JP3096174B2 - Gas insulated switchgear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a gas insulated switchgear for a backbone system such as a UHV, and more particularly to an improved arrangement of gas insulated electrical equipment.

[0002]

2. Description of the Related Art UHV power transmission improves the system stability associated with long-distance large-capacity power transmission, large-power transmission such as a main outer ring system, and solves technical problems such as an increase in system short-circuit current and transmission line routes. As an effective power transmission method that can reduce the number and transmission loss, its development and practical use are being promoted in Japan and other countries. In such a UHV system, as described below, the arrangement of a lightning arrester that suppresses overvoltage generated in the system is an extremely important factor in realizing miniaturization of equipment.

[0003] That is, when a high voltage such as UHV is applied, charging current between electric wires and between electric wires and the ground surface increases. Therefore, in a system of 550 kV or less, a phenomenon having relatively little effect becomes apparent and affects facilities. Will be. For example, in the conventional 275 kV and 500 kV systems, one surge arrester is installed for each phase at the line entrance and at the transformer end in order to protect devices such as circuit breakers and transformers from lightning surge.

[0004] However, in the 1000 kV system, the layout of the substation facilities has been increased, and the distance between the line entrance and the circuit breaker has been increased. Therefore, 1000k
In the V system, it is necessary to provide two line-side lightning arresters for each phase on the pipeline bus line closer to the line than the circuit breaker in order to protect the circuit breaker from lightning surge that enters when the circuit breaker is released.

Further, for the following reasons, it may be necessary to provide three line-side lightning arresters for each phase on the pipeline bus. That is, the transmission line of the 1000 kV system has a longer distance than the lower system in order to exhibit a function as a power transporting means from a power source in a remote place. For example, in a 550kV system, the total length of the transmission line is 100k at maximum.
m, but up to 250 km for a 1000 kV system
Also reach. Furthermore, the 1000 kV transmission line has a large conductor configuration to reduce corona noise.
For example, in a 500 kV system, a maximum of six conductors constitute one phase conductor, whereas in a 1000 kV system, eight conductors constitute one phase conductor.
It constitutes a phase conductor for each phase. As a result, 1000 kV
In the system, the charging capacity of the line is much larger than in the 500 kV system.

For this reason, the level of the sustained overvoltage due to the load shedding is 1.5 pu in the 500 kV system, but reaches 1.7 to 1.8 pu in the 1000 kV system. Therefore, the line-side lightning arrester requires an extremely severe energy duty. For example, 500k
The energy duty of the lightning arrester for the V system is 3 MJ, but it exceeds 100 MJ for the lightning arrester for the 1000 kV system.

In order to endure such a severe energy duty, lightning arrester elements may be connected in multiple parallel.
There is a manufacturing limit to the number of parallel arresters that can be stored in one arrester.
For this reason, in the pipeline bus, a case may arise in which it is necessary to add a third lightning arrester to the two lightning arresters and install a total of three line-side lightning arresters.

By the way, with respect to such a lightning arrester for a 1000 kV system, in order to reduce the limiting voltage and increase the duty of switching surge, the lightning arrester element is required to be four per lightning arrester.
It is considered to be connected in parallel. In this case,
The lightning arrestor itself becomes larger or larger than the circuit breaker, and becomes the largest device among the devices constituting the gas insulated switchgear. Therefore, the installation and connection configuration of the lightning arrester has a great influence on the arrangement and connection configuration of the entire gas insulated switchgear.

On the other hand, the third surge arrester, as described above,
In particular, it is installed for an AC continuous overvoltage. Therefore, unlike lightning arresters installed for lightning surges, if they are electrically connected to the line side of the circuit breaker,
The effect can be exhibited regardless of the arrangement / connection position of any part of the line. In addition, since there is hardly any example in which three lightning arresters are provided on one line, no particular standard regarding the layout design is known at this stage.

That is, the arrangement and connection of the lightning arresters in the case of three lightning arresters have a great influence on the arrangement and connection of the entire gas insulated switchgear, but have a high degree of freedom in arrangement design. Therefore, with respect to the three lightning arresters, it is desired to realize an arrangement and connection configuration that is as rational as possible and that is advantageous for downsizing the entire gas insulated switchgear.

FIG. 6 is a plan view showing an example of the arrangement of a conventional gas insulated switchgear used in such a UHV system and having three lightning arresters for each phase. In this example, a third lightning arrester is added to the gas insulated switchgear having two lightning arresters for each phase that was considered before the analysis of the UHV system progressed. The gas insulated switchgear of this conventional example is provided on the ground where the open channel K1 is formed, and the main bus 2
0 and the line side bushing 24 are connected.

In this conventional example, a main bus 2 for each of two phases and three phases is used.
0 are arranged close to and parallel to each other. From these main buses 20, transmission line circuits 30A, 30B are drawn out at right angles to the main buses 20 via respective bus-side disconnectors 21 and connected to one end of a circuit breaker 22. The other end of each circuit breaker 22 is connected to a bushing 24 via a line-side disconnector 23 and a bushing connection pipe bus 15.

The circuit breaker 22 of each pipeline bus 15
From the vicinity, the arrester connecting bus 17 is branched at a right angle, and the arrester connecting bus 17 is further connected to the circuit breaker side arrester 10 at a right angle. On the other hand, the bushing side lightning arrester 11 is connected near the bushing 24 of each pipeline bus 15. Further, a third lightning arrester 12 is further connected to the lightning arrester connection bus 17 branched from each pipeline bus 15 in a form of branching at a right angle.

[0014]

However, the conventional gas insulated switchgear having the above configuration has the following problems. That is, in the conventional gas insulated switchgear, each of the two lightning arresters for each phase is arranged so as to branch off from a single lightning arrestor connection bus branching at a right angle from the pipeline bus. For this reason, as shown in FIG.
The two arresters connected to each arrester connection bus were arranged in series in the axial direction of the main bus, and protruded greatly from the circuit breaker and the pipeline bus in the axial direction of the main bus. Such protrusion of the lightning arrester has a great effect on the arrangement of the adjacent wiring, and in particular, FIG.
In the case where adjacent lines are drawn in the same direction as in the conventional example shown in FIG. 1, the distance L between the lines in the axial direction of the main bus becomes long, and as a result, the entire gas insulated switchgear becomes large. Had occurred.

The present invention has been proposed to solve the above-mentioned problems of the prior art, and has an object to dispose at least two lightning arresters on the circuit breaker side of a pipeline bus.
An object of the present invention is to provide a gas-insulated switchgear which is small and has a large degree of freedom in design and is optimal for a UHV system by improving a connection configuration.

[0016]

In order to achieve the above object, a gas insulated switchgear of the present invention is provided on the ground where an open channel is formed, and includes a circuit breaker, a line side bushing, and the circuit breaker and bushing. And a bushing connection pipe bus for connecting the lightning arrester with the lightning arrester, wherein the pipe bus passes through the open channel and a plurality of lightning arresters are connected to the pipe bus. At least two lightning arresters are installed near a rising portion where the pipeline bus enters and exits the open channel.

[0017]

In the present invention having the above structure,
At least two of the plurality of lightning arresters can be dispersedly arranged in empty spaces on both sides of each rising portion where the pipeline bus enters and exits the open channel. For this reason, in the vicinity of the circuit breaker, it is not necessary to arrange two lightning arresters in series in parallel with the axial direction of the main bus, so that the lightning arrester does not protrude greatly in the axial direction of the main bus, and The influence of the protrusion on the arrangement of adjacent lines can be minimized. In particular, according to the present invention, when adjacent wirings are drawn out in the same direction, the distance between lines in the axial direction of the main bus can be reduced, and the entire gas insulated switchgear can be downsized.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plurality of embodiments of the present invention will be specifically described below with reference to the drawings. The same members as those in the conventional example shown in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted.

A. First Embodiment (1) Configuration of First Embodiment: FIGS. 1 to 3 This embodiment is a typical embodiment of a gas insulated switchgear of the present invention, and FIG. FIG. 2 is a plan view showing the arrangement of the insulated switchgear, FIG.
FIG. 2 is a single-line diagram showing an example of a UHV system line corresponding to the device. The gas-insulated switchgear of this embodiment is
As shown in FIG. 1 and FIG.
1 is provided on the ground. Further, in the present embodiment, as in the above-described conventional example, the main bus 20 of each of two lines and three phases is used.
Are arranged close to and parallel to each other. From these main buses 20, power transmission lines 31A and 31B are drawn out at right angles to the main buses 20 via respective bus-side disconnectors 21 and connected to one end of a circuit breaker 22. The other end of each circuit breaker 22 is connected to a bushing 24 via a line-side disconnector 23 and a bushing connection pipe bus 15.

In this embodiment, the pipeline bus 15 passes through the open channel K1, and the road R is on the open channel (FIG. 2). In the vicinity of each circuit breaker 22 in this pipeline bus 15,
The rising section 13 into the open channel K1 is provided in a staggered manner (FIG. 1). That is, each pipeline bus 1 of the transmission line 31A
5, two external phase start-up sections 13 are connected to the main bus 20
, And the rising portion 13 of the inner phase is closer to the bushing 24 than the rising portion 13 of the outer phase. Also, among the respective pipeline buses 15 of the transmission line 31B,
The two-phase start-up unit 13 near the transmission line 31A is located at an equal distance from the main bus 20, and the remaining one-phase start-up unit 13
Are closer to the main bus 20 side than the rising portions 13 of these two phases.

An arrestor connection bus 37 branches off from the upper part of the riser 13 (FIG. 2).
The lightning arrester 10 is connected to 7 (FIG. 1). These lightning arresters 10 are provided near the main bus 20 in the vicinity of the rising portion 13, specifically, in the empty space on both sides of the open channel K 1.

On the other hand, in the pipe bus 15 near the bushing 24 inside the open channel K1, the rising portions 14 to the outside of the open channel K1 are provided in a zigzag manner. That is, the start-up unit 14 of each pipeline bus 15 of the transmission line 31A is connected to the transmission line 31B.
From the side, it is provided so as to approach the main bus 20 side sequentially,
The rising portion 14 of each pipeline bus 15 of the transmission line 31B is provided symmetrically.

An arrestor connection bus 38 branches off from the upper portion of the rising section 14 (FIG. 2).
A lightning arrester 11 is connected to 8 (FIG. 1). These lightning arresters 11 are provided near the bushing 24 in the vicinity of the rising portion 14, specifically, in the empty space on both sides of the open channel K1.

The lightning arrester 12 is connected to the bushing 24 of each pipeline bus 15.

(2) Functions and effects of the first embodiment As described above, according to the gas insulated switchgear of the present embodiment,
For each pipeline bus 15, three lightning arresters 10, 11, 1
2, two lightning arresters 10 and 11 are distributed and arranged in parallel with the pipeline bus 15 in the free space on both sides of the rising portions 13 and 14 where the pipeline bus 15 enters and exits the open channel K1. One lightning arrester 10, 11 does not protrude in the direction of the adjacent line in series with the axial direction of the main bus 20. For this reason, the space in the axial direction of the main bus 20 between the transmission line lines 31A and 31B drawn in the same direction is reduced by reducing the space for installing the lightning arrester to be secured on the side of the pipeline bus 15. In addition, the entire gas insulated switchgear can be downsized.

In particular, according to the present embodiment, the lightning arresters 10, 1
Arrester connection buses 37, 38 for connecting 1 to the pipeline bus 15
Are branched from the upper portions of the rising portions 13 and 14, respectively. For this reason, it is not necessary to newly provide a branch portion of these surge arrester connection buses 37 and 38 on the pipeline bus 15, and the configuration of the entire gas insulated switchgear can be simplified. B. Second Embodiment FIG. 4 In the present invention, the lightning arresters arranged near the open channel can be arranged only on one side of the pipeline bus for each transmission line (second embodiment). That is, FIG. 4 is a plan view showing the arrangement and connection configuration of the vicinity of the open channel portion of the pipeline bus according to the second embodiment of the present invention. In the second embodiment,
Each of the two lightning arresters 10 and 11 of each phase is a pipeline bus 15
Is arranged only on one side, and the open channel K2 is formed in a substantially rhombic shape when viewed from above in accordance with the arrangement of the rising portions 13 and 14. The second embodiment has the advantage that the flow of the operator's movement during the maintenance and inspection is shortened and simplified, and the maintenance and inspection is facilitated.

C. Third Embodiment FIG. 5 In the present invention, each lightning arrester can be arranged with its longitudinal direction being horizontal (third embodiment). That is, FIG. 5 is a plan view showing the arrangement and connection configuration of the vicinity of the bushing in the third embodiment of the present invention. The third embodiment has an advantage that the center of gravity of the lightning arrester 12 is lowered, so that it is excellent in earthquake resistance.

D. Other Embodiments Note that the present invention is not limited to the above-described embodiments, and specific device configurations and connection / arrangement configurations of respective units can be appropriately changed. For example, the arrangement of two lightning arresters for each phase in the vicinity of the rising portion is not limited to those illustrated in the first embodiment or the second embodiment, and each lightning arrester is installed on either side of the pipeline bus. It is up to you to do it. Regarding the staggered arrangement of the start-up portions of each phase, the start-up portions of any phase may be arranged closer to the main bus.

[0029]

As described above, according to the present invention, by improving the arrangement of the lightning arresters which greatly affects the arrangement of the adjacent wiring, it is possible to reduce the size and increase the degree of freedom in design.
An optimal gas insulated switchgear for a UHV system can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing an arrangement of a gas-insulated switchgear according to a first embodiment of the present invention.

FIG. 2 is a side view of the device.

FIG. 3 is a single-line diagram showing an example of a UHV system line corresponding to the apparatus.

FIG. 4 is a plan view showing an arrangement and connection configuration of a pipeline bus in a portion near an open channel portion in one transmission line in a second embodiment of the present invention.

FIG. 5 is a plan view showing an arrangement and connection configuration near a bushing in one transmission line in a third embodiment of the present invention.

FIG. 6 is a plan view showing an arrangement configuration of an example of a conventional gas insulated switchgear.

[Explanation of symbols]

 10, 11, 12: surge arrester 13, 14: start-up part 15: bushing connection pipe bus. 17, 18, 37, 38: surge arrester connection bus 20: main bus 21: bus side disconnector 22: circuit breaker 23: line side disconnector 24: bushing 30, 31: transmission line

Claims (1)

(57) [Claims] 1. A circuit breaker, a line side bushing, and a bushing connection pipe bus connecting the circuit breaker and the bushing, the pipe bus being provided on a ground where an open channel is formed, wherein the pipe bus is In a gas insulated switchgear in which a plurality of lightning arresters are connected to the pipeline bus via an open channel, the at least two lightning arresters of the plurality of lightning arresters may be connected to the pipeline bus in and out of the open channel. A gas insulated switchgear characterized by being installed near a raising part.