JP2008262865A - Insulator set - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulator set that can constrain dropping of a lighting arrester in the event of flow of the short-circuit current without increasing a mounting bracket in thickness more than required. <P>SOLUTION: An insulator set 30 has an insulator string 4 that is provided between a transmission line tower and a power cable to give insulating support of the power cable, and a lighting arrester 1 fixed to a lighting arrester mounting bracket 2 leading out of a fixing part of the insulator string 4 on the transmission line tower. An extension part 2a is mounted in a protruding state that is melted down by the arc arising in the event of flow of the short-circuit current on the opposite side of the insulator string 4 from a lighting arrester fixing position of the lighting arrester mounting bracket 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a insulator device provided with a lightning arrester, and more particularly to a structure for preventing the lightning arrester from falling.

  In recent years, lightening of lightning arresters (lightning arresters for power transmission) has been realized (1/5 or less compared to the prior art). Along with this, lightning protection devices are currently being installed on the transmission towers of transmission lines in order to further improve the reliability of power transmission facilities and prevent lightning accidents. There are various verification items that must be satisfied in order to install a lightning arrester on a transmission tower. Among the verification items is a test called a pressure release test (or arc resistance test). The purpose of this pressure release test is to make sure that the lightning arrester is energized with the accident current expected in the event of a system failure and that the internal elements of the lightning arrester body do not cause explosive scattering due to the arc generated by that current. It is in.

  In this pressure release test, an alternating current of 20 kA or more is specified as a short-circuit current, and the energization time is defined as 0.2 seconds. Since the target lightning arrester for power transmission is installed at a high place such as a power transmission tower, it is different from those used at power stations and substations, as well as the lightning arrester itself, not to mention explosive scattering. The mounting brackets for attaching are not allowed to fall. Therefore, it is necessary to make the shape of the lightning arrester mounting bracket appropriate to prevent dropping due to melting.

  This lightning arrester mounting bracket is generally long and narrow, and is cantilevered with one end fixed to the insulator fixing part of the power transmission tower (the insulator mounting bracket for fixing the insulator to the power transmission tower). In many cases, the lightning protection device is fixed to the tip of the lightning protection device (see, for example, Patent Documents 1 to 3).

JP 61-240515 A (FIG. 6) JP-A-3-245713 (FIGS. 3 and 4) JP-A-2005-302584 (FIGS. 1 and 5)

  However, according to the above conventional lightning arrester mounting bracket, it is fastened together with the above-mentioned insulator mounting bracket, and the main focus is on mounting the lightning arrester on the insulator, and the thickness of the bracket is larger than a predetermined value. By doing so, it was designed to withstand arc heat. In other words, no attempt has been made to suppress this by devising the shape other than the thickness against the occurrence of an arc caused by a short-circuit current flowing through the lightning arrester and the metal fitting being melted.

  The present invention has been made in view of the above, and suppresses the fall of the lightning arrester when a short-circuit current flows through the lightning arrester and an arc is generated without increasing the thickness of the mounting bracket more than necessary. It is an object to obtain an insulator device that can be used.

  In order to solve the above-described problems and achieve the object, the insulator device according to the present invention is provided between a support structure and a power transmission line with an insulating support for the power transmission line, and a support structure insulator fixing part. In the insulator device provided with the lightning arrester supported by the extending mounting bracket, when a short-circuit current flows through the lightning arrester, the extension portion that is melted by the arc generated by this short-circuit current is fixed to the lightning arrester of the mounting bracket. It is characterized by being provided so as to protrude from the position on the opposite side to the insulator.

  According to the insulator device of the present invention, when a short circuit current flows through the lightning arrester and an arc is generated, the arc collects in the extension portion, and the extension portion first melts. And this extension part is provided in the opposite side to the insulator from the lightning arrester fixing position of the mounting bracket, and does not contribute to the support of the lightning arrester, so the support of the lightning arrester is maintained. As a result, the lightning arrester can be prevented from dropping when a short-circuit current flows and an arc is generated without increasing the thickness of the mounting bracket more than necessary, and the arc collects in the extension portion and stays here. Therefore, the insulator can be protected from the arc.

  Embodiments of an insulator apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a side view of Embodiment 1 of the insulator device according to the present invention. 2 is an enlarged side view showing a portion (H portion) of the lightning arrester of FIG. FIG. 3 is an enlarged side view showing a portion of the lightning arrester of the conventional transmission line support device shown in FIG. In the present embodiment, an example in which the present invention is applied to a series of tension insulators is shown.

  In FIG. 1 and FIG. 2, the insulator device 30 of the present embodiment is installed on a power transmission tower (supporting structure) (not shown) standing on the ground, and insulates and supports the power transmission line from the power transmission tower. The insulator device 30 supports the power transmission line from the power transmission tower by fixing the upper connection plate 3 to the power transmission tower and connecting the lower connection plate 7 to a power transmission line (not shown). The tension type insulator device 30 is pulled by the weight of the transmission line, and generally supports the transmission line in a state of being inclined obliquely downward from the transmission tower.

  The insulator device 30 includes an insulator string 4 and a lightning arrester 1. The insulator series 4 is composed of a plurality of clevis-type suspension insulators, and is provided between the connecting plate 3 and the connecting plate 7 to suspend the power transmission line. On the other hand, the lightning arrester 1 has its upper end fixed to a lightning arrester mounting bracket (mounting bracket) 2 extending from the insulator link fixing portion (insulator fixing portion: connecting plate 3) of the power transmission tower with two fixing bolts 2b. , And extending in a predetermined direction with respect to the insulator series 4.

  The lightning arrester 1 is configured by laminating a plurality of zinc oxide elements and covering the periphery with an insulating material such as silicone rubber or an organic insulator, and a horn 5 is provided at the tip. On the other hand, an arc horn 6 is provided on the connecting plate 7 which is the tip of the insulator series 4, and a series gap is formed by the horn 5 and the arc horn 6, and the gap length is set so that discharge is surely generated in this portion. Has been adjusted.

  As clearly shown in comparison with the conventional example shown in FIG. 3, an extension 2 a is provided on the side opposite to the insulator 4 of the lightning arrester fixing position (position of the fixing bolt 2 b) of the lightning arrester mounting bracket 2. . The extension portion 2a is formed by extending the elongated lightning arrester mounting bracket 2 30 mm outward from the lightning arrester fixing position. That is, the extension part 2a is provided on the axis of the lightning arrester mounting bracket 2 extending in the longitudinal direction. The extension portion 2a is actively melted by an arc generated when a short-circuit current flows through the lightning arrester 1 due to a lightning strike or the like.

  Next, the operation will be described. When a short-circuit current flows through the lightning arrester due to a lightning strike or the like, a very high-temperature arc is generated after this short-circuit current. Due to the generation of this high-temperature arc, not only the lightning arrester but also the lightning arrester mounting bracket 2 to which the lightning arrester is attached may be melted. For this reason, in order to prevent the lightning arrester and the lightning arrester mounting bracket from explosively scattering, the internal structure of the lightning arrester main body is strengthened, and the metal fitting to which the lightning arrester is attached is resistant to melting. Thus, the plate thickness was set to a predetermined value. In general, the arc moves to the opposite side of the insulator by the electromagnetic force regardless of where it occurs. Therefore, the thickness of the lightning arrester mounting bracket is completely melted away on the opposite side of the insulator device. It was decided on the condition that there was no. For this reason, it was necessary to increase the thickness of the bracket as it moved away from the insulator device, but it is desirable that the thickness of the bracket should be constant in terms of manufacturing the bracket, so the thickness of the bracket is used to secure the lightning arrester. It was larger than necessary than the minimum thickness determined by mechanical strength.

  In order to solve this problem, in the present embodiment, the lightning arrester mounting bracket 2 to which the lightning arrester 1 is attached is extended in length, and a portion that is actively melted is provided on the lightning arrester mounting bracket 2. It was. This makes it possible to determine the thickness of the lightning arrester mounting bracket 2 from the conditions of mechanical strength that can withstand wind pressure loads and light wind vibrations that are originally required, rather than the conditions that withstand arc damage as described above. It is possible to make the thickness thick.

  The length to be extended is determined by the expected short-circuit current and energization time. The pressure release performance required for the lightning arrester 1 up to the 154 kV system class is that the magnitude of the short-circuit current is generally 40 kA and the energization time is 0.2 seconds. As a result of confirming the state of metal fusing under these conditions, it has been found that if the extension is 15 mm or more, there is no progress of fusing up to the place where the lightning arrester 1 is fixed. Since the lightning arrester 1 is installed at a high place on the power transmission tower and needs to be interrupted when it is replaced, it is not easy to replace the lightning arrester 1 including the lightning arrester mounting bracket 2. Actually, it may take several weeks to several months until the lightning arrester 1 is replaced after the accident phenomenon is discovered. Moreover, if the phenomenon in which the short-circuit current flows through the lightning arrester 1 is limited to one time, the lightning arrester 1 may not drop due to the metal fittings being broken before the lightning arrester 1 is replaced. The flowing phenomenon is often a plurality of times, and the lightning arrester 1 is not allowed to fall due to metal melt damage even in a plurality of accidents. Therefore, the length of the extension portion 2a may be appropriately increased according to the expected number of times (the lightning arrester mounting bracket 2 of the present embodiment has the condition that the energization current is 40 kA and the energization time is 0.2 seconds. Designed to withstand even when repeated twice).

  In addition, it has been confirmed by actual verification that by extending the lightning arrester mounting bracket 2 from the lightning arrester fixing position, arcs exhibiting uneasy behavior can be collected in the extension 2a and remain at this position. ing. As described above, the lightning arrester mounting bracket 2 of the present embodiment also has a function of transferring the arc generated by the short circuit current to the outside of the lightning arrester 1, that is, the side opposite to the insulator series 4 of the lightning arrester mounting bracket 2. Therefore, it is also useful for protection of the insulator series 4 desired by many users.

  As described above, the insulator device 30 according to the present embodiment is provided between the power transmission tower and the power transmission line so as to insulate and support the power transmission line, and the lightning arrester attachment extending from the fixing portion of the power transmission tower insulator 4. The lightning protection device 1 is fixed to the metal fitting 2 and is melted by an arc generated when a short-circuit current flows on the opposite side of the lightning protection device 4 from the lightning protection device fixing position of the lightning protection device mounting bracket 2. An extension 2a is projected. Therefore, when a short-circuit current flows through the lightning arrester 1 and an arc is generated, the arc collects in the extension portion 2a, and the extension portion 2a first melts. The extension portion 2a is provided so as to protrude from the lightning arrester fixing position of the mounting bracket 2 to the side opposite to the insulator 4 and does not contribute to the support of the lightning arrester 1, so that the support of the lightning arrester is retained. Is done. Thus, the lightning arrester 1 can be prevented from dropping due to the arc without increasing the thickness of the lightning arrester mounting bracket 2 more than necessary, and the arc collects in the extension portion 2a and stays there. The insulator series 4 can be protected.

  Further, in the insulator device 30 of the present embodiment, the extension portion 2a protrudes on the axis of the lightning arrester mounting bracket 2 extending in the longitudinal direction. For this reason, the lightning arrester mounting bracket 2 has a substantially rod shape and is simplified in shape, so that it is easy to manufacture.

Embodiment 2. FIG.
FIG. 4 is a side view of a second embodiment of the insulator device according to the present invention. This embodiment shows an example in which the present invention is applied to a series of suspension devices. The suspended insulator 40 has an upper connecting plate 3 fixed to a power transmission tower, a lower connecting plate 7 fixed to a power transmission line (not shown), and supports the power transmission line in a suspended state from the power transmission tower. The insulator string 44 is composed of a plurality of clevis-type suspended insulators, and hangs downward from the connecting plate 3 to suspend the transmission line. Other configurations are substantially the same as those in the first embodiment.

  Also in the insulator device 40 having such a configuration, an extension portion 2a protruding from the arc generated when a short-circuit current flows is provided on the opposite side of the lightning arrester fixing position of the lightning arrester mounting bracket 2 to the insulator station 44. Therefore, without increasing the thickness of the lightning arrester mounting bracket 2 more than necessary, it is possible to suppress the fall of the lightning arrester when a short-circuit current flows and an arc is generated, and the arc collects in the extension 2a. Therefore, there is an effect that the insulator series 4 can be protected from the arc.

  In addition, although it demonstrated regarding the case where it applied to a series tension | pulling tension insulator apparatus and a series of suspension insulator apparatuses as mentioned above as embodiment of this invention, it is not restricted to this use, For example, a duplex tension insulator apparatus and The present invention can also be applied to a suspension apparatus, a V suspension suspension apparatus using a long insulator, or a long support insulator apparatus.

  The present invention is optimally applied to an insulator device equipped with a lightning arrester as a drastic measure for improving the reliability of a transmission line and preventing lightning accidents. Insulators for power transmission lines are generally installed in power transmission towers (high places), so they are not allowed to fall under any circumstances, but even if an accidental current flows through the lightning arrester by applying the present invention, Since the metal fitting to which the lightning arrester is attached is not melted and the lightning arrester does not fall, it can be used safely.

It is a side view of Embodiment 1 of the insulator apparatus concerning this invention. It is a side view which expands and shows the part (H part) of the lightning arrester of FIG. It is a side view which expands and shows the part of the lightning arrester of the conventional power transmission line support apparatus shown compared with FIG. It is a side view of Embodiment 2 of the insulator apparatus concerning this invention.

Explanation of symbols

1 Lightning arrester for power transmission (lightning arrester)
2 Lightning arrester mounting bracket for power transmission (Mounting bracket)
2a Extension part 3 Connection plate 4,44 Insulator connection 5 Horn 6 Arc horn 7 Connection plate

Claims (6)

In an insulator device comprising an insulator provided between a support structure and a power transmission line to insulate and support the power transmission line, and a lightning arrester supported by a mounting bracket extending from the insulator fixing portion of the support structure,
When a short-circuit current flows through the lightning arrester, an extension that melts due to an arc generated by the short-circuit current is provided to protrude from the lightning arrester fixing position of the mounting bracket to the opposite side of the insulator. Characteristic insulator device. The insulator device according to claim 1, wherein the extension portion protrudes on an axis of the mounting bracket that is long in the axial direction. The insulator according to claim 1 or 2, wherein the lightning arrester is formed by laminating a plurality of zinc oxide elements and covering the periphery with an insulating material such as silicone rubber or an organic insulator. apparatus. The insulator device according to any one of claims 1 to 3, wherein the support structure is a power transmission tower erected on the ground. The insulator device according to any one of claims 1 to 4, wherein the insulator is a tension-type insulator string stretched between the support structure and the power transmission line. The insulator apparatus according to any one of claims 1 to 4, wherein the insulator is a suspended insulator string that is suspended from the support structure and supports the power transmission line.

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