Lightning suppressor for lightning protection of aircraft generator AC feeder
By connecting a varistor and a gas discharge tube in series in the AC feeder of the aircraft generator, the problems of short lifespan of varistor and difficulty in detecting latent faults in the existing technology are solved, achieving a more stable and safer lightning suppression effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-19
- Publication Date
- 2026-04-07
AI Technical Summary
In existing aircraft generator AC feeder lightning suppressors, the varistor has a short lifespan, leakage current, and hidden faults that are difficult to detect. Once the fuse blows, it can no longer provide protection, leading to safety hazards for the aircraft.
The design employs a series connection between a varistor and a voltage-switching surge protector (such as a gas discharge tube). By utilizing the insulation-open-circuit characteristic of the gas discharge tube, it does not affect the steady-state operation of the power supply under normal conditions. When lightning strikes, it conducts and transfers energy to the metal structure. The varistor then returns to its insulation state to suppress follow current, thus solving the problems of varistor leakage current and fuse latent faults.
It achieves more stable and longer-lasting lightning suppression, reduces the possibility of stealth failures, and improves the safety of the aircraft.
Smart Images
Figure CN224097407U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the field of lightning protection for aircraft power supply systems, in particular to a lightning suppressor for lightning protection of an aircraft generator AC feeder. BACKGROUND
[0002] Lightning is a common physical phenomenon in nature, and aircrafts will inevitably encounter lightning during flight, which poses a significant threat to flight safety. When lightning current passes through the aircraft fuselage, energy enters the aircraft interior through resistive coupling or aperture coupling, etc., which will have an indirect effect on the aircraft power supply system at the device port, causing device damage, performance degradation or work disturbance. In order to protect the power supply system, a separate lightning suppressor needs to be added to the feeder between the generator output and the bus bar.
[0003] The existing lightning suppressor uses a varistor and a fuse to protect against lightning. The fuse is connected in series between the varistor and the ground. When the lightning voltage reaches a certain amplitude, the varistor is turned on, and the lightning current is discharged to the ground through the varistor and the fuse. However, the varistor device has a relatively low service life, and there is a leakage current and a large capacitive effect. The fuse connected to the back end of the varistor mainly functions to prevent short circuits of the generator caused by failure of the varistor, but it cannot suppress the leakage current. When the varistor fails and lightning current is injected, the fuse will melt, and it is difficult for maintenance personnel to detect. After the damage, the lightning suppressor cannot continue to achieve lightning protection function, and this hidden failure will affect the safety of the aircraft.
[0004] The present disclosure is improved in view of the above factors, but is not limited thereto. Invention content
[0005] To this end, the present disclosure proposes a lightning suppressor for lightning protection of an aircraft generator AC feeder. The lightning suppressor of the present disclosure combines the characteristics of the protection device, and considers the design of the series connection of a voltage switch type surge protector such as a gas discharge tube and a varistor. Before the application of lightning excitation, due to the insulating open circuit characteristic of the gas discharge tube, the steady-state operation of the power supply will not be affected by the protection circuit device, and the leakage current of the varistor will be suppressed. When lightning excitation is applied from the generator end to the power supply line, the varistor is turned on, and the high-voltage breakdown inert gas discharge tube is also turned on, conducting lightning energy to the metal structure, thereby achieving lightning suppression on the power supply line. After the lightning discharge is completed, the varistor returns to the insulating state, and the gas discharge tube also suppresses the freewheeling phenomenon, and solves the hidden failure problem of only installing a fuse or a fuse, and the selection problem of a varistor leakage current and a high-power transient suppression diode.
[0006] According to a first aspect of the disclosure, there is provided a lightning suppressor for lightning protection of an aircraft generator AC feeder, comprising: a voltage-dependent resistor; and a voltage switch type surge protector, a first end of the voltage switch type surge protector being connected to a first end of the voltage-dependent resistor, thereby forming a series connection of the two, wherein this series connection of the voltage-dependent resistor and the voltage switch type surge protector is connected between a generator AC feeder and a ground of the aircraft for lightning protection of the generator AC feeder.
[0007] According to an embodiment, the generator AC feeder comprises three phase lines and a neutral line, and each of the three phase lines and the neutral line is connected with a series connection of a voltage-dependent resistor and a voltage switch type surge protector.
[0008] According to another embodiment, the voltage switch type surge protector is in a conducting state if a voltage exceeding a threshold voltage is applied, and is otherwise in an insulating state.
[0009] According to yet another embodiment, the voltage switch type surge protector is a gas discharge tube.
[0010] According to yet another embodiment, a second end of the voltage-dependent resistor is connected to the generator AC feeder, and a second end of the voltage switch type surge protector is connected to the ground of the aircraft; or a second end of the voltage-dependent resistor is connected to the ground of the aircraft, and a second end of the voltage switch type surge protector is connected to the generator AC feeder.
[0011] According to a second aspect of the disclosure, there is provided an aircraft comprising the lightning suppressor according to the first aspect of the disclosure.
[0012] Thus, the disclosure proposes a lightning suppressor for lightning protection of an aircraft generator AC feeder, which achieves lightning suppression at the generator to AC feeder by a series connection of a voltage-dependent resistor and a gas discharge tube. Compared with similar models, the lightning suppressor of the disclosure is more stable, has a longer service life, and has a lower possibility of hidden failure.
[0013] Aspects generally include methods, apparatus, systems, computer program products, and processing systems, as substantially described herein with reference to and as illustrated by the accompanying drawings.
[0014] The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows can be better understood. Additional features and advantages will be described hereinafter. The disclosed conception and specific examples can be readily utilized as bases for the designing of other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions not only follow from the scope of the appended claims, but are intended to be falling within the scope of the claims. The characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying drawings. Each of the figures is provided for the purpose of illustration and description, and is not intended as a definition of the limits of the claims. BRIEF DESCRIPTION OF DRAWINGS
[0015] So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, can be had by reference to various aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description can admit to other equally effective aspects. Like reference numerals in the various drawings can designate the same or similar elements.
[0016] Figure 1 a schematic diagram of a lightning suppressor for a generator AC feeder of an aircraft according to an example embodiment of the present disclosure is shown;
[0017] Figure 2 a schematic diagram of another lightning suppressor of the prior art is shown;
[0018] Figure 3 a schematic diagram of a lightning suppressor for a generator AC feeder of an aircraft according to an example embodiment of the present disclosure is shown; and
[0019] Figure 4 a schematic diagram of an aircraft according to an example embodiment of the present disclosure is shown. DETAILED DESCRIPTION
[0020] The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without
[0021] REFERENCE Figure 1 which shows a schematic diagram of a lightning suppressor 100 of the prior art.
[0022] As Figure 1As shown, the prior art lightning suppressor 100 protects each power supply line by a varistor 101, and a fuse 102 is connected in series between the varistor 101 and the ground. When the lightning voltage reaches a certain amplitude, the varistor is turned on, and the lightning current is discharged to the ground through the varistor and the fuse. In addition, a test point 103 is provided between the varistor 101 and the fuse 102 for testing and regular maintenance of the lightning suppressor 100. In addition, a contact 104 is provided for connecting to the corresponding power supply line. Figure 1 As can also be seen from
[0023] The inventors have realized that the varistor 101 in the lightning suppressor 100 has a low service life and can have a leakage current and a large capacitance. The main function of the fuse 102 connected to the back end of the varistor 101 is to prevent the generator from short-circuiting when the varistor 101 fails, but it cannot suppress the leakage current. When the varistor 101 fails and lightning current is injected, the fuse 102 will be blown and will not be easily detected by maintenance personnel. After the damage, the lightning suppressor 100 cannot continue to achieve the lightning protection function, and this hidden failure can affect the safety of the aircraft.
[0024] Figure 2 A schematic diagram of another prior art lightning suppressor 200 is shown.
[0025] As shown in Figure 2 The lightning suppressor 200 suppresses lightning by means of transient suppression diodes D1, D2, D3 and fuses F1, F2, F3. The transient suppression diode D1 and the fuse F1 are connected in series between the first phase (A in Figure 2 ) and the ground (PE in Figure 2 ), the transient suppression diode D2 and the fuse F2 are connected in series between the second phase (B in Figure 2 ) and the ground, and the transient suppression diode D3 and the fuse F3 are connected in series between the third phase (C in Figure 2 ) and the ground. When a lightning-induced overvoltage transient occurs on the line, the transient suppression diode is immediately turned on to a very low impedance state, discharging the lightning current and clamping the voltage. As the transient pulse energy decays, the transient suppression diode will automatically recover to a high impedance open state.
[0026] However, the transient suppression diodes D1, D2, D3 in the lightning suppressor 200 focus on low-voltage power supply protection. Due to the protection voltage and volume limitations, there is a lack of matching single transient suppression diodes. If multiple low-voltage transient suppression diodes are used in series, the protection effect and stability will also decrease, and therefore they are not suitable for protection of 230V AC power supply. In addition, the fuses F1, F2, F3 also have the risk of the above-mentioned hidden failure, and need to be regularly checked and maintained.
[0027] To this end, the present disclosure proposes a novel lightning suppressor for lightning protection of generator AC feeders. The lightning suppressor of the present disclosure is designed by series connection of a voltage switch type surge protector (e.g., a gas discharge tube) and a varistor. In the lightning suppressor of the present disclosure, before lightning excitation is applied, the steady state operation of the power supply is not affected by the protection circuit devices due to the insulation open circuit characteristic of the voltage switch type surge protector, and the leakage current of the varistor is suppressed; when lightning excitation is applied from the generator end to the power supply line, the varistor is turned on, and at the same time, the high voltage breakdown voltage switch type surge protector is broken down to make it conductive, conducting lightning energy to the metal structure, thereby achieving lightning suppression on the power supply line; after the lightning excitation ends, the varistor returns to the insulation state, thereby suppressing the freewheeling phenomenon of the voltage switch type surge protector.
[0028] Reference Figure 3 which shows a schematic diagram of a lightning suppressor 300 for lightning protection of generator AC feeders of an aircraft according to an example embodiment of the present disclosure.
[0029] As Figure 3 shown, the lightning suppressor 300 can include a varistor 301 and a voltage switch type surge protector 303. It can also be seen that a first end of the voltage switch type surge protector 303 is connected to a first end of the varistor 301, thereby forming a series connection of the two. In this embodiment, this series connection of the varistor 301 and the voltage switch type surge protector 303 is connected between a phase line A of a generator AC feeder (shown in Figure 3 Fig. 1 as a phase line A) and a ground of the aircraft for lightning protection of the generator AC feeder.
[0030] In embodiments of the present disclosure, at least one of the generator AC feeders can be protected using a series connection of a varistor and a voltage switch type surge protector, while other generator AC feeders can be protected using any other suitable means. In preferred embodiments of the present disclosure, all generator AC feeders are protected using a series connection of a varistor and a voltage switch type surge protector. As Figure 3 shown, it shows that the generator output has four AC feeders, marked as A, B, C, N, and a series connection of a varistor and a voltage switch type surge protector is connected on each AC feeder, but this is only exemplary. It will be understood that the generator can output other numbers of AC feeders (e.g., two sets of three phase lines, etc.), and at least one of these generator AC feeders is connected with a series connection of a varistor and a voltage switch type surge protector.
[0031] Thus, in a further embodiment of the disclosure, the generator AC feed line can include three phase lines and a neutral line, and each of the three phase lines and the neutral line is connected with a series connection of a voltage-dependent resistor and a voltage-switching surge protector.
[0032] In an embodiment of the disclosure, the voltage-switching surge protector is in a conducting state if a voltage exceeding a threshold voltage is applied, and is in an insulating state otherwise. Preferably, the voltage-switching surge protector is a gas discharge tube.
[0033] Although Figure 3 Although the voltage-dependent resistor 301 is shown as connected between the phase line A and the voltage-switching surge protector 303, alternatively, the voltage-dependent resistor 301 can instead be connected between the voltage-switching surge protector 303 and ground. Thus, in an alternative embodiment of the disclosure, the second end of the voltage-dependent resistor 301 can be connected to the generator AC feed line, and the second end of the voltage-switching surge protector 303 is connected to the ground of the aircraft; or the second end of the voltage-dependent resistor 301 is connected to the ground of the aircraft, and the second end of the voltage-switching surge protector 303 is connected to the generator AC feed line.
[0034] It will also be appreciated that the operating parameters of the voltage-dependent resistor 301 and the voltage-switching surge protector 303 can be selected depending on the required lightning protection needs, which will not be described here again.
[0035] The working principle of the lightning suppressor 300 of the present disclosure will be described below with the gas discharge tube as an example:
[0036] The working principle of the gas discharge tube is mainly gas discharge. When a large enough electric quantity is generated between the two stages, the inter-electrode gap will be broken down by discharge, at which time it changes from an insulating state to a conductive state, similar to a short circuit. When the gas discharge tube is in a conductive state, the voltage between the two stages will be relatively low, generally between 20-50V. The inventors found that the gas discharge tube alone as a lightning protection device has certain defects, such as the existence of a freewheeling condition during discharge. In addition, the pressure-sensitive resistor has the advantages of good nonlinearity and no freewheeling as a semiconductor device. Its principle is that before the voltage applied across it reaches the breakdown voltage, the pressure-sensitive resistor is close to an insulator, and after the voltage is higher than the breakdown voltage, it will have a relatively low resistance. However, the inventors also found that the pressure-sensitive resistor alone as a lightning protection device also has certain defects, such as aging of the pressure-sensitive resistor under a single strong pulse impact or long-term effect of a certain temperature external electric field, internal ion redistribution causing Schottky barrier distortion, thereby causing an increase in leakage current, and the leakage current increases with the increase in the voltage across the two ends. Therefore, the inventors combined the electrical characteristics of the two to achieve lightning protection for the rear-stage circuit. In the lightning suppressor of the present disclosure, when the lightning discharge is complete, the pressure-sensitive resistor returns to an insulating state, which also suppresses the freewheeling phenomenon of the gas discharge tube, and also solves the problem of hidden failure when only a fuse or a fuse is installed, and the problems of thermal failure due to the leakage current of the pressure-sensitive resistor and the selection of high-power transient suppression diodes.
[0037] Figure 4 A schematic diagram of an aircraft 400 is shown in accordance with an example embodiment of the present disclosure. In an embodiment of the present disclosure, the aircraft 400 can include a lightning suppressor in accordance with embodiments of the present disclosure, such as the lightning suppressor 300 described in conjunction with Figure 3
[0038] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments that can be practiced. These embodiments are also referred to as “examples.” Such examples can include elements in addition to those shown or described. However, the examples also can include examples having only those elements shown or described. In addition, the examples described herein can also include examples that are a combination of the examples shown or described.
[0039] In the appended claims, the terms "include" and "comprise" are open-ended, that is, specified in the claims shall cover an addition of elements falling within the same meaning as equivalents of those elements that are already specified in the claims. Additionally, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical or sequential order unless specifically indicated otherwise.
[0040] In addition, the order in which the operations are illustrated in the figures is an example. In alternative embodiments, the operations can be performed in a different order than illustrated, or the operations can be combined into single operations or split into multiple operations.
[0041] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) can be used in combination with other examples. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract allows a reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims. Also, in the above Detailed Description, various features can be grouped together to streamline the disclosure. However, the claims can not set forth every feature disclosed in the above Description. Instead, the claims can be written to include only those features necessary to implement the embodiments described in the specification and by the claims. Therefore, the claims are not to be construed as being limited to the features disclosed in the above Description, but rather are to be construed broadly according to the claims and their equivalents.
Claims
1. A lightning suppressor for lightning protection of an aircraft generator AC feeder, comprising: Varistor; as well as A voltage-switching surge protector, wherein the first terminal of the voltage-switching surge protector is connected to the first terminal of the varistor, thereby forming a series connection between the two. The series connection between the varistor and the voltage-switching surge protector is connected between a generator AC feeder and the aircraft ground for lightning protection of the generator AC feeder.
2. The lightning suppressor according to claim 1, characterized in that, The generator AC feeder includes three-phase lines and a neutral line, and each of the three-phase lines and the neutral line is connected in series with a varistor and a voltage-switching surge protector.
3. The lightning suppressor according to claim 2, characterized in that, The voltage-switching surge protector is in a conducting state when an applied voltage exceeding a threshold voltage is applied, and otherwise in an insulating state.
4. The lightning suppressor according to claim 3, characterized in that, The voltage-switching surge protector is a gas discharge tube.
5. The lightning suppressor according to claim 1, characterized in that: The second terminal of the varistor is connected to the generator AC feeder, and the second terminal of the voltage-switching surge protector is connected to the aircraft's ground; or The second terminal of the varistor is connected to the ground of the aircraft, and the second terminal of the voltage switch surge protector is connected to the AC feeder of the generator.
6. An aircraft comprising a lightning suppressor according to any one of claims 1-5.