Double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deep suppression of latent electric arc

Abstract

The present invention relates to a double-helix low-resistance high-efficiency heat transfer arc extinguishing device, comprising an upper electrode, a lower electrode and an arc extinguishing chamber, wherein one end of the upper electrode forms an upper electrode contact, and the other side is fixedly connected to the upper part of the insulator string ball head, and one end of the lower electrode forms a lower electrode contact, and the other side is fixedly connected to the connection between the conductor of the ultra-high voltage transmission line and the insulator string; the arc extinguishing chamber comprises an arc extinguishing chamber body made of epoxy resin, two spiral arc extinguishing channels are arranged in the arc extinguishing chamber body, and the two ends of the two spiral arc extinguishing channels have a common starting point and a convergence point, the upper electrode contact is fixedly located at the starting point of the two spiral arc extinguishing channels, and the convergence point of the two spiral arc extinguishing channels is fixedly provided with a graphite arc-starting electrode ball, and the graphite arc-starting electrode ball is partially exposed to the arc extinguishing chamber body; the distance between the upper electrode contact and the lower electrode contact is 80-90% of the height of the insulator string. The present invention can reduce operation and maintenance costs and greatly accelerate the extinguishing of the latent power arc after lightning impulse flashover.

Description

Technical Field

[0001] The invention belongs to the technical field of electrical ultra-high voltage power transmission and transformation, and in particular relates to a double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deeply suppressing latent power arcs. Background Art

[0002] With the construction of UHV power grid and the vigorous promotion of global energy internet, a strong smart grid with UHV power grid as the backbone is taking shape. UHV power transmission and transformation projects have the characteristics of high voltage level, long distance, large transmission power and special structure. UHV power transmission and transformation technology has great economic efficiency and long-term applicability, which is conducive to the optimal allocation of resources and is of great significance to ensuring national energy security and power reliability.

[0003] For UHV transmission and transformation projects, due to the large distance between lines, single-phase grounding faults are the main faults, accounting for 90% of the total faults, and most of them are transient faults (mainly transient faults caused by lightning strikes). After a single-phase grounding fault occurs in the UHV transmission system, the problem of latent power arc is particularly prominent; if the arc at the fault point is not extinguished in time, the UHV circuit breaker will overlap with the arc grounding fault, resulting in reclosing failure, which seriously threatens the safe and stable operation of the large power grid and the reliability of power supply.

[0004] Therefore, based on these problems, it is of great practical significance to provide a double-helix low-resistance and high-efficiency heat transfer arc extinguishing device that can deeply suppress latent power arcs and extend the maintenance cycle of UHV circuit breakers, reduce operation and maintenance costs, and improve the system stability of UHV power grids. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a double-helix low-resistance and high-efficiency heat transfer arc extinguishing device that can extend the maintenance cycle of ultra-high voltage circuit breakers, reduce operation and maintenance costs, and improve the system stability of ultra-high voltage power grids and deeply suppress latent power arcs.

[0006] The present invention solves the technical problem by adopting the following technical solutions:

[0007] A double-helix low-resistance high-efficiency heat transfer arc extinguishing device for deep suppression of latent electric arc, comprising an upper electrode, a lower electrode and an arc extinguishing chamber, wherein one end of the upper electrode forms an upper electrode contact, and the other side is fixedly connected to the upper part of the ball head of the insulator string, and one end of the lower electrode forms a lower electrode contact, and the other side is fixedly connected to the connection between the conductor of the UHV transmission line and the insulator string;

[0008] The arc extinguishing chamber comprises an arc extinguishing chamber body made of epoxy resin, two spiral arc extinguishing channels are arranged in the arc extinguishing chamber body, two ends of the two spiral arc extinguishing channels have a common starting point and a convergence point, the upper electrode contact is fixedly located at the starting point of the two spiral arc extinguishing channels, a graphite arc striking electrode ball is fixedly arranged at the convergence point of the two spiral arc extinguishing channels, and the graphite arc striking electrode ball is partially exposed from the arc extinguishing chamber body, and the angle between the connecting line between the lower electrode contact and the graphite arc striking electrode ball and the horizontal line on the insulator string side is 45°-60°;

[0009] The distance between the upper electrode contact and the lower electrode contact is 80-90% of the height of the insulator string.

[0010] Furthermore, the two spiral arc extinguishing channels are independent of each other and do not intersect with each other.

[0011] Furthermore, the two spiral arc extinguishing channels form a double helix structure.

[0012] Furthermore, the arc currents in the two spiral arc extinguishing channels are in the same direction, and have an attractive electromotive force, which causes the arc to be in close contact with the wall of the spiral arc extinguishing channel, thereby enhancing cooling.

[0013] Furthermore, an external insulation flashover prevention shed structure is provided on the outer side of the arc extinguishing chamber body.

[0014] Furthermore, the arc extinguishing device is installed on the load side of the UHV transmission line.

[0015] Furthermore, the electrode contact ends of the upper electrode and the lower electrode form a bent structure compared to the electrodes, so that the distance between the upper electrode contact and the lower electrode contact is 80-90% of the height of the insulator string.

[0016] The advantages and positive effects of the present invention are:

[0017] (1) The present invention proposes a parallel protection gap technology with a fixed channel for the occurrence and development of a UHV submerged power arc in view of the occurrence and development process of the submerged power arc; in view of the physical characteristics of the submerged power arc and in combination with the arc interruption technology, the device of the present invention can quickly extinguish the submerged power arc, deeply suppress the overvoltage formed by the submerged power arc and weaken the impact of instantaneous faults such as lightning strikes on the UHV power grid, and can significantly reduce the number of UHV circuit breaker operations, extend the maintenance cycle of the UHV circuit breaker, reduce the operation and maintenance cost, and improve the system stability of the UHV power grid;

[0018] (2) The arc extinguishing device of the present invention has a simple manufacturing process, strong operability, and low cost. It can achieve deep suppression of ultra-high voltage submerged power supply arcs for multiple times, and can avoid the ultra-high voltage circuit breaker from overlapping the submerged power supply arc fault for multiple times, thereby achieving the goal of greatly improving the success rate of transmission line fault reclosing. The installation method is simple, the use is quick, the operability is strong, the construction intensity is small, and it is suitable for large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0020] Figure 1 It is a schematic diagram of the structure of a double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deeply suppressing latent electric arcs provided in an embodiment of the present invention;

[0021] Figure 2 A structural cross-sectional view of an arc extinguishing chamber of a double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deeply suppressing latent electric arcs provided in an embodiment of the present invention; DETAILED DESCRIPTION

[0022] First of all, it should be noted that the specific structure, features and advantages of the present invention will be specifically described below by way of example, but all descriptions are only for illustration and should not be understood as limiting the present invention in any way. In addition, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature displayed or implied in the drawings, can still be combined or deleted between these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned in this document. In addition, in order to simplify the drawings, the same or similar technical features may be marked only in one place in the same drawing.

[0023] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other without conflict.

[0024] The following is combined Figure 1-2 The present invention will be described in detail.

[0025] The double-helix low-resistance high-efficiency heat transfer arc extinguishing device for deep suppression of latent electric arc provided in this embodiment comprises an upper electrode 1, a lower electrode 2 and an arc extinguishing chamber 3, wherein one end of the upper electrode 1 forms an upper electrode contact 101, and the other side is fixedly connected to the upper part of the ball head of the insulator string 6, and one end of the lower electrode 2 forms a lower electrode contact 201, and the other side is fixedly connected to the connection between the conductor of the ultra-high voltage transmission line and the insulator string 6;

[0026] The arc extinguishing chamber 3 comprises an arc extinguishing chamber body 301, in which two spiral arc extinguishing channels 302 are arranged, and the two ends of the two spiral arc extinguishing channels 302 have a common starting point and a convergence point, the upper electrode contact 101 is fixedly located at the starting point of the two spiral arc extinguishing channels 302, and a graphite arc-striking electrode ball 4 is fixedly arranged at the convergence point of the two spiral arc extinguishing channels 302, and the graphite arc-striking electrode ball 4 is partially exposed from the arc extinguishing chamber body 301 to play an arc-striking role, and the angle between the connecting line between the lower electrode contact and the graphite arc-striking electrode ball and the horizontal line on the insulator string side is 45°-60°, so that the lower electrode contact 201 and the graphite arc-striking electrode ball 4 form a " / "-shaped air gap;

[0027] The distance between the upper electrode contact 101 and the lower electrode contact 201 is 80-90% of the height of the insulator string; by partially short-circuiting the insulator string, the discharge voltage of the gap is lower than that of the insulator string. When a lightning strike occurs at the insulator string, since the discharge voltage of the gap is lower than that of the insulator string, the discharge occurs at the gap, thereby keeping the discharge arc away from the insulator string, thereby preventing the insulator string from being burned by the arc and exploding, causing a line break and other adverse situations.

[0028] It should be noted that the two spiral arc-extinguishing channels are independent of each other and do not intersect each other, and the two spiral arc-extinguishing channels form a double helix structure.

[0029] In addition, the arc extinguishing chamber outer insulation is designed to prevent the outer insulation flashover structure, and it can be considered that an umbrella skirt structure 5 is provided on the outer side of the arc extinguishing chamber body.

[0030] The arc extinguishing device is installed on the load side of the UHV transmission line.

[0031] The electrode contact ends of the upper electrode 1 and the lower electrode 2 form a bent structure compared to the electrodes, so that the distance between the upper electrode contact 101 and the lower electrode contact 201 is 85% of the height of the insulator string.

[0032] As an example, in this embodiment, the arc extinguishing device is installed on the load side of the UHV transmission line; specifically, the non-contact side (fixed end) of the upper electrode is fixed to the part where the upper part of the ball head of the insulator string is connected to the structure; the non-contact side (fixed end) of the lower electrode is fixed to the connection part between the conductor of the UHV transmission line and the insulator string; the non-arc extinguishing channel part inside the double-helix low-resistance and high-efficiency heat transfer arc extinguishing chamber structure is epoxy resin; when installed, the distance L between the upper and lower electrode contacts is approximately 80-90% of the height of the insulator string, that is, the device short-circuit the insulator string by 10-20%.

[0033] The parallel gap protection technology for transmission lines is the basis of this invention. By partially short-circuiting the insulator string, the discharge voltage of the gap is lower than that of the insulator string. When a lightning strike occurs at the insulator string, the discharge voltage of the gap is lower than that of the insulator string, so the discharge occurs at the gap, thereby keeping the discharge arc away from the insulator string, preventing the insulator string from being burned by the arc and exploding, causing severe situations such as line breakage.

[0034] When the UHV transmission line is subjected to lightning overvoltage, a stable burning arc occurs at the insulator string, which in turn triggers the action of the relay protection device, realizes the switch tripping, and eliminates the short-circuit arc fault. Then, in a relatively short time, the switch is reclosed to restore power supply. Due to the large phase-to-phase voltage of the UHV transmission line, after the switch trips, the arc plasma is not completely deionized in the original short-circuit arc channel, and the remaining arc plasma maintains burning under the action of the phase-to-phase voltage. This is the so-called latent power arc. The existence of the latent power arc causes the switch to overlap the arc plasma channel that has not been completely eliminated, causing the reclosing failure and resulting in the failure of power restoration; the function of the device of the present invention is to ensure the extinguishing of the latent power arc. First, in terms of fluid mechanics, the double helix structure has a low resistance effect, so that the arc plasma flows smoothly in the arc extinguishing chamber, realizing efficient heat transfer and accelerating cooling and extinguishing; second, the double helix structure, the arc current in the arc extinguishing channel is in the same direction, and has an attractive electric force, which makes the arc in close contact with the epoxy resin wall of the spiral arc extinguishing channel, enhancing heat transfer and accelerating cooling and extinguishing.

[0035] The present invention proposes a parallel protection gap technology with a fixed channel for the occurrence and development of a UHV submerged power arc in view of the occurrence and development process of the UHV submerged power arc; in view of the physical characteristics of the submerged power arc and in combination with the arc breaking technology, the device of the present invention can quickly extinguish the submerged power arc, has the effects of deeply suppressing the overvoltage formed by the submerged power arc and weakening the impact of instantaneous faults such as lightning strikes on the UHV power grid, can greatly reduce the number of UHV circuit breaker operations, extend the maintenance cycle of the UHV circuit breaker, reduce the operation and maintenance cost, and improve the system stability of the UHV power grid; the arc extinguishing device of the present invention has a simple manufacturing process, strong operability, and low cost, can achieve deep suppression of the UHV submerged power arc for many times, can avoid the UHV circuit breaker from overlapping the submerged power arc fault for many times, and achieves the goal of greatly improving the success rate of fault reclosing of the transmission line; the installation method is simple, the use is quick, the operability is strong, the construction intensity is small, and it is suitable for large-scale promotion and use.

[0036] The above embodiments describe the present invention in detail, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. Double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deep suppression of latent electric arc, characterized by: It includes an upper electrode, a lower electrode and an arc extinguishing chamber, wherein one end of the upper electrode forms an upper electrode contact, and the other side is fixedly connected to the upper part of the insulator string ball head, and one end of the lower electrode forms a lower electrode contact, and the other side is fixedly connected to the connection between the UHV transmission line conductor and the insulator string; The arc extinguishing chamber comprises an arc extinguishing chamber body made of epoxy resin, two spiral arc extinguishing channels are arranged in the arc extinguishing chamber body, two ends of the two spiral arc extinguishing channels have a common starting point and a convergence point, the upper electrode contact is fixedly located at the starting point of the two spiral arc extinguishing channels, a graphite arc striking electrode ball is fixedly arranged at the convergence point of the two spiral arc extinguishing channels, and the graphite arc striking electrode ball is partially exposed from the arc extinguishing chamber body, and the angle between the connecting line between the lower electrode contact and the graphite arc striking electrode ball and the horizontal line on the insulator string side is 45°-60°; The distance between the upper electrode contact and the lower electrode contact is 80-90% of the height of the insulator string.

2. The double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deep suppression of latent electric arc according to claim 1 is characterized in that: The two spiral arc extinguishing channels are independent of each other and do not intersect.

3. The double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deep suppression of latent electric arc according to claim 2 is characterized in that: The two spiral arc-extinguishing channels form a double helix structure.

4. The double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deep suppression of latent electric arc according to claim 1 is characterized in that: An external insulation flashover prevention shed structure is arranged outside the arc extinguishing chamber body.

5. The double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deep suppression of latent electric arc according to claim 1 is characterized in that: The arc extinguishing device is installed on the load side of the UHV transmission line.

6. The double-helix low-resistance and high-efficiency heat transfer arc extinguishing device for deep suppression of latent electric arc according to claim 1, characterized in that: The electrode contact ends of the upper electrode and the lower electrode form a bent structure compared to the electrodes, so that the distance between the upper electrode contact and the lower electrode contact is 80-90% of the height of the insulator string.

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