line tests and poses a great safety hazard.

[0059] In some application scenarios, related technologies generally adopt common cabinet dehumidification methods such as forced ventilation method, desiccant method, semiconductor condensation dehumidification method, and electric heating method. The forced ventilation method reduces the humidity in the cabinet by forming convection with dry air outside, but it is not applicable to the situation where the environmental humidity in the cable tunnel is also relatively high. The desiccant method is to hang desiccants in the cabinet and use the desiccants to absorb moisture to achieve the purpose of dehumidification. However, the desiccants need to be replaced manually regularly, and the maintenance cost is relatively high. In addition, the grounding box in the tunnel is deep underground, so the ventilation difficulty and the difficulty of replacing desiccants are both very large. The semiconductor condensation dehumidification method is a dehumidification method that uses a semiconductor condensation device to quickly condense the water molecules contained in the air in the cabinet space into liquid water and discharge it from the cabinet through a diversion pipe. Its advantage is rapid condensation, but the effect is not obvious in an environment with low temperature and high humidity, and the construction difficulty and cost of setting up a drainage device in the tunnel are relatively high.

[0060] In another application scenario, the electric heating method is used to dehumidify the grounding box. The electric heating method is to install a heater in the box body, and by heating, the local temperature in the cabinet rises, thereby reducing the relative humidity in the box. However, the grounding boxes in the tunnel are widely distributed along the cable line, and it is difficult and costly to lay additional power supply lines in the tunnel to provide electrical energy for the heating equipment. In addition, since the heater is installed in the grounding box in the tunnel, not only is it difficult to replace the heater battery, but also the humidity in the tunnel is relatively high, and continuous heating is usually required to keep the air in the grounding box dry. Therefore, the power consumption of the heater is relatively large, and methods such as solar power generation are not applicable to the tunnel environment. Therefore, relying solely on battery power supply cannot meet the requirements of the heating system for long-term stable operation, resulting in the problem that the heater is difficult to have a long battery life.

[0061] According to the embodiments of the present application, a condensation water prevention device 10 for a grounding box in a tunnel is provided, which can be used for a grounding box in a tunnel, and can also be used on power equipment boxes such as distribution boxes and control boxes, such as Figure 1As shown, the anti-condensation device 10 includes a heater 11, a power taking unit 12, a storage battery 13, and a control unit 14.

[0062] Among them, the heater 11 is arranged on the inner side of the side plate of the grounding box, and the heater 11 is used to heat the space around the grounding copper bar in the grounding box to evaporate the condensed water in the grounding box; the power taking unit 12 is arranged on the outer side of the side plate of the box body, and the power taking unit 12 is configured to obtain the induced voltage of the cable line 20 in the tunnel and supply power to the heater 11 when the induced voltage is sufficient; the storage battery 13 is configured to supply power to the heater 11 when the induced voltage is insufficient; the control unit 14 is configured to control at least one of the power taking unit 12 and the storage battery 13 to work when the temperature inside the grounding box is lower than the preset temperature, and control the power taking unit 12 to charge the storage battery 13 when the temperature inside the grounding box is not lower than the preset temperature.

[0063] Specifically, the heater 11 is installed on the inner side of the side plate of the grounding box to heat and evaporate the condensed water in the space around the grounding copper bar, while the power taking unit 12 is installed on the outside of the box body to obtain sufficient induced voltage from the cable line outside the grounding box to supply power to the heater 11 and serve as the main power source for the operation of the heater 11. The storage battery 13 can be installed inside the grounding box and serve as the backup power source for the heater 11.

[0064] When the temperature inside the grounding box is lower than the preset temperature, the air humidity in the tunnel is relatively high and it is easy to generate condensed water. Therefore, at least one of the power taking unit 12 and the storage battery 13 is controlled to work. Among them, the power taking unit 12 is preferably used to supply power to the heater 11, and the storage battery 13 is used to supply power when the induced voltage is insufficient, so as to continuously and stably evaporate the condensed water and maintain the dry state inside the box. When the temperature inside the grounding box is not lower than the preset temperature, the higher temperature will reduce the generation of condensed water. Therefore, there is no need to heat the inside of the box additionally. At this time, the induced voltage obtained by the power taking unit 12 is used to charge the storage battery 13 to make full use of the induced voltage generated by the operating magnetic field of the cable and improve the power utilization efficiency.

[0065] Furthermore, the control unit 14 is configured to determine the target heating power of the heater 11 according to the temperature inside the box and the historical load current of the cable line 20, and adaptively adjust the standard heating power according to the real-time load current of the cable line 20 to obtain the target heating power, so that the heater 11 operates at the target heating power.

[0066] Since the grounding copper bar has a certain surface temperature due to its own current-carrying capacity, and the greater the real-time load current of the cable line 20, the greater the current flowing through the grounding copper bar, which in turn causes the surface temperature to increase with the increase of the load current. Considering that the surface temperature of the grounding copper bar will produce a certain thermal effect on the surrounding space, it can assist in evaporating condensed water to a certain extent. In addition, the energy of the power-taking unit 12 and the storage battery 13 both come from the induced voltage of the cable line 20, and their energy supply is limited. Therefore, if the surface temperature of the grounding copper bar is high enough, the power of the heater 11 can be appropriately reduced, which can save the energy supply of the power-taking unit 12 and the storage battery 13, and further improve the long-term endurance ability of the heater 11.

[0067] Therefore, in the embodiment of the present application, the standard heating power is determined according to the box temperature and the historical load current of the cable line 20, and the standard heating power is adaptively adjusted according to the real-time load current of the cable line 20, so as to determine the heating power that can not only prevent condensed water but also save electric energy.

[0068] The anti-condensation device 10 proposed in the embodiment of the present application is provided with a heater 11, a power-taking unit 12, a storage battery 13 and a control unit 14 in the grounding box in the tunnel. The power-taking unit 12 uses the induced voltage of the cable line 20 as the main power supply of the heater 11, and the storage battery 13 is used as the backup power supply of the heater 11. The control unit 14 adaptively adjusts the heating power of the heater 11 according to the box temperature and the load current of the cable line 20 to dynamically control the heater 11 to maintain the box temperature at the desired temperature at the heating power suitable for the box temperature. Therefore, in the embodiment of the present application, the coordinated work of the power-taking unit 12 and the storage battery 13 can ensure that the heater 11 meets the demand for evaporating condensed water, and at the same time, the heating power of the heater 11 is adaptively adjusted to avoid waste of power supply energy caused by excessive heating of the box temperature by the heater 11, greatly reducing unnecessary heating energy consumption, so as to ensure that the heater 11 can have a long-term endurance under the energy provided by the induced voltage of the cable line 20, and further effectively avoid grounding box failures caused by condensed water.

[0069] In some embodiments of the present application, the control unit 14 is further configured to:

[0070] When the real-time load current of the cable line 20 is greater than or equal to the first threshold, it is determined that the induced voltage is sufficient;

[0071] When the real-time load current of the cable line 20 is less than the first threshold, it is determined that the induced voltage is insufficient.

[0072] It should be noted that in the embodiments of the present application, the first threshold is determined according to the minimum heating power of the heater 11. That is to say, only when the real-time load current of the cable line 20 reaches at least the first threshold, the corresponding induced voltage can support the operation of the heater 11. When the cable line 20 passes through the load current, a magnetic field will be generated around it, enabling the power-taking unit 12 to generate an induced voltage based on this magnetic field. Among them, the greater the real-time load current, the greater the magnetic field intensity around, and the induced voltage generated in the power-taking unit 12 will also increase accordingly. Therefore, the real-time load current of the cable line 20 is positively correlated with the induced voltage.

[0073] Therefore, in special cases such as when the cable line 20 is powered off or the voltage is too small, the real-time load current is very small, resulting in the induced voltage dropping to a level insufficient to support the operation of the heater 11. At this time, if the temperature inside the grounding box is lower than the preset temperature, the battery 13 needs to be used to supply power to the heater 11.

[0074] The embodiments of the present application realize real-time monitoring of the induced voltage according to the magnitude of the load current of the cable line 20, thereby determining whether the induced voltage is sufficient, and further enabling the control unit 14 to timely obtain the power supply capacity of the cable line 20, so as to achieve precise dynamic control of the coordinated operation of the power-taking unit 12 and the battery 13.

[0075] In some embodiments of the present application, the control unit 14 is further configured to: when the historical load current of the cable line is greater than or equal to the first threshold, determine the surface temperature of the grounding copper bar according to the historical load current of the cable line, and perform a thermal field simulation according to the current temperature inside the grounding box, the surface temperature of the grounding copper bar, and different heating powers, so as to determine the standard heating power according to the simulation results; when the historical load current of the cable line is less than the first threshold, perform a thermal field simulation according to the current temperature inside the grounding box and different heating powers, so as to determine the standard heating power according to the simulation results.

[0076] Among them, the standard heating power is used to increase the temperature inside the box and maintain it at the desired temperature.

[0077] Since when the load current is less than the first threshold, the current flowing through the grounding copper bar is very small, the thermal effect of the grounding copper bar can be ignored. Therefore, in the embodiments of the present application, only when the historical load current is greater than or equal to the first threshold, it is necessary to consider the influence of the surface temperature of the grounding copper bar on the temperature inside the box.

[0078] It should be noted that during the operation of the heater 11, the above control unit 14 adjusts the target heating power according to a preset period. Among them, the historical load current in the embodiments of the present application can be the load current of the cable line 20 at the end of the previous period, or the average load current of the cable line 20 within the previous period. In addition, the embodiments of the present application determine the historical grounding current corresponding to the historical load current flowing through the grounding copper bar, and determine the surface temperature of the grounding copper bar according to the joule heat distribution generated by the historical grounding current.

[0079] In some embodiments of the present application, a three-dimensional model of the grounding box and the heating system is established using the heat transfer analysis module in COMSOL software. For example, the size of the grounding box is set to 30 cm × 20 cm × 50 cm, the inside of the box is an air fluid domain, two heaters 11 are configured, the heaters 11 are installed on the side of the grounding box according to the spatial layout of the original equipment in the grounding box, and the spacing distance between the grounding copper bar and the side of the grounding box where the heater 11 is installed is set, and the surface temperature of the grounding copper bar is set to the surface temperature of the grounding copper bar corresponding to the historical load current. In addition, it is also necessary to set the geometric structure, thermal conductivity, density, specific heat capacity and other properties of the grounding copper bar in the above three-dimensional model, and set the current temperature inside the box to 25 °C, adjust the heaters 11 to work at different powers and simulate the thermal field distribution at the corresponding powers.

[0080] Figure 2 The thermal field simulation results of the above example are shown, as Figure 2 shown, the surface temperature of the heater 11 reaches 126 °C, which is also the highest temperature inside the grounding box. The temperature around the heater is relatively high. Due to the relatively low temperature outside the box and the relatively fast heat dissipation of the metal shell of the grounding box, the temperature drops rapidly as the distance from the heater increases.

[0081] The embodiments of the present application calculate the average temperature between the heater 11 and the grounding copper bar based on the thermal field simulation results. For example, the calculation results of the average temperature corresponding to the simulation results shown in the above example are shown in Table 1.

[0082] Table 1

[0083]

[0084] As can be seen from Table 1, when the heater 11 in the grounding box runs and reaches stability, the temperature inside the box can be increased and maintained at a certain level. In order to ensure sufficient heating efficiency so that the temperature inside the box is not too low, and at the same time to avoid damage to components due to overheating inside the box, the temperature is not too high, the desired temperature is set to 35 °C to 40 °C. Therefore, it can be obtained that in the case where the current temperature inside the box is 25 °C, the standard heating power corresponding to the historical load current is 30 W.

[0085] In the embodiments of the present application, by comprehensively analyzing the temperature inside the box, the surface temperature of the grounding copper bar, and the load current of the cable line, the standard heating power is determined by using the thermal field simulation results under different heating powers. In the embodiments of the present application, by introducing the factor of the surface temperature of the grounding copper bar into the thermal field simulation, the thermal effect generated by the grounding copper bar due to its own current-carrying is fully utilized to assist in evaporating condensed water, thereby making the thermal field simulation effect more accurate, ensuring that the standard heating power determined according to the simulation results can achieve a more precise and economical energy supply strategy, reducing unnecessary consumption and waste of inductive electric energy and battery electric energy by the heater 11, and providing an accurate data basis for the subsequent adaptive adjustment to obtain the target heating power, which is beneficial to improving the accuracy of the adaptive adjustment.

[0086] In some embodiments of the present application, the control unit 14 is further configured to execute the following adaptive adjustment process, including:

[0087] Step S1, determine the change trend of the real-time load current according to the real-time load current and the historical load current, and obtain the load current fluctuation amount. Among them, if the real-time load current is greater than or equal to the historical load current, it is determined that the real-time load current shows an upward trend; if the real-time load current is less than the historical load current, it is determined that the real-time load current shows a downward trend, and the load current fluctuation amount is the absolute value of the difference between the real-time load current and the historical load current.

[0088] Step S2, when the load current fluctuation amount is greater than or equal to the second threshold, if the real-time load current shows an upward trend, determine the first adjustment coefficient according to the difference between the load current fluctuation amount and the second threshold, and reduce the standard heating power according to the first adjustment coefficient to obtain the target heating power; if the real-time load current shows a downward trend, determine the second adjustment coefficient according to the difference between the load current fluctuation amount and the second threshold, and increase the standard heating power according to the second adjustment coefficient to obtain the target heating power. And when the load current fluctuation amount is less than the second threshold, use the standard heating power as the target heating power.

[0089] Specifically, since the load current of the cable line 20 fluctuates with the change of the load, and then the current flowing through the grounding copper bar will also fluctuate accordingly. When the current flows through the grounding copper bar, heat will be generated due to its resistance, and there is a Joule heat effect. Therefore, the change of the load current will make the surface temperature of the grounding copper bar fluctuate, and the fluctuation amplitude will be very large in the case of load mutation, which will further affect the change of the temperature inside the box. In view of the above fluctuation situation, in the embodiments of the present application, the standard heating power is further precisely adjusted according to the load current fluctuation amount and the second threshold, so as to better save the energy consumption of the power taking unit 12 and the battery 13 while meeting the anti-condensation water demand.

[0090] Among them, when the load current fluctuation amount is greater than or equal to the second threshold, if the load current of the cable line 20 shows an upward trend and the rising amplitude is large, at this time, the surface temperature of the grounding copper bar will increase significantly. If the heater 11 continues to work at the standard heating power determined above, there will be an overheating situation, resulting in waste of electric energy of the power taking unit 12. Therefore, the standard heating power is appropriately reduced according to the first adjustment coefficient to make full use of the thermal effect of the grounding copper bar to assist the evaporation of condensed water. On the contrary, if the load current of the cable line 20 shows a downward trend and the decreasing amplitude is large, at this time, the surface temperature of the grounding copper bar will decrease significantly. If the heater 11 continues to work at the standard heating power determined above, there will be an insufficient heating situation, affecting the anti-condensation effect. It is necessary to appropriately increase the standard heating power to ensure the evaporation of condensed water. Therefore, the standard heating power is appropriately increased according to the second adjustment coefficient above.

[0091] When the load current fluctuation amount is less than the second threshold, it indicates that the change amplitude of the real-time load current is not large, and then the surface temperature change of the grounding copper bar is not large. Therefore, the heater 11 can continue to work at the standard heating power determined above.

[0092] It should be noted that the greater the difference between the load current fluctuation amount and the second threshold, the greater the first adjustment coefficient and the second adjustment coefficient, that is, the load current fluctuation amount is positively correlated with the first adjustment coefficient and the second adjustment coefficient respectively.

[0093] By adaptively adjusting on the basis of the standard heating power by setting the first threshold and the second threshold in the embodiment of the present application, the heating power of the heater can be accurately controlled according to the different thermal effects generated by the grounding copper bar under different load current conditions. The target heating power obtained through adaptive adjustment can not only more accurately meet the thermal requirements for the evaporation of condensed water under different load current conditions, but also save power consumption, keep the grounding box stable and dry while maximizing power saving and reducing unnecessary energy waste, so as to avoid the risk of excessive energy consumption of the power taking unit and the storage battery, and thus is beneficial to improving the long-term endurance ability of the heater.

[0094] Further, in some embodiments of the present application, the control unit 14 is further configured to:

[0095] Determine a pre-trained load current prediction model, and input the historical load current and the real-time load current into the load current prediction model to obtain the predicted load current in the future time period according to the load current prediction model, and determine the predicted average load current in the future time period;

[0096] Compare the predicted average load current with the real-time load current, and optimize one of the first adjustment coefficient and the second adjustment coefficient according to the comparison result.

[0097] Specifically, when the real-time load current shows an upward trend, correspondingly, the surface temperature of the grounding copper bar also shows an upward trend at this time. If the predicted average load current is less than the real-time load current, it indicates that the surface temperature of the grounding copper bar may decrease in the future. Therefore, although the heating power of the heater 11 needs to be reduced at this time, the heating power of the heater 11 may still need to return to a higher level in the future. Thus, in some embodiments of the present application, the first adjustment coefficient is multiplied by a first preset parameter, where the first preset parameter is a positive number less than 1, to reduce the first adjustment coefficient, so as to appropriately reduce the degree of reduction of the standard heating power and respond in advance to the future change trend of the load current. If the predicted average load current is greater than or equal to the real-time load current, it indicates that the surface temperature of the grounding copper bar may still continue to rise in the future. Therefore, the first adjustment coefficient remains unchanged.

[0098] When the real-time load current shows a downward trend, correspondingly, the surface temperature of the grounding copper bar shows a downward trend at this time. If the predicted average load current is greater than or equal to the real-time load current, it indicates that the surface temperature of the grounding copper bar may rise in the future. Therefore, although the heating power of the heater 11 needs to be increased at this time, the heating power of the heater 11 may still need to return to a lower level in the future. Thus, in some embodiments of the present application, the second adjustment coefficient is multiplied by a second preset parameter, where the second preset parameter is a positive number less than 1, to reduce the second adjustment coefficient, so as to appropriately reduce the degree of increase of the standard heating power and respond in advance to the future change trend of the load current. If the predicted average load current is less than the real-time load current, it indicates that the surface temperature of the grounding copper bar may still continue to decrease in the future. Therefore, the second adjustment coefficient remains unchanged.

[0099] In some embodiments of the present application, as Figure 3 shown, the power taking unit 12 includes a power taking coil 121, a rectifying and voltage stabilizing module 122, and a DC / DC conversion module 123.

[0100] Among them, the power taking coil 121 is configured to generate an induced voltage according to the operating magnetic field of the cable. Among them, the coil plane of the power taking coil 121 is perpendicular to the cable line 20, and the cable line 20 passes through the center point of the coil plane;

[0101] The input end of the rectifying and voltage stabilizing module 122 is connected to the power taking coil 121, and the rectifying and voltage stabilizing module 122 is configured to perform voltage stabilization processing on the induced voltage and output a first voltage signal U1;

[0102] The DC / DC conversion module 123 is configured to perform voltage conversion on the first voltage signal U1 and output a second voltage signal U2 to supply power to the heater 11 according to the second voltage signal U2.

[0103] In the embodiment of the present application, the induction voltage of the cable line 20 is obtained through the power-taking coil 121, and the induction voltage is regulated and voltage-converted through the rectification and voltage regulation module 122 and the DC / DC conversion module 123, so that the induction voltage generated by the magnetic field during the operation of the cable can be effectively converted into a power supply that can directly drive the heater 11, thereby providing a continuous and relatively independent power supply for the heater 11. Compared with the traditional method of powering the heater 11 with a battery, powering with the power-taking unit 12 can directly obtain electrical energy from the operating magnetic field of the tunnel cable, without the need to frequently enter the tunnel to open the grounding box for battery replacement, which is beneficial to improving the endurance of the heater 11, reducing both the manual maintenance cost and improving the power utilization rate, and the circuit structure is simple and the cost is low, so the construction difficulty is greatly reduced.

[0104] Specifically, as Figure 3 shown, the cable line 20 is perpendicular to the power-taking coil and passes through the center. An alternating current induction voltage is obtained on the coil, and then a stable second voltage signal U2 is obtained through rectification by the rectification circuit and DC / DC conversion by the DC / DC conversion circuit. The control chip 141 collects the rectified first voltage signal U1 and compares it with the first preset voltage, and adjusts the rectification output by using silicon controlled rectifier (SCR) according to the comparison result, so that the first voltage signal U1 is stabilized within the set range. The first voltage signal U1 is voltage-converted through the DC / DC conversion module 123 and the second voltage signal U2 is output, and the heater 11 is powered by the second voltage signal U2, so that the heater 11 can work at the target heating power.

[0105] Furthermore, the control unit 14 includes a first controllable switch S1, a second controllable switch S2, a third controllable switch S3, and a control chip 141.

[0106] Among them, the first controllable switch S1 is connected between the DC / DC conversion module 123 and the heater 11, the second controllable switch S2 is connected between the battery 13 and the heater 11, and the third controllable switch S3 is connected between the DC / DC conversion module 123 and the battery 13;

[0107] The first output terminal of the control chip 141 is connected to the control terminal of the first controllable switch S1. The control chip 141 is configured to control the first controllable switch S1 to close when the temperature inside the grounding box is lower than a preset temperature. The first input terminal of the control chip 141 is connected to the output terminal of the DC / DC conversion module 123, and the second output terminal of the control chip 141 is connected to the control terminal of the second controllable switch S2. The control chip 141 is further configured to control the second controllable switch S2 to close when the second voltage signal U2 output by the DC / DC conversion module 123 is lower than a first preset voltage and the temperature inside the grounding box is lower than the preset temperature, so as to supply power to the heater 11 through the storage battery 13. The second input terminal of the control chip 141 is connected to the output terminal of the rectification and voltage regulation module 122, and the third output terminal of the control chip 141 is connected to the control terminal of the rectification and voltage regulation module 122. The control chip 141 is further configured to compare the first voltage signal output by the rectification and voltage regulation module 122 with a second preset voltage, and generate a control signal according to the comparison result and send it to the control terminal of the rectification and voltage regulation module 122.

[0108] In the embodiment of the present application, by setting the storage battery 13, it is ensured that the heater 11 can still obtain effective power supply when the induced voltage of the cable line 20 is insufficient, which guarantees the continuous operation of the heater 11 under special working conditions. Thus, through the dynamic switching between the power taking unit 12 and the storage battery 13, while improving the reliability of the anti-condensation device, the reasonable distribution and flexible utilization of electric energy are realized, and the stability of the anti-condensation performance is ensured to the greatest extent.

[0109] In addition, in the embodiment of the present application, the control chip 141 compares the first voltage signal U1 corresponding to the induced voltage with the second preset voltage, and controls the rectification and voltage regulation module 122 to adjust according to the comparison result, so as to realize the voltage stabilization processing of the first voltage signal U1, and further improve the power supply quality of the power taking unit 12.

[0110] Specifically, the control chip 141 collects the temperature inside the grounding box through the temperature sensor. When the temperature inside the box is lower than the set temperature T1, if the second voltage signal U2 output by the DC / DC conversion module 123 is greater than or equal to the first preset voltage, it indicates that the induced voltage is sufficient. Therefore, the first controllable switch S1 is controlled to close to start the heater to heat and increase the local temperature, convert the condensed water into water vapor and discharge it. And when the temperature inside the box reaches the set maximum temperature T2, the first controllable switch S1 is controlled to open to stop the heater 11 from working, so that the temperature inside the grounding box is always maintained within the range of T1 to T2. At the same time, the control chip 141 controls the third controllable switch S3 to close to charge the battery 13 by using the DC / DC conversion module 123. If the second voltage signal U2 output by the DC / DC conversion module 123 is lower than the first preset voltage, it indicates that the induced voltage is insufficient. Therefore, the control chip 141 controls the second controllable switch S2 to close to supply power to the heater 11 through the battery 13.

[0111] Correspondingly, please refer to Figure 4 , an embodiment of the present application provides a grounding box 1, which includes a grounding copper bar 30, a box body 40, and the anti-condensation water device 10 described in the above embodiment, wherein the anti-condensation water device 10 is arranged inside the grounding box 1.

[0112] The further function descriptions of the above various modules and units are the same as those in the corresponding above embodiments, and will not be repeated here.

[0113] The grounding box 1 proposed in the embodiment of the present application keeps the temperature inside the box at the desired temperature and has a long battery life through the anti-condensation water device 10 arranged inside the grounding box 1. Therefore, while ensuring that the demand for evaporating condensed water is met, the heating power of the anti-condensation water device 10 is adaptively adjusted to avoid waste of power supply energy caused by excessive heating of the anti-condensation water device 10 to the temperature inside the box, greatly reducing unnecessary heating energy consumption, which is beneficial to the long battery life of the anti-condensation water device 10, and effectively avoiding grounding box failures caused by condensed water.

[0114] In some embodiments of the present application, as Figure 5 shown, the box body 40 includes a box cover 41 and a box bottom 42, and the box cover 41 and the box bottom 42 are connected by hinges and bolts. The grounding copper bar 30 is fixed on the box bottom 42 through a metal fixing member, and a temperature sensor 50 is arranged on the grounding copper bar 30.

[0115] Currently, cable grounding boxes in tunnels generally consist of an integral non-detachable box body and a flat box cover, which are connected and fixed by multiple groups of bolts. When it is necessary to repair the wiring terminals inside the box and conduct test wiring in the grounding box, the operating space for the staff is narrow and the work is extremely inconvenient. Considering the convenience of working inside the box, the embodiment of the present application proposes asFigure 5 For the box structure shown, when wiring or maintenance work needs to be carried out at the terminal or the grounding busbar, first remove the bolt, and the box cover 41 can be turned outwards with the hinge as the axis, providing sufficient operating space for the work inside the box. Therefore, through the connection structure between the box cover and the box bottom in the embodiment of the present application, sufficient operating space can be provided for the work inside the grounding box, which is beneficial to the maintenance work and improves work efficiency.

[0116] Furthermore, in some embodiments of the present application, as Figure 5 shown, a one-way breathing valve 411 is provided on the box cover 41, and the one-way breathing valve 411 is used to discharge the water vapor converted from the condensed water.

[0117] At present, most of the grounding boxes used in tunnels are not sealed, and both the cable inlet and the connection of the cover plate communicate with the outside. The environmental humidity in the tunnel is also relatively high. If no certain sealing measures are taken, the air convection inside and outside the grounding box is too fast, which will greatly reduce the dehumidification effect of the heater. Therefore, sealant is used to seal and block the cable inlet position and the connection of the cover plate.

[0118] When the heater 11 in the grounding box 1 works and the temperature inside the box is stable between 35°C and 40°C, the condensed water inside the box evaporates due to heat and the temperature rise causes the air pressure inside the box to be relatively high. In order to limit air convection while maintaining the air pressure balance inside and outside the grounding box, a one-way breathing valve 411 is installed on the box cover 41. When there is an air pressure difference between the inside and outside of the grounding box and the air pressure P1 inside the box is greater than the air pressure P2 outside the box, the gas passes from the inside of the box to the outside through the breathing valve, and the outside air cannot enter, so the purpose of balancing the air pressure can be achieved. Therefore, through the one-way breathing valve structure provided on the box cover 41 in the embodiment of the present application, the function of limiting air convection while maintaining the air pressure balance inside and outside the grounding box is realized, and thus the anti-condensation water effect is effectively improved.

[0119] In some other embodiments of the present application, as Figure 6 shown, the anti-condensation water device 10 includes a heater 11, a power taking unit 12 and a control unit 14. Compared with the previous embodiments, in this embodiment, the anti-condensation water device 10 does not have a storage battery 13, but the storage battery 13 is arranged outside the tunnel to improve the working safety of the grounding box in the tunnel.

[0120] The systems, devices, modules or units described in the above embodiments can be specifically implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer can be, for example, a personal computer, an industrial computer, a control terminal and other devices and their combinations.

[0121] For the convenience of description, when describing the above device, various units are described separately according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0122] It should also be noted that the term "comprising", "including" or any other variation thereof is intended to cover a non-exclusive inclusion, so that a process, method, commodity or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the said element.

[0123] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the differences between each embodiment and other embodiments are emphasized.

[0124] The above description is only for the embodiments of the present application and is not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

[0125] Although the embodiments of the present application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. An anti-condensation water device for a grounding box inside a tunnel, characterized in that, The anti-condensation device includes: a heater, which is arranged inside the side plate of the box body of the grounding box, and the heater is used to heat the surrounding space of the grounding copper bar in the grounding box to evaporate the condensed water in the grounding box; a power-taking unit, which is arranged outside the side plate of the box body, and the power-taking unit is configured to obtain the induced voltage of the cable line in the tunnel and supply power to the heater when the induced voltage is sufficient; a storage battery, which is configured to supply power to the heater when the induced voltage is insufficient; a control unit, which is configured to control at least one of the power-taking unit and the storage battery to work when the temperature inside the grounding box is lower than a preset temperature, and control the power-taking unit to charge the storage battery when the temperature inside the grounding box is not lower than the preset temperature; the control unit is configured to determine the standard heating power of the heater according to the temperature inside the box and the historical load current of the cable line, and adaptively adjust the standard heating power according to the real-time load current of the cable line to obtain the target heating power, so that the heater works with the target heating power; wherein, when the real-time load current of the cable line is greater than or equal to a first threshold, it is determined that the induced voltage is sufficient, and when the real-time load current of the cable line is less than the first threshold, it is determined that the induced voltage is insufficient; the control unit is further configured to determine the surface temperature of the grounding copper bar according to the historical load current of the cable line when the historical load current of the cable line is greater than or equal to the first threshold, and perform a thermal field simulation according to the current temperature inside the grounding box, the surface temperature of the grounding copper bar and different heating powers, so as to determine the standard heating power according to the simulation results; and determine the change trend of the real-time load current according to the real-time load current and the historical load current, and obtain the load current fluctuation amount; when the load current fluctuation amount is greater than or equal to a second threshold, if the real-time load current shows an upward trend, determine a first adjustment coefficient according to the difference between the load current fluctuation amount and the second threshold, and reduce the standard heating power according to the first adjustment coefficient to obtain the target heating power, if the real-time load current shows a downward trend, determine a second adjustment coefficient according to the difference between the load current fluctuation amount and the second threshold, and increase the standard heating power according to the second adjustment coefficient to obtain the target heating power; The control unit is further configured to: determine a pre-trained load current prediction model, input the historical load current and the real-time load current into the load current prediction model, obtain a predicted load current within a future time period according to the load current prediction model, and determine a predicted average load current within the future time period; when the real-time load current shows an upward trend, if the predicted average load current is less than the real-time load current, multiply the first adjustment coefficient by a first preset parameter to reduce the first adjustment coefficient; when the real-time load current shows a downward trend, if the predicted average load current is greater than or equal to the real-time load current, multiply the second adjustment coefficient by a second preset parameter to reduce the second adjustment coefficient.

2. The anti-condensation water device according to claim 1, characterized in that, The control unit is further configured to: When the historical load current of the cable line is less than the first threshold, perform a thermal field simulation according to the current temperature inside the grounding box and different heating powers, and determine a standard heating power according to the simulation results. Wherein, the standard heating power is used to increase the temperature inside the box and maintain it at a desired temperature.

3. The anti-condensation water device according to claim 2, characterized in that, When the historical load current of the cable line is greater than or equal to the first threshold, the control unit is further configured to: When the load current fluctuation amount is less than the second threshold, use the standard heating power as the target heating power.

4. The anti-condensation water device according to claim 1, characterized in that, The power taking unit includes: A power taking coil configured to generate the induced voltage according to the operating magnetic field of the cable line, wherein the plane of the power taking coil is perpendicular to the cable line, and the cable line passes through the center point of the coil plane. A rectification and voltage stabilization module, the input end of which is connected to the power taking coil, and the rectification and voltage stabilization module is configured to perform voltage stabilization processing on the induced voltage and output a first voltage signal. A DC / DC conversion module configured to perform voltage conversion on the first voltage signal and output a second voltage signal to supply power to the heater according to the second voltage signal.

5. The anti-condensation water device according to claim 4, characterized in that The control unit includes: A first controllable switch connected between the DC / DC conversion module and the heater. A control chip, the first output end of which is connected to the control end of the first controllable switch, and the control chip is configured to control the first controllable switch to close when the temperature inside the grounding box is lower than the preset temperature.

6. The anti-condensation water device according to claim 5, characterized in that, The control unit further includes: A second controllable switch connected between the storage battery and the heater. The first input end of the control chip is connected to the output end of the DC / DC conversion module, the second output end of the control chip is connected to the control end of the second controllable switch, and the control chip is further configured to control the second controllable switch to close when the second voltage signal output by the DC / DC conversion module is lower than a first preset voltage and the temperature inside the grounding box is lower than the preset temperature, so as to supply power to the heater through the storage battery.

7. The anti-condensation device according to claim 5 or 6, characterized in that, The control unit further includes: The second input terminal of the control chip is connected to the output terminal of the rectification and voltage regulation module, and the third output terminal of the control chip is connected to the control terminal of the rectification and voltage regulation module. The control chip is further configured to compare a first voltage signal output by the rectification and voltage regulation module with a second preset voltage, and generate a control signal according to the comparison result and send it to the control terminal of the rectification and voltage regulation module.

8. A grounding box, characterized in that, The grounding box includes: A grounding copper bar; A box body; And the anti-condensation device according to any one of claims 1-7 above, wherein the anti-condensation device is arranged inside the grounding box.

9. The grounding box according to claim 8, characterized in that, The box body includes a box cover and a box bottom, and the box cover and the box bottom are connected by hinges and bolts. The grounding copper bar is fixed on the box bottom by metal fixing pieces; Wherein, a one-way breathing valve is arranged on the box cover, and the one-way breathing valve is used to discharge the water vapor converted from the condensed water.

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