Lightning protection device for tethered balloon communication system

Abstract

A lightning protection device of a tethered balloon communication system, comprising: a lightning protection net, a shielding layer, a protection circuit; the lightning protection net wraps the tethered balloon; the shielding layer is installed outside the communication module and the communication line of the tethered balloon and is connected with the lightning protection net; the protection circuit is connected inside the communication module and is used for protecting common mode and differential mode interference caused by lightning; the lightning protection net arranged outside the tethered balloon, the shielding layer and the protection circuit arranged inside the communication module are designed according to the characteristics of the communication system in the tethered balloon, the communication module and the communication line are treated in all directions, the damage caused by lightning to the communication module of the tethered balloon and the radiation and conduction interference in the lightning process are effectively reduced, the normal work of the communication module in the lightning process is ensured, and the accuracy and reliability of data transmission are ensured.

Description

Technical Field

[0001] This invention relates to the field of communication technology for tethered balloon platforms, and more specifically to a lightning protection device for a tethered balloon communication system. Background Technology

[0002] A tethered balloon is an aerostat that gains buoyancy from the gas inside its bladder and is secured by cables. Utilizing the tether cable, aerodynamic lift, and residual buoyancy, it can remain at a fixed altitude for an extended period within a specific area of ​​the air. A tethered balloon typically consists of a sphere, telemetry and control (TT&C) system, flight control system, power supply, tethering cable, and anchoring facilities. Communication connections exist between the following components:

[0003] (1) Between the spherical sensor and the measurement and control / flight control equipment;

[0004] (2) Between the power supply system and the flight control equipment;

[0005] (3) Between the onboard measurement and control equipment and the ground;

[0006] (4) Between the load and the measurement and control equipment.

[0007] Communication between these devices enables real-time transmission of environmental parameters, sphere formation status, flight attitude, power supply operating status, and load test data, providing decision-making support for the flight process and is crucial for ensuring successful flight and the acquisition of effective test data for the load. Unlike other fully airborne aerostats, tethered balloons are connected to ground facilities via tethering cables, essentially creating a protrusion ranging from hundreds to thousands of meters in height between the ground and high altitude, making them highly susceptible to lightning strikes.

[0008] Tethered balloons differ significantly from fixed-location buildings and power systems on the ground in their susceptibility to lightning strikes. They operate in four states: low-altitude ground suspension, launch, descent during recovery, and high-altitude operation. The parameters they are subjected to lightning strikes for differ from those of typical ground equipment. Therefore, tethered balloon systems fall under the category of lightning protection in high-exposure areas, which increases the complexity and cost of protection efforts. The sphere of a tethered balloon is made of non-metallic, non-conductive insulating material, fundamentally different from ordinary aircraft.

[0009] Given the importance of tethered balloon communication systems and the urgency of lightning protection, lightning protection design is necessary to ensure the normal operation of the communication system. Summary of the Invention

[0010] To address the critical importance and urgent need for lightning protection in existing technologies for tethered balloon communication systems, necessitating lightning protection design to ensure normal operation, this invention proposes a lightning protection device for a tethered balloon communication system. The tethered balloon communication system includes: a communication module located within a sensor on the outside of the tethered balloon, and a communication line connecting the communication module and the gondola; the lightning protection device includes: a lightning protection network, a shielding layer, and a protective circuit.

[0011] The lightning protection netting encloses the tethered balloon;

[0012] The shielding layer is installed outside the communication module and communication line of the tethered balloon and is connected to the lightning protection network;

[0013] The protection circuit is connected inside the communication module and is used to protect against common-mode and differential-mode interference caused by lightning.

[0014] Preferably, the communication module includes a first communication module located in the sensor at the top of the tethered balloon and a second communication module located in the sensor at the bottom of the tethered balloon, both of which are connected to the pod via the communication line.

[0015] Preferably, the lightning protection network includes: multiple lightning rods (1), multiple lightning protection cables (2), and grounding cables (8);

[0016] The multiple lightning rods (1) are distributed on the surface of the tethered balloon and are located around the first communication module; the multiple lightning protection cables (2) are connected in sequence and suspended on each lightning rod (1) to form a mesh structure and then wrap around the tethered balloon;

[0017] The grounding cable (8) is grounded after being connected to the mesh structure.

[0018] Preferably, the lightning rod (1), the lightning rod (2), and the grounding cable (8) are all conductors.

[0019] Preferably, the lightning protection network covers the first communication module and at least covers the top to the head and the middle of the body of the tethered balloon.

[0020] Preferably, the shielding layer includes: a metal shielding shell (10), a communication line shielding layer (11), and a connecting line (12);

[0021] The metal shielding shell (10) encloses the first communication module and the second communication module, and is connected to the metal connectors of the first communication module and the second communication module;

[0022] The communication line shielding layer (11) wraps around the communication line;

[0023] The communication line is connected to the metal connectors of the first communication module and the second communication module.

[0024] Preferably, the metal shielding shell (10), the double shielding layer (11) and the connecting line (12) are all conductors.

[0025] Preferably, the connecting line (12) is connected to the lightning rod (2).

[0026] Preferably, the protection circuit includes: a first protection circuit and a second protection circuit; both the first communication module and the second communication module include: a communication power line and a communication signal line;

[0027] The first protection circuit is connected at the inlet of the communication power line;

[0028] The second protection circuit is connected at the entrance of the communication signal line.

[0029] Preferably, both the first protection circuit and the second protection circuit include a three-level protection circuit, which is cascaded and connected to the interface between the first communication module and the second communication module.

[0030] The first cascaded protection circuit is a common-mode discharge circuit; the second cascaded protection circuit is a common-mode filter circuit; and the third cascaded protection circuit is a voltage clamping circuit.

[0031] Preferably, the first cascaded protection circuit in the first protection circuit includes: a varistor RV and a gas discharge tube GDT;

[0032] One end of the varistor RV is connected to the positive terminal of the power supply, and the other end is connected to the negative terminal of the power supply.

[0033] One end of the gas discharge tube (GDT) is connected to the grounding point, and the other end is connected to the negative terminal of the power supply.

[0034] Preferably, the second cascaded protection circuit in the first protection circuit includes: a resettable fuse PPTC, a common-mode inductor CML, a differential-mode capacitor C1, a common-mode capacitor C2, and a common-mode capacitor C3;

[0035] One end of the common-mode inductor CML is connected to the resettable fuse PPTC, and the other end is connected to the differential-mode capacitor C1;

[0036] One end of the differential mode capacitor C1 is connected to the common mode capacitor C2, and the other end is connected to the common mode capacitor C3;

[0037] The common-mode capacitor C3 is connected to the grounding point.

[0038] Preferably, the third cascaded protection circuit in the first protection circuit includes a bidirectional TVS diode.

[0039] Preferably, the first cascaded protection circuit of the second protection circuit includes: gas discharge tube GDT1 and gas discharge tube GDT2;

[0040] One end of the gas discharge tube GDT1 is connected to the positive terminal of the differential signal line, and the other end is connected to the ground point;

[0041] One end of the gas discharge tube GDT2 is connected to the negative terminal of the differential signal line, and the other end is connected to the grounding point.

[0042] Preferably, the second protection circuit, the second cascaded protection circuit, includes: a common-mode inductor CML.

[0043] Preferably, the second protection circuit and the third cascaded protection circuit include a TVS diode bridge circuit.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] A lightning protection device for a tethered balloon communication system includes: a lightning protection net, a shielding layer, and a protective circuit; the lightning protection net surrounds the tethered balloon; the shielding layer is installed outside the communication module and communication line of the tethered balloon and is connected to the lightning protection net; the protective circuit is connected inside the communication module to protect against common-mode and differential-mode interference caused by lightning. This invention, considering the characteristics of communication systems in tethered balloons, designs a lightning protection net and shielding layer arranged outside the tethered balloon, and a protective circuit installed inside the communication module to provide comprehensive lightning protection for the communication module and communication line. This effectively reduces damage to the tethered balloon communication module and reduces radiation and conducted interference during lightning strikes, ensuring the communication module can operate normally during lightning strikes and guaranteeing the accuracy and reliability of data transmission. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the overall structure of the lightning protection device for a tethered balloon communication system according to the present invention;

[0047] Figure 2 This is a schematic diagram illustrating the structure of the tethered balloon lightning protection network of the present invention;

[0048] Figure 3 This is a schematic diagram of the shielding of the communication line and the metal shell shielding of the present invention;

[0049] Figure 4 This is a structural diagram of the internal circuit composition of the communication power supply lightning protection module of the present invention;

[0050] Figure 5 This is a structural diagram of the internal circuit composition of the communication signal lightning protection module of the present invention;

[0051] Among them, 1. multiple lightning protection rods, 2. multiple lightning protection cables, 3. sensors on the top of the tethered balloon, 4. first communication line, 5. sensors on the bottom of the tethered balloon, 6. second communication line, 7. tether cable, 8. grounding tether cable, 9. gondola, 10. metal shielding shell, 11. communication line shielding layer, 12. connecting line. Detailed Implementation

[0052] To better understand the present invention, the following description, in conjunction with the accompanying drawings and embodiments, will further illustrate the content of the present invention.

[0053] Example 1:

[0054] This invention provides a lightning protection device for a tethered balloon communication system. The communication system includes: a communication module located within sensors on the outside of the tethered balloon, wherein the sensors include sensors located at the top and bottom of the tethered balloon; the communication module located within the sensors at the top of the tethered balloon is a first communication module and the communication module located within the sensors at the bottom of the tethered balloon is a second communication module; the first communication module is connected to the pod via a first communication line and the second communication module is connected to the pod via a second communication line.

[0055] The present invention provides a lightning protection device for a tethered balloon communication system, such as... Figure 1 The components shown include: lightning protection network, shielding layer, and protective circuit.

[0056] The lightning protection netting encloses the tethered balloon;

[0057] The shielding layer is installed outside the communication module and communication line of the tethered balloon and is connected to the lightning protection network;

[0058] The protection circuit is connected inside the communication module and is used to protect against common-mode and differential-mode interference caused by lightning.

[0059] Furthermore, the lightning protection device can be divided into two parts: an internal and an external section. The external section includes a lightning protection network and a shielding layer; the internal section includes protective circuits. The lightning protection device can also be divided according to the lightning protection zone, including direct lightning strike protection zones and lightning shielding protection zones. The external section belongs to the direct lightning strike protection zone and provides lightning protection for the sensor communication module and communication lines.

[0060] The lightning protection network includes: multiple lightning rods 1, multiple lightning protection cables 2, and grounding cables 8;

[0061] The multiple lightning rods 1 are distributed on the surface of the tethered balloon and are located around the first communication module; the multiple lightning protection cables 2 are connected in sequence and suspended on each lightning rod 1 to form a mesh structure that wraps around the tethered balloon;

[0062] Furthermore, lightning protection rods 1 are distributed from the top of the tethered balloon to the head and down to the middle of the balloon body. Lightning protection cables 2 are connected to each lightning protection rod 1 from the top of each lightning protection rod 1 and suspended on the lightning protection rod 1.

[0063] The grounding cable 8 is connected to the mesh structure and then grounded. The lightning protection network can conduct lightning into the ground, preventing lightning from directly striking the communication system and providing effective protection for the communication equipment. The layout of the entire lightning protection network ensures that the tethered balloon communication system is within the coverage area of ​​the network, forming the first layer of the lightning protection system.

[0064] The distribution and connection of lightning protection networks are as follows: Figure 2 As shown, the first communication module inside sensor 3, installed at the top of the tethered balloon, is connected to the control module inside gondola 9 via first communication line 4. The second communication module inside sensor 5, installed at the bottom of the tethered balloon, is connected to the control module inside gondola 9 via second communication line 6. The tether 7 is fixed to the surface of the balloon and mechanically connected to the grounding tether 8 for overall tethering of the balloon.

[0065] The lightning rod 1, the lightning rod 2, and the grounding cable 8 are all conductors.

[0066] Furthermore, the lightning rod 1 is made of metal oxide; the lightning rod 2 is a conductor made of metal, such as copper; and the grounding cable 8 is a conductor made of metal, such as copper.

[0067] The lightning protection network covers the first communication module and at least covers the top of the tethered balloon from the top to the head and from the top to the middle of the body.

[0068] The shielding layer includes: a metal shielding shell 10, a communication line shielding layer 11, and a connecting line 12;

[0069] The metal shielding shell 10 encloses the first communication module and the second communication module, and is connected to the metal connectors of the first communication module and the second communication module;

[0070] Furthermore, this level of lightning protection primarily focuses on the first communication module located within sensor 3 at the top of the tethered balloon, the second communication module located within sensor 5 at the bottom of the tethered balloon, and the first communication line 4 and the second communication line 6. The first and second communication modules are shielded by a metal shielding shell 10, which is connected to the lightning arrester cable via copper wire to achieve equipotential bonding.

[0071] Lightning protection for communication lines, such as Figure 3 As shown, the communication line shielding layer 11 encloses the first communication line 4 and the second communication line 6, and the communication line shielding layer 11 is a double shielding layer.

[0072] The first communication line is connected to the metal connector of the first communication module; the second communication line is connected to the metal connector of the second communication module.

[0073] Furthermore, the metal connector is in close contact with the metal shielding shell 10 and the communication line shielding layer 11, forming an overall shield.

[0074] The metal shielding shell 10, the double shielding layer 11, and the connecting wire 12 are all conductors.

[0075] Furthermore, the double shielding layer 11 is made of braided metal wires such as copper and aluminum; the connecting wire 12 is a conductor made of copper; and the metal shielding shell 10 is made of metal.

[0076] The connecting line 12 is connected to the lightning rod 2.

[0077] Furthermore, the connection between the double shielding layer 11 and the grounding wire, which is ultimately connected to the lightning rod 2 and the grounding cable 8, has a suppressive effect on electromagnetic induction and electrostatic induction caused by lightning.

[0078] The first and second communication modules are equipped with protection circuits. These protection circuits employ a multi-level protection and step-by-step reduction method, using components such as gas discharge tubes, varistors, resettable fuses, common-mode inductors, capacitors, and clamping diodes to protect against common-mode and differential-mode interference caused by lightning.

[0079] The protection circuit includes: a first protection circuit and a second protection circuit; both the first communication module and the second communication module include: a communication power line and a communication signal line;

[0080] The first protection circuit is connected at the inlet of the communication power line;

[0081] The second protection circuit is connected at the entrance of the communication signal line.

[0082] Furthermore, surge protection measures are implemented at the interfaces between the first and second communication modules and the connecting lines. Surge protection includes protection for both the communication power lines and communication signal lines, and the protection locations include not only the first communication module but also the second communication module.

[0083] Both the first and second protection circuits include a three-level protection circuit, which is cascaded and connected to the interface between the first and second communication modules.

[0084] The first cascaded protection circuit is a common-mode discharge circuit; the second cascaded protection circuit is a common-mode filter circuit; and the third cascaded protection circuit is a voltage clamping circuit.

[0085] Furthermore, for lightning protection of the communication power line, a multi-level protection approach is adopted, with each level progressively reducing the energy loss. The DC power supply is connected at the interface between the first and second communication modules, and after protection, it enters the subsequent power supply circuit. The protection circuit includes two levels of protection, with a decoupling circuit between the two levels to block energy. First, a varistor and a gas discharge tube are used for the first level of protection, dissipating most of the energy generated by lightning strikes or lightning electromagnetic pulses. Then, a resettable PPTC fuse, along with common-mode inductors, differential-mode capacitors, and common-mode capacitors for filtering, blocks energy. Finally, a bidirectional TVS diode is used for voltage clamping to protect the downstream electronic circuitry.

[0086] The lightning protection circuit for communication signal lines is connected between the external communication line and the internal communication chip. For differential communication signals, protection is achieved through common-mode discharge, common-mode filtering, and voltage clamping. The common-mode discharge uses a gas discharge tube, which has low capacitance, does not affect high-speed signal transmission, and has a large current capacity, capable of dissipating most of the lightning strike energy. The common-mode inductor absorbs signal spikes, and a TVS bridge circuit is used in the subsequent stage to clamp the signal line voltage and has extremely low junction capacitance, ensuring no impact on high-speed communication signal transmission.

[0087] The above-described protection for communication power supply and communication signals involves connecting, integrating, and encapsulating the internal components, while leaving external interfaces for connection to power lines and signal lines, enabling modular use.

[0088] The first cascaded protection circuit in the first protection circuit includes: a varistor RV and a gas discharge tube GDT;

[0089] One end of the varistor RV is connected to the positive terminal of the power supply, and the other end is connected to the negative terminal of the power supply.

[0090] One end of the gas discharge tube (GDT) is connected to the grounding point, and the other end is connected to the negative terminal of the power supply.

[0091] Furthermore, the protection circuits at the power supply inputs of the first and second communication modules are as follows: Figure 4 As shown, the power supply inputs DC+ and DC- are positive and negative, respectively. The first stage of common-mode protection uses a gas discharge tube (GDT), and the differential-mode protection uses a varistor RV. The GDT is connected in parallel between DC- and the ground point. The RV is connected in parallel between DC+ and DC-.

[0092] The second cascaded protection circuit in the first protection circuit includes: a resettable fuse PPTC, a common-mode inductor CML, a differential-mode capacitor C1, a common-mode capacitor C2, and a common-mode capacitor C3;

[0093] One end of the common-mode inductor CML is connected to the resettable fuse PPTC, and the other end is connected to the differential-mode capacitor C1;

[0094] One end of the differential mode capacitor C1 is connected to the common mode capacitor C2, and the other end is connected to the common mode capacitor C3;

[0095] The common-mode capacitor C3 is connected to the grounding point.

[0096] Furthermore, the downstream protection uses a resettable fuse PPTC connected in series after the DC+ connection line RV to suppress the large current generated by lightning strikes. After the PPTC, a common-mode filter inductor CML and differential-mode filter capacitors C1, C2, and C3 are connected to filter the differential-mode and common-mode voltage spikes after discharge.

[0097] The third cascaded protection circuit in the first protection circuit includes a bidirectional TVS diode.

[0098] Furthermore, the final stage uses a bidirectional TVS diode to clamp the voltage pulse, reducing the voltage level to the range that the downstream circuit can withstand.

[0099] The second protection circuit's first cascaded protection circuit includes: gas discharge tube GDT1 and gas discharge tube GDT2;

[0100] One end of the gas discharge tube GDT1 is connected to the positive terminal of the differential signal line, and the other end is connected to the ground point;

[0101] One end of the gas discharge tube GDT2 is connected to the negative terminal of the differential signal line, and the other end is connected to the grounding point.

[0102] Furthermore, the protection circuits at the communication signal inputs of the first and second communication modules are as follows: Figure 5 As shown, common-mode protection for the differential signal lines Sp+ and Sp- uses a gas discharge tube (GDT), connected between the signal line and the grounding point, respectively. This is used to discharge lightning strike energy.

[0103] The second protection circuit, the second cascaded protection circuit, includes: a common-mode inductor CML.

[0104] Furthermore, a common-mode inductor (CML) is used in the subsequent stage to filter out residual high-frequency interference, thus achieving decoupling.

[0105] The second protection circuit and the third cascaded protection circuit include: a TVS diode bridge circuit.

[0106] Furthermore, the final stage uses a TVS diode bridge circuit to clamp the signal, ensuring that the voltages Ss+ and Ss- on the signal lines are within the withstand voltage range of the downstream circuit.

[0107] The lightning protection device for the tethered balloon communication system provided in this embodiment is designed for the characteristics of the communication system on the tethered balloon. It covers all aspects of lightning protection, including the layout of the external lightning protection network, communication power lines and signal lines, communication modules and communication circuits. It attenuates the interference caused by lightning from the outside to the inside, ensuring that the communication module can work normally during a lightning strike and guaranteeing the accuracy and reliability of data transmission.

[0108] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A lightning protection device for a tethered balloon communication system, the tethered balloon communication system comprising: The communication module located inside the sensor on the outside of the tethered balloon and the communication line connecting the communication module and the pod; characterized in that the lightning protection device includes: a lightning protection network, a shielding layer, and a protective circuit; The lightning protection netting encloses the tethered balloon; The shielding layer is installed outside the communication module and communication line of the tethered balloon and is connected to the lightning protection network; The protection circuit is connected inside the communication module and is used to protect against common-mode and differential-mode interference caused by lightning. The communication module includes a first communication module located in the sensor at the top of the tethered balloon and a second communication module located in the sensor at the bottom of the tethered balloon. Both the first communication module and the second communication module are connected to the pod via the communication line. The shielding layer includes: a metal shielding shell (10), a communication line shielding layer (11), and a connecting line (12). The metal shielding shell (10) encloses the first communication module and the second communication module, and is connected to the metal connectors of the first communication module and the second communication module; The communication line shielding layer (11) wraps around the communication line; The communication line is connected to the metal connectors of the first communication module and the second communication module.

2. The apparatus according to claim 1, characterized in that, The lightning protection network includes: multiple lightning rods (1), multiple lightning protection cables (2), and grounding cables (8). The multiple lightning rods (1) are distributed on the surface of the tethered balloon and are located around the first communication module; the multiple lightning protection cables (2) are connected in sequence and suspended on each lightning rod (1) to form a mesh structure and then wrap around the tethered balloon; The grounding cable (8) is grounded after being connected to the mesh structure.

3. The apparatus according to claim 2, characterized in that, The lightning rod (1), the lightning rod (2), and the grounding cable (8) are all conductors.

4. The apparatus according to claim 1, characterized in that, The lightning protection network covers the first communication module and at least covers the top of the tethered balloon from the top to the head and from the top to the middle of the body.

5. The apparatus according to claim 1, characterized in that, The metal shielding shell (10), the double shielding layer (11), and the connecting line (12) are all conductors.

6. The apparatus according to claim 1, characterized in that, The connecting line (12) is connected to the lightning rod (2).

7. The apparatus according to claim 1, characterized in that, The protection circuit includes: a first protection circuit and a second protection circuit; both the first communication module and the second communication module include: a communication power line and a communication signal line; The first protection circuit is connected at the inlet of the communication power line; The second protection circuit is connected at the entrance of the communication signal line.

8. The apparatus according to claim 7, characterized in that, Both the first and second protection circuits include a three-level protection circuit, which is cascaded and connected to the interface between the first and second communication modules. The first cascaded protection circuit is a common-mode discharge circuit; the second cascaded protection circuit is a common-mode filter circuit; and the third cascaded protection circuit is a voltage clamping circuit.

9. The apparatus according to claim 8, characterized in that, The first cascaded protection circuit in the first protection circuit includes: a varistor RV and a gas discharge tube GDT; One end of the varistor RV is connected to the positive terminal of the power supply, and the other end is connected to the negative terminal of the power supply. One end of the gas discharge tube (GDT) is connected to the grounding point, and the other end is connected to the negative terminal of the power supply.

10. The apparatus according to claim 8, characterized in that, The second cascaded protection circuit in the first protection circuit includes: a resettable fuse PPTC, a common-mode inductor CML, a differential-mode capacitor C1, a common-mode capacitor C2, and a common-mode capacitor C3; One end of the common-mode inductor CML is connected to the resettable fuse PPTC, and the other end is connected to the differential-mode capacitor C1; One end of the differential mode capacitor C1 is connected to the common mode capacitor C2, and the other end is connected to the common mode capacitor C3; The common-mode capacitor C3 is connected to the grounding point.

11. The apparatus according to claim 8, characterized in that, The third cascaded protection circuit in the first protection circuit includes a bidirectional TVS diode.

12. The apparatus according to claim 8, characterized in that, The second protection circuit's first cascaded protection circuit includes: gas discharge tube GDT1 and gas discharge tube GDT2; One end of the gas discharge tube GDT1 is connected to the positive terminal of the differential signal line, and the other end is connected to the ground point; One end of the gas discharge tube GDT2 is connected to the negative terminal of the differential signal line, and the other end is connected to the grounding point.

13. The apparatus according to claim 8, characterized in that, The second protection circuit, the second cascaded protection circuit, includes: a common-mode inductor CML.

14. The apparatus according to claim 8, characterized in that, The second protection circuit and the third cascaded protection circuit include: a TVS diode bridge circuit.

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