JP3663019B2 - Insulator protection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an insulator cover type insulator protection device used in a high voltage or extra high voltage distribution line.
[0002]
[Prior art]
Conventionally, a cap metal fitting is provided at the head of the insulator body, and the insulated metal wire that supports the insulated wire with a part of the covering peeled off by the cap metal fitting is provided via a pin attached to the base metal fitting fixed to the lower end of the insulator body. For the electric wire support device that is attached to and supported by the arm of the power pole, the outer periphery of the cap metal fitting is covered with an insulating cover, and an inner surface side of the insulating cover is provided with a current limiting element having voltage nonlinearity, The charge side electrode of the current limiting element is connected to the cap fitting in an elastically contacted manner via a contact piece, and a discharge electrode is connected to the ground side electrode of the element, the discharge electrode Is already provided on the current limiting element side (the edge side of the insulating cover) on the lower surface side of the insulating cover, and an insulating cover type insulator protecting device which has been opposed to the base metal fitting provided at the lower part of the insulator body through the discharge gap has already been provided Proposed.
[0003]
The above device is intended to protect against damage to the insulator caused by the continuation arc and disconnection of the insulated wire.When an abnormal voltage such as lightning surge enters the distribution line and propagates through the insulated wire, the discharge gap A flash is generated, and the electric wire is discharged through a route of an insulated wire, a cap fitting, a charge side electrode, a current limiting element, a ground side electrode, a discharge electrode, a discharge gap, a base fitting, an arm bracket, and a ground. That is, the occurrence of a continuation arc is prevented by passing the lightning surge through a current limiting element having excellent voltage nonlinearity during discharge.
[0004]
[Problems to be solved by the invention]
However, when the conventional insulator protection device is used in a salt damage area or the like, the discharge operation may not function normally. In other words, when conductive particles such as salt adhere to the surface of the insulator and the resistance value of the insulator surface decreases, the creeping streamer extends from the base metal and is attached to the head of the insulator. Although it reaches the protective device, the discharge electrode provided on the lower surface side of the insulator protective device does not easily catch the creeping streamer, so if an abnormal voltage such as a lightning surge enters the distribution line and propagates through the insulated wire In the normal operation, a direct flashing is induced between the charging part such as the cap metal fitting and the base metal fitting on the ground side without passing through the current limiting element. There was a problem of generating.
[0005]
[Means for Solving the Problems]
The present invention solves the above problems,
A cap fitting (6) for supporting the insulated wire (4) is attached to the head (2b) of the insulator (2), and the cap fitting (6) is electrically connected to the insulated wire (4). The outer periphery of the metal fitting (6) is covered with an insulating cover (21) provided with a current limiting element (36) having voltage nonlinearity on the inner surface side, and the charging side electrode (36a) of the current limiting element (36) is It is electrically connected to the cap fitting (6), the ground side electrode (36b) of the element (36) is connected to the discharge electrode (40), and the discharge electrode (40) is connected to the insulating cover (21). The base metal fitting (12) provided at the lower part (2d) of the insulator (2) through the discharge gap (G) is discharged.
The discharge electrode (40) is formed in a ring shape, and is in contact with or close to the side peripheral surface of the insulator (2) so as to be able to capture the streamer that develops the front and back of the insulator (2). The present invention proposes an insulator protection device characterized by being arranged .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings shown in FIGS.
[0007]
1 to 6 show a first embodiment.
First, the wire support device 1 will be described. Denoted at 2 is a lever body having a deep groove 2a having an opening at the lower end formed in a body portion thereof, and a recessed portion 2c for latching formed on the outer periphery of the head portion 2b.
[0008]
Reference numeral 3 denotes a clamp metal fitting. The metal fitting 3 has a lower portion 5a engaged with the retaining recess 2c and two upper support bolts 5 protruding upward, and an insulated wire 4 fitted in the center. In order to fix the support bolt 5 and the cap fitting 6 to the head 2b of the insulator body 2 by providing the fitting recess 6a for the cap bolt 6 inserted into the support bolt 5 and screwing the support fitting 5 into the support bolt 5. On the upper side of the presser fitting 9, the presser fitting 9 in which both sides are inserted into the support bolts 5 and the central portion 9 a protruding downward is brought into contact with the upper face side of the insulated wire 4. The nut 10 that is screwed into the support bolt 5 to press the presser fitting 9 downward, and the support bolt 5 that is fitted with the recess 7a in the fitting recess 6a of the cap fitting 6 are inserted into one of the support bolts 5. Tapping washer 7 and heel It is constituted by a rubber packing 11, which is deposited at close contact to the head 2b of the body 2.
[0009]
Reference numeral 12 denotes a base metal fitting fixed to the lower end 2d of the insulator body 2 with an adhesive 13 such as cement, and a bolt-like pin 14 projecting downward is fixed on the lower surface side of the metal fitting 12. Is inserted into the mounting hole 15a of the arm metal 15 from the upper surface 15b side, and a nut is screwed onto the threaded portion of the pin 14 protruding from the lower surface of the arm metal 15 to fix the insulator body 2 to the arm metal 15. Has been.
[0010]
Next, the insulating cover type insulator protection device 20 will be described. An insulating cover 21 is detachably attached to the head portion 2b of the insulator body 2 so as to cover the outer periphery of the cap fitting 6 and the clamp fitting 3 serving as a charging unit when the insulated wire 4 is supported. The whole has a cap shape, the upper end thereof is closed, and the lower end has an opening hole 22.
[0011]
The insulating cover 21 is made of a synthetic resin such as polyethylene or EVA resin or a rubber such as EPM or EPDM, which has a weather resistance and an insulating property that are improved by adding a flame retardant to improve flame retardancy and self-extinguishing properties. The upper wall 23, the electric wire insertion part 24, the lower wall 25, and the discharge electrode support plate 26, which will be described later, are divided into two in the left-right (vertical) direction, with the upper end connecting part 21a formed horizontally. The body 27A, 27B is combined (attached) (see FIG. 2).
[0012]
Reference numerals 23a and 23b denote upper walls of the divided bodies 27A and 27B. The upper walls 23a and 23b are formed vertically, and when the divided bodies 27A and 27B are joined (attached), both the upper walls 23a and 23b are formed into a cylindrical shape. It is formed to become. Reference numerals 25a and 25b are lower walls formed continuously from the upper walls 23a and 23b, and are formed so as to have a cylindrical shape that expands toward the bottom when the divided bodies 27A and 27B are joined (attached). ing.
[0013]
Reference numerals 24a and 24b denote cylindrical and tapered electric wire insertion portions which are located between the upper walls 23a and 23b and the lower walls 25a and 25b of the insulating cover 21 and project toward the side of the insulating cover 21. The diameters of the same portions 24a and 24b are slightly larger than the outer diameter of the insulated wire 4 to be inserted. Reference numerals 28a, 28b, 28c, and 28d are fitting portions when the divided bodies 27A and 27B are joined (attached), and are composed of four sets of fastening rivets and holes that are provided facing each other.
[0014]
Reference numeral 29 denotes a pressure relief window provided in total (see FIG. 2) on the mating surface 30 (see FIG. 3) below the lower walls 25a and 25b in both divided bodies 27A and 27B of the insulating cover 21, and in normal times. It is closed by a fastening portion composed of a flange 31 provided in one pressure release window 29 and a hole 31 ′ provided in the other pressure release window 29, but when the current limiting element 32 described later is destroyed. When an arc is generated in the insulating cover 21 due to an external fault or the like, if the pressure in the cover 21 is increased by the arc, the flange 31 and the hole 31 'are thereby removed, and the pressure release window 29 is bent. Is opened toward the side of the cover 21, and the arc and pressure in the cover 21 are quickly released out of the cover 21 to prevent the insulation cover 21 from being damaged. The fastening force of the fastening part composed of the flange 31 and the hole 31 'is fastened with a force smaller than the fastening force of the fitting parts 28a, 28b, 28c and 28d of the insulating cover 21 (see FIG. 3). . With such a configuration, double-sided pressure relief windows are formed on both sides of the insulating cover 21.
[0015]
Reference numerals 33a, 33b, 33c, and 33d denote bowl-shaped shielding portions that protrude from the inner surfaces of the lower walls 25a and 25b, and each shielding portion is formed in a step shape in the vertical direction. When the insulating cover 21 is attached to the head 2b of the insulator body 2, the end portions 33a ', 33b', 33c 'are close to the side peripheral surface 6a of the cap fitting 6. Further, the end 3d ′ of the shielding portion 33d provided on the lowermost side is provided so as to be close to the side peripheral surface on the upper surface side of the fold 2e of the head 2b of the insulator 2. Therefore, it is difficult for conductive particles (fouling substances) such as salt to enter the insulating cover 21.
[0016]
36 is a current limiting element having an arc-shaped cross section viewed from a plane mainly composed of zinc oxide (ZnO) having excellent voltage non-linearity. A charging side electrode 36a is disposed on the upper side of the element 36 and a lower side thereof. Is provided with a ground side electrode 36b, and the current limiting element 36, the charging side electrode 36a, and the ground side electrode 36b are integrally molded 37 with synthetic resin, rubber or the like. Further, the current limiting element 36 is built in a housing portion 27 a formed in one divided body 27 of the insulating cover 21 so that the charging side electrode 36 a protrudes into the insulating cover 21.
[0017]
Further, pressure release holes 27b and 27b for releasing the pressure into the insulating cover 21 when the current limiting element 36 is destroyed and the internal pressure rises at the upper and lower portions of the inner wall of the storage portion 27a. 'Is provided (see FIGS. 4 and 5).
[0018]
Reference numeral 26 denotes a discharge electrode support plate adhered or welded to the lower surface of the insulating cover 21. The discharge electrode supporting plate 26 is formed in a semicircular shape using the same member as the insulating cover 21, and the head 2b of the insulator 2 with the insulating cover 21 open. When the cover is closed after being attached to the insulator body 2, it enters the lower surface side of the fold 2 e of the insulator body 2, and an opening hole 22 is formed along the side peripheral surface of the insulator body 2 to close the lower surface of the insulating cover 21.
[0019]
Reference numeral 39 denotes a connection plate made of a conductive metal plate. Reference numerals 40 and 40 denote discharge electrodes disposed in the opening hole 22 portion and provided close to the side peripheral surface of the insulator 2. The connection plate 39 is provided on the inner surface side of one discharge electrode support plate 26, and the support plate 26 is bonded or welded to the lower surface of the insulating cover 21, so that one of the connection plates 39 is connected to the current limiting element 36. It is elastically connected to the ground side electrode 36 b and the other is connected to the discharge electrode 40. The discharge electrodes 40, 40 are each formed in a semicircular shape close to the side surface of the insulator 2, and the divided bodies 27A, 27B of the insulating cover 21 are combined (attached) to form the insulator 2. The two discharge electrodes 40 and 40 come close to or come into contact with each other and become one ring shape. The gap D between the discharge electrode 40 and the insulator 2 is set to a size that allows the creeping streamer of the insulator 2 to be captured by the discharge electrode 40, for example, about 3 mm.
[0020]
Reference numeral 41 denotes a contact piece fitted and fixed to the charging side electrode 36a, which is formed of a plate material made of a conductive material having elasticity such as a stainless steel plate, a phosphor bronze plate or a brass plate, and has an insulating cover-21. When attached to the insulator 2, the inner piece 41 a is elastically adhered to the side peripheral surface of the cap fitting 6, and the charging-side electrode 36 a and the cap fitting 6 of the charging portion are electrically connected. It is like that.
[0021]
Next, FIG. 7 is an enlarged view of the main part of another embodiment of the present invention, in which the ring-shaped discharge electrode 40 'is provided in contact with the side peripheral surface on the lower surface side of the fold 2e of the insulator 2. It is. As a result, the discharge electrode 40 ′ in which the creeping streamer extending from the base metal 12 to the creeping surface of the insulator 2 is brought into contact with the insulator 2 can be reliably supplemented.
[0022]
Other structures are the same as those in the first embodiment.
Next, the operation of the insulator protection device having the above configuration will be described.
The protective device is set by attaching the insulating cover 21 containing the current limiting element 36 to the head 2b of the insulator 2 as described above. In such a state, abnormal voltage such as lightning surge propagates through the insulated wire 4. In this case, the abnormal voltage is generated by the insulated wire 4 -cap fitting 6 -contact piece 41 -charging side electrode 36a-current limiting element 36-grounding side electrode 36b-connecting plate 39-discharge electrode-40-discharge gap G-base fitting 12. The armature 15 is discharged through the path of the earth, and at the same time, the continuity of the commercial frequency is interrupted by the current limiting element 36 interposed in the discharge path. This prevents accidental heat breakdown and disconnection of the insulated wire 4.
[0023]
Further, even when conductive particles such as salt adhere to the surface of the insulator and the resistance value of the insulator is lowered, the insulating cover 21 is attached to the head 2b of the insulator 2 when the ring is attached. Since the discharge electrode 40 provided in a shape is provided close to or directly on the outer peripheral surface of the insulator 2, the creeping streamer extending from the base metal fitting 12 is reliably captured by the ring-shaped discharge electrode 40, and abnormal voltage is generated. Even if it has entered, since it is reliably discharged to the ground through a normal discharge path, the continuity arc is blocked by the current limiting element 36, and a reliable protection operation can be expected.
[0024]
Further, when an external flash occurs due to an excessive abnormal voltage, the current limiting element 36 is destroyed by an arc and the internal pressure rises, the pressure is released into the insulating cover 21 through the pressure release holes 27b and 27b '. Further, each pressure release window 29 is opened as shown in FIG. 8 by the pressure, and is released to the outside through the opening 43. Thereby, it can prevent that the insulating cover 21 opens widely with the said pressure, remove | deviates from the insulator 2, and falls.
If the continuation arc continues to flow even after the pressure release window 29 is opened, the arc flows between the cap fitting 6 exposed to the opening and the base fitting 12 and flows. The arc continuity is immediately interrupted, for example, after 0.4 seconds by a substation circuit breaker.
[0025]
【The invention's effect】
As described above, since the insulator protection device of the present invention is provided with the discharge electrode in the vicinity of the outer peripheral surface of the insulator body, the resistance value of the insulator body surface decreases when used in a salt damage area or the like. The creeping streamer from the base metal can be reliably captured by the discharge electrode. As a result, even if an abnormal voltage such as a lightning surge propagates through the insulated wire and enters the insulated wire, the abnormal voltage is discharged to the ground via a normal discharge path, and the continuity arc can be interrupted.
[0026]
Moreover, since the discharge electrode is formed in a ring shape, the creeping streamer extending from the base metal fitting can be reliably captured at any part of the insulator.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state in which an insulator protecting device according to a first embodiment of the present invention is attached to an insulator body.
FIG. 2 is a view of a divided body with an insulator protecting device opened from the inner surface side.
FIG. 3 is a side view of the insulator protecting device.
FIG. 4 is an enlarged cross-sectional view showing a pressure release hole of a current limiting element portion of the insulator protection device.
FIG. 5 is an enlarged cross-sectional view of a main part of the insulator protecting device.
FIG. 6 is an enlarged cross-sectional view of a charging side electrode portion of the insulator protection device.
FIG. 7 is an enlarged sectional view of a main part of another embodiment of the present invention.
FIG. 8 is a side view of the insulator protection device in a state where a pressure release window is opened.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electric wire support apparatus 2 Insulator body 4 Insulated electric wire 6 Cap metal fitting 12 Base metal fitting 21 Insulation cover 36 Current limiting element 36a Charging side electrode 36b Grounding side electrode 40 Discharge electrode 41 Contact piece G Discharge gap

Claims (1)

A cap fitting (6) for supporting the insulated wire (4) is attached to the head (2b) of the insulator (2), and the cap fitting (6) is electrically connected to the insulated wire (4). The outer periphery of the metal fitting (6) is covered with an insulating cover (21) provided with a current limiting element (36) having voltage nonlinearity on the inner surface side, and the charging side electrode (36a) of the current limiting element (36) is It is electrically connected to the cap fitting (6), the ground side electrode (36b) of the element (36) is connected to the discharge electrode (40), and the discharge electrode (40) is connected to the insulating cover (21). The base metal fitting (12) provided at the lower part (2d) of the insulator (2) through the discharge gap (G) is discharged.
The discharge electrode (40) is formed in a ring shape, and is in contact with or close to the side peripheral surface of the insulator (2) so as to be able to capture the streamer that develops the front and back of the insulator (2). An insulator protection device characterized by being arranged in a row.

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