Device for suppressing transient potential difference between rail bars in non-electrified section

Abstract

The invention discloses a device for suppressing transient potential difference between rail bars in a non-electrified section, a multi-electrode discharge gap combination formed by connecting a multi-electrode gas discharge tube and a piezoresistor in parallel is designed, and when the transient potential difference between the rail bars is caused by lightning stroke and the amplitude exceeds the action threshold of the multi-electrode discharge gap combination, the transient potential difference between the rail bars is suppressed. The multi-electrode discharge gap combination is switched on instantly, the potential difference between the rail bars is balanced, and the differential mode overvoltage between the rail bars is suppressed, so that trackside equipment is protected, and the fault probability of equipment such as a trackside rail transformer coil, a matched resistor and a circuit breaker is greatly reduced. In addition, the multi-electrode discharge gap combination is fixed in an insulating tube with a plug, is encapsulated by epoxy resin, is mounted in a protection box made of an SMC material, and is connected with the rail bars through rail connecting wires, so that the transient overvoltage suppression requirement between the rail bars can be met, the protection box is fixed at the bottoms of the rail bars, and the mounting mode is simple, convenient and easy to implement; and the device can adapt to the complicated working conditions of trackside temperature, humidity and vibration.

Description

Technical Field

[0001] The invention relates to the technical field of lightning protection for trackside equipment in non-electrified sections, and in particular to a device for suppressing transient potential differences between rails in non-electrified sections. Background Art

[0002] During thunderstorms, rainwater enters the earth through rails, sleepers, and ballast beds, creating a relatively low impedance path between the rails and the earth. Lightning currents formed by lightning connection or electrostatic induction on rails or nearby structures are conducted along the rails, and the lightning currents are discharged into the ground through the channels formed by rainwater, and form a certain potential rise on the rail surface. The grounding resistance of two rails in different sections is different, and some sections even have significant differences. When lightning current passes through, due to its high-frequency characteristics, it is affected by the skin effect when conducting on the rails, and is mainly concentrated on the surface of the rails for conduction. Due to the existence of the rail's own impedance and the unbalanced grounding resistance to the ground, different potential rises will be formed on the two rails, and a potential difference will be formed between the two rails. The potential difference will be added to the equipment connected to the rails, causing failure of the connected equipment.

[0003] At present, the protection of the rail side of track circuit equipment in non-electrified sections is relatively simple, and there are roughly three forms: 1) a modular surge protector is installed on the rail side of the box; 2) a simple method of connecting a varistor in series with a discharge tube is used on the track transformer; 3) no protective equipment is installed, and the product's own insulation ability is relied on to resist lightning interference. Judging from the operation of the equipment on site, these measures cannot effectively solve the problem of the harm of differential mode overvoltage between rails to trackside equipment of the track circuit. When the ground lightning current is large or the signal equipment is close to the lightning strike point, the amplitude of the lightning current intruding from the rail is large. After only the SPD clamping of the equipment port, there is still a high amplitude of lightning overvoltage, which leads to frequent lightning damage failures of signal equipment.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a device for suppressing transient potential differences between rails in a non-electrified section, which can balance the potential difference between rails, suppress differential mode overvoltage between rails, and reduce trackside equipment failures.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A device for suppressing transient potential difference between rails in a non-electrified section comprises: a multi-electrode discharge gap combination; wherein the multi-electrode discharge gap combination comprises: a multi-electrode gas discharge tube and a varistor, the varistor is connected in parallel with the middle electrode of the multi-electrode gas discharge tube, and the electrodes at both ends of the multi-electrode gas discharge tube are connected to track connecting wires.

[0008] It can be seen from the technical solution provided by the present invention that a multi-electrode discharge gap combination composed of a multi-electrode gas discharge tube and a varistor connected in parallel is designed. When a lightning strike causes a transient potential difference between the rails, and the amplitude exceeds the action threshold of the multi-electrode discharge gap combination, the multi-electrode discharge gap combination will be instantly turned on to balance the potential difference between the rails, suppress the differential mode overvoltage between the rails, thereby protecting the trackside equipment and greatly reducing the failure probability of trackside track transformer coils, matching resistors, circuit breakers and other equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0010] Figure 1 A schematic diagram of a multi-electrified discharge gap combination in a device for suppressing transient potential difference between rails in a non-electrified section provided by an embodiment of the present invention;

[0011] Figure 2 A schematic diagram of the installation of a device for suppressing transient potential differences between rails provided in an embodiment of the present invention;

[0012] Figure 3 The embodiment of the present invention provides Figure 2 sectional view; wherein part (a) is an overall sectional view, and part (b) is a sectional view of a local area;

[0013] Figure 4 A schematic structural diagram of a multi-electrode discharge gap combination provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0014] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0015] First, the terms that may be used in this article are explained as follows:

[0016] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0017] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not contain technical feature elements other than the technical feature elements explicitly listed, except for the conventional impurities related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in the clause, and the elements recorded in other clauses are not excluded from the overall claim.

[0018] Unless otherwise specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this article can be understood according to specific circumstances.

[0019] The following is a detailed description of a device for suppressing transient potential differences between rails in a non-electrified section provided by the present invention. The contents not described in detail in the embodiments of the present invention belong to the prior art known to professional and technical personnel in the field. If no specific conditions are specified in the embodiments of the present invention, the conventional conditions in the field or the conditions recommended by the manufacturer shall be followed. The instruments used in the embodiments of the present invention, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0020] An embodiment of the present invention provides a device for suppressing transient potential differences between rails in a non-electrified section, which mainly includes: a multi-electrode discharge gap combination (a multi-electrode gas discharge gap and a varistor combination); wherein the multi-electrode discharge gap combination includes: a multi-electrode gas discharge tube and a varistor connected in parallel, and track connecting wires are also connected to both ends of the multi-electrode gas discharge tube.

[0021] In addition, the device also includes: a protective box, which is fixedly installed at the bottom of the rail (rail); wherein the protective box includes: a protective box body and a protective cover; the multi-electrode discharge gap assembly is fixed in the protective box body, the protective cover is covered, and the track connection line is passed through the tubes on both sides of the protective box body respectively until the pins of the track connection line are passed out. The track connection line is connected to the rail, which can meet the installation and use requirements of the trackside signal equipment.

[0022] Exemplary: the protective box is made of SMC material.

[0023] The principle of the above device is as follows: the multi-electrode discharge gap combination is in a high-impedance state under normal circumstances, and is in a low-impedance state when the overvoltage exceeds the action threshold value. Specifically: when a lightning strike causes a transient potential difference between the rails, and the amplitude exceeds the action threshold of the multi-electrode discharge gap combination, the combined discharge gap will be turned on instantaneously, balancing the potential difference between the rails and suppressing the differential mode overvoltage between the rails.

[0024] Considering that the device for suppressing the transient potential difference between the rails is installed between the rails, it is necessary to avoid the possibility of the failure mode causing the red light band. There are two general failure modes of diode discharge tubes: open circuit and short circuit. When a short circuit occurs, it will cause a red light band failure in the track circuit, affecting the operation of the signal equipment. Therefore, the multi-electrode gas discharge tube described in the present invention includes a plurality of electrodes connected in series. Even if a part of them fails due to a short circuit, there is no short circuit between the remaining electrodes, and the whole will not have a short circuit failure, and will not cause a "red light band" failure. The parallel connection of varistors can reduce the DC breakdown voltage and impulse breakdown voltage of the multi-electrode gas discharge tube, thereby achieving a better transient overvoltage suppression effect between the rails.

[0025] like Figure 1 As shown, a structural example of a multi-electrode discharge gap combination is shown. The multi-electrode gas discharge tube is specially designed, the middle electrode is connected in parallel with the varistor, and the electrodes at both ends are connected to the track connecting wire. Preferably, the middle electrode is an electrode with a reserved welding hole for welding the varistor; the electrodes at both ends are provided with screws for connecting the track connecting wire. Preferably, the track connecting wire is connected to the rail, and a through hole is opened at the waist of the rail, and the plug pin of the track connecting wire is inserted into the through hole to achieve a fixed connection between the track connecting wire and the rail.

[0026] Preferably, in order to facilitate the passage of electrons to form arc discharge more easily when the multi-electrode gas discharge tube is turned on, thereby reducing the conduction time of the discharge gap combination, a grid-shaped through hole is provided inside the middle electrode of the multi-electrode gas discharge tube; in addition, the grid-shaped hole can prevent the arc from burning only a certain part of the metal during the arc discharge, causing local metal damage, which is not conducive to the use of the gas discharge tube.

[0027] Preferably, considering that the lightning activity in the application environment is relatively strong, the number of the varistors is multiple (for example, 2), and the multi-electrode gas discharge tube is connected in parallel with all the varistors via a discharge tube connecting line.

[0028] For example, considering the requirements of the application scenario, the DC breakdown voltage of each level of the multi-electrode gas discharge tube can be 90V, and the nominal discharge current is not less than 40kA. The varistor voltage can be 68V, and the nominal discharge current is 10kA.

[0029] Preferably, since the multi-electrode discharge gap combination is located beside the track, moisture-proof, waterproof and vibration-proof should be considered. Therefore, the multi-electrode discharge gap combination is fixed in an insulating tube, and insulating tube plugs (for example, rubber plugs) are used at both ends of the insulating tube, and epoxy resin is poured inside the insulating tube to meet the requirements of on-site application; wherein the track connection line passes through the insulating tube plug and is connected to the electrodes at both ends of the multi-electrode gas discharge tube by bolts.

[0030] For example, the size of the insulating tube may be φ65×150 (length)×1 mm (thickness). This size is only an example and may be adjusted according to actual conditions or experience in actual applications.

[0031] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the solution provided by the embodiment of the present invention is described in detail below with reference to specific examples and related drawings.

[0032] like Figure 2 As shown in FIG. 1 , it is a schematic diagram of the installation of a device for suppressing the transient potential difference between rails. Figure 3 As shown, Figure 2 A cross-sectional view of a device, wherein part (a) is a cross-sectional view of the entire device and part (b) is a cross-sectional view of a local area; Figure 4 As shown in FIG. 1 , it is a schematic diagram of the structure of the multi-electrode discharge gap combination; the 1664 (mm) involved in the figure is the length of the entire device, that is, the total length of the thin tubes at both ends of the protection box body, which are also part of the protection box body. This length is only an example and can be adjusted according to actual conditions or experience in actual applications. The devices corresponding to each mark in the figure are shown in Table 1.

[0033] Table 1: Correspondence between reference symbols and device names

[0034]

[0035] In combination with the above drawings, the method of combining the multi-electrode discharge gap and encapsulating it in the insulating tube, the method of fixing the multi-electrode discharge gap and the protection box, and the method of fixing the protection box are introduced respectively below.

[0036] 1. The multi-electrode discharge gap is combined and sealed in an insulating tube.

[0037] The multi-electrode gas discharge tube 9 is connected to two varistors 8 through the discharge tube connecting wire 10. The track connecting wire 11 passes through the insulating tube plug 6 and is connected to both ends of the multi-electrode gas discharge tube 9 by bolts, and then the whole is placed in the insulating tube 7, and the track connecting wire 11 is leaked outside the insulating tube 7. During this part of the processing, the varistor 8 cannot touch the metal sheet of the discharge tube 9 to avoid discharge flashover problems. Install the insulating tube plug 6 at one end on the insulating tube 7, and then pour epoxy resin from the other end of the insulating tube 7 until the insulating tube 7 is filled flat, and the end filled with epoxy resin is also covered with the insulating tube plug 6.

[0038] 2. Fixing method of multi-electrode discharge gap combination and protection box.

[0039] The potted insulating tube 7 with the track connecting wire 11 is hung in the air until solidified, and then fixed in the SMC material protection box body 1, and covered with the SMC material protection cover 2. The track connecting wire 11 is passed through the tubes on both sides of the protection box body 1 with iron wires until the pins of the track connecting wire 11 are passed through.

[0040] 3. How to fix the protective box.

[0041] The protection box is fixed to the bottom of the rail by means of a U-shaped fixing card, a T-shaped fixing card 4, a hook-shaped fixing card and bolts.

[0042] During on-site installation, clamp the bottom of the rail with the T-shaped fixing card 4 and the hook-shaped fixing card 5 on the protective box body 1, and tighten the bolts on the fixing card 3 to lock the position. The position of the hook-shaped fixing card 5 can be adjusted to adapt to the width of the bottom of the rail. A φ10 drill bit can be used to drill a hole at the waist of the rail, and the hole must penetrate the rail. Drive the pin of the track connection line 11 into the hole at the waist of the rail to achieve a reliable connection with the rail.

[0043] The above device provided by the embodiment of the present invention mainly achieves the following beneficial effects:

[0044] (1) The use of a multi-electrode discharge gap combination can suppress differential mode overvoltage between rails and reduce trackside equipment failures. After adding grid-shaped holes to the middle electrode of the multi-electrode discharge tube, arc discharge is more likely to form inside, reducing the conduction time of the discharge gap combination, reducing the impulse discharge voltage, achieving better equipment protection effects, and greatly reducing the failure probability of trackside track transformer coils, matching resistors, circuit breakers and other equipment. In addition, the use of a multi-electrode series solution can avoid short-circuit failures and avoid the problem of "red light bands" in the track circuit caused by it.

[0045] (2) The multi-electrode discharge gap assembly is fixed in an insulating tube with a plug and encapsulated with epoxy resin. After epoxy encapsulation, the multi-electrode discharge gap assembly is installed in a protective box made of SMC material and connected to the rails through track connecting wires, which can meet the transient overvoltage suppression requirements between rails. The protective box is fixed to the bottom of the rails through stainless steel U-shaped fixing cards, T-shaped fixing cards, hook-shaped fixing cards and bolts. The installation method is simple and easy to implement, and can adapt to the complex working conditions of temperature, humidity and vibration beside the rail.

[0046] Technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above.

[0047] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A device for suppressing transient potential difference between rails in a non-electrified section, characterized in that: include: A multi-electrode discharge gap combination; wherein the multi-electrode discharge gap combination comprises: a multi-electrode gas discharge tube and a varistor connected in parallel, and track connecting wires are also connected to both ends of the multi-electrode gas discharge tube.

2. A device for suppressing transient potential difference between rails in a non-electrified section according to claim 1, characterized in that: The multi-electrode gas discharge tube comprises a plurality of electrodes connected in series, a middle electrode is connected in parallel with the varistor, and electrodes at both ends are connected to track connecting lines.

3. A device for suppressing transient potential difference between rails in a non-electrified section according to claim 2, characterized in that: The middle electrode is an electrode with a reserved welding hole for welding the varistor; the electrodes at both ends are provided with screws for connecting the track connecting wire.

4. A device for suppressing transient potential difference between rails in a non-electrified section according to claim 1 or 2, characterized in that: A grid-type through hole is provided inside the middle electrode of the multi-electrode gas discharge tube.

5. A device for suppressing transient potential difference between rails in a non-electrified section according to claim 1 or 2, characterized in that: There are multiple varistors, and the multi-electrode gas discharge tube is connected in parallel with all the varistors via a discharge tube connecting line.

6. A device for suppressing transient potential difference between rails in a non-electrified section according to claim 1 or 2, characterized in that: The track connecting line is connected to the rail, and a through hole is opened at the waist of the rail. The pins of the track connecting line are inserted into the through hole to achieve a fixed connection between the track connecting line and the rail.

7. A device for suppressing transient potential difference between rails in a non-electrified section according to claim 1 or 2, characterized in that: The multi-electrode discharge gap assembly is fixed in an insulating tube, both ends of the insulating tube are provided with insulating tube plugs, and epoxy resin is poured inside the insulating tube; wherein the track connecting wire passes through the insulating tube plug and is connected to the electrodes at both ends of the multi-electrode gas discharge tube by bolts.

8. A device for suppressing transient potential difference between rails in a non-electrified section according to claim 1, characterized in that: The device also includes: a protective box, which is fixedly installed at the bottom of the rail; wherein the protective box includes: a protective box body and a protective cover; the multi-electrode discharge gap combination is fixed in the protective box body, the protective cover is covered, and the track connecting line is passed through the tubes on both sides of the protective box body respectively until the pins of the track connecting line are passed out.

9. A device for suppressing transient potential difference between rails in a non-electrified section according to claim 8, characterized in that: The protective box is fixedly mounted on the bottom of the rail and comprises: The protection box is fixedly installed on the bottom of the rail by means of a U-shaped fixing card, a T-shaped fixing card, a hook-shaped fixing card and bolts.

10. A device for suppressing transient potential difference between rails in a non-electrified section according to claim 8 or 9, characterized in that: The protective box is made of SMC material.

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