JPH05225843A - Structure of applying lightning arrester insulator to transmission line - Google Patents

Abstract

PURPOSE:To prevent the power failure accident by flashing over a surge current to a transmission line of upper phase and making use of the transmission of upper phase as a ground wire, and suppressing the penetration of a large-scale of surge current to the transmission lines of middle and lower phases, even it a lightning surge current enters the top of a steel tower. CONSTITUTION:In a power transmission line of 154KV or highter with no ground wire at the top of the body of a steel tower, lightning arrester insulators 11 are mounted corresponding to the transmission lines 9b and 9c of the middle phase and the lower phase, without mounting a lighting insulator to the said upper phase. The aerial insulation gap Z between the arcing horns 18 and 19 on the ground side and the charge side attached to both ends of the insulator 6a of the upper phase where the lightning arrester insulator 11 is not mounted is lessened than the aerial insulation gap before mounting the lightning arrester insulator 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention separates a ground-faulted phase from a transmission line in a short time individually in a transmission line that does not use a ground wire, and re-injects it after a certain time to continue power transmission. The present invention relates to an applied structure of a lightning arrester device in a transmission line of a voltage class of 154 KV or higher having a protection system capable of operating.

[0002]

2. Description of the Related Art Generally, in a power transmission line of 154 KV or more, ground faults are individually disconnected from the power transmission line by a circuit breaker in a short time so that no voltage is applied. A protection system is used that continues.
In such a transmission line, the support arm for supporting the upper-phase, middle-phase, and lower-phase transmission lines with respect to the tower main body is upper,
The upper and middle phase and lower phase power transmission lines are respectively supported via the support insulator in which a large number of suspension insulators are connected in series at the tip of each support arm.
Further, the tower top of the tower also has a communication function, and a ground wire is installed to divert the lightning surge current that has entered the tower top of the tower main body to reduce the lightning surge current flowing to the tower body. There is. When a surge current due to a lightning strike enters such a transmission line, the surge current is quickly discharged to the ground through the steel tower,
A surge arrester device is installed corresponding to each of the three-phase power transmission lines in order to prevent and interrupt a follow-up current based on an operating voltage that occurs thereafter to prevent a ground fault and further improve reliability.

[0003]

In the above-mentioned structure to which the lightning protection insulator device is applied, the lightning surge current due to the lightning strike on the tower top or the ground wire, which occupies most of the electric shock, flows into the tower body by the shunting effect of the ground wire. Is suppressed, the shunt current to the lightning arrestor is reduced accordingly, and even when a lightning arrester with a normal capacity is used, there is no particular problem of exceeding the obligation and causing conductive breakdown.

However, in the steel tower without the ground wire, the lightning surge current that has entered the top of the tower directly enters the lightning arrestor from the support arm through the tower body without shunting the lightning surge current. When an insulator is used, there is a problem that it exceeds the withstand capacity and the probability that the lightning protection insulator will be conductively broken becomes very high, resulting in a decrease in reliability. In order to prevent this, it is possible to use a large-capacity lightning arrester for each phase, but it is extremely difficult to apply it in consideration of its manufacturing cost and pillar work.

The object of the present invention is to solve the above-mentioned problems of the prior art and to provide a type of 154K in which a ground wire is not installed.
In the applied structure of the lightning arrester device in the transmission line of V or more, it is possible to prevent the minimum power failure by using the protection system of the transmission line when a lightning surge enters, without using a large-capacity lightning arrestor. Another object of the present invention is to provide an applied structure of a lightning arrester device in a power transmission line, which enables easy manufacturing and pillar work.

[0006]

In order to achieve the above-mentioned object, the present invention separates grounded phases individually from a transmission line with a circuit breaker in a short time and re-injects after a certain time elapses.
It is equipped with a protection system that can continue power transmission, and is installed on the tower main body in order from the tower side, and the upper, middle, and lower three-phase power transmission lines are attached to the middle and lower three-phase support arms through supporting insulators. In a transmission line of which the transmission voltage is 154 KV or more, which is supported and does not use a ground wire on the upper part of the steel tower body, the lightning arrester is provided in correspondence with the middle-phase and lower-phase transmission lines without mounting the lightning protection insulator on the upper phase. The means of mounting the insulator device is adopted.

Further, according to the present invention, the air insulation distances of the arcing horns on the ground side and the charging side, which are attached to both ends of the upper-phase transmission line support insulator which does not include the lightning arrester device, are set before the lightning arrester device is mounted. It is better to make it smaller than the air insulation interval.

[0008]

In the present invention, since the ground wire is not installed on the tower top of the tower, when the lightning surge current enters the tower top or the upper phase transmission line, the potential rise is one of the three phases. Most of the lightning surge current is discharged from the tower body to the ground by causing a flashover between the largest upper-phase support arm and the transmission line. Also, the upper-phase transmission line is interrupted by a circuit breaker at a power plant or substation. At this time, since the two phases of the middle-phase power transmission line and the lower-phase power transmission line continue power transmission, no power failure will occur.

Further, the probability that a large-scale lightning surge current will intrude into the middle phase and the lower phase such that the lightning insulator having the normal capacity will be conductively broken is extremely small due to the shielding effect of the transmission line in the upper phase,
It does not have to be considered substantially. Therefore, it is possible to use the normal-capacity lightning insulators for the middle phase and the lower phase. Furthermore, since it is only necessary to use two lightning protection insulators for the entire three-phase, the number of lightning protection insulators can be reduced, and the manufacturing and mounting work thereof can be facilitated to reduce the cost.

If the air insulation distance between the grounding side and the charging side arcing horns located in the upper phase is made smaller than the air insulation distance before the lightning arrestor device is installed, surge current is generated during electric shock. Since it flashes over the air insulation interval more quickly, it promotes the shunting action of the lightning surge current, further reducing the surge current flowing to the side of the lightning protection insulator, reducing its duty, and using a small capacity lightning protection insulator. Can be used.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a tower 1 has support arms 2a, 2b, 2c and 3a, 3b, 3c in upper, middle and lower stages.
Are horizontally supported by a cantilever, and each support arm 2a-
Suspension insulator series 5a to 5c and 6a to 6c as supporting insulators, in which a large number of suspension insulators are connected in series via an upper suspension metal fitting 4, are suspended at the tip ends of 2c, 3a to 3c, and each suspension insulator. Three-phase power transmission lines 8a to 8c of one line and three-phase power transmission lines 9a to 9c of other lines are installed below the 5a to 5c and 6a to 6c via a lower connecting metal fitting 7, respectively. Transmission line 8a and transmission line 9c, Transmission line 8b and transmission line 9
b, the power transmission line 8c and the power transmission line 9a are transmission lines of opposite phases.

Further, in FIG. 1, the right supporting arm 3a.about.
A mounting adapter 10 is horizontally cantilevered and fixed to the tips of the middle-phase and lower-phase support arms 3b and 3c among 3c, and a lightning protection insulator 11 is suspended and fixed to the mounting adapter 10 by bolts. (Hereinafter, the side of the middle-phase support arm 3b will be described to simplify the description). As shown in FIG. 2, these lightning protection insulators 11 include a pressure-resistant insulating cylinder 12 made of reinforced plastic such as FRP, a resistance element 13 housed in the pressure-resistant insulating cylinder 12, and a rubber on the outer periphery and inside of the pressure-resistant insulating cylinder 12. It is composed of a molded insulating jacket 14.

Further, a discharge electrode 16 on the ground side is attached and fixed to the electrode-side electrode fitting 15 of each lightning protection insulator 1. The lower suspension metal fitting 7 of the suspension insulator string 6b supports the discharge electrode 17 on the power-supply side, and the tip of the discharge electrode 17 is the discharge electrode 16 on the power-supply side.
With a predetermined discharge gap G.

The upper hanging fitting 4 and the lower connecting fitting 7 have arcing horns 1 on the grounding side and the charging side for preventing the surface flashover of the insulators 5a-5c and 6a-6c.
8 and 19 are attached. In this embodiment, the air insulation distance Z between the arcing horns 18 and 19 on the side of the upper-phase insulator 6a is made smaller than the air insulation distance before the lightning arrestor 11 is mounted, so that the lightning surge current flashes. It is easy to overrun. The minimum value of the air insulation distance Z is a value that can withstand the switching surge current.

In this embodiment, as shown in FIG. 1, the lightning protection device is not attached to the upper phase power transmission line 9a. In this applied structure, direct lightning strikes to the middle phase and the lower phase are prevented by the upper phase power transmission line 9a, and the upper phase power transmission line 9a itself substantially has a function as a ground wire. Further, since there is no ground wire at the top of the steel tower 1, a part of the lightning surge current that has entered the top of the tower 1 flashes over the upper phase insulating support insulator 6a and is transmitted to the transmission line 9a and the remaining lightning. Surge current is lightning protection insulator 1
1 and the power transmission lines 9b and 9c and the ground respectively. Therefore, the upper-phase power transmission line 9a becomes a ground fault and the power transmission line 9a
Only a is temporarily cut off by a breaker (not shown) in a substation or the like. However, the middle and lower phase transmission lines 9b,
Since power transmission continues for each of 9c, the upper phase transmission line 9
Even if power failure occurs in a for a short time, power transmission continues,
It is possible to prevent a power failure accident on the load side. After a short time required for extinguishing the arc at the time of the ground fault, the circuit breaker is reclosed, power is again transmitted through the power transmission line 9a, and the initial state of three-phase power transmission is restored.

Further, since the upper-phase power transmission line 9a has a function as a ground wire for the middle-phase and lower-phase power transmission lines 9b and 9c, the middle-phase lightning arrester 11 and the lower-phase lightning protection insulator are provided. The intrusion of a large-scale lightning surge current into 11 is practically equal to none, and therefore, the lightning arrester 11 having a normal capacity can be used.
Moreover, even if a large-scale lightning surge current enters the tower top of the steel tower 1, the lightning surge current does not have a lightning insulator, so the impedance is smaller than that of the middle phase and the lower phase. Since more current is shunted to the arm 3a, the same result as when a normal-sized lightning surge current enters the middle-phase and lower-phase lightning arrester 11 is obtained. It is possible to prevent destruction.

Further, in this embodiment, the arcing horn 1 is used.
Since the air insulation distance Z of 8 and 19 is smaller than the air insulation distance before the lightning insulator 11 is mounted, the lightning surge current shunted from the main body of the tower to the upper phase support arm 3a is further increased. Therefore, the shunt effect can be enhanced.

As described above, in the above embodiment, the original purpose of the lightning arrester device can be achieved only by mounting two lightning arresters of normal capacity on the support arms 3b and 3c of the middle phase and the lower phase. Manufacturing and pillar work can be easily performed to reduce costs.

The present invention is not limited to the above embodiment, but can be carried out as follows. (1) In the above-described embodiment, the lightning arrester 11 is attached to the support arms 3b and 3c for the right middle and lower phases in FIG. 1, but the lightning arrester 1 is attached to the support arms 2b and 2c for the left middle and lower phases.
Wear 1. Or wear lightning protection on both sides.

(2) Use an electric wire support type lightning arrestor of a type in which the support insulators 6b and 6c directly have the function of the lightning arrestor 11.

[0021]

As described above in detail, according to the present invention, in the transmission line of 154 KV or more in which the ground wire is not installed on the tower top of the steel tower, when the lightning surge current enters the tower top or the upper phase transmission line. In addition, the surge current is shunted between the upper-phase transmission line and the tower by flashing between the arc horns of the upper-phase transmission line support insulators, and the lightning surge to the lightning-insulator of the middle-phase and lower-phase transmission lines is divided. It reduces the shunt of current,
This has the effect of eliminating continuity damage due to the duty of the lightning arrestor being exceeded.

Further, according to the present invention, the number of lightning protection insulators can be reduced, the mounting work can be easily performed, the cost can be reduced as a whole, and the power transmission can be continued in the middle phase and the lower phase to prevent a power failure. There is an effect that can be done.

Further, when the air insulation distance between the grounding side and the charging side arcing horns located in the upper phase is made smaller than the air insulation distance before the lightning arrester device is mounted,
Since the surge current flashes over the air insulation interval earlier during an electric shock, it further promotes the shunting effect of the lightning surge current, further reducing the surge current flowing to the side of the lightning protection insulator, reducing its duty, and as a lightning protection insulator. There is an effect that even a small capacity can be used.

[Brief description of drawings]

FIG. 1 is a front view showing an applied structure of a lightning protection insulator device in a power transmission line of the present invention.

FIG. 2 is an enlarged front view of the lightning arrester insulator device.

[Explanation of symbols]

1 steel tower, 2a-2c, 3a-3c support arm, 5a
~ 5c, 6a ~ 6c suspension insulator series as a support insulator, 8a
~ 8c, 9a ~ 9c power transmission line, 11 lightning insulators, 18,
19 Arcing horn, Z Insulation distance in air.

Claims (2)

[Claims] 1. A protection system is provided, which is capable of individually disconnecting a ground-faulted phase from a power transmission line with a circuit breaker, re-closing the power after a certain time, and continuing power transmission.
Mounted on the tower body in order from the tower side, support the upper, middle, and lower three-phase transmission lines through the support insulators for the middle and lower three-phase support arms, and use the ground wire on the upper part of the tower body. In the transmission line having a transmission voltage of 154 KV or more, the lightning arrester device is attached to the upper phase in correspondence with the middle-phase and lower-phase transmission lines. Structure of Lightning Insulator Device in Japan. 2. The lightning protection device according to claim 1, wherein the grounding side and the charging side arcing horns are attached to both ends of the upper phase transmission line supporting insulator without mounting the lightning protection device. Applied structure of lightning arrester device in transmission line that is smaller than the previous air insulation interval.