JPS6358007B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas insulated switchgear, and more particularly to a gas insulated switchgear in which the arrangement of a composite gas insulated switchgear is improved.

Conventionally, the arrangement of composite gas-insulated switchgear is as follows:
For example, it is configured as shown in FIG. In the figure, 1 is a shingle breaker that stores a shingle section along with SF ₆ gas in a horizontally grounded tank, and 2 is an air butting. It is placed in the section. The other terminal portion is placed on a disconnecting section 3 tank installed at the other end of the cutter 1. The terminal portion of each air bushing 2 is connected to an air bus insulated to the atmosphere or to a line lead-out lead. One terminal portion 4 of the disconnector 3 is connected to the terminal portion 4' of the disconnector 1 via a through-type current transformer 5 in the middle. A terminal portion 8 of an earthing switch 7 is provided at a terminal portion 6 connected to the bushing 2 of the disconnector 3. In addition, a lightning arrester 9 is installed to ensure insulation coordination between the gas-insulated switchgear and lightning surge, and the terminal portion 9' of the lightning arrester 9 is connected to the terminal portion 6 of the disconnector 3.
This conductor 10 is used to arrange a capacitance type intermediate electrode 11 coaxially cylindrical with the conductor 10 for detecting the voltage on the line side.

In such a configuration, since the earthing switch 7 is disposed at a relatively upper portion of the disconnector 3,
As it operates, various sliding metal powders are generated, and these sliding powders fall into the tank of the disconnector 3 and land on the insulating spacer 12 that supports one terminal part 4 of the disconnector 3. It will accumulate. The adhesion of metal powder to the insulating spacer 12 in this manner leads to deterioration of insulation performance when the gas insulated switchgear is used for many years. In particular, in recent years, large-scale, large-capacity power transmission (550 KV, 12 KA, transmission line constant length of 200 km or more) is becoming a reality, and the responsibility for opening and closing the earthing switch used in gas-insulated switchgear applied to such power transmission systems has also increased. It is more severe than the conventional type, and an example of its opening/closing capacity is 90KV-1500A.
Induction current reduction is required. In order to provide the earthing switch with such opening/closing ability, a gas blowing function, so-called puffer blowing, or the like is employed at the contact portion. It is difficult to accommodate such a grounding switch 7 in the tank of the disconnecting switch 3 because the opening/closing mechanism section 13 becomes too large. In addition, the amount of dust generated when the induced current is interrupted will inevitably increase, and this will accumulate on the insulating spacer 12, resulting in a decrease in the dielectric strength of the insulating spacer 12, which will inevitably result in a long lead surface insulation distance. It becomes necessary to consider adopting a shaped insulating spacer or a slightly larger spacer. Furthermore, since the earthing switch 7 is installed at a relatively high location, a special operation floor or the like is required for operation and inspection.

The present invention has been made in view of the above points, and at the same time improves the workability of inspecting earthing switches, it also facilitates the integration of various devices and improves reliability in the era of large-capacity power transmission. The purpose is to provide insulated switchgear.

An embodiment of the present invention will be described below with reference to FIG. In the figure, reference numeral 21 denotes a shroud disconnector which houses a shingle disconnector whose one end is connected to a bushing 21a established on the tank inside a horizontally placed grounded tank and which is filled with insulating gas, and which is connected to one end in the axial direction of the tank. A terminal portion 22 is provided in a protruding manner. 23 is this terminal part 2
This is a current transformer placed outside the pipe line No. 2. Reference numeral 24 denotes a disconnector which is disposed at the other end of the shield breaker 21 and has a disconnecting section housed in a tank and is filled with insulating gas.
is connected to a conductor in one terminal portion 22 of the terminal. The other terminal portion 26 is led out through an insulating spacer into a bushing support tank 28 that establishes an air bushing 27. Note that 24a is a mechanical part of the disconnector 24. Inside the bushing support tank 28 are a conductor 29 connected to one terminal 26 of the disconnector 24, a conductor 31 on the extension axis of the center conductor 30 of the bushing 27, and a grounding switch 3 disposed at the end of the conductor 29.
The opening/closing mechanism part 35 of the earthing switch 32 is provided at the bottom of the bushing support tank 28.
An operating mechanism section 33 is disposed therein, and an intermediate electrode 36 is disposed concentrically around the outer periphery of the fixed contact 34 to form a voltage detection device having a voltage detection function using capacitive partial pressure. In particular, the reason why they are arranged around the fixed contact 34 is that since this surface area is larger than that of the conductor 31, the area facing the intermediate electrode 36 can be increased, and therefore a large capacitance can be obtained. . Further, in order to protect the gas insulated switchgear when a lightning surge enters through the power transmission line, a lightning arrester 37 is disposed on the outermost side on the extension of the breaker tank axis via the bushing support tank 28. It is connected to the conductor 31 by a detachable conductor 38.

By adopting such an arrangement, it is possible to cope with the increase in the capacity of the wire cutter 21, which has continued to make remarkable progress in recent years. In other words, the number of shear fractures tends to be halved by improving the shear cutting performance. for example
The 300KV class is going from 2 points to 1 point, and the 550KV class is going from 4 points to 2 points. This means that the axial length of the tank of the breaker 21 is shortened. In contrast, bushing 21a,
27 In order to ensure the air insulation distance between heads, when considering a single chopstick or disconnector, it is necessary to attach the bushing to the tank at an angle. However, in a composite switchgear, it is not necessary to arrange the bushings at an angle by rationally arranging each component. That is, erecting the bushing perpendicularly to the shaft and disconnection tank axis is easy in terms of seismic strength and setting the strength of the opening of the bushing erected portion, and the tank is also easy to manufacture. In order to secure the aerial distance between the bushings, the required distance is secured by arranging a disconnector in the middle between the bushings. As an example, if the voltage is 550KV, the cable break is 2 points, and a bushing is established on the disconnect switch, the distance will be about 4.5m, which is smaller than the minimum required distance of 5m for insulation, but as in the present invention, When established on the bushing support tank 28, the distance is approximately 6 m, which is a sufficient distance. In addition, with this arrangement, the disconnector 24 and the grounding switch 32 are separated into separate containers, so the duty of opening and closing the grounding switch 32 applied to a large-capacity power transmission network has become severe, as detailed above. Although the amount of dust caused by the cutting increases, since the bushing can be placed at the lower part of the bushing support tank 28, the dust does not stain the surface of the insulating material. Therefore, the reliability of insulation performance is dramatically improved. Furthermore, since the operating mechanism section 33 of the earthing switch 32 can be set at the same level as the operating mechanism section 24a of the disconnecting switch 24, a special operation floor is not required for operation inspection, and operation can be easily performed from the ground level. becomes. In addition, by making the conductor 38 for connection with the lightning arrester 37 in the bushing support tank 28 a removable conductor, the elements of the lightning arrester 37 can be removed by removing the conductor 38 during withstand voltage tests in the factory and after installation on site. Since it is possible to avoid applying severe voltage stress to the device, it is also possible to prevent deterioration of the life of the device.

Therefore, according to the configuration of the present invention, it has good insulation properties as a composite switchgear applied to a large-capacity power transmission system, and even when a small size switch or a disconnector is applied, the required insulation distance between bushings can be secured. This is preferable from the viewpoint of the overall arrangement of the substation by reducing the size of the entire substation without providing unnecessary busbar portions, and by arranging the bushings at both ends in a straight line. Additionally, since the disconnect switch and earthing switch are set at the same operating level and can be aligned in the same direction, maintenance and inspections do not require a special operation floor, and all work can be done at ground level. .

Further, as shown in FIG. 3, a disconnector tank 44 is disposed at the axial end of the shield disconnector 41, and a movable contact 43 of the disconnector is slidably arranged in the axial direction of the shield disconnector.
A disconnector 42 in which the operating mechanism portion 45 is disposed on one side, such as at the bottom or side of the disconnector tank 44.
may be formed. One terminal 46 of the disconnector 42
is connected to the terminal 47 of the disconnector 41 via a conductor 48 supported by an insulating spacer, and the other terminal 49
A conductor 51 protrudes from the axial extension of the tank of the breaker 41 and is provided on the extension shaft of the bushing conductor 51 housed in the bushing support tank 50.
Connect to a. A movable contact portion operated by an opening/closing mechanism portion 54 and an operating mechanism portion 55 provided at the lower part outside the bushing support tank 50 is opposed to the fixed contact portion 53 of the earthing switch 52 provided at the end of the conductor 51a. will be placed. Note that 59 is a lightning arrester connected via a detachable conductor 58.

In the switchgear shown in FIG. 3 having such an arrangement, the supporting position of the bushing 56 is lower than that of the switchgear shown in FIG. Therefore, the earthquake resistance of the bushing 56 is also advantageous. This reduces the bending rigidity of the bushing support tank 50 and also reduces the bending rigidity of the frame 57 that supports it, which is economically advantageous in manufacturing the tank 50.

In addition, FIG. 4, in which the same parts as in FIG. Since the support level can be lowered to the same level as the bushing provided at one end of the shank and disconnector 41, the seismic strength of the bushing can be further strengthened. can be supported. Furthermore, if the earthing switch 52 is configured to have an opening on the side opposite to the tank disconnector 42 to which a gas compartment insulating spacer can be attached,
It is possible to install line-side protection equipment such as the lightning arrester 59 that can be protected in terms of insulation coordination, and all equipment can be arranged in a straight line. This allows the opening/closing device itself to have the operating devices for each device on the side of the tank rather than the bottom, making it possible to place the center of gravity even lower.

As explained above, according to the present invention, the air insulation distance of the bushing can be ensured without intervening a special busbar device in the middle, in response to the further miniaturization of the disconnector. By separating the disconnector and the earthing switch with gas, when the earthing switch reaches the required number of operations (for example, 200 times as the inspection standard for earthing switches with current switching capability), the earthing switch can be removed. Only a portion of the gas can be recovered and the contacts can be easily inspected through a manhole (not shown) provided in the earthing switch. Further, when the contact portion of the earthing switch is disposed at the lowest position, there is an advantage that a structure in which dust and cutting dust caused by current switching is difficult to accumulate on the insulating spacer can be easily obtained.
Furthermore, since the operating devices for each device are set at a relatively low level, there is an advantage that no special operating floor is required for maintenance, inspection, and manual operation of the operating devices.
On the other hand, line-side protective equipment such as lightning arresters should be disconnected during withstand voltage tests in the factory and after installation on-site, in order to avoid activation of the arrester and to prevent deterioration of the life of the arrester element due to overvoltage. Conventionally, a disconnector for a lightning arrester or the like is installed, and the disconnector stops its function during normal operation so that it functions only as a connecting conductor, which is uneconomical. On the other hand, the present invention focuses on the fact that the conductor only needs to be disconnected during the withstand voltage test, and it is functionally sufficient and economical if the conductor is arranged so that it can be attached and detached within the bushing support tank. It can be configured as follows. Furthermore, a voltage detection device can be formed by arranging an intermediate electrode concentrically around the fixed contact of the earthing switch, and this device can be formed in the bushing support tank, so that a special tank for the voltage detection device is required. There is no need to use a , and in this respect as well, it is possible to have a very economical configuration.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a configuration prior to the present invention;
FIGS. 2 to 4 are sectional views showing schematic configurations of different embodiments of the present invention. 21...Shiya disconnection, 21a...Butsing, 2
2... Terminal part, 23... Current transformer, 24... Disconnector, 25, 26... Terminal part, 27... Bushing, 28... Bushing support tank, 29... Conductor, 30... Center conductor, 31...Conductor, 32...
Earthing switch, 33... Operating mechanism section, 34... Fixed contact, 35... Switching mechanism section, 36... Intermediate electrode, 37... Lightning arrester, 38... Detachable conductor.

Claims (1)

[Scope of Claims] 1. A horizontal grounding device in which a first bushing is established on one side, the center conductor of the first bushing is connected to one terminal portion, and an insulating gas is filled in the folded portion. A tank-shaped shield disconnector and a shield disconnector that has a grounded tank that extends in the axial direction on the other side are those in which the disconnect section is housed in a tank that is connected and connected with a gas compartment, and the other side of the shield disconnector is a grounded tank that extends in the axial direction. A grounding switch is installed in a tank which is connected to the disconnector in an axially extending part of the grounding tank on the opposite side of the disconnector from the above-mentioned disconnector and which is separated from the disconnector by gas. It consists of a bushing support tank which is housed and filled with insulating gas, and a second bushing established on the top of this bushing support tank. A gas insulated switchgear characterized in that the other pole side of the disconnection section is connected to a fixed side electrode of a grounding switch and a center conductor of a second bushing via a conductor. 2. The gas insulated switchgear according to claim 1, wherein a grounding switch is disposed in the lower part of the bushing support tank. 3. A horizontally grounded tank-shaped shingle with a first bushing established on one side, a shingle cut where the center conductor of the first bushing is connected to one terminal, and an insulating gas filled in. On the other side of the disconnector, the axially extending portion of the grounded tank is connected to the disconnector. The earthing switch is housed in a tank which is connected to the disconnector on the opposite side of the disconnector to the axial extension of the earthing tank and is separated from the disconnector by gas, and the insulating gas is It consists of an enclosed bushing support tank and a second bushing established on the upper part of the bushing support tank, and the other terminal part of the sheath disconnection part and the one pole side of the disconnection part are connected via a conductor, The other pole side of the disconnecting section is connected to the fixed side electrode of the earthing switch and the center conductor of the second bushing via a conductor, and the other pole side of the disconnecting section is connected to the fixed side electrode of the earthing switch and the center conductor of the second bushing. A gas insulated switchgear characterized in that a voltage detection device is configured by arranging an intermediate electrode at the top. 4. The gas insulated switchgear according to claim 2, wherein the intermediate electrode is arranged around the fixed side electrode of the earthing switch.