Lightning current absorption device based on nano rare earth ceramic energy absorption resistor, lightning protection circuit and lightning protection system

Abstract

The invention discloses a lightning current consumption device based on a nano rare earth ceramic energy-absorbing resistor, which comprises the nano rare earth ceramic energy-absorbing resistor and an insulating assembly, and is characterized in that the two ends of the nano rare earth ceramic energy-absorbing resistor are respectively connected with corresponding metal plates in a pressing manner, and electrode connecting rods penetrate through the two metal plates; two ends of each electrode connecting rod are respectively connected with the nano rare earth ceramic energy-absorbing resistor and the electrode; the insulation assembly encloses the nano rare earth ceramic energy-absorbing resistor, and the two electrodes extend out of the outer side of the insulation assembly; the nano rare earth ceramic energy-absorbing resistor has the advantages of no inductance, high voltage resistance, high transient power absorption capability and high heat energy conversion rate. Meanwhile, the invention further discloses a lightning protection circuit and a lightning protection system. The lightning current consumption device can efficiently absorb lightning current energy, and solves the problem that in the prior art, a surge protection device SPD is frequently damaged due to the fact that the bearing capacity of the surge protection device SPD on the direct-current component of lightning is extremely low.

Description

Technical Field

[0001] The invention belongs to the technical field of lightning protection, and in particular relates to a lightning current absorbing device, a lightning protection circuit and a lightning protection system based on a nano rare earth ceramic energy absorbing resistor. Background Art

[0002] Existing lightning protection technologies are all based on the perspective of quickly and smoothly discharging lightning current. By building lightning rods, lightning strips (nets), ground grids, etc., a lightning current path is artificially designed and constructed so that the lightning current can be smoothly discharged into the earth and neutralized. The method of introducing lightning current into the earth for neutralization through lightning protection measures such as lightning rods, lightning strips (nets), ground grids, etc. has been widely used for hundreds of years. It avoids the loss and casualties caused by direct lightning strikes on buildings, people, animals and equipment. However, the secondary disasters of lightning current discharge such as step voltage and ground potential counterattack near the lightning strike point still cause a large number of casualties and equipment damage. Although with the development of technology, there are corresponding protection measures for the above secondary disasters, but it takes a lot of manpower, material and financial resources, and it cannot ensure absolute safety. At the same time, the above-mentioned various grounding isolation technologies mainly block the energy of lightning high-frequency ground potential counterattack to a certain extent through high-frequency suppressors, etc., and the effect on low-frequency energy such as continuous current and DC component of lightning is very limited.

[0003] At present, in power supply and electronic information systems, in order to prevent lightning energy from damaging equipment, most of the current pulse energy entering the system is discharged through surge protectors (non-linear elements). However, surge protectors SPD are still often damaged due to energy overload and other reasons, especially damage caused by the current counterattack of lightning rods or down conductors into the ground. In this case, the counterattack energy is not only generated by the lightning pulse, but also includes the energy process of the entire lightning. Especially in the harsh environment of lightning directly striking the line or the discharge ground network directly counterattacking, it is difficult for surge protectors SPD that have only passed laboratory pulse energy testing to fully protect, resulting in a high probability of damage to SPD and back-end protection equipment. In summary, traditional surge protectors SPD are mainly designed to handle high-frequency transient overvoltages and have poor tolerance for low-frequency DC components. The continuous current and M component of lightning together constitute the DC component, which causes the SPD to continue to heat up, which is one of the main reasons for SPD damage. At present, there is no completely effective solution to this problem. Summary of the invention

[0004] The first purpose of the present invention is to overcome the shortcomings and deficiencies in the prior art and to provide a lightning current absorption device based on nano rare earth ceramic energy absorbing resistors, which can efficiently absorb lightning current energy and solve the problem in the prior art that surge protectors SPDs are often damaged due to their extremely low ability to withstand the DC component of lightning.

[0005] The second object of the present invention is to provide a lightning protection circuit, which can effectively protect equipment from damage by lightning current and improve the lightning tolerance of the surge protector SPD and back-end equipment.

[0006] Another object of the present invention is to provide a lightning protection system, which can effectively protect various equipment and personnel from damage caused by lightning strikes and has good application prospects.

[0007] The objective of the present invention is achieved through the following technical scheme: a lightning current dissipation device based on a nano rare earth ceramic energy absorbing resistor comprises a nano rare earth ceramic energy absorbing resistor and an insulating component, the two ends of the nano rare earth ceramic energy absorbing resistor are respectively crimped with corresponding metal plates, both metal plates are penetrated by electrode connecting rods, and the two ends of each electrode connecting rod are respectively connected to the nano rare earth ceramic energy absorbing resistor and the electrode; the insulating component forms an enclosure for the nano rare earth ceramic energy absorbing resistor, and the two electrodes extend out of the outside of the insulating component; the nano rare earth ceramic energy absorbing resistor has the performance of no inductance, high voltage resistance, high transient power absorption capacity and high thermal energy conversion rate.

[0008] Preferably, the nano rare earth ceramic energy absorbing resistor is formed by mixing rare earth components with aluminum oxide, pressing into blocks, and then firing at high temperature; the rare earth component includes at least one of bauxite, kaolin, talc, graphene, lanthanum oxide, and cerium oxide.

[0009] Preferably, the insulating component comprises an insulating sealed tank body, the interior of the sealed tank body has a cavity, the nano rare earth ceramic energy absorbing resistor is located in the cavity and is surrounded by insulating coolant, the insulating coolant is used to absorb the heat generated by the nano rare earth ceramic energy absorbing resistor.

[0010] Preferably, the insulation assembly further comprises a pressure relief device, which is connected to the cavity via a pressure relief conduit, and is used for releasing the pressure in the cavity.

[0011] Preferably, the insulating sealed tank body comprises an insulating sealed shell and an insulating sealed end cover, and the two insulating sealed end covers are respectively arranged at the upper end and the lower end of the insulating sealed shell to form a tank body structure; the material of the insulating sealed tank body is engineering plastic with insulating, fireproof and heat-resistant properties.

[0012] Preferably, the insulating coolant includes at least one of a water-based insulating coolant, mineral oil, and synthetic ester.

[0013] Preferably, the two electrodes are both made into bolt column structures for connection with a grounding system or a grounding bar.

[0014] Preferably, the metal plate is a copper plate or an aluminum plate.

[0015] A lightning protection circuit comprises a surge protector and a lightning current absorbing device using the above-mentioned nano rare earth ceramic energy absorbing resistor, wherein the surge protector is connected in series with the lightning current absorbing device to form a voltage dividing and energy absorbing circuit structure, and the surge protector is connected in parallel with the equipment to be protected; the lightning protection circuit is used to absorb and discharge lightning current.

[0016] The lightning protection system comprises a grounding system, a grounding bar and the above-mentioned lightning protection circuit, wherein the lightning protection circuit is connected in series between the grounding system and the grounding bar.

[0017] Compared with the prior art, the present invention has the following advantages and effects: (1) The present invention provides a lightning current absorption device based on nano rare earth ceramic energy absorption resistors. The lightning current absorption device uses nano rare earth ceramic energy absorption resistors as core components. The nano rare earth ceramic energy absorption resistors have the advantages of non-inductive, high voltage resistance, high transient power absorption capacity (transient power reaches 30 kJ) and high thermal energy conversion rate (the conversion rate of electrical energy to thermal energy reaches 97%). The lightning current absorption device has the advantages of efficiently absorbing lightning current energy and can absorb the full frequency band energy of lightning (including DC components), thereby reducing the probability of lightning energy impact damaging surge protectors SPD and rear-end protection equipment in severe lightning environments, and establishing a firewall for surge protection of power supplies and electronic information systems.

[0018] The lightning current absorption device solves the problem in the prior art that the surge protector SPD is often damaged due to its extremely low tolerance to the direct current component of lightning.

[0019] (2) The lightning protection circuit of the present invention forms a voltage-dividing and energy-absorbing circuit structure by connecting a lightning current absorbing device in series with a surge protector SPD, which can greatly reduce the load of the lightning current on the surge protector SPD. On this basis, the surge protector is connected in parallel with the equipment to be protected, which effectively protects the equipment from damage by lightning current and improves the lightning tolerance of the surge protector SPD and the back-end protection equipment.

[0020] (3) The lightning protection system of the present invention ensures that lightning current can be safely introduced into the earth by connecting a lightning current absorption device and a surge protector SPD in series between the grounding system and the grounding bar, thereby effectively protecting various types of equipment and personnel from damage caused by lightning strikes. The system has broad application prospects and is suitable for high-voltage and high-current lightning protection systems. The applicable fields include power systems, communication systems, transportation systems, petroleum and chemical industries, buildings and infrastructure, new energy fields, and industrial control systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the lightning current dissipation device based on nano rare earth ceramic energy absorbing resistor of the present invention.

[0022] Figure 2 The figure is a circuit diagram of the lightning current absorption device of the present invention.

[0023] Figure 3 The residual voltage waveform and current waveform at both ends of the surge protector SPD after the nominal discharge current of 20kA (8 / 20 waveform) in Example 1 impacts the series circuit.

[0024] Among them, 1 is an electrode, 2 is an insulating sealed end cover, 3 is an insulating sealed shell, 4 is an electrode connecting rod, 5 is a metal plate, 6 is a nano rare earth ceramic energy absorbing resistor, 7 is a pressure relief device, and 8 is an insulating coolant. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0026] Example 1 like Figure 1 The structure diagram of the lightning current absorption device based on the nano rare earth ceramic energy absorption resistor is shown, including a nano rare earth ceramic energy absorption resistor and an insulating component. The two ends of the nano rare earth ceramic energy absorption resistor are respectively crimped with corresponding metal plates. Specifically, in this embodiment, the metal plate is a copper plate or an aluminum plate. Electrode connecting rods are passed through the two metal plates, and the two ends of each electrode connecting rod are respectively connected to the nano rare earth ceramic energy absorption resistor and the electrode; the two electrodes are made into a bolt column structure for connecting to the grounding system (referring to the grounding network of the entire building, including grounding electrodes and grounding wires, etc.) or the grounding bar. Specifically, the bolt column structure makes the installation and maintenance of the device more convenient, and ensures a reliable connection between the electrode and the grounding system or the grounding bar, thereby improving the stability of the device. The insulating component forms an enclosure (enclosing structure) for the nano rare earth ceramic energy absorption resistor. The setting of the insulating component ensures the safe operation of the nano rare earth ceramic energy absorption resistor under high voltage environment, while preventing the external environment from affecting it. The two electrodes extend out of the insulating component; the nano rare earth ceramic energy absorbing resistor has the performance of non-inductive, high voltage resistance, high transient power absorption capacity (transient power reaches 30kJ, equivalent to the bearing capacity of 30 Imax40kA MOV chips) and high thermal energy conversion rate.

[0027] Specifically, in this embodiment, the nano rare earth ceramic energy absorbing resistor has the characteristics of being resistant to instantaneous large current and high temperature, and the conversion rate of electrical energy into thermal energy is 97%, which can instantly absorb strong lightning current. The technical parameters of the lightning current absorption device include: thermal conductivity is 0.04J / (s·cm·℃), material specific heat is 2J / (cm³·℃); the technical parameters of the nano rare earth ceramic energy absorbing resistor include: rated energy is a single impact maximum energy of 500J / cm³, temperature coefficient is -0.05%~-0.15% / ℃, voltage coefficient is -0.5~-7.5% / kV / cm, surface temperature rises to 200℃ in a short time, 150°C when working for a long time, impulse voltage is no more than 2kV for a single piece, compressive strength is 12000N / cm², and material density is 2.2g / cm³.

[0028] like Figure 1 As shown, in this embodiment, the lightning current absorption device of the present invention uses nano rare earth ceramic energy absorbing resistors as core components, which can greatly reduce the size of the device and facilitate installation and use. If a metal resistance wire is used to produce a product with the same resistance value as the lightning current absorption device (in this embodiment, the resistance range of the lightning current absorption device is 0.25Ω~0.3Ω), and the product cannot have inductance, then a metal resistance wire of hundreds of meters in length is required, which is obviously impossible to actually produce and apply. It can be seen that the present invention avoids the inductance problem caused by the excessive length of traditional metal resistance wires by innovatively using nano rare earth ceramic energy absorbing resistors, ensures that the performance of the device will not be affected by the inductance effect when the lightning current passes through, and solves the limitations of traditional metal resistance wires in practical applications.

[0029] The present invention utilizes the excellent electrical insulation performance and high temperature stability of the nano rare earth ceramic material itself. The nano rare earth ceramic energy absorbing resistor has the performance of non-inductive, high voltage resistance, high transient power absorption capacity and high heat energy conversion rate, thus ensuring that the lightning current absorption device can efficiently absorb lightning current energy and can absorb the full frequency band energy of lightning including DC components, solving the problem of frequent damage of surge protectors SPD due to their extremely low tolerance for DC components of lightning in the prior art. When the lightning current absorption device is applied to protect the surge protector SPD, the probability of lightning energy impact damaging the surge protector SPD and the rear-end protection equipment in a severe lightning environment can be reduced, and a firewall can be established for surge protection of power supply and electronic information systems.

[0030] like Figure 2As shown in the figure, the working principle of the lightning current absorption device is as follows: when the SPD is activated, the internal resistance will instantly drop to below 0.1Ω, while the lightning current absorption device is 0.3Ω. The lightning current absorption device accounts for 75% of the total resistance of the series circuit of the two, 0.4Ω. According to Joule's law W=i²Rt, the energy consumption of the lightning current also accounts for 75%, while the voltage and energy consumption on the SPD only account for 25% of the total lightning energy.

[0031] The nano rare earth ceramic energy absorbing resistor is made by mixing rare earth components with aluminum oxide, pressing them into blocks, and then firing them at high temperature; the rare earth components include at least one of bauxite, kaolin, talc, graphene, lanthanum oxide, and cerium oxide.

[0032] Specifically, the combination of rare earth components and aluminum oxide makes the nano rare earth ceramic energy absorbing resistor have excellent electrical properties and thermal stability. By pressing into blocks and high-temperature firing, the uniformity and reliability of the nano rare earth ceramic energy absorbing resistor are ensured.

[0033] The insulating component includes an insulating sealed tank body, which seals and protects the nano rare earth ceramic energy absorbing resistor. The inner part of the edge sealed tank body has a cavity, and the nano rare earth ceramic energy absorbing resistor is located in the cavity and is filled with insulating coolant around it. The insulating coolant is used to absorb the heat generated by the nano rare earth ceramic energy absorbing resistor. Specifically, the nano rare earth ceramic energy absorbing resistor cooperates with the insulating coolant, and the theoretical energy absorption reaches 2MJ. By sealing the outer side of the nano rare earth ceramic energy absorbing resistor with an insulating sealed tank body and then injecting the insulating coolant, the nano rare earth ceramic energy absorbing resistor can be cooled in time, and its ability to withstand lightning current impact and the number of times can be improved. The insulating coolant includes at least one of a water-based insulating coolant, a mineral oil, and a synthetic ester. Specifically, in actual application, different types of insulating coolants can be selected according to different needs to improve the applicability of the device.

[0034] The insulating assembly further includes a pressure relief device, which is connected to the cavity through a pressure relief conduit, and is used to release the pressure formed in the insulating sealed tank body, i.e., in the cavity, due to the volume expansion of the insulating coolant after being heated. Specifically, this arrangement can prevent the insulating sealed tank body from being damaged due to excessive pressure, and extend the service life of the lightning current absorption device in harsh environments.

[0035] Specifically, the insulating sealed tank body includes an insulating sealed shell and an insulating sealed end cover. The two insulating sealed end covers are respectively arranged at the upper end and the lower end of the insulating sealed shell to form a tank body structure. The design of the insulating sealed shell and the end cover ensures the sealing and mechanical strength of the tank body. The insulating sealed tank body is made of engineering plastics with insulating, fireproof and heat-resistant properties. In actual application, different insulating materials can be selected according to actual needs to adapt to different application scenarios.

[0036] The following is a detailed description and verification of the application effect of the lightning current absorption device through experimental data: Test conditions: Use a zinc oxide surge protector (maximum current Imax is 40kA, nominal discharge current is 20kA, 8 / 20 waveform) in series with a lightning current absorption device, and pass two pulse impact tests of 40kA and 60kA (8 / 20 waveform) respectively.

[0037] Table 1 Waveform parameters of impulse test of zinc oxide surge protector with maximum flow rate of 40kA in series with lightning current absorption device

[0038] Test results: (1) The surge protector SPD was not damaged after being subjected to the above four test currents. The residual voltage waveform was normal, and the zinc oxide varistor voltage (430V) and leakage current (4μA) were both normal.

[0039] (2) The voltage across the lightning current absorption device reaches 5 kV (saturation), while the peak residual voltage across the surge protector SPD is only 2.2 kV, and then remains at around 700 V.

[0040] (3) After the lightning current absorption device is connected in series, the current of the series circuit decays from 60kA to 40.8kA, a decay of 32%; when the series circuit is impacted with a nominal discharge current of 20kA (8 / 20 waveform), the current peak value of the surge protector SPD decays to 14.53kA, a decay of 27.4%. The residual voltage waveform and current waveform at both ends of the surge protector SPD are as follows: Figure 3 shown.

[0041] (4) The lightning current absorption device basically did not generate heat after multiple impact tests, indicating that it still has a large energy absorption space.

[0042] The above experimental results show that after the zinc oxide surge protector is connected in series with the lightning current absorption device, the latter absorbs most of the energy in the circuit, and the load of the surge protector is significantly reduced, which can better protect the surge protector SPD from severe lightning environments. The lightning current absorption device based on nano rare earth ceramic energy absorbing resistors of the present invention has an absorption effect on energy in all frequency bands of lightning, especially the DC component.

[0043] Example 2 A lightning protection circuit includes a surge protector and a lightning current absorbing device based on the nano rare earth ceramic energy absorbing resistor described in Example 1, such as Figure 2As shown, the surge protector is connected in series with the lightning current absorption device to form a voltage division and energy absorption circuit structure, which can significantly reduce the load of the surge protector SPD. On this basis, the surge protector is connected in parallel with the equipment to be protected. The lightning protection circuit is used to absorb and discharge lightning current, effectively protect the equipment from damage by lightning current, and improve the lightning protection system's ability to withstand lightning.

[0044] Example 3 A lightning protection system comprises a grounding system, a grounding bar and a lightning protection circuit as described in Example 2, wherein the lightning protection circuit is connected in series between the grounding system and the grounding bar; the lightning protection system is used to conduct lightning current into the earth to protect the safety of equipment and personnel.

[0045] Specifically, in this embodiment, the lightning protection system can be used on the basis of combining the lightning current absorption device with the existing power supply and electronic information system SPD protection, and the lightning current absorption device is connected in series between the grounding system and the grounding bar, so as to absorb the energy of each frequency band of lightning and also include the DC component of lightning, and reduce the damage of lightning energy impact to SPD and rear-end protection equipment in severe lightning environments (such as direct lightning strikes and line shunting). The lightning protection system can effectively protect various equipment and systems from lightning damage by absorbing and discharging lightning current, and has a wide range of application prospects. It is suitable for high-voltage and high-current lightning protection systems, and the applicable fields include power systems, communication systems, transportation systems, petroleum and chemical industries, buildings and infrastructure, new energy fields, and industrial control systems.

[0046] The above embodiments are preferred implementations of the present invention and are not intended to limit the present invention. Any other changes or other equivalent replacement methods that do not deviate from the technical solutions of the present invention are included in the protection scope of the present invention.

Claims

1. A lightning current dissipation device based on nano rare earth ceramic energy absorbing resistor, characterized in that: It comprises a nano rare earth ceramic energy absorbing resistor and an insulating component, wherein the two ends of the nano rare earth ceramic energy absorbing resistor are respectively crimped with corresponding metal plates, the two metal plates are penetrated by electrode connecting rods, and the two ends of each electrode connecting rod are respectively connected to the nano rare earth ceramic energy absorbing resistor and the electrode; the insulating component forms an enclosure for the nano rare earth ceramic energy absorbing resistor, and the two electrodes extend out of the outside of the insulating component; the nano rare earth ceramic energy absorbing resistor has the properties of non-inductive, high voltage resistance, high transient power absorption capacity and high thermal energy conversion rate.

2. The lightning current dissipation device based on nano rare earth ceramic energy absorbing resistor according to claim 1 is characterized in that: The nano rare earth ceramic energy absorbing resistor is made by mixing rare earth components with aluminum oxide, pressing them into blocks, and then firing them at high temperature; the rare earth components include at least one of bauxite, kaolin, talc, graphene, lanthanum oxide, and cerium oxide.

3. The lightning current dissipation device based on nano rare earth ceramic energy absorbing resistor according to claim 1 is characterized in that: The insulating component comprises an insulating sealed tank body, the interior of the sealed tank body has a cavity, the nano rare earth ceramic energy absorbing resistor is located in the cavity and is surrounded by insulating coolant, the insulating coolant is used to absorb the heat generated by the nano rare earth ceramic energy absorbing resistor.

4. The lightning current dissipation device based on nano rare earth ceramic energy absorbing resistor according to claim 3 is characterized in that: The insulation assembly further comprises a pressure relief device, which is connected to the cavity via a pressure relief conduit and is used to release the pressure in the cavity.

5. The lightning current dissipation device based on nano rare earth ceramic energy absorbing resistor according to claim 3 is characterized in that: The insulating sealed tank body comprises an insulating sealed shell and an insulating sealed end cover, wherein the two insulating sealed end covers are respectively arranged at the upper end and the lower end of the insulating sealed shell to form a tank body structure; the insulating sealed tank body is made of engineering plastics with insulating, fireproof and heat-resistant properties.

6. The lightning current dissipation device based on nano rare earth ceramic energy absorbing resistor according to claim 3 is characterized in that: The insulating coolant includes at least one of a water-based insulating coolant, mineral oil, and synthetic ester.

7. The lightning current dissipation device based on nano rare earth ceramic energy absorbing resistor according to claim 1 is characterized in that: The two electrodes are both made into bolt column structures for connection with a grounding system or a grounding bar.

8. The lightning current dissipation device based on nano rare earth ceramic energy absorbing resistor according to claim 1 is characterized in that: The metal plate is a copper plate or an aluminum plate.

9. Lightning protection circuit, characterized in that, It comprises a surge protector and a lightning current absorbing device based on a nano rare earth ceramic energy absorbing resistor according to any one of claims 1 to 8, wherein the surge protector is connected in series with the lightning current absorbing device to form a voltage dividing and energy absorbing circuit structure, and the surge protector is connected in parallel with the equipment to be protected; the lightning protection circuit is used for absorbing and discharging lightning current.

10. Lightning protection system, characterized in that, The invention comprises a grounding system, a grounding bar and a lightning protection circuit according to claim 9, wherein the lightning protection circuit is connected in series between the grounding system and the grounding bar.

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