JPH06342685A - Arc horn for over-head wire provided with follow current cutting device - Google Patents

Abstract

PURPOSE:To provide a light and compact follow current cutting device at a low cost, which can protect an over-head wire equipment from the lightning damage. CONSTITUTION:A basic part of a follow current cutting device 14, of which copper wire 19 is inserted into an intermediate position of an insulating cylindrical body 15, is fixed to the tip of an arc horn 18 arranged in the grounding side so that the copper wire 19 is opposite to the tip of an arc horn arranged in the line. When the follow current is flowed between both the arc horns, the follow current is cut within a predetermined time by the blast of the high pressure gas generated inside of the insulating cylindrical body 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a follow-current cutoff device provided in a grounding side arc horn of a support insulator device for overhead transmission / distribution lines.

[0002]

2. Description of the Related Art In a support insulator device for overhead transmission and distribution lines, if a flashover occurs between an arc horn installed on the ground side and a line on the side of a line due to lightning, the equipment will be damaged due to a follow current (arc). It may be accompanied by damage or damage, and rarely a two-circuit simultaneous flashover accident may occur, which may have a great impact on customers. For this reason, due to the recent development of the knowledge-intensive industrial society and the advanced information society, high-quality power such as prevention of short-time blackouts has been required.

Therefore, as a means for eliminating the inconvenience caused by a short-time power failure, for example, a lightning protection horn insulator device for overhead power transmission lines (Japanese Patent Laid-Open No. 62-71117) shown in FIG. 10 has been proposed.

[0004]

However, since the lightning protection insulator 51 used in the above-mentioned conventional device is expensive, its application is limited to the lightning-prone area and some important lines. Further, in the conventional device, the transmission line support insulator mechanism 52 and the lightning protection insulator 51 are arranged with a space therebetween, and the conductor side arc horn 53 of the power transmission line support insulator mechanism 52 and the discharge electrode of the lightning protection insulator 51. There is a disadvantage that the mechanism for stabilizing the predetermined air gap G with 54 is complicated and the size is increased.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an arc horn equipped with a light-weight, small-sized, and inexpensive follow-current cutoff device which can solve the above-mentioned inconvenience.

[0006]

Means and Actions for Solving the Problems In an arc horn for an overhead wire provided with a follow current cutoff device of the present invention,
At the tip of the line-side arc horn, attach the base of the follow-current cutoff device, which is a conductive member inserted in the middle of the insulating cylinder, to the tip of the ground-side arc horn protruding outward. The conductive members are opposed to each other and fixed to each other, and the continuous flow is interrupted within a predetermined time by jetting high-pressure gas generated in the insulating cylinder when the continuous flow flows between the two arc horns. To do.

In the present invention, it is considered that the follow-up current can be promptly shut off for the following reason. If a follow-up flow due to a lightning strike flows through the conductive member provided in the insulating cylinder between the ground side arc horn and the line side arc horn, the arc will melt the inner surface of the insulating cylinder. As a result, decomposed gas is generated, and the oxidation reaction of this decomposed gas and the radiant heat of the arc heat the air in the insulating cylinder, causing the pressure in the insulating cylinder to rise rapidly. This high-pressure decomposed gas, air, etc. violently spout from the open end of the insulating cylinder together with the arc, and the pressure effect and diffusion action increase the dielectric strength of the generated gas, as well as the arc length and cooling action. The arc resistance increases, while the inside of the insulating cylinder becomes a kind of vacuum state, and the dielectric strength between the tip of the arc horn and the conductive member increases, resulting in the arc being cut off. .

In this case, the conductive member of the follow current cutoff device is
It is doubtful that the use of a metal wire that melts instantly in the arc of a single lightning strike can cope with the next lightning strike. This question can be solved by using a metal material that can withstand several lightning strokes. However, this metal material has more severe breaking performance than the former case where one electrode point is eliminated, so the through-hole diameter of the follow-current blocking device is selected to be small so as to further increase the internal pressure of the insulating cylinder and increase the insulation recovery characteristics. There is a need to.

Bird damage can be prevented by inserting an insulating tube into the grounding side arc horn equipped with a follow current cutoff device. Further, if the cap is fitted to the follow current cutoff device, the cap will always come off when the follower current cutoff device operates, so that it is possible to confirm the presence or absence of a flashover.

[0010]

EXAMPLES Examples of the present invention will be described with reference to the drawings. The transmission line suspension device shown in FIG. 1 has a series of insulators connected to a suspension device mounting bracket 2 fixed to the lower surface of a steel tower arm 1 via a plate-type U clevis 3 and a ground side horn mounting bracket 4. 5
The suspension clamp 7 is attached to the lower end of the series insulator insulator 5 through the track side horn mounting metal fitting 6, and the grounding side arranging in which both ends of the grounding side horn mounting metal fitting 4 are horizontally fixed and fixed. -The horns 8, 8 and the track-side horn fixed to both ends of the track-side horn mounting bracket 6 with the tip end facing upward.
The horns 9 and 9 are opposed to each other with a predetermined air discharge gap. Incidentally, 10 is an armor rod wound around an electric wire.

The ground side arc horn 8 is covered with an insulating tube 13 made of soft vinyl chloride over the entire length, and a follow-flow shutoff device 14 as shown in FIG.

The follow current cutoff device 14 shown in FIG. 2 has a mounting hole 17 in a base portion 16 of a straight insulating cylinder 15 made of hard vinyl chloride.
And a conductive member such as a copper wire 19 which is orthogonal to the through hole 18 of the insulating cylinder 15 is inserted in the middle, and a soft or hard vinyl chloride cap 20 is attached to the tip end of the cap 20 as needed. It is inserted through. The follow current cutoff device 14 is inserted into the grounding side arc horn 8 through the mounting hole 17 for a predetermined length. Also in this case, an adhesive is used. The copper wire 19 has one end facing the through hole 18 and the other end facing the tip of the track side arc horn 9, and is a thin wire which is instantly melted by an arc caused by one stroke. The insulation distance L ₁ between the tip of the ground side arc horn 8 and the copper wire 19 is equal to the commercial frequency withstand voltage (provided that the area between the copper wire 19 and the line side arc horn 4 is the same).
(Value obtained by deducting the voltage share) is set so as not to be longer than the interval where the flood ratio is not applied and an appropriate follow-current cutoff function can be obtained according to the supply voltage. When the supply voltage is 19.1 KV as in this embodiment, the insulation interval L ₁
Is about 3 cm. Further, the length from the tip of the ground side arc horn 8 to the free end of the insulating cylindrical body 15 (through hole length) L
_In this embodiment, ₂ are three types of 6 cm, 8 cm, and 10 cm.

The test was conducted with an insulator device of 33 KV overhead electric wire. Attach a follow current cutoff device to the tip of the ground side arc horn, and connect the tip of the ground side arc horn to the tip of the line side arc horn via the copper wire insertion point of the follow current cutoff device. A follow-up current was generated by the fuse line. The test was carried out under the following conditions. Supply voltage ・ ・ 19.1KV (33KV divided by the square root of 3) Continued current ・ ・ ・ 200A, 400A (one-line ground fault compatible) 2000A (corresponding to short circuit fault) Continued current duration ・ 0.3 seconds The following table shows an example of the test results of the continuous current interruption device.

[Table 1] *: The adhesion part between the grounding side arc horn and the follow current cutoff device has come off. ×: Failure arc continued until the end of failure continuation (interruption impossible).

From the test results shown in Table 1, the interruption time is summarized for each through-hole length L ₂ of each follow-current interruption device as shown in FIG.

In this test, in order to measure the shared voltage of the follow current interruption device, iron screws were fixed in place of the copper wire 19 at the place where the copper wire 19 was inserted in the follow current interruption device 14 shown in FIG.
Fig. 4 shows the voltage applied between the V ₁ ··· grounding side arc horn 8 and the iron screw (insulation interval L ₁ is about 3 cm) V ₂ ··· grounding side arc horn 8 to the line side arc horn -Voltage applied to terminal 9 (insulation interval of about 45 cm) Under the condition that the follow current is 200 A, V ₁ and V ₂ measurement waveforms when the follow current is interrupted in 0.5 cycle are shown. Since the follow flow was carried out with a reactor load, the
Vibration voltage (peak value 37.3K)
After the occurrence of V, the amplitude rate of 13.8, and the frequency of 1.7 KHZ, the recovery voltage (the peak value of 27 KV and the effective value of 19.1 KV) became the applied voltage V ₂ . Further, the voltage V ₁ most related to the dielectric strength recovery characteristic of the follow-current interruption device 14 after the follow-current interruption is oscillated at the re-occurrence voltage frequency, and then the recovery voltage having a peak value of about 1.44 KV is applied. Completely ark horn 8,
Since the voltage of 9 is released, the voltage becomes a low value of 0.11 KV. The recovery voltage crest value of 1.44 KV is a value that substantially coincides with the calculation result obtained from the insulation intervals L ₁ and L ₂ .

FIG. 5 shows the result of examining the change in the arc voltage when the continuous current is 400 A and the arc continues to the end of the continuous current. The arc voltage of the voltage V ₁ has a relatively high value because the insulation distance L ₁ is as short as about 3 cm, but the internal pressure rise is high and the arc length is extended.

Regarding the increase in the through-hole pressure of the follow-current cutoff device,
The pressure increase in the through-hole 18 of the follow-flow blocking device 14 causes a shocking increase in the pressure due to the air inside the abruptly heated and expanded air because the through-hole 18 is very narrow. This pressure increase has a waveform in which the first peak value shows the maximum value during the continuous current continuation period,
The pressure rises due to the first peak value of the arc power, and the pressure propagates to the left and right around the arc generation. In this test, since the follow current cutoff device 14 was small, this pressure increase was measured using a microminiature pressure transducer. FIG. 6 shows the measurement results of the first peak value of the internal pressure rise when the diameter D of the through hole of the follow flow cutoff device 14 was changed. Generally, the first pressure peak value (P-Po) due to the arc of a semi-closed system such as a pipeline can be obtained by the following equation.

[Equation 1] However,

[Equation 2] P: Pressure rise first wave height value (kgf / m ² ) Po: Initial pressure 1 × 10 ⁴ kgf / m ² R: Air gas constant 29.79 (kgfm / kgK) J: Heat work 4.19 ( KJ / kca1) Cv: Specific heat of air 0.17 (kca1 / kgK) S: Cross-sectional area of semi-enclosed system (m ² ) K: Constant terminal failure 1, central failure 2 a: Pressure propagation velocity 340 (m / sec) Wp: First peak value of arc power (KW) β: Energy efficiency that contributes to pressure increase To obtain the pressure increase from Equation 1, the first peak value Wp of arc power must be known. This Wp is the first current
It is obtained by the product of the peak value 1p and the first peak value ep of the arc voltage. The first peak value ep of the arc voltage is the current 200 to 100
It seems that it does not change in the range of about 0 A, but it is said to be roughly proportional to the square root of the internal pressure rise. Therefore, it can be estimated as shown in FIG. 7 from the measurement results of the through-hole diameter D of the follow-current cutoff device 14 of 3 mm and 6 mm. The first peak value of the arc power can also be estimated from the figure. By substituting these studied values into the formula 1, the pressure rise first peak value with respect to the through-hole diameter of the follow-current cutoff device was obtained (where β = 0.1
1) and the measurement results shown in FIG. 6 are compared with each other, the results are almost the same. Therefore, it is considered that the first pressure peak value P1max in the through hole of the follow current cutoff device can be roughly estimated by using the equation (1).

According to the test results shown in Table 1 above, the breaking time is summarized for each through-hole length L ₂ of each follow-current blocking device. In FIG. 8, when the breaking time Tb is 15 cycles, the following flow continues. Indicates that the flow continues to the end. Further, as shown in FIG. 8, the cutoff time for the through-hole diameter D of the follow-current cutoff device 14 tends to become shorter as the diameter D becomes narrower, although it depends on the follow-up value. 1-line ground fault current (200A, 400A)
The diameter D of the through-flow shut-off device 14 for shutting off the continuous flow is often 8 mm, which continues to the end of the continuous flow, and 1 in 6 mm.
Even if the case is removed, the interruption time is within Tb = 2.5 cycles. Therefore, if the diameter D of the through hole is set to 6 mm or less, it is considered that there is a sufficient possibility of blocking the continuous flow of about 200 A and 400 A. The first peak value of internal pressure rise at that time is about 20 kgf / cm ² from the result shown in FIG. If the arc extinguishing force is expected to be due to the pressure effect, it may be sufficient to find the relationship between the follow-up flow and the diameter D of the through hole so that the first peak value of internal pressure rise becomes 20 kgf / cm ² or more. . The through-hole length L ₂ of the follow-flow blocking device 14 is 60 mm, 80 mm
And the breaking performance when changing to 100 mm is 1 from 60 mm
00 mm showed a better tendency. The effect of the type of the cap 20 on the breaking performance is not sufficiently shown in the results of this test, and no difference in the breaking performance due to the presence or absence of the cap was observed. Incidentally, in the L-shaped follow current cutoff device 14 shown in FIG. 3, the rising side may be fixed to the tip of the grounding side arc horn 8. In the follow current cutoff test, the accident often comes off the arc horn. Since there was,
It is necessary to make some ingenious measures such as integrating the horn and the follow current cutoff device.

Since the copper wire 19 of the insulating cylindrical body 15 is melted by the arc of a single lightning stroke, it is doubtful that the following current interrupting device can cope with the next lightning stroke. Considering multiple lightning strikes, a conductive member that can withstand several lightning strokes is required. In this test, an iron-made screw having a diameter of about 2 mm was used for this conductive member, and the breaking performance was confirmed. The size of this follow-current cutoff device is such that the through-hole length L ₂ cut off by the half wave is 60 m.
m, 80 mm, through-hole diameter of 3 mm, 6 mm without cap, test results show that the through-hole length L ₂ is 60 mm, 80 mm
In both cases, when the through hole diameter was 3 mm, it was cut off by a half wave, but the through hole diameter was 6 mm
Then the arc continued until the end of the continuation. This is because when the above-mentioned screw is used as the conductive member, the arc electrode points on both sides in the follow-current interruption device are fixed, so the interruption performance is naturally severer than when one electrode point is eliminated. And
Therefore, it is necessary to further increase the pressure increase in the through hole to enhance the insulation recovery characteristic. From the results of this test, it can be assumed that the pressure increase will be about 80 kgf / cm ² .

FIG. 9 is a table showing the relationship between the insulation gap L ₁ and the breakdown voltage of the continuous current interrupting device for 33KV, 66KV, and 77KV overhead lines. As is clear from this chart, it is necessary to change the insulation distance L _{1 with} respect to the breakdown voltage when the supply voltage changes.

[0021]

As described above, according to the present invention, even if the arc horn flashes due to a lightning strike and the follow flow flows, the follow flow is ejected by the high pressure gas ejecting device for 2 cycles of the follow flow. Since the power is cut off within the range, it is possible to meet the uninterruptible demand due to the spread of OA equipment and the like, and to contribute to the stable power supply. Also,
Since the follow current is generated for a short time, the electrode point of the arc does not easily move to the armor rod, and the insulator and the electric wire can be prevented from being melted. Also,
Since the follow-current cutoff device can be provided in a small size and at a low cost, the cost can be greatly reduced as compared with the conventional lightning protection insulator, and the installation cost can be reduced because it can be installed easily and easily. Therefore, there is an advantage that it can be used without limiting the use area.

Since the insulation recovery characteristic can be increased by selecting the size of the follow current cutoff device, in particular, the through hole of the insulating cylinder, the conductive member of the follow current cutoff device can be made of a metal material capable of withstanding several lightning strikes. It can be adopted, which can reduce the inconvenience of exchanging every lightning stroke.

Bird damage can be prevented by inserting an insulating tube into the grounding side arc horn equipped with a follow current cutoff device. Also, if a cap is fitted to the tube opening end of the follow current cutoff device, the cap will come off during operation of the follow current cutoff device.
Serves as a flashing display.

[Brief description of drawings]

FIG. 1 is a front view of a series of suspension devices embodying the present invention.

FIG. 2 is a partially cutaway side view of the embodiment of the present invention.

FIG. 3 is a partially cutaway side view of another embodiment of the present invention.

FIG. 4 is an explanatory diagram of a voltage waveform of the follow current interruption device and a voltage waveform between the arc horns when the follow current is interrupted.

FIG. 5 is a chart showing a relationship between a continuous current duration and an arc voltage.

FIG. 6 is a chart showing a relationship between a diameter of a through hole of the follow-current cutoff device and a first peak value of internal pressure rise.

FIG. 7 is a chart showing a relationship between a diameter of a through hole of a follow current cutoff device, a first peak value of an arc voltage, and a first peak value of an arc power.

FIG. 8 is a chart showing a relationship between a diameter of a through-hole of the follow-flow blocking device and a follow-flow blocking time.

FIG. 9 is a table showing the relationship between the insulation distance L ₁ and the breakdown voltage of the follow current interrupt device.

FIG. 10 is a front view of a conventional device.

[Explanation of sign]

 8 Grounding side arc horn 9 Line side side arc horn 13 Insulation tube 14 Follower current interrupting device 15 Insulation cylinder 17 Mounting hole 18 Through hole 19 Copper wire 20 Cap

Front page continued (72) Inventor Yoshio Takashita 48 Omorimachi, Nara Kansai Electric Power Co., Inc. Nara Branch (72) Inventor Nishi Akira 48 Omorimachi Nara, Kansai Electric Power Co., Inc. Nara Branch (72) Inventor Yoshihisa Maeda 13-1 Isoshima-Minamicho, Hirakata-shi, Osaka, Japan Catan Co., Ltd. (72) Inventor Akihiro Katayama 13-1 Isoshima-Minamicho, Hirakata, Osaka, Japan Catan Co., Ltd. (72) Inventor, Hiroki Sakamoto 13-1 Isojima Minamimachi, Hirakata City, Osaka Prefecture

Claims (6)

[Claims] 1. A base portion of a follow-current cutoff device having a conductive member inserted in an intermediate position of an insulating cylinder at a tip portion of a ground side arc horn projecting outward, and a base portion of a line side arc horn. The conductive member is opposed to and fixed to the tip of the awning, and the high-pressure gas generated in the insulating cylinder when the follower flows between the two arc horns interrupts the follower within a predetermined time. An aerial wire for an overhead wire equipped with a follow-current interruption device characterized by
N. 2. An aerial wire for an overhead wire equipped with a follow current breaker according to claim 1, wherein the insulating cylinder is hard vinyl chloride.
N. 3. An aerial horn for an overhead wire provided with a follow current breaker according to claim 1, wherein the electrically conductive member is a metal wire which is instantly melted by an arc caused by a single electric shock. 4. An aerial horn for an overhead wire having a follow current cutoff device according to claim 1, wherein the electrically conductive member is a metal material that can withstand several lightning strikes. 5. An aerial wire ark horn having a follow current interruption device according to claim 1, 2, 3 or 4, wherein an insulating tube is attached to an arc horn for mounting the follow current interruption device. N. 6. An aerial horn for an overhead wire, comprising a follow current cutoff device according to claim 1, 2, 3, 4, or 5, wherein a cap is fitted on the open end of the insulating cylinder.